Installation and Maintenance Manual

GEI-M1031-B
17
V. MAINTENANCE (cont’d)
D. Anti-Friction Bearing Maintenance (cont’d)
2. Reassembly
Cleanliness is important when working with bearings. Before reassembling a bearing, all
bearing and machined surfaces should be thoroughly cleaned with suitable solvent.
Examine the machined fits of the end-shield, bearing housing, slinger, and grease cap for
burrs. It is important that these surfaces be smooth.
Reassembly of the bearing should be performed in the following manner:
a. Inspect the bearing housing and related parts for foreign material. Clean if
necessary.
b. The machined fits and critical surfaces of the end-shield, bearing housing, bearing
cap and bearings should be free of all nicks, scratches or burrs. If any polishing is
done, care should be taken to avoid a deposit of metal dust in and around the
bearing assembly.
c. The internal surface of the bearing housing should be coated with a thin film of the
recommended grease. The shaft and bearing cap should also receive a very light
coating of the recommended grease. These precautions, although not absolutely
essential, will guard against corrosion of the critical surfaces.
d. Heat the bearing in oil to a temperature between 50C and 125C (122F to 257F)
and place it on the shaft. Hold it against the shaft shoulder until the bearing cools.
e. Mount drive end end-shield. If an outer bearing cap was supplied, mount the outer
bearing cap to the shaft. Refer to Table 5 for bolt torque requirements. (Motor frame
sizes 143 to 286 do not have bearing caps).
f. Mount the opposite drive end end-shield to the stator frame. Refer to Table 6 for
recommended bolt torques.
g. Insert the rotor into the stator with appropriate tools. Carefully insert the rotor shaft
thru the opposite drive end end-shield.
h. Assemble the outer bearing cap at the opposite drive end if bearing cap was
supplied. Replace the shaft slinger.
i. Assemble the fan, snap-ring, grease pipes, and fan cover.
j. Mount the drive end end shield to the stator frame. Refer to Table 7 for motor shaft
endplay.
Warning
To prevent injury to eyes, safety glasses
should be used.
Table 5: Bearing Cap Bolt Torque
Frame
Size
Bolt Size
Minimum
Torque
Ft-Lb (N-M)
Maximum
Torque
Ft-Lb (N-M)
143-286
Not
Applicable
Not
Applicable
Not
Applicable
324-326
M8
14 (19)
18.7 (25)
Table 6: End Shield Bolt Torque
Frame
Size
Bolt
Size
Minimum
Torque
Ft-Lb (N-M)
Maximum
Torque
Ft-Lb (N-M)
143-145
M8
8.7 (11.7)
12.3 (16.6)
182-184
M10
14 (19)
18.7 (25)
213-215
M10
5.7 (7.74)
7.6 (10.3)
254-286
M12
49.3 (66.8)
65.8 (89.2)
324-326
M12
49.3 (66.8)
65.8 (89.2)