GE GEH-5304A User Manual

Page 21

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GEH-5304A

21

C.

Bearings

Ball bearing and roller bearing housings are packed with grease at the factory. Therefore, greasing is not
required before the motor is put into service. Since the oil in the grease will ultimately become depleted, it is
necessary to relubricate ball bearing and roller bearing motors periodically, depending on the size and type
of service (refer to Table 9).

Avoid mixing different kinds of grease. Lubricate the motor at standstill. Make sure the top grease fitting is
clean and free from dirt. Remove one of the lower grease relief plugs. Free the relief hole from any hard-
ened grease. Use a hand-operated grease gun only. Pump in grease until new grease appears at lower grease
hole. After greasing, allow the motor to run about ten minutes before replacing the grease relief plug to
permit excess grease to drain out.

Extreme pressure (EP) greases should not be used in DC machines. Insulation
deterioration and increased brush wear may result from the presence of sili-
cones.

D.

Replacement of Bearings

After the bearing brackets have been removed, a bearing puller may be used to pull the bearings from the
shaft. Protect the shaft center while using the puller. Discard the old bearing. The new bearing and all
mating parts should be kept extremely clean during reassembly.

To install a new bearing, heat the bearing to 116-127

°

C (240-260

°

F) in oil or in an oven, then slip or press

the bearing on the shaft. The bearing should be mounted tightly against the shoulder on the shaft.

After the bearing has cooled, reinstall the retaining ring where used. Fill the grease reservoir in the inner
bearing cap or cartridge 1/3 to 1/2 full of grease, butter the bearings and fill the grease reservoir in the bear-
ing bracket 1/3 to 1/2 full of grease.

Table 9

Recommended Regreasing Periods

Relubrication

Interval In Hours

Of Operation

Frame

Average

Ball

Roller

Size

RPM

Bearing

Bearing

CD2512AT-

500

36000

18000

CD2813AT

1150

15000

7500

1750

10000

5000

3000

5000

2500

Table 10

Standard Bearings for CD2512AT-CD2813AT Motors

Commutator End

Drive End

Standard Ball

Standard Ball

Oversize Ball

Oversize Roller

Frame

Basic

Basic

Basic

Basic

Size

Brg. No.

AFBMA

Brg. No.

AFBMA

Brg. No.

AFBMA

Brg. No.

AFBMA

25XX

307

35BC03X3

309

45BC03X3

310

50BC03X3

310

50RU03X3

28XX

309

45BC03X3

310

50BC03X3

311

55BC03X3

311

55RU03X3

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