A New Method Of Profile Modification For Cycloid Gear Of RV Reducer

As one of the most important parts in RV drive system,the tooth profile modification quality of cycloid gear is the key factor affecting the product performance index of RV Reducer.The traditional method of profile modification is realized by means of the setting of machine tools in the process of cycloid gear machining,such as displacement,equidistance and rotation angle.The shortcomings of complex calculation process,difficult to control the shape of profile modification curve,difficult to guarantee the accuracy of gear meshing transmission.The development of the form grinding technology make it possible for cycloid gear to adopt more flexible tooth profile modification design.The pressure angle of cycloid gear tooth profile directly affects the meshing and transmission performance of RV cycloid gear.Therefore,according to the interaction between the pressure angle and the amount of profile modification,a new design method of profile modification is proposed.This method can flexibly control the profile of cycloid gear,and the modified profile is more conform to the engineering practice.The modified cycloid-pin gear pair has good meshing contact characteristics and force transmission performance,which provides a new way for the modification design of cycloid gear of robot precision reducer.The main research contents and innovations are as follows:1.A theory and method of profile modification based on the pressure angle distribution of cycloid tooth profile is proposed.Based on the analysis of the relationship between the pressure angle distribution and the transmission performance of the cycloid-pin gear,the mathematical model of tooth profile modification is established.The method of linear,cycloid and catenary are derived by taking the pressure angle and the modification amount of the gear profile as parameters of the modification function and the backlash of the gear teeth as constraints.The characteristics of the flexibility and convenience of the new method of tooth profile modification is clarified,which is the theoretical basis for the study of the tooth profile shape and meshing characteristics of the new method of tooth profile modification.2.By means of tooth contact analysis,the transmission error and lost motion of the modified cycloid-pin gear are obtained,and the influence rules of different modification methods and tooth profile shapes on the meshing characteristics of the gear teeth are clarified.The comparative analysis of the meshing characteristics between the traditional modification and the new modification method,such as profile shape,minimum meshing clearance,transmission error,return error,etc.The influence rules of profile shape and meshing characteristics different modification methods are clarified,in order to ensure and verify that the new modification profile has better meshing characteristics and force transmission performance.3.A pre-control and optimization method of tooth profile modification based on the requirements of transmission error and backlash is presented.The influence of profile modification parameters on profile shape and meshing characteristics is studied,a multi-objective solution model of profile modification parameters of cycloid gear is established,and uses genetic algorithm to solve the model,the modification parameters meeting the transmission performance requirements and the profile curve more in line with the actual engineering.4.The software of RV cycloid gear tooth profile modification design and meshing analysis system is developed,and the RV transmission performance test of the modified cycloid-pin gear pair is carried out.The system can quickly complete the modification design,meshing performance analysis and modification parameter optimization,realize the pre-control of the modification tooth profile and transmission accuracy;the RV Reducer performance testbed is built,the transmission error and lost motion is obtained,based on this,theory and method the cycloid gear modification design,meshing contact analysis and tooth profile modification optimization is improve,in order to the cycloid profile and its kinematic accuracy after modification can meet the requirements of engineering practice.