Effect of friction coefficient and maximum contact pressure on the spalling depth of gear teeth flank

Abstract

Spalling is a phenomenon that occurs on gear tooth flanks by contact fatigue loading. Contact loading results to shear stress in tooth below the surface. In repeating contact loading, shear stress also repeats. Repeated shear stress causes subsurface crack initiation. Some parameters such as maximum contact pressure and friction coefficient can effect on the position of maximum shear stress and spalling depth as a result. In this study, the stress field of some case study is determined by simulation. The positions of maximum shear stress are compared with the experimental spalling depth of literature. Results are in good agreement and it validates the simulation method used in the present work. Some different conditions for maximum contact stress and friction coefficient are simulated. Results show that depth of spalling increases with increasing the maximum contact pressure. In addition spalling depth decreases with increasing the friction coefficient. This result agrees with literature that state in high friction coefficient pitting occurs instead of spalling.