the dynamic characteristics of wide-helical gears directly affects the performance of the turbine system. In order to evaluate the dynamic characteristics of the single degree of freedom gear
the varying of the mesh stiffness is taken place by the varying of the contact line length to solve the tooth mesh stiffness and gear pair mesh stiffness. The minimum acceleration along the action line is taken as the optimization object function
and dynamic optimization design method of gear used in ship is given in this paper.