Measurement and evaluation of time-varying meshing stiffness of faulty gears under different types

When operating under complex conditions, gear failure is inevitable, and gears are often accompanied by multiple failures. In view of this phenomenon, this paper establishes a pitting crack coupling failure model and sets four different fault levels, from healthy to severe. Time-varying meshing stiffness (TVMS) decreases with the occurrence of faults, such that it could be employed as a gauge to assess the level of failure. Firstly, considering that the base circle and the tooth root circle do not coincide, the improved potential energy method is used to solve the TVMS under different fault degrees. Secondly, the effects of crack depth, angle, pitting radius, depth and number on meshing stiffness are studied. Then, the result of the potential energy method is verified by the finite element method, and the consequence shows that the difference between the two is within 5%, which indicates the effectiveness of the proposed model. Finally, when the crack degree is certain, the influence of pitting evolution on the meshing stiffness of the coupling model is studied.