Monitoring the lubricant condition in a low-speed rolling element bearing usinghigh frequency stress waves

摘要

This paper presents the results of an investigation into the development of areliable, nonintrusive and effective technique capable of accessing thelubrication condition within a low-speed rotating bearing. This uniquemonitoring system is known as pulse injection technique (PIT) and involvestransmitting a Dirac pulse through a bearing via a stress waves (SW) sensor.Analysis of measured stress wave signatures differentiated between a properlyand poorly lubricated bearing. This method was found to be effective as stresswave propagation is sensitive to the transmission path, which in turn isaffected significantly by the type and amount of grease present in the vicinityof the working elements of a bearing. The ability of this technique to monitorthe lubrication condition within a bearing whilst in operation could be utilisedto determine the appropriate time for grease replenishment or addition.