工业机器人用RV减速器热-流-结构耦合场作用下的非线性振动研究

RV reducer is the bottleneck of the development of industrial robots. With the industrial robot precise instantaneous position, power transmission, RV Reducer appeared to work at high temperatures, the body vibration and bearing wear. This project focuses on solving two scientific problems, including the nonlinear vibration mechanism of RV reducer under the effect of thermal-flow- structure coupling field and the effect of coupling field on the stability of the system. First, a set of the fine features of RV reducer model design method is put forward. Secondly, nonlinear dynamic model of RV reducer under the heat flow structure of multi physical coupling field is established on the basis of the method. Nonlinear vibration rule and the mechanism of vibration are revealed under different operating conditions, complex boundary conditions. Again, the influence rule of dynamics is explored based on the multi physical coupling model with influence of elastic deformation, the meshing stiffness, bearing characteristics and other nonlinear factors of the system. And it revealed the sensitivity of various factors influence on the stability of the system. Finally, theoretical model can be evaluated and corrected by matching with the fine model and model test principle, test technology and combined with the traditional and Grating Technigue. The project utilizing comprehensively the interdisciplinary knowledge for a research on nonlinear vibration characteristics of RV reducer under the multi physics coupling field has important scientific significance.

RV减速器是制约我国工业机器人发展的瓶颈，随着对工业机器人精密瞬时定位、传递大动力的要求，RV减速器出现了工作温度高，机体振动和轴承磨损问题。本项目着重解决热-流-结构耦合场作用下RV减速器的非线性振动机理和耦合场对系统稳定性的影响规律两大科学问题。首先，提出一套RV减速器整机精细特征模型设计方法；其次，在此方法的基础上，建立热-流-结构多物理耦合场作用下RV减速器非线性动力学模型，阐述不同工况、复杂边界条件下系统的非线性振动规律，揭示其振动机理；再次，在多物理耦合场模型基础上，探索弹性变形、啮合刚度、轴承特性等非线性因素对系统的动力学影响规律，揭示各因素对系统稳定性影响的敏感程度；最后，采用精细模型和试验模型相匹配的原则，结合传统和光栅相结合的测试技术对理论模型进行评价和校正。本项目综合利用多学科交叉知识，研究多物理耦合场下系统非线性振动特性对RV减速器国产化有着积极的科学意义。

RV减速器的结构复杂，传动性能要求比较高，再加上我国在结构制造工艺、精度技术、振动动态特性等方面存在不足，导致RV减速器的国产化困难重重。本项目结合国内外动力学、仿真与测试技术的最新进展，基于数值计算和有限元分析方法建立了对RV减速器系统的研究体系。首先针对关键部件摆线针轮传动的结构优化，首次将差分进化法应用于摆线轮的修形研究中，确定出最佳修形方式并计算出最佳修形量，运用数值分析法对优化后的模型从初始啮合间隙、变形量、接触力以及回转角等方面进行分析，保证修形后的摆线轮工作部分的齿廓曲线与相应的转角修形的偏差值最小；其次在修形基础上，分析了摆线针轮传动过程中，曲柄轴承承受摆线轮的传递受力情况以及对RV减速器稳定性的影响；建立基于修形基础的RV减速器整机模型，运用有限元法分析不同转矩下其啮合特性并在考虑摩擦热载荷，热对流因素下探讨了轴承和曲柄轴的稳态温度场分布和热变形；基于应力-强度分布干涉理论，建立了摆线针轮可靠性数学模型，通过灵敏度计算分析出接触疲劳极限、使用系数、齿间载荷分配系数等参数对可靠度的影响；运用集中质量法建立包括时变啮合刚度、侧隙、单项误差等因素的整机的非线性动力学模型，对其非线性特性、传动精度等进行了相关的研究。本项目的研究揭示了RV减速器结构对整机传动性能和非线性特性的重要影响和机理，为RV减速器整机的传动特性和非线性特性研究提供了理论依据。