In order to explore the influence of flexible factors on transmission accuracy of RV reducer,taking BX40E reducer as the research object,the dynamic model of multi-freedom RV reducer was established,the dynamic response of the system was extracted,comprehensively considering the influence of elastic deformation of support and elastic deformation of gear contact on dynamic transmission accuracy.The error contribution of contact and support deformation to dynamic transmission error under variable load and variable speed conditions was calculated,and the sensitivity of transmission error of BX40E reducer to various flexible factors was quantitatively analyzed.The results show that the transmission error increases with the increase of load,and the smoothness of output speed decreases with the increase of load and speed.The contact deformation of the secondary transmission contributes the most to the transmission error,followed by the supporting flexibility.The sensitivity of the transmission error to the support stiffness at “cycloid gear-crank” and “planetary frame-crank shaft” is higher than those at other supports,and the sensitivity to the contact stiffness of the second gear is higher than that of the first transmission.