Usage:
1. Remove the generator drive assembly. See the topic, GENERATOR DRIVE ASSEMBLY.
2. Remove the vented rear cover. See the topic, GENERATOR COVERS.
3. Mark and disconnect field supply wires (1) from the brush holders.
PREPARING TO REMOVE ROTATING FIELD
1. Field supply wires (two). 2. Bolts (four).
NOTE: The four brushes can be lifted from their slots in the brush holder to help prevent damage to the brushes when removing the rotating field.
4. Carefully position the generator on end.
5. Remove bolts (2) from the generator cover.
REMOVING THE ROTATING FIELD
3. Eyebolts. 4. Hub. 5. Rotating field.
6. Install two 1/2"-13 NC forged eyebolts (3) in hub (4).
7. Attach a hoist to forged eyebolts (3) and slowly lift rotating field (5) from the generator.
8. Install rotating field (5) in the generator in the reverse order of removal.
Disassembly and Assembly
1. Unbend lock (3) and remove nut (4).
PREPARING TO REMOVE BEARING RETAINER AND BRUSH YOKE ASSEMBLY
1. Brush holders (two). 2. Bearing retainer and brush yoke assembly. 3. Lock. 4. Nut.
2. Lift the brushes (5) from their slots in the brush holder (1).
3. Install two 3/8"-16 NC bolts [6 in. (152 mm) long] in bearing retainer and brush yoke assembly (2) and use the block from 1H3112 Bearing Puller, 5F7366 Screws and 8B7560 Step Plate to remove the bearing and the bearing retainer and brush yoke assembly.
BEARING RETAINER AND BRUSH YOKE ASSEMBLY AND BEARING REMOVE
5. Brushes (four).
4. Inspect the bearing.
NOTE: Heat the bearing to facilitate installation. The shielded side of the bearing must be toward the field poles.
If only the bearing or the bearing retainer and brush yoke are to be removed, it is not necessary to remove the rotating field from the generator. First remove the generator covers. See covering topic. Next mark and disconnect the field supply wires from the brush holders and continue with the disassembly by following the Steps 1 through 4.
NOTE: While the bearing retainer and brush yoke assembly are removed from the rotor shaft, inspect the contacting surfaces of the collector rings. If the surfaces are discolored, either green or blue, clean the rings. Cleaning collector rings is covered in the Operation and Maintenance Instructions. If the rings have spotted blotches, or are rough and pitted, the rotor assembly can be removed and the rings turned and polished in a lathe. The rings can be turned without removing the rotor assembly from the generator by using a 9H2436 Collector Ring Turning Tool.
To use 9H2436 Collector ring Turning Tool (6), it is necessary to lift the brushes form each collector ring and disconnect the wire to each brush holder. Remove the bolts securing bearing retainer and brush yoke assembly (2) to generator cover (7) and rotate the bearing retainer 90° from its normal location. Reinstall the bolts. Install the collector ring turning tool to the generator cover. On lower kW capacity generators, it is necessary to rotate the generator cover to provide clearance when mounting the Collector Ring Turning Tool.
TURNING COLLECTOR RINGS
2. Bearing retainer and brush yoke assembly. 6. 9H2436 Collector Ring Turning Tool. 7. Generator cover.
5. If the collector rings can not be reconditioned and must be replaced, first mark and disconnect two wires (8) from the rings.
6. The collector rings can be removed by using an 8H700 Puller with an 8B7560 Step Plate.
7. When installing collector rings, make certain the field wires can be connected to the field wire terminals on the rings. Use a tube or pipe (with slightly larger ID than the rotor shaft OD) against only the hubs of the collector rings and press the collector rings on the rotor shaft. Never apply any force against either a ring or the insulation material bonded between ring and hub.
NOTE: New collector rings must be turned and polished concentric with the rotating field shaft.
REMOVING THE COLLECTOR RINGS
8. Wires (two).
HUB REMOVAL
8. Remove the hub by using 8B7548 Push Puller with 8B7550 Legs, 9S5800 Pump Group with 7F9540 Hydraulic Puller, 8B7560 Step Plate and two 8B7559 Adapters as shown.
9. Heat the hub to facilitate hub installation. Align the slot in the hub with the key in the rotor shaft and press the hub on the shaft.
NOTE: The rotating field assembly must be balanced whenever any part of the rotating field assembly has been disturbed or replaced. The use of a balancing machine is necessary to determine the weights required to obtain proper balance. Make reference to GENERATOR REWIND DATA for balance specifications.