谐波减速器柔轮力学特性分析

College of Mechanical Engineering of Chongqing University, Chongqing, China May 2015
中文摘要
摘
要
谐波减速器是一种利用可控变形的柔性构件产生的变形波进行运动或动力传 递的新型传动装置，由于其具有其他传动装置所难以达到的特殊性能，因此在航 天装备和机器人领域得到越来越广泛的应用。但是，工程实践表明，谐波减速器 平均无故障工作的时间较短， 其最突出的问题是柔轮的可靠性、 使用寿命不理想， 输出端扭转刚度不足。作为谐波减速器主要构件的柔轮是一个薄壁壳体，受波发 生器和外部负载的双重作用，在循环弹性变形的状态下工作，既承受弯曲应力， 又承受扭转应力，很容易发生疲劳失效。因此，对谐波减速器的柔轮进行力学特 性方面的分析有着重要的意义。 本文以谐波减速器的柔轮为主要研究对象，完成了下列工作： ①介绍了谐波减速器的工作原理、传动特点及应用领域，对柔轮在波发生器 作用下的变形、应力和疲劳强度进行了理论计算。 ②根据课题要求，设计了一种传动比为 100 的谐波减速器，利用有限元分析 软件 ANSYS Workbench 建立了柔轮——波发生器有限元非线性接触模型，分析了 柔轮在波发生器作用下的变形规律和应力分布，结果表明柔轮齿圈与光滑筒体连 接处和光滑筒体与筒体底部过渡处为柔轮的应力危险区域。 ③分析了柔轮在不同长径比和不同壁厚参数下的变形规律和应力分布。然后 对柔轮应力危险区域进行结构参数调整和优化设计，建立了有限元非线性接触模 型，重点分析了柔轮的应力分布情况，结果表明经过对结构参数的优化设计，柔 轮应力危险区域的应力分布得到明显改善。 ④首先对两种不同结构参数的谐波减速器柔轮进行了扭转刚度有限元分析， 得到了柔轮的扭转刚度，然后设计并搭建了一套谐波减速器扭转刚度测试系统， 通过对测试数据的分析得到了它们的扭转刚度。测试结果表明经过结构参数优化 的机型一的扭转刚度比未经结构参数优化的机型二扭转刚度要高得多，同时通过 对照有限元分析的结果，两者得到的谐波减速器的扭转刚度呈现出一致性，表明 了结构参数的优化有利于提高谐波减速器的扭转刚度。 关键词：谐波减速器，柔轮，力学特性，有限元分析，扭转刚度
A Thesis Submitted to Chongqing University in Partial Fulfillment of the Requirement for the Professional Degree
By Xie.Hengpeng
Supervised by Prof. Wang Jiaxu Specialty: ME(Mechanical Engineering Field)
III
重庆大学硕士学位论文
area is improved markedly after the structure optimization design. ④First of all, this thesis carries on a finite element analysis of flexsplines’ torsional rigidity between two harmonic reducer with different structure parameter and acquires the flexspline’s torsional rigidity. Then the author designs and establishes a harmonic reducer’s torsional rigidity test system. Through the analysis of the test data, the author gets the torsional rigidity of harmonic reducer. The experimental reusults show that the torsional rigidity of Model One with optimized structure parameter is higher than that of Model Two without optimized structure parameter. At the same time by comparing the results of finite element analysis, we find that both of their harmonic reducers’ torsional rigidity show the consistency. That is to say, the optimization of structure parameter can help to improve the torsional rigidity of harmonic reducer. Key Words: harmonic reducer; flexspline; mechanical characteristics; finite element analysis; torsional rigidity
谐波减速器柔轮力学特性分析
重庆大学硕士学位论文
（专业学位）
学生姓名：解恒鹏 指导教师：王家序 教 授
学位类别：工程硕士（机械工程领域）
重庆大学机械工程学院
二 O 一五年五月
The Mechanical Characteristics Analysis of Harmonic Reducer’s Flexspline
IV
目
录
目
录
中文摘要..........................................................................................................................................I 英文摘要....................................................................................................................................... III 1 绪 论......................................................................................................................................... 1
I
重庆大学硕士学位论文
wenku.baidu.comII
英文摘要
ABSTRACT
Harmonic Reducer is a new type of gearing transmission which using elastic deformation wave generated by flexible thin-wall components to transmit power. Compared to traditional gearing transmission, it is a kind of gearing transmission with smaller volume, lighter quality, higher transmission ratio and transmission accuracy. Therefore, it is applied more and more extensively in the field of space mechanism and industrial robots. However, engineering practice indicates that harmonic reducer’s average trouble-free working time is shorter, the most prominent problem is that its flexspline’s reliability and service life is not ideal, the output rigidity of the whole machine is stiffness. As the main component of harmonic reducer, flexspline is a thin-shell and it will suffer alternating bending stress as well as torsional stress under the working state of repeated elastic deformation, so fatigue fracture will happen easily. In view of this, it is of important significance to analyze the mechanical characteristics of harmonic reducer’s flexspline. This thesis takes the harmonic reducer’s flexspline as its research object and finished the following work: ①Introducing the working principle, transmission characteristics and application fields of harmonic reducer as well as the theoretical formula deduction of deformation, stress and fatigue strength of flexspline. ②According to the project requirement, this thesis designs a harmonic flexspline with 100 reduction ratio, establishes a finite element nonlinear contact model of flexspline and wave generator based on finite element analysis software ANSYS Workbench. This thesis also analyze the deformation and distribution of stress of flexspline under the action of wave generator, it turns out that the junction of flexspline’s gear ring and its smooth cylinder as well as the transition of smooth cylinder and its bottom can be taken as the stress dangerous areas for flexspline. ③Analyzing the effect of different length to diameter ratios and different wall thickness parameters on the influence of flexspline’s deformation and stress distribution. Then, the author takes structure optimization design for flexspline’s stress dangerous area, establishes the finite element contact model and analyzes the stress distribution of flexspline. The author finds that the stress distribution of flexspline’s stress dangerous