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5
MAINTENANCE
 
A. PRELIMINARY INSTRUCTIONS
 
5A1. General. Extreme vigilance and care should be practiced in the inspection, cleaning, and repair of parts. Personnel performing repair work should use common sense in judging whether or not a part should be put back into service or discarded. If there is any doubt regarding this, replace the part. With the exception of bearings and electrical equipment, corrosion should be removed from parts by washing them in clean fresh water. Dry the parts thoroughly, and apply a light film of gyro oil to prevent rusting or corrosion. Use Navy-approved cleaning fluid to clean grease and oil from the parts. Keep bearings oiled and clean by wrapping them in wax paper, or cloth, until needed for assembly. The area in which the repair work is being performed should be kept in an absolutely clean condition in order to prevent any dust and dirt from getting on the parts.   5A2. Operating the system on a static head. This operation is a means of checking the operation of the log system and other equipment connected to the log system while the ship is at rest on the surface. By shutting off the pressure on one side of the bellows, unequal pressure is obtained on the bellows, and the system will operate at one speed in the same manner as if the ship were underway. This permits the checking and inspection of the system under operating conditions. Operate on the static head as follows: Turn the valves from the secured position as shown in Figure 3-2 to the static head operating position as shown in Figure 3-7. The system will now operate at approximately 5 knots. After inspection, turn the valves to their secured position as shown in Figure 3-2. The pump motor should then stop turning and the speed pointers should beat zero.
 
B. MAINTENANCE OF RODMETER
 
5B1. Testing for obstruction in the rodmeter. The rodmeter may become clogged with jellyfish, mud, seaweed, or other foreign matter. Consequently the pressure difference will not be normal, and the mechanism will not register correctly. The following test must be performed when the ship is on the surface: Position the vent cocks and valves as shown in Figure 5-1. If a full stream of water does not flow from both vent cocks, it is an indication that the particular line not flowing is clogged.

5B2. Blowing out the rodmeter. This operation should be performed with the rodmeter in its extended, or operating, position. It is good practice to blow out both lines even if the tests for obstruction indicate that only one line is clogged, as foreign matter has undoubtedly entered both passages. Blow out the rodmeter in the following manner: Disconnect the hose from the static pressure valve nipple on the control unit. Pinch the

  Figure 5-1. Vent cocks positioned to check clogged rodmeter.
1. DYNAMIC PRESSURE VALVE
2. VENT COCK
3. BYPASS VALVE
4. VENT COCK
5. STATIC PRESSURE VALVE
Figure 5-1. Vent cocks positioned to check clogged rodmeter.
 
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end of the hose to prevent leakage of water. If the line is completely clogged, water will not leak from the hose. Connect the low-pressure air line of the ship to the static hose, and blow the obstruction out of the hose and rodmeter into the water outside of the ship. Do not apply the low-pressure air hose to the lines that enter the control unit, as air pressure will damage the sensitive mechanism. When a full stream of water is obtained from the static hose, install the end of the hose over the nipple on the static pressure valve and install the hose clamp to secure the hose in position. Blow out the dynamic line in the same manner.

5B3. Removing solid obstructions from the rodmeter. If obstructions are not removed by blowing out the rodmeter with compressed air, the following operations will be necessary:

Raise the rodmeter to its fully housed position (Figure 5-2). Close the sea valve. Unlatch the stop bracket at the top of the hoist assembly by opening and removing the lock which secures the bracket in position above the rodmeter, and swing it to one side out of the way (Figure 5-2). Remove the lower end of the rodmeter from the sea valve extension by raising the rodmeter to the

  upper sprockets. Using a soft brass wire, dig out the obstructions from the orifices (openings) at the lower end of the rodmeter.

Do not use steel wire or a drill to clean the orifices as they may score the orifices or break off in the openings.

Blow out the rodmeter as described in Section 5B2 with the exception that the rodmeter need not be extended into the sea. Have one crew member hold his hand near the orifices to detect the flow of air which indicates that the orifice and tubing are clear. Repeat the operation until all passages are clear. Align the lower end of the rodmeter with the opening in the sea valve extension and lower the rodmeter to its fully housed position (Figure 5-2).

At this point the tip of the rodmeter is approximately 1 inch above the sea valve gate. Open the sea valve. Swing the stop bracket to its normal position above the rodmeter and secure in place with the lock. It is important that the stop bracket be in position above the rodmeter at all times except during the above operation, or when the rodmeter is being replaced. Lower the rodmeter to its normal housed position or to its fully extended position as desired. Place the hoist crank in the brackets provided, and replace the deck plate over the sea valve.

 
C. REPLACING DAMAGED RODMETER
 
5C1. General instructions. If the rodmeter is bent so that it cannot be drawn up into the ship, it will be necessary to install a spare rodmeter. Do not attempt to force the damaged rodmeter up into the ship, as the hoist mechanism may be damaged. The removal and installation operations should be carried out only when the ship is surfaced. If the damaged rodmeter is to be salvaged, it may be accomplished if a diver is available. Lower the diver over the side of the ship so that he can rig a line around the damaged rodmeter. Secure the other end of the line to the ship so that the rodmeter may be pulled out of the water after it is pushed out of the sea valve. The rodmeters of all submarines are equipped with two valve assemblies mounted on the upper end openings of the   rodmeter (see Figure 5-3), instead of the conventional nipple installation as shown in Figure 5-4. This necessitates a different procedure for removing and installing the clamp and guard assembly. These two procedures will be covered in the following operations.

5C2. Breaking out the spare rodmeter. Break out the spare rodmeter and place it alongside of the hoist mechanism so that it will be immediately available when needed.

5C3. Rumoring the clamp and guard assembly (nipple installation). (See Figure 5-4.) Loosen the hose clamps and remove the two lengths of hose from the nipples on the upper end of the rodmeter. Unscrew the longest nipple (after nipple) and plug the hole in the rodmeter with a wooden plug. Remove the

 
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Figure 5-2. Rodmeter in secured position.
Figure 5-2. Rodmeter in secured position.
  forward nipple in the same manner. Remove the two nuts and bolts that secure the clamps, and guard to the rodmeter and remove the clamp and guard assembly. Raise the guard, by means of the hoist, up against the stop bracket above the rodmeter (Figure 5-2).

Figure 5-3. Rodmeter with valves installed.
Figure 5-3. Rodmeter with valves installed.

5C4. Removing the clamp and guard assembly (valve installation). Loosen the two hose clamps (one on each hose) that secure the ends of the hose to the nipples provided on the valve assemblies at the upper end of the rodmeter (Figure 5-3). Remove the hose and clamps. Remove the two bronze nuts and bolts that secure the two clamps and the guard to the top of the rodmeter, and remove the clamps. Raise the guard and yoke assembly up against the stop bracket by means of the hoist provided for raising the rodmeter.

 
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It may be necessary to remove one or both valve handles from the valve stems in order to get enough clearance to raise the guard.

This is accomplished by removing the two nuts (one on each handle) that secure the valve handles to the valve stems, and by removing the handles. Make a rough sketch of the position of the valve assemblies so that they can be installed in their original position on assembly. Spread the two valve assemblies apart so that one of them can be unscrewed without interference from the other valve assembly. Unscrew and remove the lower valve assembly from the elbow which connects this valve assembly with the opening in the top of the rodmeter. Plug the elbow opening with a wooden plug. Unscrew the complete valve assembly from the other opening on top of the rodmeter, and plug this opening in the rodmeter with a wooden plug. Unscrew and remove the elbow of the lower valve assembly from the top of the rodmeter, and plug the opening in the top of the rodmeter with a wooden plug.

5C5. Installing the valve assemblies in the top of the rodmeter. (See Figure 5-3.) The spare rodmeter is equipped with nipples and a clamp and guard assembly. For those ships which have valve assemblies installed instead of the conventional rodmeter nipples, the following procedure is necessary to install the valve assemblies in the spare rodmeter:

1. Remove the clamp and guard assembly from the spare rodmeter by removing the two bronze nuts and two bolts that secure the clamps and guard in position at the upper end of the rodmeter, and remove the clamps and guard.

2. Unscrew and remove the two nipples from the top of the rodmeter.

3. Apply a coating of white lead compound to the threads of the valve assemblies to be installed.

4. Install the elbow of the lower valve assembly (previously removed from the damaged rodmeter) in the after (static) opening in the top of the rodmeter. Refer to the sketch previously made at disassembly, and tighten this elbow to its original position.

  5. Install the valve assembly in this elbow, tightening the valve until secure. Be sure that the valve stem is facing upward.

6. Disassemble the second valve assembly by unscrewing the horizontal nipple and valve assembly from the elbow and nipple assembly. Also remove the valve bottom and stem assembly from the valve body. This disassembly is necessary in order to obtain the proper clearances while installing the second valve assembly in the rodmeter.

7. Install the elbow and nipple in the forward (dynamic) opening on top of the rodmeter. Tighten until the elbow is in its original position. Refer to the sketch made previously for the position of the elbow.

8. Install the valve body and nipple into the elbow.

9. Install the valve bottom and stem assembly into the valve body, making certain that the valve stem is facing upward.

5C6. Installing the clamp and guard assembly. (See Figure 5-4.) The two clamps and the guard are stamped at their ends. These numbers should be adjacent to one another when these pieces are assembled on the rodmeter. Place the two clamps around the upper end of the spare rodmeter in such a manner that the clamps are over the knock-out pins provided at the top of the rodmeter. Place the guard between the clamps. Align the mounting holes in the three pieces, and install the two bronze bolts and nuts that secure the clamp and guard assembly to the rodmeter. Tighten the nuts securely.

5C7. Installing the spare rodmeter. (See Figure 5-4.) The following procedure should be used in installing the rodmeter:

1. If the damaged rodmeter is partially raised, push it downward until the knock-out pin rests on top of the packing gland in the sea valve extension. It may be necessary to use a heavy hammer and wooden block to start the rodmeter downward.

2. Place the tip of the spare rodmeter on top of the damaged rodmeter, being sure that the dynamic orifice in its leading edge is facing forward. Note the arrows stamped on the

 
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rodmeter for facing the rodmeter in the proper direction.

3. Remove the cotter pin and the clevis pin which secure the old guard to the lifting bar on the hoist chain, and remove the old guard. Align the opening in the lifting bar with the opening provided in the guard on the spare rodmeter, and install the clevis pin and cotter pin which secure the lifting bar to the guard assembly.

4. Place the loose end of the dynamic hose over the nipple provided on the dynamic fitting on top of the rodmeter. The opposite end of this hose is attached to the pump. Secure the hose to the nipple by tightening the hose clamp on the end of the hose. Place the end of the static hose on the nipple provided on the fitting on top of the rodmeter. The opposite end of the static hose is attached to the control unit. Secure the hose to the nipple by tightening the hose clamp on the end of the hose.

5. Remove the knock-out pin from the damaged rodmeter. Push downward on the spare rodmeter to drive the damaged rodmeter downward and out of the ship.

6. Vent the system in accordance with the instructions in Section 3A3.

  Figure 5-4. Cutaway view of Pitometer rodmeter.
Figure 5-4. Cutaway view of Pitometer rodmeter.
 
D. MAINTENANCE OF PUMP
 
5D1. General. The pump is removed, disassembled, inspected, cleaned, repaired, adjusted, and lubricated whenever the leakage from the pump exceeds three drops per minute; or whenever the pump becomes noisy due to worn bearings or because the impeller blades are hitting on the cover.

5D2. Period of overhaul. If possible, the pump assembly should be removed, disassembled, cleaned, inspected, lubricated, adjusted, and/or repaired, if necessary, every 45 days. If the tactical situation does not warrant servicing the pump at 45-day intervals, it should be overhauled after every patrol to keep the pump operating correctly. A shorter

  or longer interval of overhaul is left to the discretion of the commanding officer.

5D3. Removing the pump. (See Figure 5-5.) Have the rodmeter in its secured position with the sea valve closed. Disconnect the two lengths of hose from the pump by loosening the two hose clamps (one on each hose) that secure the hose to the nipples on the pump, and remove the hose and clamps. Remove the four nuts that secure the pump to the spacer (mounting) rods, and remove the pump assembly from the spacer rods.

5D4. Disassembly of the pump assembly. (See Figure 5-7.) Following is the procedure for disassembling the pump assembly.

 
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Figure 5-5. Pump installed.
Figure 5-5. Pump installed.
1. Remove the 11 screws that secure the pump cover jacket to the pump housing, and remove the cover jacket. Do not remove the marked orifice plate.

2. Remove the 12 screws that secure the housing cover to the housing, and remove the housing cover. Lift the rubber gasket off the housing. Turn the pump assembly over so that the impeller blades are facing downward, and rest the pump assembly on the cover jacket with the impeller blades in the opening in the cover jacket. Do not rest the impeller blades on an uneven surface as they will be damaged.

3. Remove the four screws that secure the housing jacket to the pump housing, and remove the housing jacket.

4. Loosen the two setscrews (one on each piece) that secure the coupling and the fan on the impeller shaft, and remove the coupling and fan.

  Figure 5-6. Removing impeller shaft lock nut.
Figure 5-6. Removing impeller shaft lock nut.
 
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Figure 5-7. Pump disassembled.
1. HOUSING JACKET SCREW
2. PUMP HOUSING JACKET
3. COUPLING SET SCREW
4. PUMP COUPLING
5. PUMP FAN
6. FAN SETSCREW
7. END CAP SCREW
8. END CAP
9. LOCK NUT
10. LOCK WASHER
11. BALL BEARING
12. BEARING INNER RACE SPACER
13. BEARING OUTER RACE SPACER
14. SHIELD WASHER
15. THROWER DISK
16. PUMP HOUSING
17. GASKET
18. ROTARY SEAL INSERT
19. SEAL RING
20. PUMP HOUSING COVER
21. PUMP IMPELLER, ASSEMBLY
22. VENT COCK
23. ORIFICE PLATE SCREW
24. HOSE CONNECTING NIPPLE TO CONTROL UNIT
25. PUMP COVER JACKET
26. ORIFICE PLATE
27. HOUSING COVER SCREW
28. HOSE CONNECTING NIPPLE TO RODMETER (DYNAMIC)
29. COVER JACKET SCREW

Figure 5-7. Pump disassembled.
5. Remove the four screws that secure the end cap to the pump housing, and remove the pump end cap.

6. Bend down the lug of the external toothed lock washer that secures the lock nut in position. Using the special lock nut wrench (Figure 5-6), remove the lock nut from the end of the impeller shaft. Do not place the impeller blades in a vise. Lift off the lock washer. Pull the impeller assembly out of the pump housing.

7. Insert a brass or fiber rod V inch in diameter into the pump housing from the impeller end of the pump housing and push out the two ball bearings, two spacers, thrower disk, and shield washer from the pump housing. Do not use a steel rod as the parts will become burred, and the bearings will not align properly at assembly.

  5D5. Disassembly of the impeller assembly. (See Figure 5-8.) The impeller assembly is disassembled as follows:

1. The rotary seal bellows is disassembled from the impeller assembly when visual inspection reveals the fade of the bellows to be grooved, burred, or badly corroded.

2. Remove the eight screws that secure the impeller gasket ring to the impeller, and remove the gasket ring. Remove the gasket from the ring or from the impeller if the gasket is sticking to the impeller. Carefully pull the rotary seal bellows from the impeller and off the impeller shaft.

3. Place the impeller shaft in a soft-jawed vise in such a manner that the pin that secures the shaft to the impeller is parallel to the jaws of the vise. Using a pin punch, drive out the pin from the impeller and the, impeller

 
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Figure 5-8. Impeller disassembled.
Figure 5-8. Impeller disassembled.

shaft. The impeller shaft is disassembled from the impeller only if a gap between the shaft and the impeller indicates that the pin that secures the shaft to the impeller has been distorted, or sheared off due to the application of too much pressure on the lock nut which secures the bearings and spacers to the impeller at a previous assembly operation.

5D6. Inspection and repair of impeller shaft. (See Figure 5-8.) Inspect the impeller shaft for straightness. Inspect the shaft for security of mounting in the impeller. The impeller shaft should be securely mounted in the impeller, and the pin that secures the shaft to the impeller should be in place. A gap between the impeller shaft and the impeller is

Figure 5-9. Checking length of rotary seal bellows
Figure 5-9. Checking length of rotary seal bellows

  an indication that the pin that secures the shaft to the impeller has been distorted, or sheared off at a previous assembly. If the shaft is not straight, or the pin has been distorted or sheared off, remove the pin from the shaft and impeller. Press a new shaft into the impeller, and install a new, 3/32-inch monel pin which secures the shaft to the impeller. A bronze pin may be substituted for the monel pin if the latter is not available, but do not use steel or stainless steel pins as they will corrode and fail prematurely. If the threads are damaged, touch them up on a lathe. The diameter of the screws is 0.391 inch (10 mm), 32 threads per inch.

5D7. Inspection of the impeller blades. (See Figure 5-8.) Inspect the impeller blades for straightness and depth. The blades should be straight. The depth of the impeller blades on a new, impeller is 0.189 inch. If the impeller blades are worn more than 0.002 inch below the depth of the blades of a new impeller, that is, the depth of blades is less than 0.187 inch, the impeller should be replaced, or the calibration of the system will be incorrect.

5D8. Inspection of the rotary seal bellows. (See Figure 5-8.) Visually inspect the face of the rotary seal bellows. If worn, pitted; or corroded, replace the bellows and gasket. Use KR monel bellows for replacement, if available. Use monel or bronze screws on the gasket ring. Do not use stainless steel screws on the gasket ring as the steel screws corrode badly when used with monel. Check the

Figure 5-10. Stretching rotary seal bellows.
Figure 5-10. Stretching rotary seal bellows.

 
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Figure 5-11. Refacing rotary seal insert.
Figure 5-11. Refacing rotary seal insert.

dimension from the impeller hub to the bellows face (Figure 5-9). This dimension is very critical and should be exactly 13/32-inch. If the bellows is too short (dimension more than 13/32-inch), the pump may leak excessively. If the bellows is too long (dimension less than 13/32-inch), the seal faces will wear rapidly, and may make the pump too tight. This latter fault will cause the pump to bind at low speeds.

