工业机器人用RV减速器的齿廓动态磨损特性

Dynamic Wear Characteristics of Tooth Profile of RV Reducer for Industrial Robot

针对工业机器人用精密RV减速器齿廓动态磨损难以准确预测的问题,以BX-40E减速器为实例,基于广义Archard磨损公式,通过等效实验求得不同位置条件下减速器的磨损系数,并在磨损预测过程中考虑磨损演化后不同位置条件变化的影响。根据变形协调理论和Langkali-Nikraves接触力模型确定齿间载荷分配与接触压力,考虑时变齿廓磨损与啮合力激励,采用解析建模方法建立了传动系统齿廓动态磨损数值计算模型。对比磨损系数取定值的齿廓磨损曲线,磨损数值与齿面分布规律均存在显著差异,整体差异随磨损次数增加而加剧,得出考虑接触位置条件差异的磨损系数对齿面磨损量化的准确性与必要性。摆线轮、针齿轮的齿面磨损深度曲线沿齿廓呈非对称不规则的倒“W”形,靠近齿根齿顶的部分因磨损而率先脱齿后再啮合,造成冲击,从而出现微突峰。在摆线齿廓凹凸过渡位置几乎不发生磨损。随磨损次数增加磨损峰峰域变窄,磨损率增势非均匀减缓。啮合力与压力角之间成一次函数映射关系。文中研究结果可为提高摆线针齿轮的减磨减振性能提供理论基础。

In order to overcome the difficulty in accurate prediction of the dynamic wear of tooth profile of precision RV reducer for industrial robot,this paper took BX-40E reducer as an example,obtained the wear coefficients under different position conditions through equivalent experiment based on the generalized Archard wear formula,with the consideration of the influence of different position conditions after the wear evolution in the wear prediction process.According to the deformation coordination theory and Langkali-Nikraves contact force model,the load distribution and contact pressure between teeth were determined.Considering the time-varying tooth profile wear and meshing force excitation,the numerical calculation model of dynamic tooth profile wear of transmission system was established by analytical modeling method.As compared with the tooth profile wear curve with the constant wear coefficient,both the wear value and the tooth surface distribution are significantly different,and the overall difference increases with the increase of wear times.The accuracy and necessity of quantifying the tooth surface wear with the wear coefficient taking into account the difference of contact position conditions were obtained.The wear depth curve of cycloid gear and needle teeth presents an asymmetric and irregular inverted“W”shape along the tooth profile.Due to the wear,the teeth near the tooth root and tooth top first fall off and then mesh,resulting in impact and micro protrusion peak.There is almost no wear at the concave convex transition position of cycloid tooth profile.With the increase of wear times,the wear peak area becomes narrower,and the non-uniform increase of wear rate slows down.There is a functional mapping relationship between the meshing force and the pressure angle.The results of the study provide a theoretical basis for improving the wear reduction and vibration reduction of cycloidal needle gear.