Abstract: A new concept of impact in gear meshing based on contact dynamics and physical model of gear drive is put forward. The phenomenon of contact/impact between the meshing tooth pair caused by the velocity difference at the meshing point is studied. The model of contact-impact of gear meshing is built, and the solution algorithm is given. The influences of different impact velocity and impact position on the resultant impact force, impact time and impact stress are analyzed, and the maximal impact forces at each impact position and each impact velocity are calculated and compared by using the analytical calculation equation, so as to verify the validity of the numerical calculation result. The research shows that both impact velocity and impact position have significant influences on the resultant impact force, impact time and impact stress. Besides, the distributions of the maximal stress points on the tooth surface during the impact process under different impact conditions are also given, thus providing reference for in-depth research of contact fatigue and accumulated fatigue. The calculation result shows that the maximal contact stress points concentrate in the nearby area of the middle of tooth breadth.

Key words: Contact, Gear transmission, Impact, Mesh