Linear bearings are linear motion systems. Due to the contact of the bearing ball with the bearing jacket, the ball is rolling with minimal frictional resistance, so the linear bearing has a small friction and is relatively stable, maintaining a high degree of precision, High rigidity of the performance. The retainer and the ball are nested in the cylindrical outer cylinder, and the retainer is fixed to the outer cylinder with the retaining ring at both end ends. The guide circuit on the retainer allows the ball to be smoothly circulated to obtain Smooth and smooth linear motion. Used in food machinery, semiconductor manufacturing equipment, precision machine tools and other equipment.