Friction measurement indicating the transition between fully flooded and starved regimes in elasto-hydrodynamic lubrication

Abstract

Lubricant starvation in rolling element bearings can have different origins, such as high speed, large size or grease lubrication. However, the overall result is a performance reduction, involving a friction increase, a bearing life decrease or both. As such it is desirable to be able to predict when starvation will occur for a certain combination of geometry, operating conditions and lubricant. Previous work used optical interferometry to predict the onset of starvation and the ensuing oil film thickness reduction. A starvation parameter was derived linking lubrication parameters (viscosity), amount of oil and operating conditions (load, speed) to predict the onset of starvation. The current paper attempts to predict the onset of starvation through friction measurements on a ball-on-disc test device. The starvation parameter values obtained from friction measurements are similar to the ones found through optical interferometry.