Use special tools for bearing installation and removal
Advanced installation tools can avoid bearing damage caused by improper tools and operations during installation. For example, when installing the bearing, the staff used the copper rod knocking method, which is easy to cause uneven axial force on the bearing, causing deformation of the cage, damage to the rolling elements, and large clearance. The copper powder flies into the bearing cage, which is easy to cause bearing failure.
Check the bearing before installation
For old bearings, check the ball (column) surface for burrs, scratches, cracks. Whether the radial clearance and axial clearance of the old bearing are qualified, generally only the radial clearance is measured. For new bearings, first check that the bearing type is correct. Refer to Table 1 for the radial clearance standards of rolling bearings. For example: Model 6318 deep groove ball bearing, the inner diameter of the bearing is 90mm, the radial clearance range is 0.016 ~ 0.046mm, and the maximum wear amount of the bearing can also be found to be 0.25mm
.
Check the matching dimensions of the bearing and the rotor shaft
When assembling the motor, it is also necessary to carefully check the matching size of the bearing and the rotor shaft when the bearing is installed (Table 2), and the matching size of the bearing outer ring and the end cover hole.
Control the quantity of bearing and bearing chamber oil
Too much oil in the bearing and the box will cause the bearing rolling element to slip, causing the rolling element to change from rolling friction to sliding friction, and damage the bearing rolling element. When it rises, the degree of grease decreases, the lubricating oil film of the rolling element becomes thinner, and the lubrication condition is poor, which is easy to cause abnormal noise of the bearing, slip on the surface, and shorten the life of the bearing. Generally, there is a bearing oil chamber on the side of the motor end cover (except for motors designed with double-sealed bearings). According to the speed of the motor, the amount of oil that can be filled in the bearing chamber can be implemented according to the following standards: when the motor speed is less than 1500r/min, the amount of oil added is the bearing chamber. 2/3 of the volume. When the speed is between 1500 and 3000r/min, it is 1/2 of the bearing chamber volume. When the speed is more than 3000r/min, it should be less than or equal to 1/3 of the bearing volume. In the actual working process, for the bearings running at high temperature and high speed, the bearings with sealing surfaces should be used as little as possible, the oil storage capacity of the motor oil cap should be increased, and the oil nozzles should be installed to improve the operating life of the motor bearings.
