Evaluation model of mesh stiffness for spur gear with tooth tip chipping fault

Tooth tip chipping that the top of a tooth breaks away from lower portion is one of the common gear faults which will affect the dynamic characteristics of gears. In the assumption of plane-fracture tooth tip chipping, the tooth surface fracture line tilted configuration relatively to the gear axis is a curve, which is simplified to a straight in previous studies. However, such simplification will cause an estimate error of mesh stiffness. Therefore, to accurately estimate the mesh stiffness, failure models of tooth tip chipping for both internal gear and external gear are established by means of analytic geometry method in this paper. The fracture curve Eq. is derived by using analytic geometry method. And the mesh stiffness of the fault gear is derived via potential energy method and verified by the finite element method (FEM). The influence of different fault severity on the mesh stiffness is analyzed. The analysis results show that the proposed model can accurately evaluate the mesh stiffness of gears with tooth tip chipping and the modeling method can also be applied to other fault types.