What is the Reason for the Bearing of the Hammer Crusher to Lock? How to Solve it?

The so-called bearing lock means that the bearing generates a lot of heat during operation, and the heat cannot be dissipated in a short time. The bearing temperature rises sharply and eventually the bearing locks. This phenomenon is very common in equipment overhaul and production service sites. The specific reasons for the heating of the bearing are as follows.

1. Improper assembly

1). The outer ring of the bearing and the bearing seat hole or the inner ring of the bearing and the shaft do not match properly during assembly.

During the assembly process, sometimes the inner hole is not ground and its size is not measured, and a new bearing is replaced for assembly. After the test run, it is found that the temperature rise is too high. During the disassembly and measurement, it was found that the bearing seat hole had been deformed, causing the outer ring of the bearing to be partially squeezed, resulting in a smaller radial clearance of the bearing, uneven rotation of its rolling elements, and increased wear. The clearance between the inner ring of the bearing and the shaft is too large, and the inner ring of the bearing rotates with the rolling elements and the shaft, causing friction to cause the bearing to heat up and vibrate.

2). Improper bearing heating temperature control during assembly.

If the temperature of the bearing heater is too high during the heating operation, it will cause tempering, resulting in reduced hardness and precision, thereby increasing the bearing temperature and causing the bearing to wear and damage.

3). Improper bearing clearance adjustment during assembly.

In actual work, many installations are sometimes debugged only by feel, and the clearance is too large or too small to meet production needs. If the axial clearance is too small, it is easy to cause bearing heating, accelerate pitting, and even cause rolling elements to get stuck or glued; If the axial clearance is too large, the impact force of the kinematic pair increases and the rigidity decreases, which will cause abnormal noise during operation, and even cause severe vibration or damage to the cage.

2.Oil seal problem

Oil seals are sealing components used to seal the rotating shaft in mechanical equipment. The cavity is basically stationary, so oil seals are also called rotating shaft lip seals. For oil seals with auxiliary lips, the auxiliary lips play a role in dust prevention and prevent impurities from invading to extend the life of the oil seal. However, the auxiliary lips are often poorly lubricated and have large friction, causing dry friction and damage to the oil seal. Therefore, when installing double-lip oil seals, be sure to fill the space between the lips with grease.

3. Clearance problem

During the assembly process, if the size of the spacer is not carefully checked and the assembly test is carried out, the temperature will rise rapidly after a certain period. The size of the outer ring of the bearing is determined by the end cover and the stop of the bearing seat. The size of the spacer is reduced, and the size of the inner ring will be adjusted by the round nut. Finally, it is tightened, and the axial clearance of the bearing becomes smaller, causing it to heat up during operation.

4. Lubrication problem

The grease in the bearing should not be too much. If the amount of grease is too large, the friction torque will increase and the bearing temperature will rise; If the amount of grease is too small, reliable lubrication cannot be obtained and dry friction will occur. Generally speaking, the appropriate amount of grease is 1/3 to 1/2 of the total void volume in the bearing. Therefore, it is necessary to regularly add an appropriate amount of grease according to the use requirements.