SR4 Generator with VR3 or VR4 Voltage Regulator Caterpillar

Removal Procedure

Start By:

1. Remove the exciter field and remove the exciter armature. Refer to Disassembly and Assembly, "Exciter - Remove and Install" and Disassembly and Assembly, "Rotor - Remove and Install".

Illustration 1	g00615777
(1) Protective strip

1. Put protective strips (1) of cardboard, plastic or curved sheet metal between the rotor assembly and the stator assembly. The pieces should be as long as the rotor assembly. During removal of the end housing, these pieces protect the rotor and the stator from damage.

2. The generator bearing is retained in the generator end housing. On the inside of the generator end housing, a bearing cap or retaining bars are used to retain the bearing.

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Illustration 2	g00854020
(2) Bolts (3) Retaining Bars

3. If the generator end housing is equipped with retaining bars (3), remove the four bolts (2) that fasten the retaining bars to the generator end housing. Remove the retaining bars.

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Illustration 3	g00854023
(4) Bearing Cap

4. If the generator end housing is equipped with bearing cap (4), remove the necessary bolts which fasten the bearing cap to the generator end housing. Pry the bearing cap out of the generator end housing. The bearing cap remains with the rotor shaft. If a bearing lube line is attached to the bearing cap, remove the lube line.

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Illustration 4	g00854025
(5) End Housing (6) Bolts

Note: The weight of end housing (5) varies with the size of the generator. Larger end housings require the use of a hoist.

5. Attach a hoist to end housing (5). Remove bolts (6) that fasten end housing (5) to the generator. Use a pry bar to separate the end housing from the generator. Some end housings have provisions which allow the use of forcing screws. Lift the end housing from the generator and remove the end housing from the generator.

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Illustration 5	g00854021
(7) Tooling

6. Attach tooling (7). Remove the bearing.

Two-Bearing Generator

Note: On two-bearing generators, there is a bearing on each end of the generator. To remove the bearing that is located at the drive end of the generator, use the following procedure.

For removal of the bearing at the drive end of the generator, begin by removing the drive coupling. Refer to Disassembly and Assembly, "Coupling - Remove".

Illustration 6	g00615814
(1) Bolts

1. The generator bearing is retained in the generator end housing. On the inside of the generator end housing, a bearing cap retains the bearing.

   Remove bolts (1) which fasten the bearing cap to the generator end housing. Pry the bearing cap out of the generator end housing. The bearing cap remains with the rotor shaft. If a bearing lube line is attached to the bearing cap, remove the lube line.

2. Put a mark on the drive end housing and the generator housing. This will ensure proper alignment during installation.

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Illustration 7	g00615816
(2) End Housing (3) Bolts

3. Attach a hoist to end housing (2). Remove bolts (3) which fasten end housing (2) to the generator. Use a pry bar to separate the end housing from the generator. Some end housings have provisions which allow the use of forcing screws. Lift the end housing from the generator and remove the end housing from the generator.

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Illustration 8	g00615820
(4) Removal Tool 1U-6415

4. Attach tooling (4). Remove the bearing.

Illustration 9	g00615824
Replaceable bearing wear sleeve (inside view of end housing) (5) Bearing wear sleeve

Some end housings have a bearing wear sleeve (4) which is replaceable.

Installation Procedure

To install the bearing that is located at the exciter end of the generator, use the following procedure.

1. Use a bearing induction heater in order to heat the bearing to 149 °C (300.2 °F).

2. While the bearing is 149 °C (300.2 °F), place the bearing on the shaft.

3. Install the generator end housing. If the generator end housing is equipped with a bearing cap, attach the bearing cap to the end housing. Install bolts and tighten the bolts.

4. If equipped, attach bearing lube line to the bearing cap.

5. If the generator end housing is equipped with retaining bars, attach the retaining bars to the end housing. Install the bolts and tighten the bolts.

Two-Bearing Generator

Note: On two-bearing generators, there is a bearing on each end of the generator. To install the bearing on the drive end of the generator, use the following procedure.

1. Use a bearing induction heater in order to heat the bearing to 149 °C (300.2 °F).

2. While the bearing is 149 °C (300.2 °F), place the bearing on the shaft.

3. Attach a hoist to the generator end housing. Attach the generator end housing to the generator. Install the bolts and tighten the bolts.

4. Attach the bearing cap to the end housing. Install the bolts and tighten the bolts.

5. If equipped, attach bearing lube line to bearing cap.