Abstract: A accurate three-dimensional model of spiral bevel gears for automobile is established according to the cutting principle of duplex helical method.The modal analysis is carried out by using ABAQUS,and the natural frequencies and mode shapes in different orders are obtained.The dynamic characteristic under different loads and speed of the gear pair is simulated by ADAMS.The simulation results show that the natural frequency of the gear pair is so high that it’s difficult to achieve.When the speed of pinion is about 3 800 r/min,the meshing frequency is closed to the first order natural frequency,and the resonance may occur,which should be avoided.Under the same speed,the heavier the load,the smaller the amplitude of vibration acceleration.Under the same load,the higher the speed,the greater the amplitude of vibration acceleration.This study can provide reference for the optimal design of spiral bevel gears.

Key words: spiral bevel gears, duplex helical method, modal analysis, natural frequency, mode shape, vibration characteristics