Analysis Of Contact Characteristics Of Cycloidal Pin Of RV Reducer Based On Fractal Theory

RV reducer is mainly used for industrial robot joint reducer,and it is one of the important parts and components that China's industrial strong base plan pays attention to.Research on RV reducers is mainly focused on cycloidal pin gear transmission.As an industrial robot's joint reducer,its working efficiency and precision directly affect the performance of the entire robot.RV reducer is a two-stage transmission,whose core component is the cycloid pin wheel transmission mechanism.Therefore,the contact characteristics of cycloidal gear teeth and needle teeth are taken as the research focus.The W-M function and the vector function are comprehensively applied to obtain the two-dimensional and three-dimensional rough topographical expressions of the cycloid wheel and pin tooth.The topographical maps are drawn with Matlab.The FEIQUANTA 650 scanning electron microscope is used to compare and verify the twodimensional cross-sectional view of the cycloid test specimen.The field-emission electron microscope is used to compare and verify the three-dimensional micro-plane scanning and the three-dimensional rough morphology of the cycloid gear tooth specimen.According to the created morphological model,the contact ratio coefficient between the cycloidal gear teeth and the needle teeth is established.In addition,the influencing factors of the exposure proportionality coefficient are analyzed,and the influence trends of different influencing factors on the exposure proportionality coefficient are obtained.The simulation of the contact proportionality coefficient formula is verified by simulation experiments.Considering friction,a fractal contact model of a single pair of cycloidal gear teeth and needle teeth is constructed.The effects of friction factors,macro and micro characteristics of the joint surface on the contact characteristics are obtained.The results show that under the same load,the contact area in the micro factors increases with the increase of the friction factor.When the friction factor is below 0.3,the increase in real contact area is small,and when the friction factor is greater than 0.3,the increase in real contact area is larger;The contact area increases first and then decreases with increasing roughness of the joint surface;In the macro factors,the contact area decreases with the increase of the needle tooth radius,decreases with the increase of the center distance,increases with the increase of the center circle radius of the needle wheel,and decreases with the increase of the number of needles.Figure 59;Table 5;Reference 55...