For motor bearings, both motor manufacturers and motor users know that for heavy-load motors, cylindrical roller bearings will be used at the shaft extension end of the motor, and for particularly large and heavy-loaded motors, sliding bearings will be used.

In the actual bearing selection and application process, it will be found that some motors will have more obvious vibrations under no-load conditions, but will become very stable under load conditions. This is the matching relationship between bearing selection and load size.

For the shaft extension end of heavy-load motors, when selecting rolling bearings, cylindrical roller bearings are selected, and the non-shaft end is a two-bearing structure with ordinary ball bearings; for occasions with strict axial positioning, a three-bearing structure will be used, that is, a double bearing structure with one ball and one column is used at the shaft extension end, and a ball bearing is also used at the non-shaft extension end; and for ordinary load motors, especially small-sized motors, a two-bearing structure with ball bearings at both ends is more often used; this is the basic principle for selecting motor load and bearing models.

In addition to the selection of motor bearing types, the selection of bearing specifications is also particularly important, that is, the load that the bearing can withstand should match the load of the motor, and the specification should be increased or reduced according to the actual working conditions of the motor. For standardized bearing manufacturers, they are fully capable of providing customers with bearing selection solutions, and make necessary special process or size adjustments based on the actual matching working conditions of the user's motor.

In fact, different motor transmission methods have different load requirements for bearings, such as pulley transmission, coupling transmission, and gear transmission. In the coupling transmission method, the correlation between the load and torque of the bearing system is relatively small. For pulley-driven motors, the bearing system will be affected by the tightness of the belt and the size of the pulley; while for gear transmission, the bearing system is directly affected by the torque.