Rules of variation of contact stress in gear engagement were obtained by means of dynamic simulation in ANSYS after the three-dimensional parameterize finite element model was created.Based on the effects of original manufacturing errors

rotational speed and load on gear drive

expanded response surface method was adapted in multiple stochastic virtual test of the meshing gear to compute the reliability;and reliability sensitivity of each parameter was given in quantitative probability

providing a theoretical base for fatigue strength calculation and dynamic optimum design of the drive gear mechanism.The effects of different parameters’ original manufacturing error on gear contact stress were got.