Rockwell Automation 1329L AC Induction Motors User Manual - Manual (Page 19)

AC Induction Motors 19
Frequent bearing checks are recommended. If temperatures become
excessive, investigate immediately for the cause. Total bearing
temperatures should not exceed 121 degrees C (250 degrees F).
Causes for high bearing temperature are:
• Contaminated grease.
• Insufficient grease or excessive amount.
• Incorrect grease.
• Excessive load or thrust due to misalignment or motor overload.
• Loose bearings.
• Bearing failure.
• Excessive ambient temperature.
Replacement bearings should be ordered from Rockwell Automation
in order to obtain the same carefully selected bearing as the original.
Bearings should never be exposed by disassembly of the motor unless
absolutely necessary for inspection or replacement of the bearing or
maintenance in other parts of the machine. Protect good bearings
from dirt and contamination at all times. Most bearing failures are
caused by dirt.
The open ball bearings for motor frames L180 - L320 are the same
regardless of whether application is coupled or belted. Belted duty for
frames UL360 and UL440 requires the use of roller bearings.
Coupled duty uses ball bearings.
Disassembly and Reassembly
Instructions Axial Float
Motors have a wave spring washer between the drive end bracket and
bearing. The opposite drive end bearing is positioned axially by a
float restricting inner cap. Axial float (including bearing internal
clearance) should be within the limits listed below. The L440 frame
spring is located on the opposite drive end.
Axial Float
Anti-Friction Bearing Assemblies
The bearings are positioned and secured in a machined cavity in the
end brackets. Open type ball bearings are used for direct coupled and
belt drive applications for frames L180 - L320 (employ ball bearings
at both ends) and are protected by inner caps at both ends.
Frames UL360, UL400 and UL440 employ a cylindrical roller
bearing on the drive end for belt drives, and a ball bearing for coupled
service.
Frame Maximum Minimum
L180 - L440 1.29 mm (0.051 in.) 0.33 mm (0.013 in.)