Table IX - Maximum permissible temperature rises (cont'd.).
NOTE: Squirrel-cage and mechanical parts (such as brush holders, brushes, pole tips), may attain such
temperatures as will not injure the motor in any respect.
resistance. - The motors shall be capable of withstanding the high-impact shock test
specified in MIL-S-901 and 18.104.22.168.
- The bearings shall be mounted as follows:
(a) Opposed shoulder method. - Where this method is employed, the end play of the shaft. shall be
adjusted to compensate for any relative movement that may occur between the shaft and the
housing due to temperature differential between these parts. In no case shall this end play
exceed .045 inches.
(b) Fixed-free method. - When this method is employed, the bearing shall be secured on the shaft
by means of locknuts and lockwashers or by a locknut utilizing a nylon insert to effect locking.
The pulley end or back end bearing shall be clamped axially in the housing by suitable housing
and end cap shoulders. End caps shall be secured by screws or bolts in such a manner that
the screws or bolts shall be capable of being removed without dismantling the motor. For
gear motors the front end bearing shall be clamped in the housing.
22.214.171.124.2 Bearing pre-load washers or springs. - Bearing pre-load washers or springs or both may
be used to attain required end-play.