The outer diameter of the auxiliary roll and the auxiliary sleeve shall be 0.1-0.3mm smaller than the shaft diameter. When installation, the surface coated with grease inside the bearing outer ring first, stand by needle surface within tight (in the last one needle, clearance shall be maintained), then replace the shaft neck of the roller bearing inner ring or auxiliary sleeve into the outer ring hole, and make it face alignment installed shaft end face or installed on the shaft bearing inner ring end face, and then use pressure on the press or hammer knock.