5D9. Adjusting-the rotary seal bellows. (See Figure 5-10.) If the bellows are found to be too short, as described in Section 5D8, they may be stretched as follows: Place a thin strip of metal, such as the smooth edge of a hacksaw blade, between the folds of the rotary seal bellows. Turn the bellows around so that the metal blade will stretch the bellows uniformly. After each turn, measure the distance between the impeller hub to the bellows face. Repeat the spreading operation until the dimension between the impeller hub and bellows face is exactly 13/32-inch. When the bellows is too long, as described in Section 5D8, compress the bellows by hand (while installed on impeller shaft) until the dimension between the impeller hub and the bellows face is exactly 13/32-inch. When the rotary seal bellows is at proper dimension, the bellows face must move freely inward and outward along the shaft.

  5D10. Inspection of the rotary seal insert. (See Figure 5-7.) Visually inspect the seal insert for pitting, corrosion, or grooves indicating wear. If pitted or badly corroded, the seal insert should be replaced. If lightly worn (grooved) the seal may be refaced. If the seal insert is bronze, and a monel insert is available, the bronze insert should be replaced with the monel insert. If a monel replacement is not available, the bronze insert may also be refaced. However, the bronze insert will continue to corrode even though refaced and should be replaced by a monel insert at the first opportunity.

5D11. Refacing the old seal insert. (See Figure 5-11.) Place the pump housing in a lathe. Align the housing up to 0.0005 inch, using a dial indicator on the monel liner face. Take light cuts across the seal insert face until score marks are removed. Undercut the inner face at the inside diameter of the insert 0.010 inch below the face of the seal insert. Occasionally when an old seal insert is refaced, enough metal is removed so that the

Figure 5-12. Pressing out rotary seal insert.
Figure 5-12. Pressing out rotary seal insert.

 
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pump will leak when installed, due to a looseness between the insert, micarta ring, and the bellows. This may be remedied by disassembling the pump and stretching the bellows to take up the space between the bellows and the seal insert.

Figure 5-13. Installing rotary seal insert.
Figure 5-13. Installing rotary seal insert.

5D12. Replacing the seal insert. (See Figures 5-12 and 5-13.) Place the pump housing on the bed of an arbor press with the large end of the housing downward. Using a special rod as shown in Figure 5-12, press out the seal insert. To install a new seal insert, place the housing on the bed of an arbor press with the small end of the housing downward. Put a moderate amount of pipe compound on the outer surface of the shoulder of the insert and on the inner surface of the opening through the housing liner. Place the new seal insert in the housing with the shouldered end

  of the seal downward. Using a special seal installing tool as shown in Figure 5-13, press the seal insert into housing.

5D13. Refacing the new seal insert. (See Figure 5-11.) At manufacture, the dimensions of the seal insert are such that it may be faced to allow for removal of burrs or score marks from the seal surface after the pressing operation. This precaution is also taken to allow

Figure 5-14. Checking rotary seal insert.
Figure 5-14. Checking rotary seal insert.

for facing the seal in the event it is not pressed true in the housing. Reface a new seal insert as follows: Place the pump housing in a lathe. Align the housing up to 0.0005 inch, using a dial indicator on the monel liner face. Take light cuts across the seal insert face until the proper dimension of 0.764 inch is reached and the face of the seal insert is smooth. This dimension is the distance from the monel liner face of the housing to the face of the seal insert, and is determined with a depth gage as shown in Figure 5-14.

5D14. Inspection of the seal ring. (See Figure 5-7.) Visually inspect the seal ring. The ring must be perfectly flat, or it should be 0.0005 inch thicker at its outer edge. If it is worn on either side, the ring should be replaced. The seal ring should always be

 
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replaced if the rotary seal bellows or the seal insert surfaces have been changed. Some pump assemblies are still equipped with the carbon ring. Replace the carbon ring with a micarta ring. In emergencies when micarta seal rings are not available, a ring turned from lignum vitae would be satisfactory. Cut across the grain of the wood to the approximate size; soak in water for a day, and while it is moist, turn it to the exact thickness and flatness. This ring must be kept wet thereafter or it will warp out of shape, making it worthless.

5D15. Inspection and repair of the thrower disk and shield washer. (See Figure 5-7.) The thrower disk and shield washer need not be replaced unless they are badly worn or bent. Using a straightedge, inspect the pieces for flatness. Visually inspect the thrower disk and shield washer for burrs. Remove nicks from the inner surfaces of the thrower disk and shield washer with a bearing scraper. Remove score marks from surfaces with a finecut file.

5D16. Cleaning and inspection of the bearings. (See Figure 5-7.) Thoroughly clean the bearings with Navy-approved cleaning fluid. Dry the bearings thoroughly. In cases where the grease has become hardened within the bearing, the bearing should be allowed to soak in the cleaning fluid until the grease has softened, and then swished back and forth in the cleaning fluid until all grease and dirt are removed from the bearing. Visually inspect the bearings for pitting resulting from corrosion, and if they are pitted, replace the bearings. The bearings should be smooth and operate freely. Turn the bearing by hand, and note any clicking noise which indicates a cracked ball, or a piece of metal or dirt within the bearing. If the bearing is thoroughly clean, and clicking or binding exists when the bearing is rotated by hand, the bearing should be replaced: If the bearing is worn so that there is excessive side play, or excessive end play between races, it should be replaced. After cleaning and inspection, oil the bearings with light oil, and pack the bearings with grease, Navy, Symbol 14L3. Wrap the bearings in waxed paper until they are to be assembled.

  5D17. Cleaning and inspection of the bearing spacers. (See Figure 5-7.) Thoroughly clean and dry the two bearing spacers. Examine them for pitting, cracks, or scored end surfaces. Spacers with ends that are not smooth should be replaced. Measure the length of the spacers. The inner bearing spacer should be from 0.029 to 0.033 inch longer than the outer spacer in order that the bearings seat properly when assembled on the impeller shaft. The outer spacer should be 0.625 inch long.

5D18. Assembling the shaft and impeller. (See Figure 5-8.) Place the impeller shaft in the impeller hub. Align the hole in the shaft and the hole in the impeller hub, and install the pin that secures the shaft to the impeller hub. Be sure that the ends of the pin are flush with the impeller hub, and that the surfaces at the ends of the pin are smooth.

5D19. Installing the rotary seal bellows. (See Figure 5-8.) Place the rotary seal bellows on the impeller shaft with the recessed end of the bellows toward the impeller. Install the rubber gasket over the seal bellows and up against the impeller (not inside the bellows). Place the gasket ring over the bellows. Align the mounting holes in the gasket ring and the holes in the impeller, and install the eight screws which secure the gasket ring to the impeller. Check the dimensions of the rotary seal bellows as described in Section 5D8.

5D20. Installing the impeller assembly. (See Figures 5-7 and 5-15) Place the seal ring (micarta ring if available) over the impeller shaft and up against the face of the rotary seal bellows. Place the pump housing over the impeller shaft with the large end of the pump housing toward the impeller. Place the thrower disk on the impeller shaft with the large flat surface of the ring toward the impeller. Install the shield washer on the impeller shaft with the flat surface of the washer facing away from the impeller. Install the inner ball bearing on the impeller shaft with the shield end of the bearing toward the impeller. Place the inner and outer bearing spacers on the shaft so that they are adjacent to the inner ball bearing just installed. Fill the bearing spacers one-half full with grease, Navy Symbol 14L3.

 
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Figure 5-15. Cutaway view of rotary pump.
1. IMPELLER SHAFT
2. PUMP FAN
3. ROTARY SEAL INSERT
4. SEAL RING
5. ROTARY SEAL BELLOWS
6. VENTING COCK
7. HOSE CONNECTING NIPPLE, TO CONTROL UNIT
8. PUMP IMPELLER
9. HOSE CONNECTING NIPPLE, TO RODMETER
10. DRIP FITTING
Figure 5-15. Cutaway view of rotary pump.
 
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Do not fill the spacers more than one-half full with grease.

Install the outer bearing on the impeller shaft with the shield end of the bearing facing away from the impeller. Carefully press the ball bearing on the impeller shaft by hand until the bearing is aligned with, and adjacent to, the inner and outer bearing- spacers previously installed. Place the toothed lock washer on the impeller shaft with the teeth facing upward (away from the impeller). Place the lock nut on the impeller shaft with the chamfered end of the nut toward the impeller. Using the special lock nut wrench (Figure 5-6), and holding the impeller blades with one hand, tighten the lock nut reasonably tight.

Do not force-tighten this nut, or the pin that secures the impeller shaft to the impeller hub will be sheared off.

Align one of the slots in the lock nut with one of the teeth in the lock washer, and bend the tooth upward to secure the lock nut in position.

5D21. Installing the end cap. (See Figure 5-7.) Place the end cap over the end of the impeller shaft and up against the small end of the pump housing. Align the mounting

Figure 5-16. Checking impeller clearance.
Figure 5-16. Checking impeller clearance.

  holes, and install the four screws that secure the end cap to the pump housing. There should be a gap of approximately 0.002 inch or more between the housing and the end cap. This end cap clamps the outer race of the outer ball bearing and therefore holds the entire ball bearing and impeller assembly in proper position. Do not file off or cutoff the end cap to eliminate this gap.

5D22. Checking the impeller blade clearance. (See Figure 5-16.) Using a thickness gage, check the clearance between the housing end of the impeller blades, and the monel liner of the pump housing as shown in Figure 5-16.

5D23. Installing the fan and coupling. (See Figure 5-7.) Place the fan on the impeller shaft with the hub of the fan toward the impeller. Align the setscrew in the fan hub with the flat side of the impeller shaft, and tighten the setscrew to secure the fan on the shaft. Place the half-coupling on the end of the impeller shaft with the lugs of the coupling facing away from the impeller. Carefully align the end of the coupling with the end of the impeller shaft and tighten the setscrew that secures the coupling to the impeller shaft. The face of the coupling must be flush with the end of the impeller shaft.

5D24. Installing the housing jacket. (See Figure 5-7.) Place the housing jacket in position over the pump housing, and install the four screws that secure the housing jacket to the pump housing.

5D25. Installing the pump cover. (See Figure 5-7.) Place the rubber cover gasket in the groove provided in the impeller end of the pump housing. Place the finned pump cover in position on the impeller end of the pump housing. Align the cover so that the vent cock is directly opposite the drip fitting on the pump housing. Install the 12 screws that secure the cover to the pump housing. The vent cock should be repaired at this time. Inspect and clean the vent cock as follows: Remove the nut or cotter pin that secures the spring and valve assembly in the vent cock body. Lift the valve assembly from the vent cock body. Clean corrosion from all parts of the vent cock, and lubricate with a small amount of waterproof grease.

 
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Figure 5-17. Pump drive motor installed.
Figure 5-17. Pump drive motor installed.
5D26. Installing the cover jacket. (See Figure 5-7.) Place the cover jacket in position on the pump housing, and secure it with the brass or bronze screws provided.

5D27. Installing the pump. (See Figure 5-5.) Before installing the pump, test it under pressures up to 200 pounds per square inch at a speed as low as 1 knot in accordance with the instructions given in Chapter 7. Slide the pump assembly on the spacer rods, making certain that the went cock on the pump is facing upward. Be sure that the coupling on the pump drive motor shaft is flush with the end of the drive shaft. Place the rubber block in one half of the pump coupling. Move the pump to the left until the two halves of the coupling are properly engaged; then install the four nuts that secure the pump assembly on the spacer rods. Install the dynamic hose from the control unit on the upper nipple on the pump, and tighten the hose clamp to secure the hose to the nipple. Install the dynamic hose from the rodmeter on the lower pump nipple, and tighten the hose clamp to secure the hose on the nipple. Vent the system in accordance with the instructions given in Section 3A3.

  Figure 5-18. Removing upper brush.
Figure 5-18. Removing upper brush.
 
45

 
E. MAINTENANCE OF PUMP DRIVE MOTOR
 
5E1. Removing the brushes. See Figures 5-17 and 5-18.) Remove the 10 screws that secure the cover on the rotary distance transmitter case and remove the cover. This is necessary in order to make the upper brush accessible. Remove the pipe plug from the bottom of the rotary distance transmitter case. Unscrew and remove the two caps (one on each side of the motor) that secure the brushes in position in the motor. Carefully lift the two brushes out of the motor.

5E2. Inspection and repair of the brushes. Visually inspect the brushes. They should show a polished surface on the end that contacts the commutator. The brushes should not be less than 3/8-inch long from the contact end to the shoulder where the brush spring is attached. Brushes showing wear nearing the 3/8-inch dimension should be replaced. If the brush contact surface is pitted, smooth off the surface, using fine sandpaper wrapped around a cylindrical object. The brushes can be

  rubbed across the surface without affecting the curvature of the face.

5E3. Installing the brushes. (See Figures 5-17 and 5-18.) Place the lower brush in the hole provided in the lower side of the motor. Compress the brush tension spring by hand, and install the cap which secures the lower brush in the motor. Install the upper brush in the hole provided in the top of the motor in the same manner. Install the pipe plug in the hole in the bottom of the rotary distance transmitter case. Install the case cover.

5E4. Removing the armature. (See Figures 5-17 and 5-19.) Remove the pump (see Section 5D3.) Remove the brushes (see Section 5E1). Remove the two screws that secure the gear guard to the rotary transmitter case and remove the gear guard. Loosen the socket head setscrew that secures the drive motor coupling on the motor shaft, and remove the coupling and rubber spacer. Remove the four screws that secure the back end shield on the motor

Figure 5-19. Pump drive motor partially disassembled.
1. SLOW SPEED SHAFT
2. GEAR HOUSING
3. BACK END SHIELD
4. WORM
5. BALL BEARING
6. SPACER WASHER
7. BRUSH HOLDER CAPS
8. BRUSHES
9. ARMATURE CORE AND SHAFT
10. BRUSH SPRINGS
11. COMMUTATOR
12. PIPE PLUG
13. MOTOR FRAME
14. TOP BRUSH HOLDER
15. PIPE PLUG HOLE
Figure 5-19. Pump drive motor partially disassembled.
 
46

field ring, and remove the back end shield and armature assembly :from the pump motor. The armature assembly can then be carefully pulled out of the back end shield for inspection of bearings.

5E5. Inspection of the bearings. (See Figure 5-19.) Visually inspect the two bearings on the armature shaft for evidence of pitting due to corrosion. Turn the bearings by hand. They should turn easily and freely. A clicking noise indicates that one or more of the balls is cracked, and the bearing must be replaced. A damaged bearing is removed by using a bearing puller. Press the replacement bearing onto the shaft in place of the damaged bearing.

5E6. Assembly of the armature. (See Figures 5-17 and 5-19.) Align the worm, spacers, and bearing on the end of the armature shaft with the opening in the back end shield, and carefully push the armature assembly into the back end shield. Place the armature inside the motor, being careful when inserting the shaft through the opening in the front end shield. Align the mounting holes in the back end shield with the holes in the field ring, and install the four screws that secure the back end shield to the field ring of the motor. Turn the pump drive shaft by hand to be sure that the armature and gears are turning freely. Install the gear guard. Install the two brushes (see Section 5E3). Install the coupling on the armature shaft and secure with the setscrew provided. Install the rubber spacer. Install the pump (see Section 5D27).

5E7. Removing the pump drive motor as a unit. See Figure 2-8.) Disconnect the hose and remove the pump (see Section 5D3). Disconnect the armature and field wires from the

  terminal block on the bottom of the rotary distance transmitter case by removing the four screws from the terminal block and carefully lifting off the wire terminals with the blade of a screwdriver. Remove the gear guard. Loosen the two stop screws that secure the spacer rod in the motor mounting bracket, and pull the pump drive motor assembly to the left and off the rotary, distance transmitter case.

5E8. Installing the pump drive motor. (See Figures 5-17 and 2-8.) Align the two upper spacer rods with the motor mounting bracket, and slide the motor assembly to the right as far as the stop on the spacer rod will allow. Make sure that the gears at the left end of the motor are properly meshed and that the spacer rod is against the motor mounting bracket. There should be a slight amount of backlash between the two external gears. If the gears do not mesh properly when the stop is against the motor mounting bracket, it will be necessary to relocate the stop. This is accomplished as follows: Drill out the pin that secures the stop on the spacer rod. Slide the motor assembly to the right until the gears at the left end of the motor are properly meshed. Slide the stop over against the motor mounting bracket and locate the pinhole. Drill a hole through the spacer rod. Install a new pin through the stop and the spacer rod. Install the gear guard. Connect the two armature and the two field wires to the terminal block on the counter mounting plate inside the rotary distance transmitter case. The terminal block and terminals on the wires are marked for the location of wires. The corresponding terminals are marked as follows A+, A-, F+, and F-. Install the pump (see Section 5D27).

 
F. TRANSTAT ASSEMBLY
 
5F1. Removing the transtat assembly. (See Figure 5-20.) The transtat assembly is removed as a unit as follows: Remove the four screws and toothed lock washers that secure the transtat mounting base to the plate back of the rotary distance transmitter. Carefully lift the defective unit from the plate, and turn   the assembly to make the wire connections more accessible. Remove the nuts and flat washers that secure the wire terminals to the posts on the transtat assembly. Mark the wires for ready identification at assembly. Loosen the setscrew that secures the gear on the right side of the transtat assembly and
 
47

remove the gear. Place the gear on the new or rebuilt transtat assembly to be installed and

Figure 5-20. Removing transtat.
Figure 5-20. Removing transtat.

  tighten the setscrew to secure the gear on the shaft.

5F2. Installing the transtat assembly. (See Figure 5-20.) Place the new transtat assembly with its assembled gear in position in front of the rotary distance transmitter in such a manner that the wires can be connected. Place the three wires, previously marked, on their corresponding marked posts, and secure each terminal with a flat washer and nut. Place the transtat assembly in position on the mounting plate provided on the back of the rotary distance transmitter case, making certain that the gears are meshed, and install the four screws and toothed lock washers that secure the transtat assembly in the case. Rotate the transtat gearing by hand over its entire range and note the position of the center brush of the transtat at the instant the upper and lower limit switches are operated. The brush must still be on the transtat winding. Do not force the gearing beyond the point where the switches are actuated. If the brush is not on the winding at each position, loosen the three clamp screws passing through the core; shift the core radially to the proper position, and tighten the screws. Recheck for proper operation.

