3000 Frame SR5 Electric Power Generation Caterpillar

Two Bearing Generator Flexible Coupling Removal

Start By:

1. Remove the terminal box. Refer to Systems Operation, Test and Adjust, Disassembly and Assembly, KENR8990, "Terminal Box - Remove" section.
2. Remove the generator. Refer to Systems Operation, Test and Adjust, Disassembly and Assembly, KENR8990, "Generator - Remove" section.

Note: The coupling may be serviced without the complete removal of the generator if desired. The generator can be pushed rearward on the generator set base rail. After the generator is pushed away from the engine, there should be enough clearance to service the coupling if desired.

Remove the Rubber in Shear Type of Coupling

Note: The flexible coupling does not require disassembly when removing the generator. The inner flexible element will slide out of the outer coupling ring as the generator is pushed away from the engine.

Illustration 1	g01578214
Rubber in Shear Type Coupling (1) Outer ring (2) Rubber flexible element (3) Hardness specification

1. Remove the outer ring mounting bolts for the coupling. If necessary, remove the outer ring of the coupling from the engine flywheel.

   Note: Care must be taken in the process of removing the ring. The ring may need to be pried off.

2. Remove the mounting bolts for the inner member of the coupling. Carefully pry the rubber flexible element flange of the coupling from the generator hub.

   Note: The coupling flexible element components weigh approximately 22.7 kg (50 lb). The outer ring weight is approximately 5 kg (11 lb).

Remove the Rubber in Compression Type Coupling

Illustration 2	g01578343
Exploded View of the Coupling (4) Cover plate (5) Silicone blocks (6) Inner hub (7) Outer hub

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Illustration 3	g01578539
(10) Coupling assembly (11) Outer hub mounting bolts (12) Engine flywheel (13) Engine flywheel housing

1. The coupling should remain attached to the generator hub as the generator is removed. Remove the mounting bolts (11) that assemble the coupling to the engine flywheel (12) .

   Note: If there is no need to service or to inspect the inner silicone blocks (5) , then do not disassemble the coupling.

2. Remove the generator. Refer to the Refer to Systems Operation, Test and Adjust, Disassembly and Assembly, KENR8990, "Generator - Remove" section.

3. Install a 138-7575 Link Bracket (15) on the coupling. Use a suitable lifting device in order to support the coupling. Remove the inner element mounting bolts. Remove the complete coupling assembly. Refer to Illustration 4.

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Illustration 4	g01596192

4. If the inner silicone blocks (5) are to be replaced or inspected, set the coupling assembly with the flywheel flange down toward the floor. Remove the rear cover plate (4) .

5. Pull out the silicone blocks or gently pry out the silicone blocks. Do not use any lubricant.

Generator Drive Hub Removal - Taper Lock

The Taper Lock hub is available on the 3055 frame, 3066 frame, and 3068 frame generators that are used for the C175-20 packages. Refer to Illustration 5 for a picture of the taper lock drive hub.

Illustration 5	g02719917
Taper lock drive hub (20) Cap head bolts (21) Jacking bolt threads

Note: Check the position of the taper lock hub before removal. Record the location of the taper lock hub.

The taper lock hub can be removed after all of the cap head bolts (20) are removed.

1. Remove all cap head bolts (20) .

2. Install 3 of the cap head bolts into the threads (21) for jacking bolts. The jacking bolts are used to separate the two parts of the taper lock hub.

   Note: Ensure that the jacking bolts are tightened as evenly as possible. Each jacking bolt must be turned only a small about each time until the taper lock hub separates.

3. After the taper lock hub is apart, remove the cap head bolts from the jacking bolt threads (21) . Discard all of the original cap head bolts.

4. Use new cap head bolts for the taper lock hub when the taper lock hub is assembled.

Important Safety Information

Work safely. Most accidents that involve product operation, maintenance, and repair are caused by failure to observe basic safety rules or precautions. An accident can often be avoided by recognizing potentially hazardous situations before an accident occurs.

