A Numerical Study of Friction in Isothermal EHD Rolling-Sliding Sphere-Plane Contacts With Spinning

This paper presents a study of the spinning influence on film thickness and friction in EHL circular contacts under isothermal and fully-flooded conditions. Pressure and film thickness profiles are computed with an original Full-System FEM approach. Friction was thereafter investigated using a classical Ree-Eyring model to calculate the longitudinal and transverse shear stresses. An analysis of both the velocity and shear stress distributions at every point of the contact surfaces has allowed explaining the fall of the longitudinal friction coefficient. Moreover in the transverse direction, spinning favors large shear stresses of opposite signs, decreasing the fluid viscosity by non-Newtonian effects. These effects have direct consequences on the friction reduction that is observed in presence of spinning. They are expected to further decrease friction in real situations due to shear heating.Copyright © 2010 by ASME