The dynamic modeling of a gear transmission is studied based on the multi-body contact dynamic theory

and the method of getting the parameters for the meshing contact model is presented. The multi-body contact model of developmental mixed type gear transmission is established by ADAMS software. The simulation results give a visualized dynamical description of the meshing process and get the dynamic meshing force with the given input velocity and load. The simulation also discloses the periodicity waving phenomena of the system output

which induced by the stiffness activation and impact activation.