Transmission Efficiency Study And Experimental Analysis Of RV Reducer Under Different Working Conditions

With the proposal of “Made in China 2025”,energy-saving and green development has become the main trend of industrial development.RV reducer,as a kind of high precision instrument with large transmission ratio and compact structure,is widely used in industrial robot and other fields.The demand for RV reducers is increasing rapidly in Chinese industry,and their transmission efficiency is closely watched.It is an important link to improve the transmission efficiency of reducer to explore the power loss,transmission efficiency and its influencing factors of reducer.This paper analyzes the power loss and transmission efficiency of the reducer under different working conditions through the establishment of theoretical models and experimental analysis.The main work is as follows:(1)Analyze the structural characteristics and transmission principle of RV-40 E reducer,and get the rotating speed of components under a certain working condition.The static analysis model of involute gear,cycloid gear,pin gear housing,output disc and crank shaft considering the rotation of crank shaft is established.The forces of involute spur gear,cycloid gear,support bearing and rotary arm bearing with the rotation of crank shaft are obtained by solving the static balance equation.Solid Works is used to build a virtual prototype of the reducer,and ADAMS is used to conduct dynamics analysis of the second stage cycloidal gear of the reducer.It lays a theoretical foundation for the power loss analysis of RV reducer.(2)Load-independent power loss analysis of reducer.The load-independent power loss model of gear and bearing is established,and the influencing factors of load-independent power of gear and bearing are analyzed.The reliability of the load-independent power loss model was verified by testing the load-independent power loss of the RV reducer.The distribution and change of power loss of reducer under different working conditions in practice are analyzed.The results show that the load independent power loss caused by the first planetary deceleration mechanism is the largest,the load-independent power loss caused by the bearing is the second,and the load independent power loss caused by the cycloid gear is the least.(3)Load-dependent power loss analysis of reducer.Based on the time-varying relative velocity,normal load and friction coefficient,the mixed lubrication friction power loss model of spur gear,cycloid gear and bearing was established successively,and the time-varying loaddependent power loss of gear and bearing was analyzed.The accuracy and reliability of the load-dependent power loss model of the reducer are verified by experiments.The change of load-dependent power loss of components under different working conditions and its contribution to the load-related power loss of reducer are analyzed.The results show that the load-dependent power loss caused by bearing plays a dominant role in the actual operation of the reducer,followed by that of cycloid gear and the least of spur gear.(4)Experimental study on transmission efficiency of RV reducer.Taking a certain type of domestic RV-40 E reducer as a prototype,the test of considering the influence of different working conditions on the power loss and transmission efficiency of the reducer was carried out through the test platform of transmission efficiency.Taking input speed,output torque and working temperature as variables,the overall load-dependent loss and load-independent loss of RV reducer and their effects on transmission efficiency were studied by single factor test.Taking the transmission efficiency of the RV reducer as the response value,the Box-Behnken test design was adopted.The mathematical model between transmission efficiency and various factors was established by polynomial fitting of the experimental data,and the influencing factors of transmission efficiency were analyzed based on response surface analysis method.The experimental results show that the load torque and working temperature have a significant effect on the transmission efficiency of the RV reducer,while the input speed has no significant effect on the efficiency.