 
G. MAINTENANCE OF FOLLOW-UP MOTOR
 
5G1. Testing the follow-up motor. (See Figure 5-21.) Test the operation of the follow-up motor in the following manner: Remove the cover from the rotary distance transmitter case. Disconnect the wire lead from the center terminal on the motor terminal block. This terminal is marked C. Move the transtat brush arm well away from its limit switch. Using a screwdriver, alternately short-circuit the terminals marked CW and CCW with the center terminal. The motor will run first clockwise and then counterclockwise if it is operating properly. If the motor is binding, or inoperative, replace it.

5G2. Removing the follow-up motor. (See Figure 5-21.) Disconnect the wires from the terminal block on the motor. Tag the wires for ready identification. Remove the three

  screws and the toothed lock washers that secure the motor assembly to the mounting plate, and remove the motor.

5G3. Exchanging the pinion and spur gear assembly. The replacement of the spur gear on the follow-up motor follows exactly the same procedure as that described in Section 5M5 for the gear replacement of the lead screw drive motor.

5G4. Installing the follow-up motor. (See Figure 5-21.) Place the follow-up motor assembly in position on the mounting plate. Install the three screws and toothed lock washers that secure the motor to the mounting plate. Connect the wires to the terminal block on the motor. Tighten the terminal screws. Install the cover on the case.

 
48

 
H. REMOVAL AND INSTALLATION OF ARMATURE RECTIFIERS
 
5H1. Removing the armature rectifiers. (See Figure 5-22.) Burned-out rectifiers are detected by the presence of deposits of molten metal on the bottom of the rectifier disks. This metal has the appearance of melted solder. Remove the rectifiers in the following manner: Remove the case cover. Unsolder the lead wires to each armature rectifier and tag each wire to make certain that it is installed in the same position on the new rectifiers. Remove the four screws and toothed lock washers that secure the rectifier brackets to the mounting plate and remove both rectifiers as a unit.

5H2. Replacing the rectifier stacks in the rectifier assembly. (See Figure 5-22.) Remove the four nuts (two at each end) that secure the brackets to the rectifier studs, and remove the brackets. Save any spacer washers that may be installed on the rectifier studs for replacement on the new rectifiers. Place the spacer washers, if used on the old rectifier

Figure 5-21. Removing follow-up motor.
1. TERMINAL BLOCK
2. FOLLOW-UP MOTOR
3. TRANSTAT MOUNTING PLATE
4. TRANSTAT, ASSEMBLY
5. MOTOR BRACKET

Figure 5-21. Removing follow-up motor.

  assembly, on the studs of the new rectifiers in the same position as previously installed.

This is important in order that the same space between the mounting brackets will be maintained.

Place the two rectifiers in the mounting brackets in the same position as the previously removed rectifiers, making certain that the name plates are facing in the same direction, and install the four lock washers and nuts (two at each end) that secure the brackets to the rectifier studs. If the replacement rectifiers have square plates (slightly higher current capacity) be sure that the bakelite spacer, furnished with this type, is properly installed between the two stacks. The spacer prevents the stacks from touching if they should become loose during operation. The angle brackets provided are held between the inside face of the mounting brackets and the adjacent nuts. Two spacer washers may be

Figure 5-22. Rectifiers installed.
1. RECTIFIER STUD
2. NUT
3. LOCK NUT
4. ARMATURE RECTIFIERS
5. MOUNTING BRACKET
6. BRACKET SCREW
7. COUNTER MOUNTING PLATE
8. FIELD RECTIFIER
9. COUNTER MOUNTING PLATE WITH MOTOR TERMINAL BLOCK
Figure 5-22. Rectifiers installed.

 
49

Figure 5-23. Removing self-synchronous transmitter.
1. ARMATURE RECTIFIER
2. SELF-SYNCHRONOUS TRANSMITTER (60 REVOLUTIONS PER MILE)
3. SELF-SYNCHRONOUS TRANSMITTER (360 REVOLUTIONS PER MILE)
4. FIELD RECTIFIER
5. DISTANCE COUNTER
6. COUNTER MOUNTNG PLATE WITH MOTOR TERMINAL BLOCK
7. MOUNTING STRAP
Figure 5-23. Removing self-synchronous transmitter.
 
50

removed to compensate for the thickness of the two angle brackets.

Be sure to hold the lock nut adjacent to the inside of the bracket while tightening the outer nut to prevent the distortion of the plates.

  5H3. Installing the armature rectifier. (See Figure 5-22.) Place the rectifier assembly in position on the mounting plate and secure with the four screws and toothed lock washer provided. Connect the wires to the terminals with solder.
 
I. REMOVAL AND INSTALLATION OF FIELD RECTIFIER
 
5I1. Removing the field rectifier. (See Figure 5-22.) Evidence of a burned-out field rectifier is the presence of deposits of molten metal on the bottom of the plates. Remove the field rectifier as follows: Unsolder the lead wires from the rectifier terminals. Tag the wires for location. Remove the four screws and toothed lock washers that secure the rectifier assembly to the counter mounting plate, and remove the rectifier.   5I2. Installing the field rectifier. (See Figure 5-22.) The new rectifier and brackets are replaced as a unit. Place the rectifier assembly in position on the counter mounting plate. Install the four screws and toothed lock washers that secure the rectifier assembly to the counter mounting plate. Connect the lead wires to the rectifier terminals with solder.
 
J. REMOVAL AND INSTALLATION OF SELF-SYNCHRONOUS TRANSMITTER
 
5J1. Removing the distance transmitter. (See Figure 5-23.) Remove the cover from the case. Remove the two screws and toothed lock washers that secure the counter mounting plate to the transmitter mounting strap, and swing the counter assembly to one side out of the way. Remove the four screws and toothed lock washers that secure the transmitter mounting strap to the mounting cradle, and remove the strap. Pull the motor out of the cradle as far as the wires will allow, and disconnect the two wires from one of the brush blocks, and three wires from the opposite brush base. Tag the wires for identification. Lift the transmitter from the case. The other transmitter is removed in the same manner.

5J2. Installing the distance transmitter. (See Figure 5-23.) Place the transmitter on the

  forward edge of the case so that the wires may be connected. Connect the three wires to the terminals in the rear brush block. Connect the two wires to the front brush base. Place the transmitter in position in the cradle with the gear on the shaft properly meshed with the slow speed gear train in the case. Place the mounting strap in position and install the four screws and toothed lock washers that secure the strap to the cradle. Place the counter mounting plate with the counter in position on the transmitter mounting strap, making certain that the dowel holes in the plates are properly aligned with the dowel pins on the strap. Install the two screws and toothed lock washers that secure counter mounting plate to the transmitter mounting strap. The other transmitter is installed in the same manner. Install the case cover.
 
K. MAINTENANCE OF CONTROL UNIT
 
5K1. Checking and cleaning the contact points. (See Figure 2-7.) Remove the cover from the control unit case and place the top of the cover on the lower dowel pin of the case in such a manner that the dowel pin hole in the top edge of the cover is engaged in the bottom dowel pin in the case. Secure in this   position with one screw. This causes the unit to hang level in the gimbal bracket. It is apparent that the control unit contact points are not properly adjusted if the pump motor does not stop running when the rodmeter is secured, and the bypass valve on the control unit is open.
 
51

Figure 5-24. Valves in position for adjusting
contacts.
1. DYNAMIC PRESSURE VALVE
2. VENT COCK
3. BYPASS VALVE
4. VENT COCK
5. STATIC PRESSURE VALVE
Figure 5-24. Valves in position for adjusting contacts.

Clean the contact points in the following manner: Insert a piece of ordinary note paper between the contact points. Manually press the contact arm against the paper and adjacent contact point, and drag the paper across the points. This will usually remove any film of oil or dirt which may be present on the points. If this does not stop arcing between the points, clean the contact points with fine crocus paper or with a jeweler's file. Operate the system on the static head to determine whether this procedure has remedied the trouble.

5K2. Checking the position of the contact arm. (See Figure 5-25.) Remove the cover from the control unit case and hang it on the lower dowel pin. Place the valves in position for adjusting the contacts (Figure 5-24.) This places the static pressure only on both sides of the bellows, insuring that it is in the neutral, or center, position. Unless otherwise specified, all adjustments on the control unit are made with the valves in this position. Adjustments can be made while the ship is underway on the surface, but not while submerged. Back off screws No. 2 and No. 7 until

 

Figure 5-25. External contact arm in center position.
1. TERMINAL LUG A
2. ADJUSTABLE THUMB SCREW A
3. CONTACT SCREW A
4. CONTACT POINT A
5. CONTACT POINT B
6. CONTACT SCREW B
7. ADJUSTABLE THUMB SCREW B
8. TERMINAL LUG B
9. EXTERNAL CONTACT ARM
Figure 5-25. External contact arm in center position.

the stationary contact levers are completely open. Check to see that arm No. 9 is centered between stationary contact points No. 3 and No. 6. Manually move arm No. 9 upward and downward to see that it works freely and returns to the center position. If it is in good order, adjust the contact points as described in Sections 5K3 and 5K4. If the contact arm does not move freely or if it cannot be moved to each side of its center position because the internal lever strikes a stop rod, the interfering stop rod will have to be backed off slightly in the manner described in Sections 5K9 and 5K10. If the stop rods do not interfere and the arm still does not return to the center position, it will be necessary to attempt to position the contact arm by adjusting the

 
52

Figure 5-26. End view of contact arm clamps.
1. PIPE PLUG OPENING
2. INNER CONTACT ARM CLAMP
3. CONTROL UNIT CASE
4. OUTER CONTACT ARM CLAMP
Figure 5-26. End view of contact arm clamps.

contact arm clamps. This is performed in the following manner: position.Remove the pipe plug from the end of the case to make the inner clamp accessible, as shown in Figure 5-26. Slightly loosen the inner clamp screws. Slightly loosen the clamp screws from the outer clamp. Carefully hold the arm in the center position with one hand, and tighten the outer clamp screws so that an equal space is maintained between the clamp and the end of the arm. Then carefully tighten the inner clamp screws in the same manner. Clamp screws must be securely tightened, and equal space must be maintained between the inner surfaces of the contact arm and the bearing plate at the bellows housing. If the arm continues to bind, it is an indication of corrosion or damaged inner parts of the bellows assembly or faulty bellows linkage installation. If this is the case, disassemble the bellows as described in Sections 5K12 through 5K16. Inspect, clean, and repair parts if necessary, as described in Section 5K17. Assemble the bellows as described in Sections 5K18 through 5K29. Adjust the contacts as described in Sections 5K3 and 5K4. Reset the stop rods as described in Section 5K8, 5K9, and 5K10.

  5K3. Adjusting the upper contact without using the lamp. (See Figure 5-27.) Adjusting the contacts without using a test lamp is the regular procedure used. However, an alternate method of adjusting the contacts with the use of a test lamp is also employed. Both methods are explained.

Set the valves and vent cocks as shown in Figure 5-24. This insures equal pressure on the bellows. Deenergize or turn off the 2Y circuit on the control board. Remove the cover from the rotary distance transmitter, and disconnect either the 2Y1 or the 2YY1 wire from the left end of the terminal block. This is done to prevent the pump from operating while adjustments are being made. Energize the 2Y circuit by turning the control panel switch to the ON position. Manually push down the external contact arm until the transtat brush arm in the rotary distance transmitter travels approximately one-third of its distance from the lower limit switch. This allows sufficient movement of the brush arm while making adjustments. Turn down screw No. 5 until the follow-up motor in the rotary distance transmitter starts running smoothly. When the upper contacts first touch, the follow-up motor will operate unevenly. Continue to turn down screw No. 5 slowly, three-quarters of the distance between the holes in the head of the screw (approximately 15 to 18 degrees). Secure screw No. 5 in this position by means of the lock screw in front of the contact mounting bracket.

5K4. Adjusting the lower contact without using the lamp. (See Figure 5-2$.) Break the electrical contact on the upper lamp socket by loosening the terminal screw and removing one wire from the terminal. This is done so that the transtat motor will operate when both contacts are touching. Normally the transtat motor will not operate when both contacts are touching the: contact arm. Turn up screw No. 6 until the follow-up motor in the rotary distance transmitter just starts operating, then back off screw No. 6 slowly, three-quarters of the distance between the holes in the screwhead (approximately 15 to 18 degrees). Secure screw No. 6 in this position by means of the lock screw in front of

 
53

Figure 5-27. Adjusting upper contacts by the lamp method
1. LAMP
2. TERMINAL LUG A
3. TERMINAL LUG B
4. UPPER LAMP SOCKET
5. ADJUSTABLE THUMB SCREW A
6. CONTACT SCREW A
7. CONTACT POINT A
Figure 5-27. Adjusting upper contacts by the lamp method

the contact mounting bracket. Reinstall the wire terminal on the terminal of the upper lamp socket. This is necessary in order that the follow-up motor will run down. The follow-up motor should then run down until the transtat brush arm hits its lower limit switch. If the brush arm does not hit the lower limit switch and the follow-up motor does not stop, it is an indication that the contact points were not set properly. Personnel will have to reset the contact points, being very careful to slowly turn the contact adjusting screws the proper amount as discussed above.

5K5. Preparing the system before adjusting contacts with the test lamp. This is an alternate method of adjusting the contact points. Two lamps are provided to make this adjustment. These lamps are mounted in a bracket in the upper right side of the control mounting plate. Use only one lamp when making this adjustment. The other lamp is a spare only. Set the valves and vent cocks as shown in Figure 5-24, in order to insure equal pressure on the bellows. Deenergize, or turn off the 2Y circuit switch on the control panel.

  Remove the cover from the rotary distance transmitter. Disconnect either the 2Y1 or the 2YY1 wire from the left end of the terminal block in the rotary distance transmitter. This is done to prevent the pump from operating while adjustments are being made. Energize the 2Y circuit from the control panel. Manually push down on the contact arm until the transtat brush arm travels approximately one-third of its total distance from the lower limit switch. This allows sufficient movement of the brush arm while making adjustments. Move the wire from the upper terminal to the lower terminal of the upper lamp socket as shown in Figure 5-27. The lower lamp socket is prepared in the same manner as shown in Figure 5-28.

5K6. Adjusting the upper contact using the lamp method. (See Figure 5-27.) Remove one of the lamps from the bracket in the rear of the case. Install the lamp in the upper socket. Turn down screw No. 5 until the lamp burns without flickering. Then slowly continue to turn down screw No. 5 for three-quarters of the distance between the holes on the screwhead

Figure 5-28. Adjusting lower contacts
by the lamp method.
1. TERMINAL LUG A
2. TERMINAL LUG B
3. LAMP
4. CONTACT POINT
5. CONTACT SCREW B
6. ADJUSTABLE THUMB SCREW B
7. LOWER LAMP SOCKET
Figure 5-28. Adjusting lower contacts by the lamp method.

 
54

(approximately 15 to 18 degrees). Secure screw No. 5 in this position by means of the lock screw on the upper contact bracket.

5K7. Adjusting the lower contacts, using the lamp method. (See Figure 5-28.) Remove the test lamp from the upper socket and install it in the lower lamp socket. This breaks the contact in the upper socket, and permits proper adjustment of, the lower contact. Turn screw No. 6 slowly upward until the lamp glows; then slowly back off screw No. 6 until the lamp does not glow. Continue to back off screw No. 6 slowly for three-quarters of the distance between the holes in the screwhead (approximately 15 to 18 degrees). Secure the screw in this position by means of the lock screw in front of the mounting bracket. Remove the lamp from the socket and install it in the carrying bracket back of the control mounting plate. Remove the wires from the upper and lower lamp socket terminals and install them in their original position on the sockets as shown in Figures 5-27 and 5-28. If the follow-up motor in the rotary distance transmitter does not drive the transtat brush arm to the lower limit switch, it is an indication that the contacts are not properly adjusted, and that the operation of the adjusting contact points will have to be repeated. Check the setting of the upper and lower stop rods and reset if necessary (see Sections 5K8, 5K9, and 5K10) before operating the log. The contact setting made may be thrown off adjustment if the stops are incorrectly set.

5K8. Adjustable stop rods. (See Figure 529.) Two adjustable stop rods are provided in the bellows assembly to limit the upward and downward motion of the bellows, thus preventing possible damage to the interior parts of the bellows housing, and to the contact mechanism at times of excessive pressure differences. These pressure differences often cause the bellows to stretch slightly from the newly installed position and consequently necessitate adjustment of the stops as well as of the contact points. Older type bellows assemblies are equipped with stop rods that are only partly threaded throughout the length of the rod. In the event that these old

  Figure 5-29. Adjustable stop rods installed.
Figure 5-29. Adjustable stop rods installed.

type rods become damaged or stripped, the complete bellows assembly must be disassembled to remove them. In the newer type of bellows assembly, the stop rods are threaded throughout the entire length and may be removed without dismantling the bellows housing.

5K9. Setting the lower adjustable stop rod. (See Figures 5-29, 5-30, and 5-3l.) Remove the cover from the control unit case. Unscrew and remove the lower cap to make the lower stop rod accessible. Remove the pipe plug from the dower side of the case. Using the socket wrench, loosen the lock nut that secures the stop rod in position. Place a finger on the contact arm and hold the arm slightly downward. Turn the lower stop rod inward (clockwise) until the stop rod contacts the bellows stud and starts to push the contact arm upward. Continue to turn the stop rod until the gap between the upper contact points is reduced to approximately 1/32-inch.

 
55

Figure 5-30. Setting upper adjustable stop rod, old installation. Special combination screwdriver and wrench inserted through upper pipe plug opening in case
1. BELLOWS HOUSING
2. UPPER TOP CAP REMOVED
3. LOWER STOP CAP REMOVED
Figure 5-30. Setting upper adjustable stop rod, old installation.

Tighten the lock nut to secure the stop rod in this position. Set the valves and vent cocks as shown in Figure 5-42 (Position 7). This causes the water to force the bellows downward. The upper contacts should be open approximately 1/32-inch. If the points are not open this amount, reset the lower stop rod. Make certain that the lock nut on the lower stop rod is tight. Install the lower cap. Turn the valves and cocks to the desired position.

