Causes and Measures of Bearing Damage
Causes and Measures of Bearing Damage
2022年3月23日
Main Functions of Lubricants
Main Functions of Lubricants
2022年3月23日

Common Faults of Bearings and Their Countermeasures

  • The grease injected from the middle of the upper part of the bearing pedestal and the outer side of the bearing pedestal (towards the roll head) can not well enter the bearing of the rolling mill, and is easy to be lost, resulting in poor oil on the working surface of the bearing when the rolling mill is working, resulting in early failure of the bearing.
  • Therefore, the oil circuit of the bearing pedestal is improved, and an oil injection port is added on the inner side of the bearing pedestal (towards the roll body) to improve the grease injection effect. The bearings have been well lubricated. Most rolling mills now use grease lubrication. Due to the structure of the vertical rolling mill, the service life of the bearing is prolonged when the roll rotates.Common Faults of Bearings and Their Countermeasures
  • Inject specified grease or lubricating oil according to the requirements of main engine components;
  • When assembling large bearings and products with large surplus between bearings and shaft and seat holes, the bearings must be heated in oil bath, and the oil temperature is about 80 ℃;Common Faults of Bearings and Their Countermeasures
  • When disassembling the bearing, special tools for drawing must be used, and it is strictly prohibited to directly knock the bearing with iron tools;
  • When assembling and disassembling the bearing, the rolling element and cage shall not be stressed or deformed.
  • Rolling bearings can be used for a long time if they can be correctly selected and used without mistakes; Under the condition of correct selection and use, the damage state is peeling. On the other hand, there are unexpected early injuries that can not stand the use of early injuries; 
  • As the reasons for the early damage, there are insufficient consideration on the use of lubrication, the invasion of foreign matters, the error of bearing installation and the large deflection of the shaft, the accuracy of the shaft and bearing housing, and the insufficient research on materials. It can be said that these reasons overlap with each other more often.Common Faults of Bearings and Their Countermeasures
  • There are generally two kinds of fault phenomena of rolling bearing: one is that the temperature of the bearing installation part is too high, and the other is that there is noise in the bearing operation.

1. Bearing temperature too high

  • When the main engine is running, the part where the bearing is installed is allowed to have a certain temperature. When touching the shell of the main engine by hand, it should be normal to feel that it is not hot. Otherwise, it indicates that the bearing temperature is too high.Common Faults of Bearings and Their Countermeasures
  • The reasons for high bearing temperature include: the quality of lubricating oil does not meet the requirements or deteriorates, and the viscosity of lubricating oil is too high; Main engine assembly is too tight (insufficient clearance): bearing assembly is too tight; The rotating load of the bearing race on the shaft or in the shell is too large; Broken bearing cage or rolling element, etc.Common Faults of Bearings and Their Countermeasures

2. Bearing noise

  • The rolling bearing is allowed to have a slight running sound during operation. If the sound is too loud or there is abnormal noise or impact clattering sound, it indicates that the bearing is faulty.Common Faults of Bearings and Their Countermeasures
  • The causes of rolling bearing noise are complex. One is the wear of the supporting surfaces of the inner and outer rings of the bearing. This kind of wear destroys the supporting relationship between the bearing and the shell, the bearing and the shaft, causes the axis to deviate from the correct position, and the bearing produces abnormal noise when running under load.
  • When the bearing is tired, the metal on its surface will peel off; It will also increase the radial clearance of the bearing and produce abnormal noise. In addition, insufficient bearing lubrication, dry friction and bearing breakage will produce abnormal sound.
  • After the bearing is worn and loose, the cage is loose and damaged, which will also produce abnormal noise.Common Faults of Bearings and Their Countermeasures

Troubleshooting method,Common Faults of Bearings and Their Countermeasures

(1) When replacing the bearing, carefully check the new bearing, and carefully check the shaft diameter, bearing seat hole and rotor;

(2) When assembling and disassembling the bearing, strictly implement the maintenance process and operate carefully to avoid bearing damage caused by improper assembly and disassembly;

(3) Refuel and change the oil on time to ensure that the working condition of the bearing is always in good condition;

(4) Check carefully during operation, and eliminate the hidden trouble in time if it is found.
    Common Faults of Bearings and Their Countermeasures