By establishing a simplified six degree of freedom dynamic mathematical model of gear system and a rigid body dynamic analysis model of gear system with advanced gear feature module and bearing module, the dynamic response characteristics of the system without pitting and with pitting are studied, and the influence of pitting on the response characteristics of the system is mainly discussed. The results show that the gear meshing stiffness value decreases due to the pitting feature, especially in the pitting feature area; the dynamic transmission error curve under the pitting feature fluctuates obviously in the single double meshing range; the meshing force decreases to 0 in the pitting feature area along the tooth profile direction, and increases to 0 in the non pitting feature area along the tooth width direction If the local contact stress exceeds the limit contact stress of gear material, it will lead to the occurrence and expansion of fatigue pitting under the action of cycle.

The above results show that the pitting characteristics of the tooth surface make the system produce local unbalanced dynamic response, such as the increase of response amplitude, the decrease of meshing stiffness, and so on. The performance of these unbalanced response characteristics paves the way for the research of gearbox fault diagnosis and monitoring in the later stage.