5K10. Setting the upper adjustable stop rod. (See Figure 5-31.) Remove the pipe plug from the upper end of the case to make the stop rod accessible. Remove the cap from the top of

  Figure 5-31. Setting upper adjustable stop rod,
new installation.
Figure 5-31. Setting upper adjustable stop rod, new installation.

the bellows housing. Using the socket wrench as illustrated in Figure 5-31, loosen the lock nut on the stop rod. Turn the stop rod downward (clockwise) while holding the contact arm up against the upper contact screw until the stop rod contacts the inside of the bellows head. Continue to turn the stop rod until the gap between the lower contacts is reduced to approximately 1/32-inch; then tighten the lock nut on the stop rod. Set the vent cocks and valves as shown in Figure 5-42 (Position 3). Water pressure will now force the, contact arm upward. The lower contacts should be open approximately 1/32-inch. If the contacts are not open this amount, reset the upper stop rod. Make certain that the lock nut on the stop rod is tight. Install the cap on the bellows housing. Turn the valves and vent cocks to the desired position. Check the operation of the system by operating it on the static head as described in Section 5A2.

5K11. Checking the control unit after adjustment. Check the control unit, after adjusting the contact point and setting the stop rods, in order to make certain that the unit is operating properly. Perform the following operations: Deenergize the 2Y circuit by turning the switch on the control panel to the OFF position. Reconnect the 2Y1 or 2YY1

 
56

circuit, whichever was previously disconnected, in the rotary distance transmitter. Energize the 2Y circuit. Operate the system on the static head as described in Section 5A2. The system should operate and register approximately 5 to 10 knots, depending on the waterline above the unit. The transtat brush arm should oscillate or hunt slightly. Turn the valves and vent cocks to position (Figure 5-24). The transtat arm should drive down until the pump and motor stop, and should then continue to drive down until the follow-up motor is stopped by the limit switch. If satisfactory, turn the valves and vent cocks to the secured position or the operating position, whichever is desired.

5K12. Removing the control unit from its case. (See Figure 5-32.) Remove the cover retaining screws and the cover. Remove the static and dynamic hose from the nipples.

  Break the piping unions and remove the two hexagonal nipples. Disconnect the three wire leads that connect the outside current source with the terminal block and pull the wires to one side out of the way. Remove the three screws and toothed lock washers that secure the mounting plate to the case, and lift the plate and the assembled control unit out of the case by means of the handles provided.

5K13. Removing the bellows assembly from the plate. (See Figure 5-33.) Disconnect the pigtail wire from the terminal on the auxiliary center contact block. Remove the handle screws and the two handles. Unscrew and remove the handle studs that secure the bellows housing to the mounting plate, and remove the studs and complete bellows assembly. Be careful that the contacts on the external contact arm are not damaged.

Figure 5-32. Control unit removed from case.
Figure 5-32. Control unit removed from case.
 
57

Figure 5-33. Pigtail wiring connection.
Figure 5-33. Pigtail wiring connection.

5K14. Removing the bellows housing corer. (See Figure 5-34.) Remove the external arm clamp retaining screws and clamps, and remove the contact arm. Remove the three screws that secure the housing and cap with the lower adjustable stop screw to the housing cover. Drain the water from the bellows. Remove the cap screw from the bellows extension post, and the ten housing cover screws and lift the housing cover from the assembly.

5K15. Disassembly of housing cover. (See Figure 5-38.) Remove the shoulder screw that secures the shaft seal bellows to the contact lever shaft. Detach the two pillow blocks and bearing assemblies from the housing cover after removing the shoulder screws. (The external contact arm was removed previously.) It may be necessary to tap the end of the contact arm shaft lightly with a soft hammer or wooden block to loosen the bearings and sockets. Remove the contact lever shaft. Detach the bellows seal cap after removing the three seal cap screws. Remove the shaft seal bellows, bellows stud, and gasket.

5K16. Disassembly of the bellows housing. (See Figure 5-43.) Remove the screws that secure the bellows holding ring to the housing, and remove the ring. Lift the bellows and

  Figure 5-34. Bellows housing, cover removed.
1. BELLOWS HOUSING COVER
2. GASKET
3. SEAL BELLOWS ASSEMBLY
4. CAP (BELLOWS SEAL)
5. CONTACT LEVER SHAFT
6. BELLOWS SHOULDER SCREW
Figure 5-34. Bellows housing, cover removed.

the bellows gasket from the housing. Unscrew and remove the cap, gland liner, packing, and stop rod from the top of the housing.

5K17. Inspection and repair. Examine the gaskets for cracks and torn edges. Replace any damaged gaskets. Examine the contact arm shaft for score marks. Remove any scoring with an oilstone or crocus paper. Examine the threads of the adjustable stop rods. I the threads are slightly damaged, chase them with a stock and die. Replace badly damaged stop rods. Carefully examine the pressure bellows and shaft seal for cracks or pin holes. Fill the bellows with kerosene and note any evidence of seepage, which indicates cracks or holes. Replace damaged bellows. If the bellows does not leak, thoroughly clean the kerosene from

 
58

Figure 5-35. Bellows installed on housing.
Figure 5-35. Bellows installed on housing.

the bellows to prevent damage to any rubber parts. Carefully examine the bearings; Turn the bearings slowly by hand. They should turn freely. A clicking noise and binding indicate cracked balls.

5K18. Installing the pressure bellows in bellows housing. (See Figure 5-35.) Place the bellows gasket in the recess provided in the bellows housing. Carefully place the bellows on the top of the gasket so that the bellows flange is properly seated over the gasket. Place the bellows holding the ring over the bellows. Align the mounting holes and install the ten screws that secure the ring to the housing. Check the length of the pressure bellows with the bellows extension post installed. Adjust the free length of the bellows so that the top of the extension post projects 31/32-inch outside of the outer (machined) surface of the bellows housing.

5K19. Assembling and installing the bellows housing cover. (See Figures 5-37, 5-38, and 5-39.) Mount the seal bellows and stud with a gasket in the housing cover. Place the cover with a rubber gasket on the bellows housing. Then carry out the following procedure:

1. Align the seal bellows stud with the bellows extension post, and loosely install the cap screw that secures the seal bellows stud

  Figure 5-36. Cutaway view of seal bellows
assembly.
1. BELLOWS HOUSING COVER
2. GASKET
3. SEAL BELLOWS ASSEMBLY
4. CAP (BELLOWS SEAL)
5. CONTACT LEVER SHAFT
6. BELLOWS SHOULDER SCREW
Figure 5-36. Cutaway view of seal bellows assembly.

to the bellows extension post. Tighten the seal bellows cap retaining screw.

2. Assemble the ball bearing in the pillow blocks (one to each block) and install the ball bearing retainers on the pillow blocks. Assemble the pillow blocks on the ends of the contact lever shaft (one at each end), then place the contact lever shaft in position over the seal bellows and adjacent to the bellows housing cover with the side of the shaft marked TOP toward the cover. Secure the pillow blocks to the cover with four screws (two to each block).

3. Install the seal bellows shoulder screw through the hole in the contact lever shaft, and tighten the screw securely.

4. Tighten the cap screw that secures the seal bellows stud to the bellows extension post.

5. Assemble the lower adjustable stop screw in the following manner: Install the

 
59

short screw into the gland nut. Slide the gland liner on the stop screw with the concave surface of the liner facing away from the head of the stop screw. Place sufficient packing against the concave surface of the liner; then screw the stop-screw assembly into the housing end cap. In replacing the packing, do not use more than necessary, as too much will prevent the proper adjustment of the stop screw. Be sure that the stop screw is well backed out. Place the stop screw assembly in position on the bellows housing cover, being sure that the gasket is in place, and secure with the three screws provided. Tighten securely.

6. Assemble the upper adjustable stop screw in the housing cap in the same manner as the lower stop screw. Be sure that the stop screw is well backed out of the cap. Install the housing cap with its assembled stop screw on top of the bellows housing.

5K20. Checking the bellows assembly for friction. Temporarily install the external

  contact arm and clamps on the contact arm shaft. Move the contact arm upward and downward. If the arm operates stiffly in one direction, unscrew the adjustable stop rod on the stiff side of the arm. Set a small tool or block at the outer end of the external contact arm to act as a marker. Manually move the contact arm first in one direction and then in the opposite direction, approximately 1/32-inch each way. The arm should return to its original position if the bellows components were properly installed. If the bellows contact arm does not return to its original position, the bellows should be disassembled, and the cause of the binding determined and eliminated. Remove the contact arm and clamps from the bellows cover. Install the balance of the cover screws. Place the bellows subcover and its gasket in position on the housing cover, and secure with the six screws provided.

5K21. Installing external contact arm. (Figures 5-40 and 5-41.) Place the external contact

Figure 5-37. Bellows housing assembly, old installation.
Figure 5-37. Bellows housing assembly, old installation.
 
60

Figure 5-38. Bellows housing cover with housing
end cap and stop rod removed, new installation.
Figure 5-38. Bellows housing cover with housing end cap and stop rod removed, new installation.

arm in position on the contact lever shaft. Install the contact, arm clamps, making certain that the assembly marks on the clamps correspond with those on the arm. Install the four zinc-plated steel screws (two to each clamp) that secure the arm clamps to the external contact arm. Be sure that there is

  Figure 5-39. Bellows housing cover assembled,
new installation.
Figure 5-39. Bellows housing cover assembled, new installation.

clearance between each clamp and the adjacent ball bearing retainer.

5K22. Installing the bellows assembly on the mounting plate. (See Figures 5-32 and 5-33.) Carefully place the bellows housing on the mounting plate. Align the mounting holes

Figure 5-40. Bellows housing assembly.
1. BELLOWS HOUSING
2. BELLOWS HOUSING COVER
3. BELLOWS HOUSING COVER SCREW
4. EXTERNAL CONTACT ARM
5. HOUSING END CAP SCREW
6. HOUSING END CAP
7. GLAND NUT
8. LOWER ADJUSTABLE STOP SCREW (SHORT)
9. PIGTAIL
10. BALL BEARING RETAINER
11. EXTERNAL CONTACT ARM CLAMP
12. CONTACT ARM CLAMP SCREW
13. PILLOW BLOCK RETAINING SCREW
14. PILLOW BLOCK
15. BELLOWS SEAL CAP
16. CONTACT LEVER SHAFT
17. BELLOWS SHOULDER SCREW

Figure 5-40. Bellows housing assembly.
 
61

Figure 5-41. End view of contact arm clamps.
1. PIPE PLUG OPENING
2. INNER CONTACT ARM CLAMP
3. CONTROL UNIT CASE
4. OUTER CONTACT ARM CLAMP
Figure 5-41. End view of contact arm clamps.

and install the four handle studs that secure the housing to the plate. Remove the terminal screw from the right side of the auxiliary center contact block. Lift of f the wire, and place the pigtail connection on the block. Place the wire over the pigtail and install the terminal screw. Place the handles in position on the studs, and install the handle retaining screws.

5K23. Aging the bellows. (Figure 5-42.) Aging the control unit bellows is necessary any time a new bellows is installed, or if the old bellows has been bent out of its normal position. The bellows, like any metal spring, will return to a certain position when an applied pressure is released, unless the pressure has been sufficient to bend it and cause the bellows to set in a new position. If there are stresses retained in the metal from bending or stretching, the bellows will not return at once to the original position, but may creep slowly to that point. To be certain that all stresses are removed from the bellows it should be put through an aging operation. The aging operation consists of impressing a pressure first on the inside of the bellows and then on the outside, while gradually reducing the impressed pressure to zero.

  Figure 5-42. Valve positions for aging the bellows.
Figure 5-42. Valve positions for aging the bellows.
 
62

Figure 5-43. Exploded view of bellows assembly.
*1. UPPER ADJUSTABLE STOP SCREW (LONG).
*2. BELLOWS CAP.
*3. GLAND LINER
*4. PACKING
5. BELLOWS HOUSING.
6. BELLOWS GASKET.
7. RUBBER GASKET.
8. BELLOWS.
*9. BELLOWS EXTENSION POST.
10. BELLOWS HOLDING RING.
11. HOLDING RING SCREW.
*12. BELLOWS HOUSING COVER.
13. EXTERNAL CONTACT ARM.
14. PIGTAIL
*15. PACKING
*16. GLAND LINER.
*17. GLAND NUT.
*18. LOWER ADJUSTABLE STOP SCREW (SHORT).
*19. HOUSING END CAP SCREW (BRONZE 10-32 X 1/2 FLAT HEAD).
*20. HOUSING END CAP.
*21. GASKET.
*22. CAP SCREW (SEAL BELLOWS TO BELLOWS POST).
23. BELLOWS HOUSING COVER SCREW.
*24. GASKET.
*25. SEAL BELLOWS.
*26. BELLOWS SEAL CAP.
*27. SEAL CAP SCREW (BRONZE 10-32 X 1/2 FLAT HEAD).
*28. PILLOW BLOCK RETAINING SCREW.
*29. BALL BEARING RETAINER SCREW (BRONZE 4-36 X 3/8 FLAT HEAD).
*30. BALL BEARING RETAINER.
*31. BALL BEARING.
*32. PILLOW BLOCK.
33. CLAMP RETAINING SCREW.
34. EXTERNAL CONTACT ARM CLAMP.
*35. CONTACT LEVER SHAFT.
*36. BELLOWS SHOULDER SCREW.

* Indicates replacement parts necessary to modify old bellows.
Figure 5-43. Exploded view of bellows assembly.
 
63

The equipment necessary to perform the aging operation is a 2-gallon tank with pressure gage, and connections capable of withstanding a pressure of 20 pounds per square inch. A pressure storage tank such as that illustrated in Figure 7-1 may be used. Fill the pressure tank approximately one-half full of water. Connect the line from the tank to the dynamic and static connections of the control unit. Vent the control unit. Make certain that the adjustable stop rods have been positioned by turning in each rod until it touches the bellows and then backing off exactly two full turns so as to have the movement on each side of the bellows equal. Loosen the contact arm clamps. With valves and vent cocks in position as shown in Figure 5-24, build up a pressure of 20 pounds per square inch in the tank. Follow the sequence of valve operations as shown in Positions 1 to 9 (Figure 5-42), being careful to permit all the water to flow from the bellows before changing the valves and cocks to the next position. Repeat this operation until the pressure in the tank reaches zero.

5K24. Installing the control unit in its case. (See Figure 2-7.) Lift the control unit into the control unit case, and secure with the three screws and lock washers. Connect the lugs on the ends of the electrical leads to the terminal block on the upper right of the mounting plate.

5K25. Installing the piping assembly. (See Figure 2-7.) Loosen the gland nuts on top of the control unit case; and place the nipples through the top of the case and into the top of the bellows housing, using a small amount of pipe compound on the threads. Tighten the nipples securely so that the tops of the lower half of the unions are parallel. Place the valve piping assembly in position on top of the nipples, with the copper tubes inside the nipples, and tighten the unions securely. Test the complete unit for leaks with 300 pounds per square inch of water pressure. (The bypass valve must be open.) Place the hose- from the rodmeter on the static nipple (right-hand). Place the hose from the pump on the left-hand nipple and tighten the hose clamps. Fill the system with water and vent

  Figure 5-44. Piping assembly, old installation.
Figure 5-44. Piping assembly, old installation.

it as described in Section 3A3. Center the contact arm, adjust the contact points and stop screws (see Sections 5K2, 5K3, 5K4, 5K9, and 5K10). In this case, the top contact adjusting screw is advanced only 1/2-hole, and the bottom screw is backed off 1/2-hole. The stop screws in the modified control unit are adjusted in the same manner as the stop rods in the older installation, except that the special stop rod wrench and screwdriver are not needed. Place the cover in position on the control unit case and secure with the cover retaining screws.

Figure 5-45. Piping assembly, new installation.
Figure 5-45. Piping assembly, new installation.

 
64

 
L. CONTROL UNIT PIPING
 
5L1. Description of modified control unit piping assembly. Most submarine control units are equipped with the conventional type of piping assembly as shown in Figure 5-44. Some, however, are equipped with a modified piping assembly that contains a safety pressure relief assembly as shown in Figure 5-45. This is a safety feature which protects the bellows when the pressure difference across the bellows exceeds approximately 25 pounds per square inch. Such a difference will occur if a hose should blow off, or if the unit is vented incorrectly when submerged. When the pressure difference exceeds 25 pounds per square inch, the diaphragm will rupture,   4. Install the vent cocks in the T-fittings. Use pipe compound.

5. Assemble the left-hand street ell, nipple, and fixed block, and install the left-hand street ell in the left-hand T-fitting. Use pipe compound.

6. Assemble the pipe fitting into the right-hand street ell, using pipe compound.

7. Slide the gland nut, bakelite washer, rubber slip joint washer, and movable block onto the pipe nipple.

8. Align the fixed and movable blocks, and loosely install the four lower movable block screws.

Figure 5-46. Pressure relief assembly disassembled.
Figure 5-46. Pressure relief assembly disassembled.
thereby equalizing the pressures on both sides of the bellows and protecting the bellows from distortion.

5L2. Modifying the control unit piping assembly. (See Figures 5-45 and 5-46.) Modify the control unit piping assembly as described in the following steps:

1. Unscrew and remove the vent cocks.

2. Remove the elbows, but leave the elbow nipples installed in the cross-connector.

3. Install T-fittings in place of the elbows in the cross-connector. Use only a small amount of pipe compound on the threads.

  9. Insert the platinum diaphragm into the gap between the blocks. Make certain that the diaphragm is properly aligned within the blocks to prevent damage to the diaphragm when the remainder of the screws are installed in the blocks.

10. Install the remainder of the block retaining screws and tighten all screws.

11. Hold the blocks with a wrench and tighten the gland nut securely.

12. Test the complete unit for leaks with 300 pounds per square inch of water pressure. The bypass valve must be open.

 
65

Figure 5-47 Cutaway view of master speed indicator.
1. SELF-SYNCHRONOUS TRANSMITTER
2. FOLLOW-UP CONTACT ASSEMBLY
3. SLIP RING AND CONTACT ASSEMBLY
4. SELF-SYNCHRONOUS REPEATER
5. UPPER DIFFERENTIAL GEAR
6. DIFFERENTIAL SPIDER
7. LOWER DIFFERENTIAL GEAR
8. CONSTANT SPEED MOTOR AND DISK
9. FRICTION ROLLER AND PINION
10. LEAD SCREW DRIVING MOTOR
11. YOKE
12. LEAD SCREW

Figure 5-47 Cutaway view of master speed indicator.
 
