The Profile Modification Investigation Of Cyclidal Gears For RV Reducers Applied In Industrial Robot

The industrial robots have been widely applied in various industries such as machinery manufacturing,power,finance and military industry.As the joint reducer of industrial robot,the RV reducer has great influence on the transmission accuracy,carrying capacity and manufacturing cost of industrial robots.Combined with the urgent demand of industrial robot for RV reducer with high carrying capacity and high transmission precision,this paper takes the RV-40 E reducer of industrial robot as an example,the key technology of cycloidal gear profile modification is systematically studied in this paper.The main contents are as follows:(1)A new composite modification method is presented which is aimed at optimizing the carrying capacity of cycloidal drive.Through the numerical analysis of the carrying capacity of the RV reducer,a mathematical model for searching optimal modification is established whose objective is the carrying capacity of the cycloidal drive.With the grid method,he optimal cyclodial gear tooth profile is obtained by numerical analysis.The numerical calculation shows that the logarithm of the meshing teeth at the same time is 8,and the maximum needle tooth force is 60.7%,52.2%,90% of equidistant modification,radial-moving modification and traditional equidistant-radial-moving modification method,respectively.(2)To improve the transmission precision of the RV reducer,a new method of cycloid gear profile modification based on backlash optimization is proposed.The two stage structure and the torque transmission path of the RV reducer are analyzed.The factors affecting the backlash are classified from the angle of the part error and the sensitivity and weight of the factors affecting the backlash are calculated.In order to reduce the backlash caused by the modification of the cycloid wheel,the deformation of the pin gear at rated load is compensated for the cycloidal gear tooth profile.After the modification method,the backlash bof the virtual prototype is 0.14 '~0.98'.(3)Based on the idea of tooth profile segmentation,a three section tooth modification method for cycloidal gear profile is proposed.Based on the analysis of the meshing process of cycloidal drive,the cycloidal gear profile is divided into tooth top section,working section and tooth root segment.According to the modification requirement,the modification section of three segments is constructed respectively.According to the requirements of specific working conditions,the modification method can design different section of tooth profile of working section and construct different modification amount.Therefore,the modification method has the feasibility of reverse design.(4)The difficulty in machining cyclodial gear is analyzed and the processing technology and heat treatment process route are designed.Three kinds of modification cycloid gears and the traditional modification cycloid gear are assembled into the whole machine as experimental comparison.According to the different modification targets of the three modification methods,the bearing capacity test table and the backlash test table of the RV reducer are designed and manufactured respectively,and the practical verification is carried out.The test results show that the proposed three methods for profile modification of cycloidal gears meet the design requirements.