Effects of lateral harmonic vibrations on film thickness in EHL point contacts

Vibrations are an integral part of machine operation and affect every elastohydrodynamically lubricated conjunctions. In the present experimental study, a rolling contact is subjected to lateral-sliding vibrations with short stroke length. Film thickness behaviour is investigated under diverse conditions including rolling speeds, stroke lengths, frequencies, loads, and variety of lubricants. The results obtained under vibrations are compared with the results for corresponding steady state conditions to determine the effects of vibrations. It is shown that the lubricant rheology and the ratio of main and lateral entrainment speed are crucial parameters where the influence of this ratio on relative film thickness and its deviations can be estimated by exponential functions uniformly for all lubricants. The thresholds for film failures were found.