What is The Rolling-element Bearings and Their 8 Lubrication Failure Mechanisms?
This article delves into the topic of rolling-element bearings, as they are commonly used mechanical components that require appropriate lubrication. Their applications span a wide range, from small, non-critical knob-adjuster support bearings to large, critical wind-turbine main bearings. The Optimum Reference State (ORS) is an essential maintenance strategy that aims to achieve an optimized return on investment. For instance, employing a run-to-failure strategy may be suitable when bearing failure does not cause immediate downtime and corrective action costs are minimal compared to regular proactive and predictive maintenance.
In practice, bearings often experience breakdowns before reaching their design life due to uncontrollable environmental and operating factors. The primary goal is to strive for the bearing's life based on the Optimum Reference State (ORS). In the case of small bearings, a well-planned relubrication schedule and a comprehensive maintenance strategy that goes beyond mere reactive measures are recommended, based on the optimum reference state.
Conducting a failure modes and effects analysis (FMEA) provides valuable insights. The analysis involves a series of questions to determine the application type, purpose, potential failure modes, resulting effects on operations, gravity of each effect, failure mechanisms, likelihood of failure, existing detection mechanisms, and their effectiveness. By answering these questions, a risk/priority number can be calculated, and suitable maintenance strategies can be proposed.
In lubricant FMEA, the root causes of lubricant failure and how they result in inadequate lubrication for the machine are identified. Notable failure mechanisms for rolling-element bearings due to lubrication issues include unsuitable lubricants, lack of lubricant, excess lubricant, hot running conditions, solid contamination, moisture contamination, mixed lubricants, and other contaminants. These failure mechanisms can lead to lubrication failure modes or contribute directly to mechanical failure modes of the bearing.
To prevent and address these issues, careful consideration of lubricant selection (viscosity, additive package, and consistency for grease) and proper regreasing volume and frequency are crucial. Additionally, timely lubricant analysis and monitoring of maintenance records and condition monitoring data play vital roles in identifying and resolving lubrication-related problems. A comprehensive approach to lubrication management ensures longer bearing life, reduced downtime, and optimized system performance.
