| RV reducer is widely used in the industry of industrial robots due to its advantages of high precision,high stiffness and large transmission ratio range.The research on transmission characteristics of the transmission precision and rotating stability of RV reducer is the important mean to ensure the positioning precision and repositioning precision of the manipulator,In addition,as the core transmission component of RV reducer,cycloidal pinwheel secondary transmission system directly affects the transmission characteristics of transmission precision,carrying capacity and rotating stability.Therefore,the modification of cycloidal gear profile is particularly important.The contents of this thesis are as follows:Firstly,the forming method of cycloidal gear profile was analysed,the equation of cycloidal gear profile was deduced by vector equation and its curvature equation was obtained based on the method,and then studied the influence of geometric parameters on the cycloidal gear profile and its curvature,which provided theoretical guidance for the establishment of dynamic models for RV reducer and the modification of cycloidal gear profile.Secondly,based on the multi-rigid body contact theory,the dynamic models of RV reducer were established,the transmission characteristics and force conditions under different loads were analyzed,then the dynamic model with geometric errors were established,the transmission precision and output rotational speed were obtained under load,and the fluctuation value of the rotational speed was evaluated by the variance of the output rotational speed.The influence of main errors on the transmission precision and fluctuation value were analyzed.Then,the transmission characteristics of RV reducer under different input rotational speed conditions were studied.The results show which errors have the most significant effect on the transmission characteristics,which should be paid more attention and improve in the processing and manufacturing.Thirdly,the modification of cycloid gear profile was studied,A variety of RV reducer models with different modification values were simulated and analyzed under load by virtual prototype technology,which obtained transmission precision and rotational speed stability,the mapping relations between them and modification values were obtained by neural network training,and then the constraint conditions were set to ensure that the modification value met the requirements of the positive backlash and rotation error of the cycloidal gear.The modification value of the minimum sum of weighted value of transmission accuracy and rotational speed stability was solved by genetic algorithm.Then the maximum meshing force between cycloidal gear and pin wheels and the number of meshing teeth at the same time and top and side clearance of cycloid wheel were calculated and analyzed,the carrying capacity was analyzed while ensuring the transmission accuracy and rotational speed stability.Finally,the transmission errors and fluctuation value of the rotational speed under different input speeds and loads and were detected and calculated in the RV reducer detection platform,which verify the theoretical analysis.The result shows that the experimental results are in good agreement with the theoretical analysis. |
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