Central film thickness in time-varying normal approach of rolling elastohydrodynamically lubricated contacts

Abstract

The effects of time-varying normal approach on the film formation of rolling elastohydrodynamically lubricated (EHL) contacts are studied by means of an inlet analysis. A modified Ertel—Grubin scheme is used to calculate the variation of central film thickness as a response of time-varying normal approach. The inlet shape approximation from Crook is used to derive simple analytical and semi-analytical solutions for the calculation of central film thickness and inlet pressures for situations of prescribed normal rigid-body displacement or prescribed load variation. The methodology is also adopted to model the pressure and clearance wave transport phenomenon shown earlier only with the use of full numerical solutions.