Waviness Amplitude Reduction in EHL Line Contacts Under Rolling-Sliding

Abstract

Due to technological pressures the lubricant film thickness in EHD contacts has decreased over the years and will continue to do so for the foreseeable future. On the other hand, financial constraints cause the surface roughness in these contacts to decrease very slowly, or might even cause an increase. As a result, the ratio of film thickness to composite roughness will continue to decrease. The question that remains to be answered is to what extent this decrease will affect the contact performance. A third development makes this question even more acute, the request of increased reliability. As a consequence, the problem of the detailed understanding of the elastohydrodynamic lubrication with rough surfaces is as urgent as ever. Recent work has shown that the features inside the contact deform, and that the level of deformation is a function of the wavelength of the feature and the contact operating conditions, including slip. This last aspect of the problem, which has not been addressed previously, forms the central topic of the current paper. Instead of studying the deformation of a real roughness profile, the deformation of its sinusoidal Fourier components is investigated.