66

5L3. Testing for leaky or punctured diaphragm. Operate the system on the static head as described in Section 5A2. If water drips continuously out of the open vent cock, it is an indication that the diaphragm is punctured.

5L4. Replacing a damaged diaphragm. (See Figure 5-45.) Hold the movable and fixed blocks with a wrench, and loosen the gland nut. Remove the two top screws from the movable block, and loosen the remainder of

  the block screws. Separate the movable block from the fixed block sufficiently to remove the damaged diaphragm. Remove the damaged diaphragm. Insert the new diaphragm between the blocks, making certain that it is aligned properly within the blocks. The diaphragm must be 0.0008 inch thick (Pitometer Log Corporation S1452B). Install the two top movable block retaining screws, and tighten all screws securely. Test for a leaky diaphragm as described in Section 5L10.
 
M. MAINTENANCE OF MASTER SPEED INDICATOR
 
5M1. General information. Provision has been made for removal of the complete unit from the case for purposes of inspection and test of the master speed indicator. Subassemblies of the unit are constructed so that they may be replaced as units. Whenever any of the components are removed, it is necessary that the instrument be recalibrated.

5M2. Replacing the pointer and dial. (See Figure 5-47.) Remove the cover retaining screws, and remove the case cover. Remove the hub cap from the pointer hub. Remove the screw that secures the pointer hub to the, speed transmitter shaft and remove the pointer assembly. Remove the six screws that secure the dial to the mounting studs and remove the dial. To install the dial, position it on the mounting studs and install the dial retaining screws. Place the pointer on the shaft of the transmitter shaft, and secured it with the screw provided. Set the pointer to exact zero, if necessary, as described in Sections 5M51 and 5M52. Install the pointer hub cap. Place the cover in position on the case and install the cover retaining screws.

5M3. Testing the lead screw drive motor. (See Figure 5-48.) Test the operation of the lead screw drive motor in the following manner: Remove the cover from the case. Disconnect the lead from the center terminal of the motor. This terminal is marked C. Rotate the gear by hand until the pointer reads several knots. Using a screwdriver, alternately short circuit the terminals marked CW and CCW with the center terminal. The motor

  will run first clockwise and then counterclockwise, if it is operating properly. If the motor is binding, or inoperative, replace it.

5M4. Removing the lead screw drive motor. (See Figure 5-48.) Remove the cover from the case. Disconnect the wires from the motor terminal, and tag the wires for ready identification. Remove the three screws and toothed lock washers that secure the motor bracket to the main mounting plate, and remove the motor assembly.

5M5. Replacing the lead screw drive motor. (See Figure 5-49.) Remove the lead screw drive motor (see Section 5M4). Remove the two fillister head screws that position the

Figure 5-48. Lead screw drive motor removed.
Figure 5-48. Lead screw drive motor removed.

 
67

motor in its bracket. Remove the two screws, lock washers, and nuts, and remove the motor from its mounting bracket as shown in Figure 5-50. Remove the reduction gear stud nut. Remove the retaining pin and washer from the old motor as shown in Figure 5-50, and remove the gears from the motor. Remove the stud nut from the new motor. Remove the retaining

Figure 5-49. Replacing lead screw drive motor,
Step 1.
Figure 5-49. Replacing lead screw drive motor, Step 1.

pin and washer from the micarta gear son the new motor, as the washer interferes with the installation of the reduction gear assembly. Place the reduction gear assembly from the old motor on the shaft of the new motor, and install the stud nut. Install the washer and retaining pin on the micarta gear shaft.

  Figure 5-50. Replacing lead screw drive motor,
Step 2.
1. MOTOR BRACKET
2. REDUCTION GEAR STUD NUT
3. REDUCTION GEAR
4. RETAINING PIN
5. WASHER
6. MICARTA REDUCTION GEAR AND PINION
Figure 5-50. Replacing lead screw drive motor, Step 2.

Place the new motor with its assembled reduction gear as shown in Figure 5-51 in position in the motor mounting bracket. Install the two fillister head screws that position the motor in its bracket. Install the two screws, lock washers, and nuts that secure the motor (Figure 5-49).

Figure 5-51. Replacing lead screw drive motor Step 3.
Figure 5-51. Replacing lead screw drive motor Step 3.
 
68

Figure 5-52. Master speed indicator, dial removed.
1. MAIN MOUNTING PLATE
2. TAPERED PIN
3. COUNTER DRIVING WORM
4. LOCATING DOTS
5. COUNTER DRIVE SHAFT MITER GEAR
6. COUNTER DRIVE MITER GEAR
7. DIAL STUDS
8. MILEAGE COUNTER
9. TOP MOUNTING PLATE
10. TOP SUPPORT STUD
11. COUNTER DRIVE HELICAL GEAR (L.H.)
12. COUNTER DRIVE SHAFT
13. COUNTER DRIVE SHAFT BRACKET
14. TOP MOUNTING PLATE MOUNTING SCREWS
15. LEAD SCREW DRIVING MOTOR LIMIT SWITCH
16. POINTER SHAFT
17. LIMIT SWITCH OPERATING SCREWS
18. CONSTANT SPEED MOTOR LIMIT SWITCH
19. LEAD SCREW DRIVING MOTOR

Figure 5-52. Master speed indicator, dial removed.
 
69

5M6. Installing the lead screw drive motor. (See Figure 5-48.) Place the lead screw drive motor and its attached bracket in position on the main mounting plate and install the three screws and toothed lock washers that secure the motor assembly to the mounting plate. Connect the wires to the terminal on the motor. Test the operation of the motor as described in Section 5M3.

5M7. Replacing the mileage counter. (See Figure 5-52.) Turn the operating shaft of the dimmer rheostat so that its forked end clears the rheostat shaft extension. Remove the 10 mounting screws that secure the main mounting plate to the case, and lift the unit out of the case. Disconnect the outside source lead wires from the terminal block. Remove the pointer and dial (see Section 5M2). Remove the four screws that secure the mileage counter to the top mounting plate, and remove the counter. Transfer the counter gear to the new counter. Place the new counter in position on the top mounting plate, and install the four counter retaining screws. Install the dial and pointer (see Section 5M2). Place the unit in its case (see Section 5M50).

5M8. Removing the top mounting plate. (See Figure 5-52.) Remove the mileage counter (see Section 5M8). Remove the tapered pin from the counter driving worm as shown in Figure 5-52, and remove the worm from the self-synchronous repeater shaft extension. Unscrew and remove the top support stud from the upper left corner of the mounting plate. Remove the screws and lock washers that secure the top mounting plate to the studs on the main mounting plate. Remove the two handle retaining screws from the upper right handle. The handle screws are staked at assembly. Swing the top mounting plate to one side out of the way.

5M9. Removing the brush block assembly. (See Figure 5-53.) Remove the top mounting plate (see Section 5M8). Remove the two screws that secure the brush block as to the studs on the main mounting plate, and carefully remove the brush block to disengage the brushes from the slip rings of the slip ring and contact assembly. Disconnect the

  wires from the brush block, and tag them for ready identification.

5M10. Replacing the spiral take-up spring. (See Figures 5-53 and 5-54.) Remove the top mounting plate as described in Section 5M8. Unscrew and remove the pin screw from the second follow-up driving gear at the left side of the spring. Loosen the setscrew that secures this second follow-up driving gear to the jackshaft. Hold the large follow-up driving gear while lifting the small follow-up

Figure 5-53. Slip ring and contact assembly,
brush block removed.
1. MAIN MOUNTING PLATE
2. TOP BRACKET
3. TAKE-UP SPRING HOOK
4. SECOND FOLLOW-UP GEARS
5. BEARING PLATE
6. SPIRAL TAKE-UP SPRING
7. BRUSH SPRING
8. FOLLOW-UP CONTACT ASSEMBLY
9. BRUSH BLOCK
10. BRUSHES
11. SLIP RING AND CONTACT ASSEMBLY
12. DIFFERENTIAL TOP BRACKET
13. JACKSHAFT
14. FIRST FOLLOW-UP DRIVEN GEAR
Figure 5-53. Slip ring and contact assembly, brush block removed.

gear from the jackshaft to prevent the spring from unwinding too rapidly. Gradually release the large gear to permit the spiral takeup spring to unwind gradually. Disengage the end of the spring from the hooks provided on the top mounting bracket and on the hub of the large second follow-up driving gear. Install the new spring in the following manner:

 
70

Figure 5-54. Installing spiral take-up spring.
1. SPRING HOOK
2. BEARING PLATE
3. SPRIAL TAKE-UP SPRING
4. LARGE SECOND FOLLOW-UP DRIVEN GEAR
5. JACKSHAFT (SMALL SECOND FOLLOW-UP DRIVING GEAR REMOVED)
Figure 5-54. Installing spiral take-up spring.

Engage the hole in one end of the spring in the hook on the hub of the large second follow-up driving gear as shown in Figure 554. Turn the large gear by hand to wind up the spring on the gear hub. Hook the loose end of the spring on the hook provided on the top mounting bracket as shown in Figure 5-54. Turn the gear until the spring is tightly wound, and then back off the gear three-quarters of a turn to give the spring the proper tension. Hold the large gear and spring in this position while installing the small second follow-up driving gear on top of the jackshaft. Align the pin screw hole and install the pin screw and setscrew to secure the small gear on the jackshaft.

5M11. Removing the follow-up contact assembly. (See Figure 5-55.) Remove the brush block assembly (see Section 5M9). Remove

  the spiral take-up spring (see Section 5M10). Remove the starting condenser from the back of the main mounting plate as described in Section 5M47. This makes the top bracket mounting screws accessible. Remove the two top bracket retaining screws and lock washers. Loosen the mounting screws on the differential top bracket, differential bottom bracket, and the main mounting bracket, so that the brackets can be slightly lifted to allow for the clearance of the dowel pins on the top bracket. Lift all the brackets away from the main mounting plate and remove the top bracket with its assembled follow-up contact assembly as shown in Figure 5-55. Remove the lock nut, tension spring, washer, and the follow-up contact assembly from the follow-up shaft.

5M12. Removing the slip ring and contact assembly. (See Figure 5-55.) Remove the follow-up contact assembly as described in Section 5M11, in order to get proper clearance for the removal of the slip ring and contact assembly. Remove the pin screw and loosen the setscrew that secures the slip ring and contact assembly to the differential shaft. The slip ring and contact assembly is removed as a unit (see Figure 5-57).

5M13. Repairing the follow-up contact assembly. (See Figure 5-56.) Under ordinary circumstances the follow-up contact assembly is replaced as a unit. However in an emergency the follow-up contact can be replaced as follows: Remove the screws from the bakelite disk, and unsolder the lead wire from the contact arm. Place the new contact arm in position on the bakelite disk, and secure with the screws provided. Solder the lead wire to the contact.

5M14. Repairing and adjusting the slip ring and contact assembly. (See Figure 5-57.) Smooth the contact points with a jeweler's file, and remove fine particles; oil, or grease with clean cloth or paper. If .the contact points are badly worn, or pitted, unscrew the contact screws from their mounting brackets, and install new contact screws. At assembly there should be a space of 1/32-inch between the contact screw point and the follow-up

 
71

Figure 5-55. Removing follow-up contact assembly and top bracket.
1. FOLLOW-UP CONTACT, ASSEMBLY
2. SLIP RING AND CONTACT, ASSEMBLY
3. DIFFERENTIAL TOP BRACKET
4. MAIN MOUNTING BRACKET
5. LEAD SCREW, ASSEMBLY
6. FIRST FOLLOW-UP DRIVEN GEARS
7. JACKSHAFT
8. TOP BRACKET
9. SPRING SHIELD

Figure 5-55. Removing follow-up contact assembly and top bracket.
Figure 5-56. Follow-up contact assembly removed.
Figure 5-56. Follow-up contact assembly removed.

contact when one of the contact points is touching the contact arm. Adjust for this clearance by turning the contact screws

  Figure 5-57. Slip ring and contact assembly removed.
Figure 5-57. Slip ring and contact assembly removed.

inward or outward until the desired clearance is obtained. Clean the slip rings with crocus paper.

5M15. Cleaning and repairing brushes. (See Figure 5-53.) The brushes on the brush block should be cleaned with crocus paper. The

 
72

brushes should move freely on their mounting studs without binding and should contact both sides of the slip ring. If they do not contact the slip ring properly, replace the brush springs.

5M16. Removing the differential and lead screw assemblies. (See Figures 5-59 and 5-60.) Since all mounting brackets on the forward face of the main mounting plate are doweled, it is necessary to raise all the brackets simultaneously to clear the dowel pins without distorting the connecting parts. Remove the follow-up contact assembly (see Section 5M11). Remove the slip ring and contact assembly (see Section 5M12). Remove the lead screw drive motor (see Section 5M4). Remove all the bracket mounting screws. Lift the jack

Figure 5-58. Lead screw yoke assembly removed.
1. TAKE-UP SPRING
2. OIL WELL COVER AND SPRING SUPPORT
3. END PLATE
4. ROLLER SHAFT AND PINION
5. FRICTION ROLLER
6. LEAD SCREW YOKE
7. LIMIT SWITCH OPERATING SCREWS
8. ROLLER AND PIVOT
Figure 5-58. Lead screw yoke assembly removed.

  screw assembly out of the differential top bracket. Carefully lift off the differential top bracket, differential bottom bracket, and the main mounting bracket in such a manner that the connecting parts will not be distorted or sprung. Loosen the setscrew that secures the guide rod in the differential bottom bracket, and pull the guide rod out of its brackets. Remove the differential from the top and bottom mounting brackets. Remove the pin screw and loosen the setscrew that secures the lead screw driven gear to the bottom of the lead screw, and remove the gear. Pull the lead screw assembly out of the main mounting bracket.

5M17. Disassembly of the lead screw assembly. (See Figures 5-58 and 5-61.) Unscrew and remove the lead screw and follow-up pinion from the lead screw yoke. Remove the end plate retaining screws, end plate, thrust spring washer, and ball bearing from the upper end of yoke. Push the roller and pinion upward as shown in Figure 5-61, and remove them from the yoke. The ball bearing on the opposite end of the yoke is removed by removing the end plate and thrust spring washer.

5M18. Cleaning and repairing the lead screw assembly. Do not attempt to remove the friction roller from the roller shaft and pinion. Replace this assembly as a unit. Thoroughly clean all parts in Navy-approved cleaning fluid. Examine the friction roller and guide rod roller for flat spots. The diameter of the friction roller should be 1.2505 inches maximum and 1.2480 inches minimum. If the roller is smaller than 1.2480 inches, replace the complete roller shaft and pinion assembly.

5M19. Assembling the lead screw assembly. (See Figures 5-58 and 5-61.) Install the lower end plate on the yoke. Place the ball bearing in the yoke with the open face of the bearing upward. Place the friction roller shaft and the pinion assembly in position in the yoke. Install the upper ball bearing in the yoke with the open end of the bearing toward the roller shaft. Place the thrust spring washer on the bearing with the protruding section of the washer away from the bearing. Install the end plate and the end plate retaining screws.

 
73

Figure 5-59. Master speed indicator, top mounting plate removed.
Figure 5-59. Master speed indicator, top mounting plate removed.
 
74

Figure 5-60. Lead screw and differential partially disassembled.
1. DIFFERENTIAL TOP BRACKET
2. DIFFERENTIAL SHAFT
3. DRIVEN SPRIAL GEAR
4. DIFFERENTIAL END PLATE AND GEAR HUB
5. UPPER DIFFERENTIAL FACE BEVEL GEAR
6. LEAD SCREW AND FOLLOW-UP PINION
7. TAKE-UP SPRING
8. SPIDER
9. DIFFERENTIAL BEVEL PINION
10. SPUR GEAR (STANDARD SPEED)
11. LOWER DIFFERENTIAL FACE BEVEL GEAR
12. DIFFERENTIAL BOTTOM BRACKET
13. ROLLER AND PIVOT
14. LIMIT SWITCH OPERATING SCREWS
15. LEAD SCREW YOKE
16. DUST WASHER
17. GUIDE ROD
18. BALL BEARING
19. MAIN MOUNTING BRACKET
20. LEAD SCREW DRIVEN GEAR
21. PIN SCREW

Figure 5-60. Lead screw and differential partially disassembled.
 
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Screw the lead screw and follow-up pinion into the lead screw yoke so that the lead screw is installed approximately halfway into the yoke.

Figure 5-61. Roller shaft and pinion removed from yoke.
1. END PLATE SCREW
2. END PLATE
3. THRUST SPRING WASHER
4. BALL BEARING
5. ROLLER SHAFT AND PINION
6. FRICTION ROLLER
7. LEAD SCREW YOKE
8. TAKE-UP SPRING
9. OIL WELL COVER AND SPRING SUPPORT
Figure 5-61. Roller shaft and pinion removed from yoke.

  Figure 5-62. Pressing out short end of differential shaft.
Figure 5-62. Pressing out short end of differential shaft.

5M20. Disassembly of the differential assembly. (See Figures 5-60, 5-62, and 5-63.) Remove the four spur gear retaining screws, and the spur gear from the lower differential bevel gear. Remove the screw, retaining plate, bearing, and differential bevel pinion from the spider shaft. Support the differential bevel face gear which is mounted on the short differential shaft on bakelite or other soft blocks to protect the gear teeth. Do not use brass or steel blocks. Using a brass rod as shown in Figure 5-62, press out the shaft from the bearing. Remove the bearing from the gear. The bearings are a light press fit on the shaft, and a hand press fit in the gear housing. Remove the four screws that secure the differential end plate and gear hub to the upper differential bevel face gear, and lift off the plate and

 
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gear hub with the assembled driven spiral gear. Place the special pilot over the long end of the differential shaft as shown in Figure 5-63. Support the gear teeth on the bakelite blocks on the bed of an arbor press. Press the shaft out of the bearings. Remove the bearing from the gear housing.

5M21. Cleaning, inspection, and repair of the differential assembly. (See Figure 5-60.) Thoroughly clean all parts of the differential assembly with Navy-approved cleaning fluid. Dry all parts thoroughly. Replace all bent, broken, or heavily scored parts. If the differential shaft is lightly scored, remove the score marks with an oilstone, and polish with crocus paper. Visually inspect the bearings, and replace any cracked or otherwise damaged bearings. Remove light nicks from the gear

Figure 5-63. Pressing out long end of differential
shaft.
Figure 5-63. Pressing out long end of differential shaft.

