Analytical predictions and experimental measurements of EHL film thickness in wide elliptical and line contacts

In this study, the most widely used models for predicting the film thickness in EHL line contacts and very wide elliptical contacts are evaluated and validated using film thickness measurements. As ellipticity increases, “elliptical contact” model predictions approach the predictions by models assuming “infinitely wide/long contact”. The critical or transition ellipticity (where the trends coincide) is shown to decrease with the increasing Moes dimensionless material parameter L and Moes dimensionless load parameter M. To validate the models, the film thickness in the contact of a tapered roller on a disc is measured via optical interferometry techniques using three different base oils. Results show a good match between the various model predictions and the experimental data.