Vibrations and film thickness in grease-lubricated deep groove ball bearings.

Understanding the relevance and significance of the various replenishment mechanisms in grease-lubricated bearings is very important in choosing the appropriate lubrication strategy. This study shows that the lubricant film thickness in the ball-ring contacts of a deep groove ball bearing may increase by 10%–25% due to vibrations. The possible mechanisms behind this film thickness increase are discussed. Of the proposed contact replenishment mechanisms, the micro-lateral motion of the contact edge across the tracks caused by in-operation vibrations appears crucial. Results show that in the starved contacts, vibration plays a vital role in determining the film thickness. • Film thickness in grease-lubricated DGBB increases due to vibrations. • A model to predict the vibrations-induced film thickness increase is proposed. • Film replenishment appears to be due to a reciprocating curvilinear displacement. • Vibrations-induced film thickness increase depends on the contact size. [ABSTRACT FROM AUTHOR]