Because of its compact structure, reliable operation, dimensional standardization, convenient use and maintenance, rolling bearings are widely used in various mechanical equipment. They are mainly used as supporting elements, supporting rotating shaft or other moving bodies and bearing loads, which is a very important part. The performance of rolling bearings directly affects the use of mechanical equipment during the predetermined period of use. Therefore, all kinds of mechanical equipment use rolling bearings have strict requirements and standards. Before assembling the rolling bearing, we must ensure the cleanliness of the assembly surface, clean the foreign matter such as iron filings, burrs, dust and so on in the rolling bearing, reduce the noise and vibration caused by the running of the rolling bearing, and avoid damaging the rolling body and raceway. If the surface of the rolling bearing is coated with antirust oil, it must be cleaned with clean kerosene or gasoline and then coated with grease. The clearance of rolling bearings refers to the maximum movement of another ring along the radial or axial direction when a ring is fixed, and there are two kinds of radial clearance and axial clearance. If the clearance is too small, the friction will be increased, and the wear and tear will increase. The heat generated by the work will reduce the service life of the rolling bearing. Therefore, the clearance of the rolling bearing must be strictly controlled and adjusted when assembling. This requires strengthening inspection and maintenance, checking mechanical equipment by setting people, timing and setting machines, and carrying out preventive and corrective maintenance according to inspection records.