An involute gear pair meshing stiffness model considering time-varying friction under mixed lubrication

To investigate the meshing characteristics of involute spur gear pairs, a time-varying mesh stiffness (TVMS) model is developed in this study, which pays special attention to the nonlinearity of lubrication and friction in the meshing process. Here, to improve the modeling quality, four typical parameters are considered in the model, including the lubrication state, the non-Newtonian shear characteristics of the lubricant, the time-varying displacement of the asperity, and contact conditions along the meshing path. The proposed model provides an interdependence between tooth surface contact characteristics and gear comprehensive meshing stiffness, which can provide a guidance for enhancing the performance of involute spur gears. Furthermore, the effects of roughness, rotation speed, and load on TVMS are investigated, exhibiting distinct regional characteristics along the meshing path. Noticeable differences are observed in the intensity of disturbance in the meshing-in, meshing-out, single-tooth pair, and double-tooth pair contact areas.