The flexibility of the bushing is relatively high, and it can play a lot of roles. Generally speaking, the bushing is a kind of component that protects the equipment. The use of bushings can reduce equipment wear, vibration and noise, and has an anti-corrosion effect. The use of the bushing can also facilitate the maintenance of mechanical equipment and simplify the structure and manufacturing process of the equipment. The role of the bushing in actual work has a lot to do with its application environment and purpose. In the field of valve application, the bushing is installed in the valve cover to cover the valve stem, so as to reduce the leakage of the valve and achieve the sealing effect. In the bearing application field, the use of bushings can reduce the wear between the bearing and the shaft seat, and avoid the effect of increasing the gap between the shaft and the hole.