  Figure 5-64. Installing bearing on short end
of differential shaft.
Figure 5-64. Installing bearing on short end of differential shaft.

teeth with a knife-edge file. Gears with cracked or chipped teeth should be replaced.

5M22. Installing the gear and bearing on the short end of the differential shaft. (See Figure 5-64.) Support the shoulder on the long end of the differential shaft in a special bed plate on an arbor press as shown in Figure 5-64. This is necessary in order to prevent bending the shaft. Place one of the differential bevel face gears over the short end of the shaft with the gear teeth facing the spider. Place one of the two identical ball bearings over the short end of the shaft, and align the bearing with the opening in the gear housing. Using a special pilot as shown in Figure 5-64, press the bearing into the gear housing. Remove the assembly from the arbor press.

 
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Place the large spur gear over the short end of the shaft and install the four retaining screws that hold the spur gear to the hub of the bevel face gear.

5M23. Installing the gear and bearing on the long end of the differential shaft. Place the second bevel face gear on the long end of the differential shaft with the gear teeth toward the spider. Place the second ball bearing over the long end of the shaft and align the bearing with the opening in the gear housing. Using a special pilot as shown in Figure 5-64, press the bearing on the shaft and into the gear housing. Remove the assembly from the arbor press. Place the differential end plate and gear hub assembly over the bearing, and install the four screws that secure the end plate and gear hub assembly to the bevel face gear.

5M24. Installing the differential bevel pinion. (See Figure 5-60.) Place the bevel pinion ball bearing in the differential bevel pinion. Place the gear and bearing on the shaft of the spider with the gear teeth meshed with those of the two bevel faced gears. Install the retaining plate and screw to secure the gear and bearing to the spider shaft.

5M25. Installing the lead screw and differential assemblies. (See Figures 5-59 and 5-60.) When installing the lead screw assembly and/or the differential assembly on the main mounting plate, it is necessary that the brackets be placed in their dowel pin holes without being fastened down to the plate. The close fits of the brackets and shafts make it necessary to lift the brackets slightly as the shafts are installed to allow clearance for the various dowel pins. Place the lead screw ball bearing in the main mounting bracket. Place the dust washer over the lower end of the lead screw, and insert the lead screw through the bearing and mounting bracket. Place the lead screw driven gear on the lower end of the screw and secure with the pin screw and the setscrew. Slide the guide rod through the opening in the main mounting bracket and into the opening in the differential bottom bracket. Secure the guide rod in the differential bottom bracket with a setscrew. Place the lower end of the differential shaft into the bottom

  bracket with the spur gear in mesh with the friction roller shaft and pinion. Place the differential top bracket over the long differential shaft and over the lead screw pinion. Loosely set the dowel pins of the top bracket in the mounting plate dowel pin holes. Place the jackshaft and gear in position in the differential top bracket with the first follow-up gear on the jackshaft in mesh with the lead screw pinion. Install the slip ring and contact assembly (see Section 5M32). Install the follow-up contact assembly as explained in Sections 5M33 and 5M34. Install the bracket retaining screws loosely. Do not tighten the bracket screws at this time, as the brackets will have to be lifted slightly in order to install the top mounting bracket.

Figure 5-65. Rear view of master speed indicator
showing jack plug connections.
1. SELF-SYNCHRONOUS REPEATER (60 R.P. MILE)
2. STARING CONDENSER FOR CONSTANT SPEED MOTOR
3. SELF-SYNCHRONOUS TRANSMITTER (SPEED)
4. CONSTANT SPEED (SYNCHRONOUS) MOTOR
5. PLUG-JACK CONNECTION
6. PLUG-JACK CORD (SPARE PARTS BOX)
Figure 5-65. Rear view of master speed indicator showing jack plug connections.

 
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Figure 5-66. Removing friction disk and spider.
Figure 5-66. Removing friction disk and spider.

5M26. Removing the constant speed motor. (See Figures 5-65, 5-66, and 5-67.) Remove the lead screw and differential assemblies from the main mounting plate as explained in Section 5M16. Loosen the two setscrews that secure the friction disk and spider to the motor shaft and lift off the spider and disk assembly. Do not attempt to turn the disk on the motor shaft as the teeth on the micarta worm gear will be stripped. Disconnect the three electrical leads from the terminal block on the back of the mounting plate. These wires and terminals are marked W1, S1, and S2. Remove the four screws that secure the motor to the mounting plate from the front of the mounting plate, and remove the motor.

5M27. Removal and disassembly of the reduction gear housing. (See Figures 5-68 and 5-69.) Remove the three screws that secure the reduction gear housing assembly to the motor, and remove the housing. Remove the packing nut and felt washer from the housing. Remove the adjusting screw and nut, fiber washer, felt washer, spring, and ball from the opposite end of the high speed shaft. Remove

  the pin screw and loosen the setscrew that secures the worm gear on the shaft. Carefully pull the slow speed shaft from its housing, and lift out the worm gear, spacer washer, and spacer.

5M28. Cleaning, inspection, and repair of the reduction gear assembly. (See Figure 5-69.) Thoroughly clean all parts with Navy-approved cleaning fluid. Visually inspect the felt and fiber washers for torn edges or other damage. Replace the damaged washers. Examine the worm gear for chipped or broken teeth, and replace the damaged worm gear. Examine the slow speed shaft for score marks. Remove light score marks with an oilstone, and polish with crocus paper.

5M29. Replacing the shaft bearings. (See Figure 5-68.) Bearings are replaced if they become pitted due to corrosion, or if they are damaged. Remove the shaft bearings in the following manner: Remove the worm gear housing (see Section 5M27). Remove the four screws, two felt retainers, and felt washer

Figure 5-67. Constant speed motor removed.
Figure 5-67. Constant speed motor removed.

 
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Figure 5-68. Constant speed motor partially disassembled.
1. END PLATE SCREW
2. END PLATE
3. SHIM
4. BALL BEARING
5. FELT WASHER
6. FELT RETAINERS
7. REDUCTION GEAR HOUSING
8. LOCK NUT
9. SCREW
10. SHAFT FOR FRICTION DISK AND SPIDER
11. WORM ON MOTOR SHAFT
12. TERMINAL LUGS
Figure 5-68. Constant speed motor partially disassembled.

Figure 5-69. Worm gear housing assembly disassembled.

1. ADJUSTING SCREW AND NUT
2. WASHER
3. FELT WASHER
4. SPRING
5. BALL
6. THRUST PLATE
7. LOCATING PIN
8. GEAR HOUSING
9. PACKING NUT
10. SLOW SPED SHAFT
11. SPACER
12. SPACING WASHER
13. HELICAL GEAR
14. SET SCRW
15. PIN SCREW
Figure 5-69. Worm gear housing assembly disassembled.
 
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from the reduction gear end of the shaft. Remove the four screws, end plate, and shun from the opposite end of the shaft. In the event that the bearings will not come off the shaft by tapping, it will be necessary to remove the armature assembly as follows: Remove the motor back and shield, and pull the armature assembly from the motor frame. Remove the bearings from the shaft with a bearing puller. Press the new bearings into position on the shaft. Install the armature assembly into the motor frame, and install the back end shield. Install the shim and end plate. Install the felt washer and two felt retainers on the reduction gear end of the motor. Install the worm gear housing (see Section 5M30).

5M30. Assembly and installation of the gear housing. (See Figures 5-68 and 5-69.) Install the felt washer in the packing nut, and install the packing nut on the gear housing. Place the spacer, spacer washer, and worm gear in approximate position in the gear housing. Insert the slow speed shaft into the housing, through the reduction gear, spacers, and packing nut. Align the pin hole in the shaft and gear, and install the pin screw and setscrew to secure the reduction gear to the shaft. Install the thrust plate, ball, spring, felt washer, fiber washer, and adjusting screw and nut on the opposite end of the gear housing. Place the reduction gear housing in position on the motor, being sure to carefully engage the teeth of the worm and reduction gear. Secure with the three screws and toothed lock washers.

5M31. Installing the constant speed motor. (See Figures 5-65, 5-66, and 5-67.) Place the constant speed motor in position on the back of the main mounting plate, with the dowel pins on the motor base inserted into the dowel pin holes in the mounting plate. Install the four screws from the front of the plate which secure the motor to the plate. Connect the three wire terminals to the terminal block on the block on the rear of the mounting plate. Terminals are marked W2, S2, and S1. When a new motor is to be installed, the motor is received without terminal lugs on the wire

  end. The wires are tagged for identification, and the lugs are installed in the same manner as an old motor wiring. Install the friction disk and spider on the motor shaft, and secure with the two setscrews provided. Install the lead screw and differential assemblies as explained in Section 5M25.

5M32. Installing the slip ring and contact assembly. (See Figures 5-55 and 5-57.) Place the slip ring and contact assembly on the upper end of the differential shaft. Align the pin screw holes and install the pin screw. Install the setscrew that secures the assembly on the differential shaft.

5M33. Installing the follow-up contact assembly. (See Figures 5-55 and 5-56.) Place the follow-up contact assembly on the follow-up shaft with the contact arm located between the contact points of the slip ring and the contact assembly. Install the tension spring, washer, nut, and lock nut on the follow-up shaft in such a manner that approximately three threads of the contact shaft will be visible when the lock nut is installed. This will put the proper tension on the spring.

5M34. Installing the top mounting bracket. (See Figure 5-55.) Place the top mounting bracket with its assembled follow-up contact assembly in position on the main mounting plate by inserting the dowel pins of the bracket into the dowel pin holes provided in the main mounting plate. Secure the bracket to the plate with the two screws and lock washers provided. Install the starting condenser on the back of the main mounting plate. The starting condenser was removed to make the bracket mounting screws accessible. Tighten all the bracket mounting screws which were left loosely installed in order to position the top bracket dowels. Install the spiral take-up spring as described in Section 5M10. Adjust the contact points as described in Section 5M14.

5M35. Installing the brush block assembly. (See Figures 5-53 and 5-59.) Place the brush block assembly in position on its mounting studs, being careful to align the brushes properly on the slip rings of the follow-up contact

 
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Figure 5-70. Distance repeating self-synchronous
motor removed.
1. MOUNTING CLAMP INSTALLED
2. SELF-SYNCHRONOUS TRANSMITTER (SPEED)
3. SELF-SYNCHRONOUS REPEATER (60 R.P. MILE)
4. BAKELITE BRUSH BASE
5. SCREW
6. LOCK WASHER
7. MOUNTING CLAMP
8. WIRES DISCONNECTED FROM UPPER AND LOWER BRUSH BASES
9. SHAFT EXTENSION
10. MAIN MOUNTING PLATE
11. MOUNTING BASE
Figure 5-70. Distance repeating self-synchronous motor removed.

assembly and the slip ring and contact assembly. Install the two screws that secure the brush block to the mounting studs on the main mounting plate. Connect the lead wires to the brush block.

5M36. Removing the self-synchronous distance repeater. (See Figures 5-52 and 5-70.) Remove the master speed indicator unit from the case (see Section 5M7). Remove the pointer and dial (see Section 5M2). Remove the tapered pin that secures the counter driving worm on the repeater shaft extension, and remove the worm. Disconnect the lead wires from the two bakelite brush bases, and tag the wires for ready identification. Remove the four screws and mounting clamps that secure

  the repeater to the bracket on the back of the main mounting plate, and carefully lift the repeater from the plate.

5M37. Inspection and removal of the brushes. (See Figure 5-71.) The brushes may be removed while the repeater is mounted to the main mounting plate. Remove the brush inspection plate and name plate. Inspect the brushes and slip rings. Disconnect the wires from the brush bases and tag the wires for

Figure 5-71. Self: synchronous repeater, brushes removed.
1. SELF-SYNCHRONOUS REPEATER OR TRANSMITTER
2. SLIP RING AND BRUSH INSPECTION PLATE
3. BAKELITE BRUSH BLOCK
4. BRUSH BLOCK RETAINING SCREWS
5. SILVER BRUSHES
6. SLIP RINGS
7. STATOR LEAD WIRES
8. BRUSH SPIRNG
Figure 5-71. Self: synchronous repeater, brushes removed.

 
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ready identification. Remove the four screw; (two on each brush base) and lift off the two molded brush bases.

5M38. Maintenance of the brushes. (See Figure 5-71.) Clean the silver brushes and split rings thoroughly with crocus paper. The in. side surfaces at the ends of the brushes should be 9/16-inch apart when the brush is in the free position. Greater spacing than this is an indication of a weak brush spring. The brushes must be free on their mounting studs without excessive binding.

5M39. Installing the brushes. (See Figure 5-71.) Carefully install the brushes and brush bases on the repeater. Be sure to align the brushes carefully with the slip rings to prevent bending of the brushes. The brush bases are of a different size to prevent error in positioning them. Install the four brush base retaining screws (two on each base). Install the brush inspection plate and name plate.

5M40. Removing the bearings and damper assembly. (See Figure 5-72.) Remove the brushes (see Section 5M37). Remove the shaft

  extension by holding the shaft nut with one wrench and unscrewing the shaft lock nut with a second wrench. Remove the front plate retaining screws and the front plate. Remove the two studs and lock washers that secure the end frames to the motor shell, and remove the front end frame. Remove the shims and bearings from the front end frame. Slide the damper flywheel off the shaft. Remove the damper spring. The bearing on the slip ring end is removed after removing the back plate.

5M41. Inspection of the self-synchronous repeater bearings. (See Figure 5-72.) Clean the bearings with Navy-approved cleaning fluid. Replace damaged bearings. Turn the bearings slowly by hand and note the smoothness of operation. A clicking noise, or binding, indicates chipped or cracked balls. Replace damaged bearings. Lubricate the bearings with gyro oil.

5M42. Installing the bearings and damper. (See Figure 5-72). Place the damper spring on the damper collar with the spring ends engaged on the stud of the collar. Install the

Figure 5-72. Self-synchronous repeater, damper assembly removed.
1. DIFFERENTIAL DRIVING SPIRAL GEAR
2. FLATHEAD SCREW
3. FRONT PLATE
4. STUD AND LOCK WASHER
5. STUD AND LOCK WASHER
6. DAMPER SPRING
7. MOTOR SHAFT
8. DAMPER COLLAR
9. SHELL
10. BACK END FRAME
11. DAMPLER SPRING STUD ON COLLAR
12. SPRING ENDS
13. DAMPER SPRING STUD
14. FRONT END FRAME
15. BALL BEARING
16. SHIMS
17. SHAFT LOCK NUT
18. SHAFT EXTENSION
Figure 5-72. Self-synchronous repeater, damper assembly removed.
 
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Figure 5-73. Checking shaft extension installation.
1. SELF-SYNCHRONOUS REPEATER
2. FRONT PLATE
3. SHAFT LOCK NUT
4. DIFFERENTIAL DRIVING SPIRAL GEAR
5. SHAFT EXTENSION
Figure 5-73. Checking shaft extension installation.

damper flywheel on the motor shaft with the stud on the flywheel engaging the spring ends. Place the front end frame on the motor shell. Align the mounting holes and install the two studs and lock washers that secure the front end frame to the shell. Slide the ball bearing over the shaft and into the opening provided in the front end frame. Place the shims on top of the bearing and push downward on the shims until the outer shim is flush with the end of the frame. Install the front plate on the frame. The bearing on the slip ring end is placed in position in the frame and secured by the back plate. Place the shaft extension over the end of the motor shaft, and temporarily tighten the shaft lock nut. Measure the distance from the front plate to the gear on the extension as shown in Figure 5-73. This distance should be 1sg inches at assembly. Tighten the lock nut securely while holding the shaft nut. Turn the shaft by hand to see that the repeater operates freely. The rotor end play should be between 0.010 and 0.015 inch. Add or remove shims as necessary to obtain the required end play (Figure 5-72).

  5M43. Installing the distance self-synchronous repeater. See Figures 5-52 and 5-70.) Place the repeater in position on the back of the main mounting plate. Install the four clamps and clamp retaining screws loosely. Hold the wires in the approximate position on the brush base, and turn the motor until the wires reach the terminals. Install the lead wires in the brush bases (three wires to the upper base, and two wires to the lower base). Tighten the mounting clamps securely. Place the counter driving worm on the end of the shaft extension; align the locating dots on the gear and the gear shaft as shown in Figure 5-52, and install the taper pin. Install the dial and pointer (see Section 5M2). Install the master speed indicator in the case (see Section 5M50).

5M44. Removing the self-synchronous speed transmitter. (See Figures 5-65 and 5-74.) Remove the top mounting plate (see Section 5M8). Loosen the two socket head setscrews that secure the driven gear hub to the speed transmitter shaft, and carefully remove the gear assembly (Figure 5-74). The adjusting mechanism mounted on the rear of the gear is removed with the gear. Disconnect and tag the wires. Remove the four mounting clamp screws and mounting clamps and carefully lift the motor from the plate.

5M45. Maintenance of the transmitter. The transmitter self-synchronous motors differ from the repeaters in that they do not have a damper mechanism. Brushes are removed, inspected, and installed in the same manner as explained in Sections 5M37, 5M38, and 5M39. Bearings are removed by removing the end plates and shims. Inspect the bearings as described in Section 5M41. Install the bearings in the frames. Install the shims and end plates.

5M46. Installing the speed transmitter. (See Figures 5-65 and 5-74.) Place the transmitter in position on its bracket on the rear of the main mounting plate. Loosely install the mounting clamps. Hold one set of wires in their approximate position, and turn the motor until the wires are correctly placed in relation to the brush base. Tighten the mounting clamps. Connect the wires to the brush bases.

 
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Figure 5-74. Speed transmitter driven gear removed. With gear in place: to syncronize self-synchronous transmitter (speed) with speed repeaters, loosen lock screw.  turn adjusting screw to make final adjustment then tighten lock screw
1. SELF-SYNCHRONOUS TRANSMITTER (SPEED) DRIVEN GEAR
2. ADJUSTABLE HUB
3. SETSCREWS
4. ADJUSTING SCREW
5. LOCK SCREW
6. TENSION SPRING
7. ANCHOR BLOCK
8. FORNT OF MAIN MOUNTING PLATE
9. SELF-SYNCHRONOUS TRANSMITTER (SPEED) SHAFT
Figure 5-74. Speed transmitter driven gear removed.

