How does the motor bearing rotating ring match the fixed ring?

Update:11 Jan 2020
Summary:

The selection of the types of motor bearings should be […]

The selection of the types of motor bearings should be determined according to the type and size of the bearing, the size and direction of the load, and the nature of the load. The correct choice of bearing coordination should ensure the normal operation of the bearing to prevent relative rotation of the inner ring and the shaft, the outer ring and the housing hole during operation. Generally speaking, when the direction of the working load is constant, the rotating ring has a tighter fit than the fixed ring, because the rotating ring bears the rotating load, and the non-moving ring bears the local load. When the higher the speed, the larger the load and the more intense the vibration, the tighter the fit should be selected.

When bearings are mounted on thin-walled housings or hollow shafts, a tighter fit should also be used. However, too tight fit is disadvantageous. At this time, the internal clearance of the bearing may be reduced or even completely disappeared due to the elastic expansion of the inner and outer rings and the contraction of the outer ring. It may also be due to the irregularity of the matching shaft and seat hole surface. The shape or uneven rigidity causes irregular deformation of the inner and outer rings of the bearing, which will destroy the normal operation of the bearing. Too tight fit can also make assembly and disassembly difficult, especially for heavy machinery.