The correct bearing fit can achieve good bearing performance, give full play to the role of the bearing, and the wrong fit will lead to premature bearing damage.


The bearing capacity of the bearing is related to the bearing mounting surface, the support shaft and the housing bore. The cooperation of the rolling bearing with the shaft and the seat hole is very important. According to the requirements of bearing use, the principles that bearings should follow are mainly reflected in the following aspects:


1. Support
The circumferential direction of the bearing ring must be well supported to take full advantage of the bearing capacity. According to this requirement, the inner ring and the outer ring should adopt a tighter fit. The ring is a thin-walled component. When the gap is large, the ferrule will undergo bending deformation after loading, affecting the internal load and stress distribution, resulting in stress concentration, and the deformation of the ring also affects the rotation accuracy.


2. Slide
The ring subjected to the rotating load cannot slide in the surrounding direction on the mating surface. However, the ring subjected to a fixed load may have a slight rotation, thereby slowly changing the load area.


3. Active end support
The non-separable bearing supported on the movable end should allow the ring to move axially relative to the mating surface and the ferrule should be loosely fitted.


4. Interference fit

Interference should be controlled. Excessive interference results in negative clearance or stuck rolling elements.


5. Matching part accuracy
The mating parts must meet the required accuracy. The bearing ring is a thin-walled part, and the shape error of the journal or the seat hole is transmitted to the raceway, which reduces the accuracy of the bearing.


6. Easy to install and disassemble
This requirement is somewhat contradictory to previous requirements. The tightness of the installation process can affect the ease of installation and removal. Therefore, in practice, it is necessary to comprehensively consider the specific situation, weigh the pros and cons, and choose the most suitable cooperation method.