What is bearing locking?The locking of the bearing means that a large amount of heat is generated in the running process of the bearing, and the heat cannot be dissipated in a short period of time, resulting in a sharp rise of the bearing temperature and finally the bearing is locked. This phenomenon is very common in the overhaul of equipment and the production and service site. The causes of bearing locking are as follows:

1.Improper assembly

a.During assembly, the bearing outer ring and bearing seat hole or the bearing inner ring and shaft are not matched properly.

In the assembly process, sometimes the inner hole is not repaired and its size is not measured, and the bearing is replaced for assembly. After the test run, it is found that the temperature rise is too high. During disassembly and measurement, it is found that the bearing seat hole has been deformed, which makes the outer ring part of the bearing squeezed, resulting in smaller radial clearance of the bearing, uneven rotation of the rolling body, and increased wear. The clearance between the bearing inner ring and the shaft is too large, the bearing inner ring rotates with the rolling body and the shaft, and the friction causes the bearing to heat up and vibrate.

b.Improper temperature control during assembly.

During heating operation, if the temperature of the bearing heater is too high, it will backfire and reduce the hardness and accuracy, so that the temperature of the bearing will rise and the bearing will be severely damaged.

c.Improper bearing space adjustment during assembly

In practical work, many installations are sometimes only debugged by hand, and the gap is too large or too small to meet the production needs. If the axial clearance is too small, it is easy to cause bearing heating, accelerated pitting corrosion, or even the rolling element is stuck or damaged by gluing; if the axial clearance is too large, the impact force of the moving pair increases, and the rigidity decreases, it will cause abnormal noise in operation, and even cause serious vibration or damage to the cage.

2.Seal problem

Oil seal is used to seal the rotating shaft in mechanical equipment, and the cavity is basically static, so oil seal is also called the rotating shaft lip seal ring. For the oil seal with auxiliary lip, the auxiliary lip plays a dust-proof role to prevent the invasion of impurities, so as to extend the service life of the oil seal. However, the auxiliary lip is often poorly lubricated and has a large friction force, which causes dry friction and damage to the oil seal. Therefore, when installing the double lip oil seal, the lubricating grease must be filled between the two lips.

3.Gap problem

In the process of assembly, if the size of the spacer is not carefully calibrated and the assembly and test run are carried out, the temperature will rise rapidly after a certain period of time. The size of the outer ring of the bearing has been determined by the end cover of the bearing seat. The size of the spacer is reduced. The size of the inner ring will be adjusted by the round nut. Finally, it will be compressed. The axial clearance of the bearing will be reduced, so that it will generate heat during the operation.

4.Lubricate problem

Not too much grease in the bearing, too much grease will increase the friction torque, bearing temperature; and too little grease can not get reliable lubrication and cause dry friction. Generally speaking, the appropriate amount of grease is 1 / 3 ~ 1 / 2 of the total volume of the bearing clearance. Therefore, the appropriate amount of grease should be injected regularly according to the use requirements.