Abstract:Taking the outside meshing spur gear as the research object, the meshing stiffness of fault gear was calculated by finite element method, the fault gear surface stress distribution characteristics and the load distribution on driving wheel tooth were analyzed, the impact of fault gear pairs with tooth root crack, tooth fracture, tooth surface pitting failure on meshing stiffness and the change of the meshing stiffness of the tooth crack gear caused by load change were studied. The analysis results show that the through crack gear meshing stiffness changes obviously than oblique crack gear, the single tooth meshing stiffness change is more prominent; under the condition of low load, crack fault tooth meshing stiffness increases as the load increases, the meshing stiffness tends to a fixed value when the load exceeds a certain value; the tooth fracture size affects the gear meshing stiffness heavily.