机械工程类硕士论文：关于谐波齿轮传动柔轮应力及轮齿磨损的探究与分析
目录：
摘要 4-5
Abstract 5-6
第1章绪论 9-17
1.1课题来源与背景 9-10
1.2谐波齿轮传动简介 10-12
1.2.1谐波齿轮传动原理和特点 10-11
1.2.2谐波齿轮传动应用与研究简介 11-12
1.3柔轮应力的研究状况 12-14
1.4谐波齿轮轮齿磨损的研究状况 14-16
1.5本课题主要工作 16-17
第2章柔轮应力和轮齿磨损分析的理论基础 17-28
2.1柔轮应力分析的公式法 17-22
2.1.1柔轮在凸轮波发生器作用下产生的变形 17-18
2.1.2承载时柔轮的受力分析 18-20
2.1.3由传动载荷引起的柔轮形变 20-21
2.1.4柔轮中的应力 21-22
2.2柔轮应力计算的有限元理论基础 22-24
2.2.1有限元法概述 22-23
2.2.2接触问题有限元法的基本概念 23-24
2.3磨损过程分析 24-25
2.4磨损计算方法 25-27
2.4.1IBM磨损计算方法 25-26
2.4.2Archard磨损计算方法 26
2.4.3E.N.Ivsshov磨损计算方法 26-27
2.5本章小结 27-28
第3章柔轮应力有限元分析 28-44
3.1课题研究对象 28-29
3.2有限元模型的建立 29-33
3.2.1单元类型的选择 30
3.2.2基本模型的建立 30-31
3.2.3实体模型网格划分 31-32
3.2.4柔轮和凸轮波发生器接触对的生成 32-33
3.3空载时柔轮的应力分析 33-34
3.4负载时柔轮的应力分析 34-39
3.4.1渐开线方程的建立 35
3.4.2柔轮完整模型的建立 35-36
3.4.3齿上加载 36-37
3.4.4仿真结果 37-39
3.5结构参数对柔轮应力的影响 39-43
3.5.1三种连轴结构比较 39-41
3.5.2杯底连接处直径对齿圈应力的影响 41-42
3.5.3杯底处圆角对柔轮应力的影响 42-43
3.6本章小结 43-44
第4章柔轮轮齿磨损分析 44-56
4.1磨损模型 44-48
4.1.1齿上各点啮入啮出过程分析 44-46
4.1.2磨损公式中的参数 46-48
4.1.3轮齿磨损计算公式 48
4.2磨损后齿廓线方程的建立 48-51
4.2.1直角坐标系中的渐开线方程 49-50
4.2.2磨损后齿廓线方程的建立 50-51
4.3磨损计算 51-55
4.4本章小结 55-56
结论 56-57
参考文献 57-60
附录1 60-65
致谢 65
【摘要】 谐波齿轮传动系统具有传动比大、体积小、重量轻、传动精度高、回差小等独特的优点,国外己将其成功地应用于航空航天、原子反应堆、高能加速器、雷达系统、机器人、军事、光学仪器以及通用机械等领域。虽然国内外学者对该领域诸多问题都进行过不同程度的研究,但许多问题至今还没有定论,有些规律没有被揭示。如谐波齿轮传动中柔轮的强度计算和谐波齿轮轮齿磨损分析等问题,仍有大量的基础性工作有待开展。因此,进一步深入研究谐波齿轮柔轮强度和轮齿磨损具有重要的意义。本文首先阐述了谐波齿轮传动的基本原理及特点,通过经验公式分析了谐波齿轮传动中柔轮在空载和负载时的变形及受力状况。研究中认为柔轮的变形与厚度之比大于0.2,是几何大变形非线性问题。根据目前国内外谐波齿轮传动已取得的研究成果和存在的问题,运用弹性理论和非线性有限元分析方法,建立柔轮的三维实体有限元分析模型,对柔轮模型和波发生器模型在接触方式下进行有限元分析,研究柔轮应力场。计算了负载传动中柔轮齿上的受载分布,对负载传动中柔轮的应力进行了分析。应用柔轮有限元分析模型,研究了柔轮的若干结构要素对柔轮应力大小的影响,根据分析结果给出了各参数的推荐值,这对实际柔轮的设计有重要参考价值。本文利用边界元的思想对轮齿的齿廓面进行磨损分析。论文在研究谐波齿轮啮合特点的基础上,建立了轮齿磨损的分析模型,并结合Archard公式推导了理论磨损量的公式,该公式考虑了接触过程中齿面上的压强、滑程和磨损系数。计算时,将齿廓线离散成一系列点,通过计算各离散点的磨损量而得到齿廓线磨损后的形状。初次啮合时,压强、摩程由渐开线几何特征确定,利用磨损公式计算出各点的法向磨损量,结合各点原来的坐标值,就可以求出磨损后各点的坐标值。再利用磨损后的坐标值和三次样条插值函数得到磨损后的齿廓方程,此时,再根据磨后齿面的几何特征重新确定压强和摩程,进行下一工作时间的磨损计算。整个工作时间内齿廓线修正次数的多少依据计算精度而定。这个公式可以计算任意工作时间后的磨损量;反过来,也可以根据轮齿的许用最大磨损量来确定谐波传动失效前的工作寿命。
机械工程类硕士论文【Abstract】 Because harmonic gear drive have many merits such as big ratio of transmission, small volume and light weight, high drive accuracy, little return difference and so on, it has been applied successfully to many fields including aerospace, atomic reactor and high-energy accelerator, radar system, robot, military field, optical instrument and general machine. Though almost all fields involved harmonic gear drive have been studied by many domestic and foreign scholars, a lot of works still require to do. Such as the problem of fatigue strength and wear of gear teeth which mainly influence the life of harmonic