Time-varying mesh stiffness calculation by a novel loaded tooth contact analysis model considering EHL contact for face-gear drive

Abstract

Time-varying mesh stiffness (TVMS) is one of the primary excitations in dynamics. This study presents a novel loaded tooth contact analysis (LTCA) model to calculate the TVMS of face-gear drives under elastohydrodynamic lubrication (EHL) contact conditions. The effect of EHL on TVMS is considered by incorporating film thickness and oil film deformation into the LTCA model, with these parameters obtained through the non-Newtonian thermal EHL model developed in this study. Face-gear drives often operate under multiple tooth pair engagements, meaning that the external load on each tooth pair is unknown prior to solving the LTCA model. However, the external load is an input parameter for solving the EHL model. To account for the interaction between the LTCA and EHL models, the LTCA model is coupled with the EHL model and solved iteratively through numerical methods. In the iterative process, an artificial neural network (ANN) is used to replace the EHL model, enhancing computational efficiency. The proposed method is validated and applied to a face-gear drive to calculate TVMS. The results show that neglecting EHL leads to an overestimation of TVMS. Additionally, parametric analyses reveal that torque, speed, and certain lubricant properties influence TVMS.