A mesh stiffness model with the asperity contact for spur gear in mixed elastohydrodynamic lubrication

The gear time-varying mesh stiffness (TVMS) calculation is the basis for analyzing gear dynamics, which has considerable effects on the optimal design of gear parameters. Gear drives generally operate in mixed elastohydrodynamic lubrication (EHL), and it is significant to investigate the time-varying mesh stiffness for spur gear pairs in mixed EHL. In this work, a novel TVMS model for spur gear in mixed EHL is presented in consideration of asperity contact stiffness and oil film stiffness. The influences of gear geometric and operation parameters on TVMS are analyzed. The TVMS of spur gear pair in mixed EHL is found to be larger than that in dry contact. Results show that TVMS reduces with the increased module but increases with the large pressure angle. When tooth number of pinion is closer to that of gear, the gear TVMS becomes large. Moreover, the fluctuations of velocity and torque have a negligible effect on the TVMS of the spur gear in mixed EHL.