Bearing little knowledge of what is the function of bearing pre-tightening

General rolling bearing under working state has some clearance. But in order to achieve a specific purpose, in the configuration of bearings, bearing through certain adjustment method get certain internal load, used in negative clearance form and the using method called preloaded. For rolling bearing, appropriate pre-tightened can have the following purposes: 1, improve the rotation accuracy. After bearing preload, eliminates the internal clearance, each roller under certain load, bearing the ring from all directions, can improve the rotation accuracy, the shaft correctly in the axial and radial orientation, the axis of rotation accuracy, such as spindle bearing and measuring instruments, etc. 2, improve the rigidity. Rolling element and raceway contact place is elastic contact, the roller can be regarded as a spring. Clearance of the bearing, only several spring bearing stress direction. After preloaded bearing, have spring support in all directions, and has a certain amount of preloading, the number of rolling load more than have a game, so can improve the stiffness. Ball bearings, ball and the channel of the relationship between the contact deformation and load is nonlinear, with the increase of pre-load, contact stiffness increased. 3, improve the service life of bearing. Preloaded after the increase in the number of load rolling element, by reducing the load of each rolling element, as well as the load is evenly distributed on each roller, so can improve the service life of bearing. 4, improve the bearing damping and noise reduction. Preloaded roller and establish a stable oil film between race, improve the damping between the rolling element and raceway, can improve the dynamic characteristics of supporting structure and reduce the noise. 5, improve the dynamic performance of angular contact ball bearing. In high-speed rotating angular contact ball bearing, proper preload can prevent the steel ball gyro spin, prevent or reduce the revolution of the steel ball sliding, also can control the ball spin slide. 6, inhibition of the marks and the friction and wear. Outside the spherical bearing is actually the deep groove ball bearing a form, characteristic is its outer diameter for spherical surface, can match into the corresponding concave spherical bearing self-aligning effect. Outside the spherical bearing is mainly used to bear radial direction load primarily radial and axial load, should not be commonly alone carry axial load. Used for low roughness without vibration grain processing machine tools, or often need to start-up and shutdown control of friction and wear mechanism. 7, control the revolution and rotation of the roller slippage phenomenon. Insert ball bearing such bearing on the design also has a certain adjustable mind, easy to install, has a dual structure of sealing device, can work under harsh environment. Bearing is usually is made of casting forming. Arrange ushering bearing is deep groove ball bearing grease seal type bearing with different shapes and combination of high precision components products. Bearing assembly can pass a few bolts to install directly on the body of the mechanical device, with the heart function, can be the supplement of the grease, etc. , is a kind of installation is very simple products. As for high-frequency motor used in angular contact ball bearings and cylindrical roller bearing on the jet engine, etc. 8, compensation running wear and tear. Bearing in operation will lead to the increase of the clearance, because wear this kind of situation can be preloaded to compensate.