谐波齿轮传动的瞬态动力学特性研究

发布时间：2019-05-27 11:07

【摘要】：谐波齿轮传动利用柔轮弹性变形实现动力传递，具有结构简单、重量轻、体积小和回差小等优点，被广泛地应用于航空航天、机械人、通用机械等领域。在动力传递过程中，，柔轮作为弹性薄壁构件，在载荷作用下产生周期性变形，啮合载荷沿圆周呈非均匀分布，与柔轮中性线不相切。柔轮发生周向扭转变形的同时，还要产生一定的径向变形。因此，谐波齿轮传动的使用寿命主要取决于柔轮的疲劳寿命。本文在国家自然科学基金（No.50975295）的资助下，以B1-50-80型谐波减速器为研究对象，对谐波齿轮传动的负载工况进行了瞬态动力学仿真分析。并在此瞬态分析结果的基础上，对柔轮进行疲劳寿命分析和添加复合材料层对其疲劳寿命影响的研究。主要研究内容如下： 1）对谐波齿轮传动的额定负载工况进行瞬态动力学仿真分析，其结果表明在动载工况下柔轮的应力呈正（余）弦规律变化；且柔轮齿圈上的应力有一个增加再降低的过程；筒体上的应力总体趋势是沿轴向方向逐渐减小的。裂纹起源于柔轮的齿根部分，然后向轴线方向延伸，进而呈45°斜向扩展。 2）搭建高精度测试平台对谐波齿轮传动柔轮的各个工况进行动应变测试。测试结果表明柔轮杯身的应变呈正（余）弦规律变化，且沿杯底轴向方向逐渐减小，同截面径向应力比轴向应力大。杯底的应变随输出载荷的增加而增加，且受转速影响较小。杯底直径方向变化频率为输入和输出频率的叠加，且径向应变比切向应变大。 3）将柔轮的瞬态分析结果与测试结果进行对比分析，其结果显示该瞬态分析正确仿真了谐波齿轮传动正常工作中柔轮的真实应力状态，误差控制在允许的范围内为测试应变的15%。 4）对谐波齿轮传动柔轮的疲劳寿命进行了分析，瞬态疲劳寿命结果显示：柔轮轮齿的齿端部和齿根部是柔轮最初产生疲劳损伤的部位，且损伤沿柔轮的轴线由轮齿内侧向尾部延伸。在柔轮杯口内壁与波发生器接触的部位损伤较为严重。 5）进行了带有复合材料层的柔轮结构设计，其瞬态结果显示柔轮的最大VonMises应力由849.4MPa减小为742.6MPa，且最大应力位置由柔轮的齿根部变为柔轮齿圈内表面。疲劳结果显示复合层纠正了正常工作中柔轮齿圈产生倾斜这种现象，减少了疲劳损伤的位置，有效地提高了柔轮的疲劳寿命。
[Abstract]:The harmonic gear transmission utilizes the elastic deformation of the flexible wheel to realize the power transmission, and has the advantages of simple structure, light weight, small volume and small return difference and the like, and is widely applied to the fields of aerospace, machinery, general machinery and the like. In the process of power transmission, the flexible wheel is used as an elastic thin-wall component, and a periodic deformation is generated under the action of a load, and the meshing load is non-uniformly distributed along the circumference and is not tangent to the neutral line of the soft wheel. The flexible wheel is deformed in the circumferential direction, and a certain radial deformation is also generated. Therefore, the service life of the harmonic gear transmission mainly depends on the fatigue life of the soft wheel. In this paper, under the support of the National Natural Science Foundation of China (No. 50975,295), the transient dynamic simulation analysis of the load condition of the harmonic gear transmission is carried out with the B1-50-80 type harmonic speed reducer as the research object. On the basis of this transient analysis result, the fatigue life analysis of the soft wheel and the study of the effect of the composite layer on the fatigue life of the soft wheel are studied. The main contents of the study are as follows: 1) The transient dynamic simulation analysis is carried out on the rated load working condition of the harmonic gear transmission, and the results show that the stress of the soft wheel is in the positive (residual) string rule under the dynamic load condition, and the stress on the flexible gear ring is increased and then decreased The general trend of stress on the cylinder is to gradually decrease in the axial direction The crack originates from the root part of the soft wheel and then extends in the direction of the axis, which is in the form of an oblique extension of 45 掳. and 2) building a high-precision test platform to move each working condition of the harmonic gear transmission flexible wheel; The results of the test show that the strain of the soft wheel body is in the positive (residual) string law and gradually decreases in the axial direction of the cup bottom, and the radial stress ratio in the same section is the same as that of the axial direction. The stress is large. The strain of the bottom of the cup increases with the increase of the output load and is reflected by the rotational speed. the frequency of the change in the diameter direction of the bottom of the cup is the superposition of the input and the output frequency, and the radial strain is less than that of the tangential direction, 3) The transient analysis result of the soft wheel is compared with the test result. The result shows that the transient analysis correctly simulates the true stress state of the soft wheel in the normal operation of the harmonic gear transmission, and the error control shall be the test in the allowable range. The fatigue life of the soft wheel of the harmonic gear is analyzed by 15%.4) The results of the transient fatigue life show that the tooth end of the soft wheel and the root of the tooth are the part where the soft wheel initially generates the fatigue damage, and the damage along the axis of the flexible wheel is caused by the gear teeth And the inner wall of the soft wheel cup is in contact with the wave generator. The structural design of the flexible wheel with the composite layer is carried out. The transient results show that the maximum Von Mises stress of the flexible wheel is reduced from 849.4MPa to 742.6MPa, and the maximum stress position is determined by the tooth root of the soft wheel. and the fatigue result shows that the composite layer can correct the phenomenon that the soft tooth ring in the normal operation is inclined, the position of the fatigue damage is reduced,
【学位授予单位】：重庆大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TH132.43

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