For angular contact ball bearings, the clearance also determines its fatigue life. If the clearance is not selected properly, it is very easy to cause early failure of the bearing.
Angular contact ball bearings are generally used in pairs, and the use occasions are divided into two types: pre-clearance and pre-load. Machine tool bearings with higher rigidity requirements adopt preload configuration, and the fit interference of the shaft is very small (about a few microns), and there is no need to consider the impact of the fit interference on the working clearance when pairing. However, for bearings with large matching interference, the influence of the interference on its radial clearance must be considered. At this time, the pre-clearance configuration is mostly used. However, JB/T 10186-2000 only stipulates the pre-clearance value of 7200B and 7300B bearing series, and does not stipulate other series. Therefore, theoretical calculation is required to select an appropriate clearance range.
Factors affecting the pre-tightening of angular contact ball bearings: If the pre-tightening force of the bearing is increased, the stiffness can be improved, but excessive pre-tightening force will cause abnormal heating of the bearing, which will lead to early failure of the bearing. In positioning preloading, the preloading force depends on the bearing installation conditions, including bearing fit, centrifugal effect and temperature rise during operation.
