The response of thermal Newtonian and non-Newtonian EHL to the vertical vibration of a roller

The importance of both thermal and transient effects on elastohydrodynamic lubrication was considered in the present study under line contact conditions, representing gears, cam/followers etc. The generalized Reynolds equation was solved for both Newtonian and non-Newtonian fluids, together with the elasticity, energy and surface temperature equations under a vertical vibration using multi-level techniques. The effects of both the amplitude and the frequency on the predicted load carrying capacity, minimum film thickness, maximum hydrodynamic pressure, maximum temperature and the coefficient of friction were investigated. Comparisons were made with corresponding quasi-static and isothermal solutions to highlight the importance of transient and thermal effects in EHL contacts. The influence of the non-Newtonian property of the lubricant was found to be negligible on the predicted film profiles and pressure distributions, and to result in a slight decrease in the predicted coefficient of friction under the conditions considered.