Coupling mechanism between systematic elastic deformation and gear surface damage

Understanding the coupling mechanism between systematic elastic deformation and gear tooth surface damage is particularly helpful for us to explore the life-cycle surface damage evolution process. A deformable body dynamic model of gear transmission systems is developed to acquire the systematic elastic deformation. Then the equivalent meshing deviation parameters, which are used to quantify the systematic deformation, are imported into a hybrid finite element-analytical contact model to acquire the load distribution under non-ideal meshing conditions. Considering the concurrent effects of surface wear and pitting, a generalized surface damage model is developed based on the transient elastohydrodynamic lubrication theory. An interactive calculation scheme is built to realize the damage simulation over the life-cycle evolution process. Distinguishing from the conventional models, the proposed multi-physics model bridges the macroscopic systematic deformation and microscopic behaviours (local contact state and damage initiation mechanism). A two-staged gear test rig is utilized to verify the proposed model. Based on the proposed model, the coupling mechanism amongst the tribo-dynamic behaviours, systematic elastic deformation and life-cycle fault characteristics are analysed. It is revealed that the bending-induced asymmetric load distribution will lead to severe pitting at one edge of the gear surface; The life-cycle dynamic performance can be significantly improved by optimizing the supporting configuration. This work can provide the theoretical basis for the tooth fault prognosis, physics-based condition monitoring and configuration design.