Abstract: Aiming at the effects of the vibration behavior of the spur gear on the primary planetary transmission gear train of the RV reducer, a three-dimensional assembly model of the primary planetary transmission gear train of the RV reducer was established, based on the actual working transmission conditions of the RV reducer. Taking a certain type of RV reducer as an example, the vibration characteristics of the spur gear were analyzed in both free and meshing states, using the finite element method. The frequency distribution and modal characteristics of the spur gear in the two states were obtained. Meanwhile, the effects of the central shaft gear and crank shaft alignment on the natural frequency of the spur gear were obtained. Simulations results show that the natural frequencies of the spur gears under the actual transmission condition are significantly lower than the corresponding results in the free state, due to the constraints of the central shaft gear and crank shaft alignment. Moreover, the meshing part is the weak part for the spur gear, whose vibration amplitude is remarkably larger than other parts. Therefore, the assembly relationship between the spur gear and the central shaft gear should be paid more attention to. Above all, these results may be helpful for the analysis of the dynamic characteristics and the design of the characteristic parameter of the RV reducer.

Key words: rotary vector(RV) reducer;planetary gear;spur gear;modal analysis;finite element method