Lubricants Health Monitoring

Fault inception and growth in the components of a mechanical power drive are often heavily affected by the lubricant health. As a consequence, monitoring the lubricant health status and signaling a degradation of the lubricant properties could improve the reliability of the mechanical drive. A further merit of implementing a lubricant health monitoring system is the possibility to move from a time-based maintenance to a condition-based maintenance with the ensuing decrease of operating costs and reduction of the environmental impact. This would be of a particular advantage for those applications in which loss of operation generated by poor lubrication could cause a service disruption or lead to a safety critical condition. The proposed paper presents the initial part of an ongoing research activity on lubricants health monitoring. The work so far performed consisted of the following activities: perform a critical review of the studies addressing the lubricants condition; determine which are the significant features of the lubricants used in the majority of mechanical systems, that need to be extracted to assess the lubricant health; which occurences affect the lubricant health and how the oil health status can be assessed by different techniques , whose relative merits will be discussed; define the progression of the degradation of the lubricant health status; present the initial study of how different lubricant health monitoring techniques can be fused together to develop an efficient on-line lubricant health monitoring system. The paper thus presents the summary of the work performed to establish the fundamentals onto which a reliable PHM system for the lubricants of mechanical drives can be developed, that will be the final objective of the on-going research activity.