The assembly quality indexes of rolling bearing are mainly radial clearance and width.There is a functional relationship between the axial clearance and the radial clearance. The axial clearance can be controlled indirectly by controlling the radial clearance.

For deep groove ball bearings, cylindrical roller bearings, adjustable ball bearings and roller roller bearings, radial clearance is mainly controlled.For thrust ball bearings, thrust roller bearings and tapered roller bearings, the main control height and width;For angular contact ball bearings, the main control of the size of the contact Angle.

The basic requirement of rolling bearing assembly is that, under the premise of ensuring the assembly quality index, the fitting rate is the highest, generally more than 95%.