Install the transmitter driven gear assembly as follows: Have one crew member remove the cover from the speed and distance indicator in the conning tower. Energize the speed circuit. Hold the conning tower pointer on zero while positioning the transmitter driven gear assembly on the transmitter shaft. Then tighten the two setscrews that secure the gear hub to the shaft. This operation eliminates major movement of the driven gear on the transmitter shaft when recalibrating the instrument. Deenergize the circuit. Install the top mounting plate (see Section

  5M48). Install the dial and counter (see Section 5M2). Recalibrate the instrument (see Sections 5M51 and 5M52).

5M47. Replacing the starting condenser. (See Figure 5-65.) Remove the unit from the case (see Section 5M7). Remove the two nuts from the terminal studs, and remove the wires. Remove the two screws that secure the condenser to the main mounting plate, and remove the condenser. Place the new condenser in position on the rear of the main mounting plate, and secure it with the two screws provided. Place the wire terminals over the terminal studs, and install the terminal nuts. Install the unit in the case (see Section 5M50).

5M48. Installing the top mounting plate. (See Figure 5-56.) Place the top mounting plate in position on the mounting studs provided on the main mounting plate. Install the six screws and toothed lock washers that secure the top mounting plate to the mounting studs. Install the top support stud in the upper left corner of the top mounting plate.

5M49. Installing the counter driving worm. (See Figure 5-52.) Place the counter driving worm on the shaft extension of the distance repeating self-synchronous motor. Align the pinhole in the worm with the pinhole in the shaft in such a manner that the locating dots on the worm and shaft are adjacent to one another. This is important, as the pinhole is tapered to take a tapered pin. Install the tapered pin through the worm and shaft with the large end of the pin toward the locating dots. Place the handle in position on the upper right-hand side of the main mounting plate. Install and stake the two screws which secure the handle to the main mounting plate. Install the dial and pointer (see Section 5M2). Recalibrate the instrument (see Sections 5M51 and 5M52).

5M50. Installing the unit in its case. (See Figure 5-47.) Turn the operating shaft of the dimmer rheostat so that its forked end clears the rheostat shaft extension. Place the unit in its case, being careful not to damage the wiring. Install the 10 screws that secure the mounting plate to the case. Place the cover in position and install the cover retaining screws.

 
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5M51. Setting the lower limit switch. (See Figure 5-52.) Whenever the subassemblies of the master speed indicator are removed for purposes of cleaning, replacement, or repair, the unit must be recalibrated. The following operations are performed; Reassemble the instrument with the exception of the dial and pointer. Back off the lower lead screw limit switch, operating the screw several turns. With the instrument electrically connected to the rotary distance transmitter by means of the plug-jack cord, energize the electrical circuits, and allow the lead screw driving motor to adjust the position of the friction roller to the zero position. The friction disk should be rotating, and the roller should be stationary at its center position on the disk. Install the dial, pointer, and pointer hub. Do not install the hub cap at this time. Loosen the screws securing the pointer in position   on the hub, and set the pointer to zero. Tighten the screws to lock the pointer in the zero position, and install the hub cap. Turn up the lower limit switch operating screw so that it will open the circuit of the constant speed (synchronous) motor when the pointer reading is 0.075 knots.

5M52. Aligning the speed repeaters with the master speed indicator. (See Figure 5-74.) The transmitter driven gear of the master speed indicator is temporarily set to the zero position as described in Section 5M46. Have a crew member hold the pointer of the speed and distance indicator on zero, as described in Section 5M46. Loosen the locking screw (Figure 5-74), and turn the adjusting screw until the speed pointer is set to the exact corresponding reading of the pointer in the master speed indicator. Tighten the locking screw.

Figure 5-75. Rotary converter.
Figure 5-75. Rotary converter.
 
86

 
N. MAINTENANCE OF CONSTANT FREQUENCY SUPPLY UNIT
 
5N1. Periodic inspection and repair of the converter. Every six months, remove the grease plugs located opposite the grease cup and tube assembly. While the unit is operating, screw down the grease cups until clean grease comes out of the grease plug openings. Refill the grease cups and repeat the operation if necessary. Do not use too much grease, as some may get into the speed regulator assembly. Shut down the unit and remove the commutator and slip ring shutters. Remove the commutator brushes (see Section 5N2) and collector ring brushes (see Section 5N5). Inspect the commutator and slip rings. If the commutator and/or slip ring are pitted, or show uneven wear, dress them down with fine sandpaper or a commutator stone while the unit is operating. Do not use emery cloth as

Figure 5-76. Rotary converter, commutator
shutter removed.
Figure 5-76. Rotary converter, commutator shutter removed.

  particles from the cloth will cause serious trouble. Install the commutator brushes (see Section 5N4) and collector rings (see Section 5N7). Check all brushes to be sure that they are free in their brush holders and making positive contact with the commutator and slip rings. Install the shutters.

5N2. Removing the commutator brushes. (See Figure 5-76.) Loosen the thumbscrew and remove the commutator shutter. Disconnect the brush lead wire from the brush terminal. Lift the clip spring upward and remove the brush from the holder. The other commutator brush is removed in the same manner.

5N3. Cleaning, inspection and repair of the commutator brushes. Inspect the contact surface of the brushes for oil, grease, or a pitted condition. Clean the brush surfaces. Smooth out the pitted surfaces with sandpaper and polish with crocus paper.

5N4. Installing the commutator brushes. (See Figure 5-76.) Lift up the clip spring and insert the brush in the holder. Brushes should be free in their holders, and make positive contact with the commutator. Connect the brush lead wire to the terminal. Place the commutator shutter in position on the frame, and secure it with a thumbscrew.

Figure 5-77. Rotary converter, collector
ring shutter removed.
Figure 5-77. Rotary converter, collector ring shutter removed.

 
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5N5. Removing the collector ring brushes. (See Figure 5-77.) Loosen the shutter retaining thumbscrew, and remove the collector ring shutter. Disconnect the brush terminal by loosening the terminal screw and pulling the wire lug from the terminal. Lift up the brush holder spring, and remove the brush from its holder. The other collector ring brush is removed in the same manner.

5N6. Cleaning, inspection and repair of the brushes. Inspect the contact surface of the brushes for oil, grease, and a pitted condition. Clean the brushes thoroughly. Dress the contact surfaces with fine sandpaper.

5N7. Installing the collector ring brushes. (See Figure 5-77.) Lift up the brush holder spring and place the brush in its holder. Connect

  the wire lug to the terminal and tighten the terminal screw. The other collector ring brush is installed in the same manner. Place the collector ring shutter in position, and secure it by tightening the thumbscrew.

5N8. Removing the speed regulator assembly. (See Figures 5-78 and 5-80.) Remove the two speed regulator shutter screws and the speed regulator shutter. Loosen the two setscrews that secure the speed regulator on the armature shaft and slowly remove the speed regulator. It is necessary to remove the speed regulator slowly from the armature shaft as the spring tension on the brushes that are behind the regulator assembly may cause them to spring out of their brush boxes and become lost. Lift the brushes from their brush boxes.

Figure 5-78. Rotary converter, speed regulator and one commutator brush removed. TAG TERMINALS REVERSING TERMINALS WILL REVERSE POLARITY CAUSING RAPID DETERIORATION OF CONTACT METALS
1. COMMUTATOR BRUSH (REMOVED)
2. BRUSH HOLDER
3. COMMUTATOR BRUSH (INSTALLED)
4. BRUSH HOLDING SPRING
5. BRUSH TERMINAL SCREW
6. SPEED REGULATOR HOUSING
7. BRUSH BOX INSULATOR
8. INNER SPRING TERMINAL (POSITIVE TERMINAL)
9. ARMATURE SHAFT
10. SPEED REGULATOR BRUSHES AND SPRINGS
11. OUTER SPRING TERMINAL (NEGATIVE TERMINAL)
12. BRUSH BOX

Figure 5-78. Rotary converter, speed regulator and one commutator brush removed.
 
88

5N9. Cleaning, inspection, and repair of the speed regulator. Clean the parts in Navy-approved cleaning fluid. Examine the speed regulator brush and spring assemblies. If the brush or its attached spring is damaged, replace the complete brush and spring assembly. If the contact surfaces of the brushes are pitted, smooth them off with fine sandpaper. Examine the speed regulator contact points (Figure 5-79). Clean the pitted points with a jeweler's file. If the contact points are badly worn or burned, replace the complete speed regulator assembly.

5N10. Adjusting the speed regulator contact points. (See Figure 5-79.) Check the gap between the speed regulator contact points with a thickness gage. The points should be open 0.020 inch. Adjust the gap to 0.020 inch by means of the outer and inner contact adjusting screws. The gage should slide freely between the contact points without binding.

Figure 5-79. Checking speed regulator contact
point gap.
1. THICKNESS GAGE (SET CONTACT POINTS 0.020-INCH SPACE
2. SILVER CONTACT (POSITIVE)
3. TUNGSTEN CONTACT (NEGATIVE)
4. OUTER CONTACT ADJUSTING SCREW
5. LOCK NUT
6. INNER CONTACT ADJUSTING SCREW
Figure 5-79. Checking speed regulator contact
point gap.

  5N11. Installing the speed regulator assembly. (See Figures 5-78 and 5-79.) Carefully place the spring ends of the brush assemblies in their brush boxes. Place the metal surface of the speed regulator against the brushes, and gently compress the brush springs and brushes into the brush boxes by moving the speed regulator on the armature shaft. When the regulator is against the shoulder of the shaft, tighten the two setscrews that secure the regulator to the armature shaft. Place the speed regulator shutter in position on the speed regulator housing, and install the two speed regulator shutter screws.

5N12. Removing the armature assembly. (See Figure 5-80.) Remove the terminal box cover from the a.c. and d.c. terminal boxes, and disconnect the wires leading to outside sources. Tag the wires for ready identification. Remove the commutator shutter (see Section 5N2). Remove the collector ring shutter (see Section 5N5). Remove the speed regulator (see Section 5N8). Remove the commutator brushes (see Section 5N2). Remove the collector ring brushes (see Section 5N5). Carefully remove the spring terminals from the brush boxes in the speed regulator (Figure 5-78). Be sure to tag these wires for ready identification as they must not be reversed at assembly. Remove the four screws that secure the speed regulator housing to the armature cover, and remove the speed regulator housing. Remove the screws that secure the grease cap to the collector ring cover, and remove the grease cap. Remove the shaft nut and lock nut from each end of the shaft. Remove the screws that secure the collector ring cover to the frame and move the cover to one side out of the way. It is not necessary to disconnect the wires connecting the cover and the windings in the converter frame. Tap the end of the armature shaft lightly with a soft hammer or wooden block to loosen the armature assembly. Remove the armature assembly from the frame. Remove the ball bearing and grease from the collector ring cover and armature cover.

5N13. Cleaning, inspection, and repair of the converter. (See Figure 5-80.) Thoroughly clean all parts in Navy-approved cleaning

 
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fluid. Do not saturate electrical wiring with the cleaning fluid. Inspect the bearings for a pitted condition resulting from corrosion. Carefully turn the bearings by hand. A clicking noise or binding indicates chipped or cracked balls. Replace damaged bearings. Undamaged, or new bearings should be lubricated with ball and roller bearing grease, Navy symbol 14L3.   heavily damaged threads should be trued up with a stock and die. Inspect the commutator and collector rings. If they are pitted or show uneven wear, true them up in a lathe. The commutator of a new armature is 2 3/8 inches in diameter. Commutator bars have a wearing depth of 3/16-inch. If the commutator has worn to a diameter of less than 2 inches, replace the armature assembly.
Figure 5-80. Rotary converter partially disassembled.
1. SPEED REGULATOR SHUTTER SCREW
2. SPEED REGULATOR SHUTTER
3. SPEED REGULATOR AND SET SCREWS
4. SPEED REGULATOR HOUSING SCREW
5. TOOTHED LOCK WASHER
6. SHAFT NUT
7. BALL BEARING
8. SPEED REGULATOR BRUSHES AND BRUSH SPRINGS
9. GREASE CUP AND TUBE
10. SPEED REGULATOR HOUSING
11. LOCK NUT
12. LEATHER GREASE SEAL
13. COMMUTATOR BRUSHES
14. FRAME
15. COLLECTOR RIGN COVER
16. COLLECTOR RIGN BRUSHES
17. COLLECTOR RIGN COVER SCREW
18. SHAFT NUT
19. GREASE CUP
20. GREASE CAP SCREW
21. TOOTHED LOCK WASHER
22. LOCK NUT
23. BALL BEARING
24. LEATHER GREASE SEAL
25. ARMATURE ASSEMBLY

Figure 5-80. Rotary converter partially disassembled.
Wrap the bearings in wax paper or cloth if they are not needed immediately for assembly. Inspect the grease seals. Replace torn or otherwise damaged seals. Inspect both ends of the armature shaft for burrs or rough spots. Remove the burrs or rough spots with a fine-cut file and polish the shaft with crocus cloth. The threads on the shaft should be clean and true. Remove light burrs from the threads with a knife-edge file. More   5N14. Assembling the rotary converter. (See Figure 5-80.) Place the grease seal and ball bearing in the opening provided in the armature cover. Place the armature assembly in position in the converter frame. Place the collector ring cover on the frame. Install the grease seal and ball bearing in the opening provided in the collector ring cover. If necessary, tap the outer race of the bearing lightly with a soft hammer to properly seat the bearing.
 
90

Install the shaft nut and lock nut on each end of the armature shaft. Allow a shaft end play of 0.010 inch when installing the shaft nuts.

Place a coating of ball bearing grease around the seal in the speed regulator assembly. Hold the housing in its approximate position near the end of armature shaft and insert the two wire leads through the opening in the lower part of the housing, while carefully sliding the housing on the armature shaft. Install the four screws to secure the housing to the armature cover. Connect the wires to the terminals on the brush holders by slipping the spring terminals over the brush holders (Figure 5-78). Be sure to install the wires on their correct terminals, as reversing the terminals will cause reverse polarization with consequent rapid deterioration of the metal contacts and early failure of the converter.

Place the grease cap assembly on the collector ring cover, and secure it with the four screws and toothed lock washers provided. Install the regulator assembly (see Section 5N11). Install the collector ring brushes (see Section 5N7). Install the commutator brushes (see Section 5N4). Install the shutters on each end of the converter and secure the shutters by tightening thumbscrew. Connect the wires to the terminal blocks in the a.c. and d.c. terminal boxes. Install the covers on the terminal boxes.

5N15. Checking operation of the clock in the constant frequency control unit. (See Figure 5-81.) If the white lines of the phonic wheel motor appear stationary when viewed through the cover window, check the accuracy of the clock as follows: Allow approximately half an hour for the unit to warm up. Using a reliable stop watch, check the clock over a period of at least 2 hours. The clock should of show an error greater than 5 seconds per hour. Slight changes in the tuning fork frequency, and hence in the controlled frequency and speed of the clock, may be made by moving the driver (right-hand) phone unit by means of its adjusting nuts. Moving the unit toward the fork slows the clock action; moving the unit away from the fork speeds the clock

  action. The phone units should not be tampered with or adjusted unless absolutely necessary. After adjustment be sure to tighten the unit securely in its new position.

5N16. Checking speed of the converter. (See Figures 5-79 and 5-81.) If the white lines of the phonic wheel motor rotor do not appear stationary when viewed through the cover window, check the speed of the converter as follows: Remove the cover from the constant frequency control unit. Connect a jumper wire between the 10K and 10K1 terminals. This shorts out the rheostat. Energize the 10K circuit. Using a reliable stop watch, check the accuracy of the clock over a period of 5 minutes. If the clock is slower than 1.5 seconds per minute, deenergize the 10K circuit, remove the shutter of the speed regulator assembly, and back off the top adjustable contact screw (Figure 5-79) approximately a one-eighth turn, and recheck the clock. Repeat this adjustment, if necessary, until the desired accuracy is obtained. If the clock is faster than 0.5 second per minute, back off the inner adjustable contact screw until the required accuracy is obtained. Replace the speed regulator shutter. Deenergize the 10K circuit, and remove the jumper wire from the 10K and 10K1 terminals.

5N17. Visual check of the control unit. (See Figure 5-81.) When the unit is regulating properly, the rheostat slider should be away from the end of the rheostat and should be hunting slightly, an indication that it is continually making slight adjustments. If the rheostat slider does not regulate as described above, deenergize the 10K circuit, and allow the rotor of the phonic wheel motor to come to rest. See that all the shafts and gears are free to operate properly. Observe the tuning fork while the circuit switch is being closed. The clapper of the starting magnet should strike the fork and start it vibrating. Within a few minutes the neon light below the phonic wheel motor should glow. If the neon lamp fails to glow, visibly check the tubes to see whether or not they are incandescent. If the tubes are in good condition, and the fork still does not sustain vibration,

 
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Figure 5-81. Constant frequency control unit, cover removed.
1. CLOCK
2. 50,000-OHM RESISITOR
3. RECTIFIERS
4. CHOKE
5. CONDENSER, 2-MICROFARADS
6. 100-OHM RESISTOR
7. GRID TRANSFORMER
8. SPRING POST, ASSEMBLY
9. STARTING MAGNET, ASSEMBLY
10. 2250-OHM RESISTOR
11. PICK-UP PHONE UNIT
12. DRIVER PHONE UNIT
13. TUNING FORK
14. TUNING FORK BASE
15. AMPLIFIER TUBES, NO. 6J5G
16. POWER TUBES, NO. 25B6G
17. SUSPENDED PLATE
18. CONDENSER, 0.005-MICROFARAD
19. TRANSFORMERS
20. PHONIC WHEEL MOTOR, ASSEMBLY
21. 190-OHM RESISTOR
22. 2000-OHM RESISTOR
23. DIFFERENTIAL, ASSEMBLY
24. STARTING CONDENSER
25. CONSTANT SPEED (SYNCHRONOUS) MOTOR TERMINAL BLOCK
26. MAIN MOUNTING PLATE
27. CONSTANT SPEED (SYNCHRONOUS) MOTOR
28. TERMINAL BLOCK
29. RHEOSTAT, 450-OHMS

Figure 5-81. Constant frequency control unit, cover removed.
 
