Various morphological problems of bearings in motion

The noise and vibration of the INA bearing itself are generally very low. But for small and medium motors, office machinery, household appliances, and instruments that have special requirements for noise and smooth operation, low-noise bearings are usually used.

The rigidity of a rolling bearing is determined by the amount of elastic deformation that occurs when it bears a load. Under normal circumstances, this amount of deformation is very small and can be ignored, but in some machinery, such as machine tool spindle systems, the static and dynamic stiffness of the bearing Great influence on the characteristics of the system. Roller bearings have higher stiffness than ball bearings. Various types of bearings can also improve their rigidity to varying degrees through proper "preloading".

The working speed of rolling bearings mainly depends on their allowable operating temperature. Bearings with low friction resistance and less internal heating are suitable for high-speed operation. When only bearing radial load, deep groove ball bearings and cylindrical roller bearings can be used to achieve higher speeds. When bearing combined loads, angular contact ball bearings should be used. Specially designed high-precision angular contact ball bearings can reach extremely high speeds. The speed of various thrust bearings is lower than that of radial bearings.

In mechanical design, the size of the shaft is generally determined first, and then the bearing is selected according to the size of the shaft. Generally, ball bearings are used for small shafts; cylindrical roller bearings, spherical roller bearings, and tapered roller bearings are used for large shafts. If the radial space of the bearing installation part is restricted, a bearing with a smaller radial section height should be used. Such as needle roller bearings, some series of deep groove ball bearings, angular contact ball bearings, cylindrical roller or spherical roller bearings and thin-walled bearings. If the axial space of the bearing installation part is restricted, a bearing with a smaller width dimension can be used.

The friction resistance of ball bearings is smaller than that of roller bearings. When pure radial load is applied, the friction resistance of radial contact bearing is small; when pure axial load is applied, the friction resistance of axial contact bearing is small; when combined load is applied, the bearing is in contact Angular contact bearings whose angles are close to the load angle have the least frictional resistance. In instruments and machinery that require low friction torque, ball bearings or cylindrical roller bearings are more appropriate.

The common configuration of bearings is to install a set of axially positioned "same bearings" on one end of the shaft, and install a set of axially movable "floating bearings" on the other end to prevent thermal expansion and contraction of the shaft. Stuck phenomenon. The frequently used "floating bearing" is a cylindrical roller bearing with no ribs on the inner ring or outer ring. At this time, the inner ring and the shaft or the outer ring and the housing hole can be fitted with an interference fit. Sometimes non-separable deep groove ball bearings or spherical roller bearings can be used as floating bearings, but when installing the inner ring and shaft or outer ring and the housing hole, clearance fit should be selected to ensure that the inner or outer ring Enough freedom of axial movement.