drive is one of the most important research in harmonic gear drive. So it is very significant to study harmonic gear drive. This article mainly study the fatigue strength and the wear of gear teeth.The theory and characteristic of harmonic gear is described in this article at first. Based on the experimental result the stress and displacement of flexspline are analyzed. This is the basic theory in studying of flexspline. The displacement of flexspline is large and this is a large displacement of geometry non-linear problem. Then, according to achievements that have been achieved and shortages on study of harmonic drive at the present time, by applying elastic theory and non-linear finite element method, a 3-D model of flexspline is established. The model is analyzed by finite element contact method in order to gain stress of flexspline. The load on flexspline tooth is calculated. The stress of flexspline under load is analyzed. At last, on the basis of the model, some geometrical parameters of flexspline are analyzed and the recommendatory values of these parameters are given based on the changes of flexspline’s stress. This can help the designers a lot to design the flexspline.This article will study the wear of tooth contour face by boundary element method. A wear model is established after studying mesh character and, on the basis of the Archard formula, a formula, by which the contact stress, the wear coefficient and the sliding distance are considered, is derived for determining the theoretical wear of the flexible tooth. When calculating the wear, the tooth contour is discretized into a series of points and by calculating the wear at the points the whole tooth contour after wearing can be obtained. The stress and the sliding distance can be obtained by the geometrical characteristic of the involute at the first meshing process. The coordinates of the points after wearing can be calculated with the vertical wear value and the original coordinates. With the coordinates after wearing and cubic polynomial spline function the tooth contour function after wearing can be obtained. Then, next step of wear will be calculated with the stress and sliding distance which has been modified according to the tooth contour function after wearing. The modifying times of contour line will be decided by calculation precision. This function can be used to calculate the wear value after any work time and forecast the work life according to the maximal permitted wear value.
【关键词】 谐波齿轮传动； 柔轮； 有限元方法； 轮齿磨损； 离散化；
【Key words】 Harmonic gear drive； Flexspline； FEM； Tooth wear； Discretization；