A person must be alert to potential hazards. This person should also have the necessary training, skills, and tools in order to perform these functions properly.

Safety precautions and warnings are provided in this instruction and on the product. If these hazard warnings are not heeded, bodily injury or death could occur to you or to other persons. Caterpillar cannot anticipate every possible circumstance that might involve a potential hazard.

Therefore, the warnings in this publication and the warnings that are on the product are not all inclusive. If tools or procedures not recommended by Caterpillar are used, ensure that all of the tools and procedures are safe to use.

Ensure that the product will not be damaged or become unsafe due to the use of tools or procedures not recommended by Caterpillar.

The following warning must be heeded due the flames, gas, and heat of the process.

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Personal injury or death can result from fumes, gases and ultraviolet rays from the weld arc. Welding can cause fumes, burn skin and produce ultraviolet rays. Keep your head out of the fumes. Use ventilation, exhaust at the arc, or both, to keep fumes and gases from your breathing area. Wear eye, ear and body protection before working. Protect yourself and others; read and understand this warning. Fumes and gases can be dangerous to your health. Ultraviolet rays from the weld arc can injure eyes and burn skin. Electric shock can cause death. Read and understand the manufacturer's instructions and your employer's safety practices. Do not touch live electrical parts. See "American National Standard Z49.1, Safety in Welding and Cutting" published by the American Welding Society. American Welding Society 2501 N.W. 7th Street Miami, Florida 33125 See "OSHA Safety and Health Standards, 29 CFR 1910", available from U.S. Department of Labor. U.S. Department of Labor Washington, D.C. 20210

Shrink Fit Drive Hubs

The shrink fit drive hub is considered to be a "heavy shrink" fit installation.

The double acting cylinder produces 311 N (70,930 lbs) of rod out force at rated 68.95 kPa (10,000 psi) input.

Note: Important. The hydraulic cylinder MUST have enough stroke to remove the drive hub without stopping once the drive hub breaks free of the rotor shaft. The stroke must be 152.4 mm (6 inch) to 203.2 mm (8 inch).

Recommendation

Due to the heat that is involved with the following process, the internal diameter of the drive hub can become warped. If the original drive hub is to be reused, the inside diameter of the drive hub must be checked. The inside diameter must be checked to verify if the inside diameter of the drive hub is true and round. The drive hub ID must maintain the original shrink fit. Caterpillar suggests that a new drive hub should be installed in place of the original.

Tooling

• A fire extinguisher that is ready to be used

• High heat gloves

• Appropriate eye and (full) face protection

• Welding jackets for arm protection

• 3 Jaw Puller

• An appropriate lifting device that can support the weight of the drive hub, the adaptor, and the hydraulic assembly. (The drive hub weights approximately 70 lbs.)

• Optional - A weld blanket or heat shield to protect the front bracket from the heat of the rose bud tips

• Link assemblies (possibly used to support the drive hub during removal and installation)

• Infrared Thermometer

• Oxygen and acetylene tanks and associated equipment (hoses, gages, flint spark lighter, and tips)

Note: If available, propylene gas can be used in place of acetylene. Propylene gas has the capability of being a hotter gas than acetylene. Propylene gas can heat the drive hub to the necessary temperature in less time, which allows less heat transfer to the rotor shaft.

Preparation

1. Two qualified people are required to perform the process, three are preferred. Two people are needed to heat the drive hub while the third person operates the puller.

2. Prepare two torches equipped with "rose bud" tips. There must be enough oxygen and acetylene available to operate both tips for approximately 20 minutes.

3. A 120 VAC supply will be needed to operate the power pack for the hydraulic cylinder that is used for the puller.

Note: The double acting cylinder produces 311 N (70,930 lbs) of rod out force at rated 68.95 kPa (10,000 psi) input.

