Roller bearings, as the core components of steel rolling equipment, their operating condition directly affects production efficiency and equipment lifespan. Under harsh conditions of high temperature, heavy load and high dust content, bearings are prone to problems such as wear, overheating and even burnout. This article proposes a systematic maintenance plan from three aspects: assembly, lubrication and monitoring, to help reduce the failure rate and extend the service life of the bearings.

1 Precise control during the assembly stage

Size matching and centering capability

Before installation, use a micrometer to measure the diameter of the roller neck of the rolling mill. Ensure that the tolerance meets the requirements specified in the drawing to avoid overheating due to insufficient clearance caused by overly tight fit. 

Check the levelness of the mechanical hand and the frame trolley to prevent the rolling elements and the inner sleeve from colliding when closing, which could cause the cage to deform.

Clearance adjustment standard

Select the clearance of group C3 or C4 based on the rolling load: For cold rolling or light-load conditions, C3 is preferred; for hot rolling or heavy-load conditions, C4 is applicable. 

If the clearance is too small, the temperature will rise excessively. If the clearance is too large, the stress on the roller will increase. This needs to be verified in reverse by observing the damage phenomenon (for example, most bearing failures are caused by insufficient clearance).

2 Lubrication and Sealing Management

Oil circuit cleaning and oil quantity control

When replacing the rolling mill, thoroughly clean the quick-change connector to prevent oil residue from blocking the distributor and causing insufficient oil supply. 

Regularly inspect the condition of the seals. If there are cracks or deformations, they must be replaced immediately to prevent dust from entering the lubrication system.

Selection of lubricants

In high-temperature environments, use extreme-pressure resistant lubricating grease to ensure the stability of the oil film; for frequently started and stopped conditions, increase the frequency of lubrication.

3 Operation Monitoring and Fault Prediction

Vibration and Temperature Monitoring

Install online sensors to monitor the vibration values of the bearings in real time. Abnormal fluctuations may indicate loose bolts or wear. 

If the temperature rise exceeds 70℃, the machine must be shut down for inspection. Check for poor lubrication or abnormal clearance.

Periodic maintenance

During each shift, check the tightness of the pull rod bolts to prevent loosening of the connection due to vibration; every month, disassemble and inspect the bearing housing to remove the accumulated chips inside.

4 Conclusion

The lifespan of the rolling mill bearings is 60% dependent on the quality of maintenance. By implementing standardized assembly, dynamic lubrication management, and intelligent monitoring, the failure rate can be significantly reduced.