Are the motors sliding bearings at both ends?
Roller bearings are commonly used, and only small motors, household appliances (such as electric fans) use plain bearings. Also have one end rolling, one end sliding. It depends on your motor.
In general, both ends of the motor are using deep groove ball bearings, large motors such as 1000KW or more will generally use sliding bearings, also known as bearing.
The electric ball of a small gasoline generator has only one end of a roller bearing, and the other end is supported by an engine shaft