Drive Hub Position

Make note of the position of the original drive hub (10) that is on the rotor shaft. The important dimension is measured from the face of the drive hub flange (21) to the (machined) face (20) of the adaptor. If a new drive hub is used, ensure that dimension "A" is the same as the original drive hub.

Illustration 6	g02163823

Table 1 shows the variety of drive hub locations for different serial numbers and applications.

Note: If there is a difference between the original measured distance of the drive hub from the face of the rotor shaft and the information that is in Table 1, use the measured distance for your application.

Drive Hub Removal - Shrink Fit

Before the following procedure is attempted, read Systems Operation/Test & Adjust/Disassembly & Assembly, KENR8990, "Specifications for Heavy Shrink Fit Drive Hubs" section.

Note: The drive hub is a heavy shrink fit installation. If the hub cannot be removed by heating, then the destructive method may be used. Do not use any other method to remove the hub.

Note: A puller will be necessary in order to remove the hub after the hub is properly heated. There is also a destructive method in order to remove the hub. The hub can be cut off the main rotor shaft. Cut grooves into the side of the hub until the hub separates from the main rotor shaft. Do not cut into the main rotor shaft.

The following procedure is written to provide information for the removal and installation of the drive hub for the SR5 generators. The following procedure applies to two bearing generators.

The exact process and tooling for each application may vary. That is, the process that is documented in this publication was performed on a generator that was removed from the engine. If the generator is left on the generator base rails for servicing, the working distance will determine the puller assembly that can be used.

Even if the generator is moved away from the engine as far as possible but left on the generator base rails, the working distance may not provide enough working space for the puller that is written about in this publication.

1. Separate the generator from the engine. Refer to Systems Operation, Testing and Adjusting, Disassembly and Assembly, KENR8990 for the SR5.

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Illustration 7	g01360301
Drive hub

2. Install the adaptor, puller assembly, and safety chains. Refer to Illustration 8.

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Illustration 8	g02163830

3. Ensure that all of the mounting bolts for the adaptor are installed equally. The adaptor MUST be installed parallel to the drive hub. Proper installation will ensure that the load is distributed evenly between the mounting bolts. Proper installation will ensure that the puller assembly pulls evenly on the drive hub.

   1. Ensure that the hydraulic cylinder is fully retracted.

   2. Keep the puller assembly aligned with the drive hub and rotor shaft.

   3. Ensure that the puller assembly is supported by an appropriate lifting device.

4. Apply pre-load pressure to the puller assembly to allow the assembly to remain in place prior to heating the drive hub. 20.7 kPa (3,500 psi) input was used. Therefore, the puller was producing approximately 106.8 N (24,825 lbs) of rod out force.

5. Check that the puller assembly is aligned and safe.

6. If desired, install a weld blanket or heat shield to protect the front bracket, rotor shaft, shaft lip seal, and bearing from excessive heat.

7. From opposite sides of the adaptor, simultaneously begin to heat ONLY the backside of the drive hub at the base of the flange. Apply the heat as evenly as possible by constantly moving the rose bud tips around the drive hub. Refer to Illustration 9.

   Note: Keep heat away from the hydraulic cylinder of the puller and away from the generator rotor shaft.

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Illustration 9	g02163877

8. Ensure that the pressure on the drive hub remains constant.

9. The drive hub should break free of the rotor shaft in approximately 4 to 8 minutes.

   Note: The time variation depends on the ambient temperature, the shrink fit of the hub, how well the heat is evenly applied, and the amount of heat that is applied to the drive hub.

   Note: The external temperature of the drive hub will exceed 315° C (600° F) to 371° C (700° F).

10. Once the hub breaks free of the rotor shaft, continue to heat the hub and continue to apply pressure with the puller until the hub is removed from the rotor shaft completely.

    Note: If the heat is removed prematurely or if the hub motion is stopped before the hub is removed completely, the hub will adhere to the rotor shaft. Damage is likely to occur to both components.