The life of a rolling bearing refers to the time or number of turns experienced from the beginning of use until fatigue spalling occurs. This paper discusses the main factors affecting bearing life reliability, emphasizes the importance of correct installation, maintenance and lubrication, and points out the common problems leading to early failure.
Key words: bearing life; Reliability; Mechanical load; Lubrication management; Environmental factor
1. Bearing life definition
The life of the bearing is usually expressed by L10, that is, under specific working conditions, 90% of the bearing can achieve the number of working hours or the number of turns without fatigue spalling. For example, if 90% of a batch of bearings of the same model can survive 30,000 hours without failure, the L10 life of that batch of bearings is 30,000 hours.
2. Key influencing factors
Mechanical load: Exceeding the rated dynamic load will significantly shorten the bearing life. Doubling the load may reduce the life to one-eighth of the original. Improper and unbalanced installation will also put additional pressure on the bearing.
Lubrication errors: The use of the wrong type of lubricant, degraded or contaminated lubricants can lead to reduced lubrication performance, which accelerates wear. Ensuring that the correct lubricant is used and its quality is maintained is crucial to extending the life of the bearing.
Contaminant intrusion: Particulate matter and moisture are the most common contaminants, which can greatly reduce lubrication and promote wear and corrosion. Effective sealing measures can prevent contaminants from entering the bearing interior.
High temperature operation: Excessive temperature not only damages the lubricant, but also directly causes adverse effects on the bearing material. Excessive lubrication (such as adding too much grease) is a common cause of heat in grease lubricated bearings.
Insufficient lubrication: After a long period of operation, the lubricating oil or grease may dry up and need to be replenished regularly. Improper re-lubrication interval is the main cause of insufficient lubrication, in addition to cold start, dry start, and failure of lubrication system components can also cause this problem.
3. Suggestions for improving reliability
In order to ensure the reliable operation of bearings during their expected life, it is necessary to follow the manufacturer's design specifications, select the appropriate bearing type, and ensure correct installation and maintenance. Regular inspection of lubrication status, timely replacement of damaged or aging lubricants, while paying attention to the elimination of potential pollution sources and control of operating temperature, these are effective measures to improve bearing reliability.
