Measure the size of the shaft and the bearing seat hole of the precision machine tool to determine the matching accuracy of the precision machine tool bearing; the outer ring and the bearing seat hole of the precision machine tool adopt a clearance fit, and the clearance is 0~+6μm (but when the precision machine tool bearing at the free end uses an angular contact ball precision machine tool bearing, the clearance can also be increased); The roundness error of the shaft and seat hole surface is less than 2 μm, the parallelism of the end face of the spacer ring used for precision machine tool bearings is less than 2 μm, and the runout of the inner end of the shaft shoulder to the outer end face is less than 2 μm; Less than 4μm; the runout of the inner end of the spindle front cover to the axis is less than 4μm.

For the installation of precision machine tool bearings on the shaft before the fixed end, thoroughly clean the precision machine tool bearings with clean kerosene. For grease lubrication, first inject an organic solvent containing 3% to 5% grease into the precision machine tool bearings for degreasing and cleaning , and then use an oil gun to fill a certain amount of grease into the bearing of the precision machine tool (accounting for 10% to 15% of the space volume of the bearing of the precision machine tool); heat the bearing of the precision machine tool to increase the temperature by 20 to 30°C.