Time Varying Mesh Stiffness Calculation of Spur Gear Pair Under Mixed Elastohydrodynamic Lubrication Condition

Abstract

A time-varying mesh stiffness model of spur gear pair, considering the influence of friction, is established based on potential energy method. The time-variant characteristic of the mesh stiffness can be represented more intuitively, by expressing the model with angle variables. And it is feasible to gain the friction coefficient of any meshing point, by establishing the time-varying friction coefficient model under mixed elastohydrodynamic lubrication. And in the model, the viscous-pressure and viscosity-temperature effects are taken into account. The results show that the friction coefficient, which has obvious time variability, is mainly affected by tooth surface roughness and sliding speed. Meanwhile, for gear mesh stiffness, friction can directly influence its value which changes more significantly in single tooth meshing area. And it can be decreased by lubrication. In addition, the model built in this paper is relatively close to the actual running state, so that it can provide a new time-varying mesh stiffness model for subsequent gear dynamics analysis.