Taking a helical gear pair as an example

the parametric three-dimensional geometric model and dynamic contact finite element analysis model of the helical gear pair are established.Based on the explicit dynamic calculation method

some dynamic characteristic are got by the numerical simulations

such as the tooth dynamic equivalent stress

tooth root bending stress

relative speed and impact force.The results show that it has a greater meshing impact during the meshing process

and obvious speed difference between driving wheel and driven wheel

the greater load torque of driven wheel

the greater the impact force becomes.At the same time

the relationships between modification of the tooth profile and the dynamic characteristics of gear pair is also studied in detail

and based on the numerical simulation data

the best parameters which could improve impact and tooth bending stress of gear pair are proposed in order to optimize the dynamic characteristics.