According to relevant information, in order to fully utilize the function and performance of the bearing, the fit between the shaft and the inner ring, the fit between the bearing seat and the outer ring, and the fit between the bearing seat and the outer ring must be appropriate. If there is a gap between the fitting parts during operation, it may cause misalignment between the shaft and the inner ring (or between the outer ring and the bearing seat). Creep is bound to occur and difficult to stop. 

This will cause significant wear on a mating surface and damage to the bearings, shaft, and bearing seat. Moreover, the heat generated by sliding can cause an increase in temperature, leading to bearing burns and even lubricant combustion. 

When assembling shafts and holes, interference fit or clearance should be retained to ensure flexible movement, and the size relationship of the mating components is the mating. There is an interference fit.