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check the transformers, coils, resistors, and condensers for open circuits or grounds.

5N18. Checking the control unit with a voltmeter. (See Figure 5-81.) Use a 1,000-ohms per-volt voltmeter.

  Using a meter of different sensitivity gives different voltage values. With a line voltage of 120 volts d.c., normal voltages should be as follows when checked between the two points listed below:
MEASURED BETWEENDESIRED VOLTAGEINDICATION
Upper terminals of right-hand transformer 130 - 150 a.c. Voltage output of amplifier to copper oxide rectifier
Inner terminals of phonic wheel motor coils 110 - 125 a.c. Voltage being supplied to coils
Outside upper terminals, secondary of left-hand transformer 20 - 30 a.c.
(150 V. range)
A.C. signal applied to grid of output tube
Outside lower terminals, primary of left-hand transformer 5 - 7 d.c.
(7.5 V. range)
Primary transformer and amplifier tube in good condition
No. 2 terminal of choke, and 10KK terminal 95 - 100 d.c. Proper amount of plate voltage, choke in good condition
Ends of 190-ohm resistor 60 - 65 d.c. Heater circuit operating correctly/td>
Tap of 2,000-ohm resistor, and 10KK terminal 9 - 12 d.c.
(15 V. range)
Grid bias on 25B6 tube
End of 1,000-ohm resistor 3.5 - 5.0 d.c.
(7.5 V. range)
Grid bias on first amplifier tube (second from left side of case)
Tap of 2,250-ohm resistor, and 10KK terminal 5 - 6 d.c.
(7.5 V. range)
Grid bias on driver tube (first from left side of case)
Terminals of synchronous motor starting condenser 250 a.c. Condenser and one winding of motor in good condition
The current in the driver (right-hand) phone should be as follows: When the tuning fork is held so that it cannot vibrate, the reading should be from 0.25 to 0.5 milliamperes a.c. When the tuning fork is vibrating, the reading should be from 3.5 to 4.0 milliamperes d.c.
 
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Figure 5-82. Phonic wheel motor and differential assembly installed.
1. RHEOSTAT
2. RHEOSTAT BRACKET
3. DIFFERENTIAL SHAFT GEAR
4. RHEOSTAT SHAFT GEAR
5. LOWER DIFFERENTIAL SPUR GEAR
6. LOWER DIFFERENTIAL BEVEL GEAR
7. DIFFERENTIAL BEVEL PINION
8. UPPER DIFFERENTIAL BEVEL GEAR
9. UPPER DIFFERENTIAL SPUR GEAR
10. PHONIC WHEEL MOTOR BASE
11. PHONIC WHEEL MOTOR FIELD CORE
12. PHONIC WHEEL MOTOR COIL
13. PHONIC WHEEL MOTOR TOP BRACKET
14. ROTOR
15. WHITE MARKS ON ROTOR
16. PHONIC WHEEL MOTOR SHAFT
17. PHONIC WHEEL MOTOR SHAFT PINION
18. DIFFERENTIAL SPIDER
19. CONSTANT SPEED (SYNCHRONOUS) MOTOR SLOW SPEED SHAFT GEAR
20. GEAR HOUSING
21. CONSTAT SPEED (SYNCHRONOUUS) MOTOR
Figure 5-82. Phonic wheel motor and differential assembly installed.
5N19. Final checking of control unit. (See Figure 5-81). If the tubes are in good condition and there are no defective transformers, coils, resistors or condensers, but the fork still will not sustain vibration, run in the pick-up (left-hand) phone unit slightly. Recheck the operation of the unit. After the above adjustment has been made so that the fork will sustain vibration, check the accuracy of the clock (see Section 5N15). It may be necessary to make slight adjustments of the driver (right-hand) phone unit as described in Section 5N5. If the synchronous motor and clock do not operate, check the wiring, brushes, and windings of the converter. If the synchronous motor alone does not operate, but the clock does operate, check the motor wiring (Figure 5-86) and also check the starting condenser. Replace the part as a unit if it is defective.

5N20. Removing the rheostat. (See Figure 5-82.) Remove the case cover. Loosen the screws that secure the clock to the support studs. Lift the clock off the studs and place it to one side. Remove the two screws that secure

  the terminal block to the block mounting studs, and place the terminal block to one side. Unsolder and tag the wire connections from the rheostat terminals. Loosen the two setscrews on the spur gear hub; then remove the gear from the rheostat shaft. Remove the clamping nut from the rheostat shaft, and remove the rheostat from its mounting bracket.

5N21. Installing the rheostat. (See Figure 5-82.) Place the rheostat in position in the bracket and install the clamping nut-on the rheostat shaft. Place the spur gear on the end of the shaft. Mesh the gear teeth with the adjoining gear and tighten the two setscrews that secure the gear on the rheostat shaft. Solder the wire connections to the rheostat terminals. Place the terminal block in position on the mounting studs, and install the two block retaining screws. Place the clock in position on the clock support studs, and tighten the thumbscrews that secure the clock on its studs. Install the case cover.

5N22. Removing the differential assembly. (See Figure 5-82.) Remove the rheostat (see

 
94

Section 5N20). Loosen two setscrews from the gear hub on the lower end of the differential shaft, and remove the spur gear. Remove the two rheostat bracket mounting screws. Loosen the screws securing the phonic wheel motor base to the mounting plate. Carefully raise the rheostat bracket from the base to clear the dowel pins; then remove the bracket from the differential lower shaft. Remove the differential assembly from the phonic wheel motor base. The disassembly, inspection, repair, and assembly of this differential are performed in the same manner as on the differential assembly of the master speed indicator.

5N23. Installing the differential assembly. (See Figure 5-82.) Place the differential upper shaft in position in the phonic wheel motor base. Place the rheostat bracket on the differential lower shaft. Carefully align the dowels on the rheostat bracket with the holes

  in the plate, and position the bracket on the mounting plate. Secure the bracket with the two screws and toothed lock washers provided. Tighten the phonic wheel motor base screws. Install the spur gear on the lower end

Figure 5-83. Removing phonic wheel motor.
Figure 5-83. Removing phonic wheel motor.

Figure 5-84. Phonic wheel motor disassembled.
1. SET SCREW
2. ROTOR PINION
3. PIN SCREW
4. MOTOR BASE
5. LAMINATED CORE
6. COILS
7. OUTER RACE
8. BALL BEARING
9. TOOTHED LOCK WASHER
10. SCREW
11. MOTOR SHAFT
12. ROTOR
13. THRUST SPRING WASHER
14. TOP BRACKET
Figure 5-84. Phonic wheel motor disassembled.
 
95

of the differential shaft, and tighten the two gear retaining setscrews. Install the rheostat (see Section 5N21).

5N24. Removing the phonic wheel motor assembly. (See Figure 5-83.) Remove the differential assembly. (see Section 5N22). Remove the two screws and toothed lock washers that secure the phonic wheel motor base to the mounting plate, and pull the motor assembly forward away from the base. Remove the two screws that secure the neon lamp and bracket to the phonic wheel motor base, and remove the lamp and bracket. Unsolder the wire leads from the cores, and tag the wires for ready identification. Lay the motor assembly aside.

5N25. Disassembly of the phonic wheel motor. (See Figure 5-84.) Remove the three screws from each coil and core assembly and remove the coils and cores from the motor base. Remove the pin screw and loosen the setscrew which secures the pinion gear on the lower end of the motor shaft, and remove the pinion. Scribe a line on the motor base and on the motor top bracket so that they may be reassembled in their original position. Remove the four screws that secure the top bracket to the motor base, and remove the top bracket from the base. The bearings may be removed from the shaft, but occasionally they stick in the base and in the top bracket. Tap the top bracket on a bench to remove the ball bearing, outer race, and thrust spring washer. Tap the motor base on a bench to remove the bearing, outer race, and bakelite washer.

5N26. Inspection and repair of the phonic wheel motor. (See Figure 5-84.) Thoroughly clean all parts with Navy-approved cleaning fluid. Replace all damaged parts. Check the coils with an ohmmeter. The coils should show approximately 350 ohms per pair. Examine the ball bearings to see that the balls rotate freely in their inner races. Remove any score marks from the motor shaft with crocus paper. If the shaft is pitted due to corrosion, replace the shaft and rotor assembly.

5N27. Assembly of the phonic wheel motor. (See Figure 5-84.) Place the bakelite washer in the motor base. Assemble the ball bearing

  in the outer race, and place the bearing assembly in the motor base. Carefully insert the motor shaft through the bearing and place the shaft and rotor in position in the motor base. Assemble the second bearing in its outer race, and place the bearing and race on top of the motor shaft. Place the thrust spring washer on the upper bearing with the center protruding section of the washer away from the bearing. Place the top bracket in its original position on the motor base. The original position is indicated by a scribed line marked at disassembly. Install the four screws and toothed lock washers that secure the top bracket to the motor base. Place the pinion gear on the lower end of the motor shaft. Align the pin screw holes, install the pin screw, and tighten the setscrew to secure the pinion gear on the shaft. Place the coils in position on their cores. Align the cores with the mounting base, and install the three screws that secure the cores and coils to the motor base.

5N28. Installing the phonic wheel motor. (See Figure 5-83.) Place the phonic wheel assembly in position on the mounting plate, and loosely install the two mounting screws and toothed lock washers provided. Do not install the mounting screws tightly at this time as the motor base must be raised slightly in order to get the proper clearance of the dowel pins when the differential assembly is installed. Solder the wires to the terminals on the cores. Place the neon lamp and bracket in position on the motor base, and install the two screws that secure the lamp bracket to the motor base. Install the differential assembly (see Section 5N23).

5N29. Removing the synchronous motor. (See Figures 5-81 and 5-85.) Remove the case cover. Disconnect the ground wire from the upper right-hand corner of the mounting plate. Loosen the six screws that secure the main mounting plate to the case, and swing the mounting plate to the left to make the synchronous motor mounting screws accessible. Disconnect the wires from the terminal block above the motor. Tag the wires for ready identification. Remove the four mounting screws and toothed lock washers from the

 
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rear of the main mounting plate, and remove the motor. The synchronous motor is the same type of motor as the constant speed motor used in the master speed indicator. Therefore, the disassembly, inspection, repair, and assembly operations are identical with those of the constant speed motor. However, the spring tension on the slow speed shaft of the motor as used in the control unit can be reduced to a minimum.   on the mounting plate screws. Place the mounting plate in position in the case and tighten the six mounting plate retaining screws. Connect the ground wire to the upper right-hand corner of the mounting plate. Install the case cover.

5N31. Removing the tuning fork condensers. (See Figure 5-81.) These two condensers are mounted to the tuning fork base. Disconnect the wires from the terminals on, the

Figure 5-85. Constant frequency control unit, main mounting plate removed.
Figure 5-85. Constant frequency control unit, main mounting plate removed.
5N30. Installing the synchronous motor. (See Figures 5-81, and 5-85.) Place the motor in position on the front of the main mounting plate. Install the four motor mounting screws and toothed lock washers from the rear side of the mounting plate. Connect the lead wires to the terminal block above the motor. Make certain that the rubber grommets are installed   condensers. Tag the wires for ready identification. Remove the four screws (two to each condenser) that secure the condensers to the tuning fork base, and remove the condensers.

5N32. Installing the tuning fork condensers. (See Figure 5-81.) Place the condenser in position on the tuning fork base, and install the two screws that secure the condenser to

 
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the base. Place the wires on the terminals of the condenser and secure them with the terminal nuts provided. The other condenser is installed in the same manner.

5N33. Removing the suspended plate. (See Figure 5-81.) Remove the four nuts (one at each corner) that secure the suspended plate spring assemblies to the mounting studs. Lift the plate and spring assemblies from the case.

5N34. Installing the suspended plate. (See Figure 5-81.) Place the suspended plate assembly in approximate position in the case. Hook the shock-absorbing springs over the spacers on the four mounting studs, and install the four nuts that secure the springs to the mounting studs.

5N35. Removing the starting magnet. (See Figure 5-81.) Unsolder the wires from the terminals on the starting magnet. Tag the wires for ready identification. Remove the suspended plate to make the mounting screws accessible (see Section 5N33). Remove the three screws and toothed lock washers from the magnet mounting studs, and remove the magnet.

5N36. Installing the starting magnet. (See Figure 5-81.) Place the starting magnet in position on the front of the suspended plate. Install the three screws and toothed lock washers from the rear of the suspended plate to secure the magnet to the plate. Install the suspended plate in the case (see Section 5N34). Solder the wires to the magnet terminals.

5N37. Removing the phone units. (See Figure 5-81.) Remove the two screws that secure the wire identification. Remove the clamping nut that secures the phone unit to the mounting bracket, and remove the phone. The other phone unit is removed in the same manner.

5N38. Installing the phone units. (See Figure 5-81.) Place the phone unit in position in its mounting bracket and secure it with a clamping nut. Place the wires in the sockets provided in the phone unit. Secure the wires in position with the two screws provided (one for each wire). The other phone unit is installed in the same manner.

  5N39. Removing the grid transformer. (See Figure 5-81.) Unsolder the wires from the terminals of the grid transformer, and tag the wires for ready identification. Remove the suspended plate (see Section 5N33.) From the back of the suspended plate, remove the four screws that secure the grid transformer to the plate, and remove the transformer.

5N40. Installing the grid transformer. (See Figure 5-81.) Place the grid transformer in position on the suspended plate. From the back of the suspended plate, install the four screws that secure the transformer to the plate. Place the wires in position on the terminals of the transformer, and solder the wires to the terminals.

5N41. Removing the output transformer. (See Figure 5-81.) Unsolder the wires from the terminals on top of the transformer, and tag the wires for ready identification. Remove the four mounting screws and lift out the transformer.

5N42. Installing the output transformer. (See Figure 5-81.) Place the transformer in position on the mounting plate. Install the four mounting screws. Solder the wires to the terminals.

5N43. Removing the resistors from the suspended plate. (See Figure 5-81.) The 2250- and 1000-ohm resistors are located to the right of the driver phone unit. Remove the two screws (one on each resistor) that secure the resistors to the studs on the suspended plate, and lift them away from the plate. Unsolder and tag the wires for ready identification, and remove the resistors.

5N44. Installing the resistors. (See Figure 5-81.) Place the 2250- and 1000-ohm resistors in position on the suspended plate. Install the two nuts (one on each resistor) that secure the resistors to the plate. Solder the wires to the terminals on the resistors.

5N45. Removing the tuning fork. (See Figure 5-81.) The tuning fork is removed only if it is damaged. Remove the two screws that secure the tuning fork to the tuning fork base and remove the tuning fork.

5N46. Installing the tuning fork. (See Figure 5-81.) Place the new tuning fork in position

 
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Figure 5-86. Constant frequency control unit wiring diagram.
1. PHONE UNIT
2. AMPLIFIER TUBE 6J5 (G)
3. POWER TUBE, 25B6 (G) OR 25L6 (G)
4. TRANSFORMER, NO. 23882
5. RESISTOR, 50,000-OHM, 25-WATT
6. RECTIFIER
7. TRANSFORMER, NO. D21
8. CONDENSER, 0.005 MFD. OR 0.01 MFD. NOTE: 0.01 MFD. USED IN CONJUNCTION WITH POWER TUBE 25L6 (G) ONLY
9. STARTING MAGNET
10. GRID TRANSFORMER, NO. 26978
11. PHONIC WHEEL MOTOR COIL
12. LAMP
13. RESISTOR, 200-OHM, 40-WATT
14. CONDENSER, 2 MFD., 600V. D.C., 200 DEG. F.
15. RESISTOR, 100-OHM, 10 WATT
16. RESISTOR, 190-OHM, 50 WATT
17. CHOKE, NO. 23534
18. RESISTOR, 2250-OHM, 10 WATT
19. RHEOSTAT
20. SYNCHRONOUS MOTOR
21. STARTING CONDENSER, 2-2.4 MFD.
22. CLOCK, 60-CYCLE, NO HOURS HAND
23. INVERTED ROTARY CONVERTER, 75-WATT
24. TROUBLE INDICATOR ON I.C. BOARD

Figure 5-86. Constant frequency control unit wiring diagram.
 
99

in the tuning fork base with the stamped number on the fork upward. Install the two screws that secure the fork in the tuning fork base. Instructions for calibrating the fork are furnished with each new fork.

5N47. Removing the choke. (See Figure 5-81.) Unsolder the wires from the terminals on the choke. Tag the wires for ready identification. Loosen the ground wire. Remove the plate to make the choke mounting screws accessible (see Section 5N29). Remove the choke mounting screws from the back of the suspended plate.

5N48. Installing the choke. (See Figure 5-81.) Place the choke in position on the front of the suspended plate. Install the choke mounting screws from the back of the plate. Install the main mounting plate in the case (see Section 5N30). Solder the wires to the terminals. Install the ground wire.

5N49. Removing the variable resistors. (See Figure 5-81) The two variable resistors are located on the right side of the main mounting plate above the synchronous motor. Remove the nuts from the resistor mounting, studs. Mark the position of the resistor clamps on the resistors. Unsolder the wires and tag them for ready identification. Remove the resistors from the studs.

5N50. Installing the variable resistors. (See Figure 5-81.) Place the resistors on their

  mounting studs. Place the resistor clamps in their original position. Solder the wires to the terminals on the resistors. Install the two nuts (one on each stud) that secure the resistors to the studs.

5N51. Removing the rectifier. (See Figure 5-81.) Unsolder the wires from the terminals of the rectifier and tag the wires for ready identification. Remove the two screws that secure the rectifier unit to the main mounting plate and remove, the rectifier.

5N52. Installing the rectifier. (See Figure 5-81.) Place the rectifier in position on the mounting plate. Install the two mounting screws. Solder the wires to the terminals on the rectifier.

5N53. Removing the 50,000-ohm resistor. (See Figure 5-81.) Mark the position of the variable resistor clamp on the resistor. Unsolder the Wires from the resistor terminals. Remove the two screws that secure the resistor mounting bracket to the plate, and remove the resistor.

5N54. Installing the 50,000-ohm resistor. (See Figure 5-81.) Place the resistor in position on the mounting plate, and install the two mounting screws. Place the variable resistor clamp in the position marked on removal. Solder the wires to the terminals on the resistor.

 
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