Causes of hammer crusher bearing lockup
The bearing lock of the crusher means that the bearing generates a lot of heat during operation and cannot dissipate the heat in a short time, which causes the bearing temperature to rise sharply and locks the bearing. So what are the reasons for the crusher's hammer and bearing lock?
1. Improper assembly
﹝1﹞. When assembling, the assembly between the bearing outer ring and the housing hole or the bearing inner ring and the shaft is improper.
In the assembly process, the inner hole was not polished and the size was measured, and then the new bearing was replaced for assembly. After the test was run, it was found that the temperature increased too high. When disassembling and inspecting the volume, it was found that the bearing seat hole was deformed, which caused the outer ring of the bearing to be squeezed, resulting in a smaller radial clearance of the bearing, uneven rotation of the rolling elements and increased wear. The gap between the inner ring of the bearing and the shaft is too large, the inner ring of the bearing rotates with the rolling elements and the shaft, and friction causes the bearing to heat and vibrate.
﹝2﹞. Improper control of bearing heating temperature during assembly.
When the temperature of the bearing heater is too high during the heating operation, it will cause backfire and reduce the hardness and accuracy, which will increase the bearing temperature and cause the bearing to increase wear and damage.
﹝3﹞. Improper adjustment of bearing clearance during assembly.
In actual work, many equipment can only be debugged by hand feeling, and the gap is too large or too small to meet production requirements. If the axial clearance is too small, it is easy to cause the bearing to heat up, accelerate pitting, and even cause the rolling elements to jam or break the joint; if the axial clearance is too large, the impact force of the moving pair will increase and the rigidity will decrease, which will cause operation In production. Abnormal sounds can even cause severe vibration or damage the cage.
2. Oil seal problem
Oil seal is a sealing element used to seal the oil of the rotating shaft in mechanical equipment, and the cavity is basically static, so the oil seal is also called a rotating shaft lip seal. For oil seals with auxiliary lip, the auxiliary lip plays a role of dust prevention and prevents the intrusion of impurities to extend the life of the oil seal. However, the auxiliary lip is usually poorly lubricated and has high friction, resulting in dry friction and damage to the oil seal. Therefore, when installing a double-lip oil seal, make sure that the gap between the lips is filled with grease.
3. Gap problem
In the assembly process, if the size of the gasket is not carefully checked and the assembly test is performed, the temperature will rise rapidly after a period of time. The size of the outer ring of the bearing is determined by the stopper of the end cover and the bearing seat. The size of the spacer is reduced, the size of the inner ring will be adjusted by the round nut and compressed, the axial clearance of the bearing will become smaller, which will cause it to generate heat during operation.
4. Lubrication problem
There should not be too much grease in the bearing. Too much grease will increase friction torque and increase bearing temperature. If there is too little grease, reliable lubrication will not be obtained and dry friction will occur. Generally speaking, the appropriate amount of grease should be 1/3 to 1/2 of the total void volume in the bearing. Therefore, it is necessary to regularly inject appropriate grease according to the requirements of use.
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