The clearance of vacuum pump bearings can be divided into radial clearance and axial clearance.

The radial clearance of the vacuum pump bearing refers to the bearing that can bear radial load in the non-preloaded state. The radial clearance is: along any angular direction in the radial direction, when there is no external load, the outer ring is relative to the inner An arithmetic average of the radial distance that the circle moves from a radial eccentric position to the opposite position.

The axial clearance of the vacuum pump bearing refers to the bearing that can bear axial load in two directions in a non-preloaded state. Its axial internal clearance is: when there is no external load, a ferrule is relatively free Another set of circles, the average value of the axial distance from one axial position to the opposite position.