As shown in Figure 1, the selection and control of shaft and NSK inlet bearing chamber tolerances: After the imported bearing is pressed, it should be flexible and unobstructed. If it is obviously inflexible, it means that the size of the shaft is too large, and the tolerance should be lowered. If the imported bearing is pressed into the shaft and the hand is rotated, there is obvious “sand” feeling. The tolerance of the shaft is too large or the roundness of the shaft is not good. Therefore, it is necessary to control the roundness when controlling the tolerance of the shaft and the imported bearing chamber. At present, many domestic manufacturers only control the tolerance and do not control the roundness.
2, the assembly method of imported bearings: Because the imported bearings are high-precision products, such as improper assembly, it is easy to damage the angular contact ball bearing channel, resulting in angular contact ball bearing damage angular contact ball bearings should have a special mold when assembling, Can't beat at will, only when pressing the shaft
Can be stressed in a small circle, only a large circle of force when pressing a large circle. At the time of assembly, air pressure or hydraulic pressure is required. When the press-fit is performed, the upper and lower molds should be outside the horizontal state. If the tilting causes the inlet bearing channel to be damaged due to the force, the imported bearing will produce a sound.
3, the prevention of assembly of foreign objects: NSK imported bearings when installed on the rotor to do dynamic balancing is easy to move the iron filings generated during the dynamic balance into the inside of the imported bearings, so it is better to load balance before loading the bearings. In order to facilitate assembly, some manufacturers apply some oil or grease to the imported bearing chamber for lubrication. However, it is often difficult for the operator to control the amount. If oil or grease accumulates in the imported bearing chamber, the bearing is imported. It is easy to enter the inside of the inlet bearing along the shaft when turning. It is good not to apply oil or grease to the imported bearing chamber. If it is not coated, it must be controlled and not accumulated in the imported bearing chamber. The service life of NSK imported bearings is closely related to manufacturing, assembly and use. It must be done at every stage to make the imported bearings in good running condition, thus extending the service life of imported bearings.