机器人关节短筒谐波减速器接触计算与分析

Contact Analysis for Short Harmonic Reducer in Robotic Joints

为了研究机器人关节常用短筒谐波减速器在不同负载下的接触应力和变形分布,采用AN-SYS有限元分析软件,建立了柔轮和波发生器面面接触的空载有限元模型,并根据实验得到的啮合力公式,对柔轮与刚轮的啮合边界条件进行了计算。在此基础上,利用前置条件共轭梯度法求解了柔轮在不同载荷下的应力与变形,分析了柔轮应力和变形与所受载荷之间的关系及其变化规律,发现负载的增大可使柔轮齿圈截面的变形和应力增量呈等比增大,且不会引起变形和应力增量分布位置的变化。通过柔轮空载的变形实验、柔轮破坏实例以及柔轮轴向应力分布实验的比较发现,所计算的结果与实验结果较为吻合,为谐波减速器短筒柔轮承载能力的计算、结构及制造工艺的优化提供了一种准确、有效的方法。

To reveal contact stress and deformation distribution of short harmonic reducer in robotic joints under different loads, an unloaded surface to surface contact finite element model between flexspline and wave generator is established. The boundary condition of the engagement between flexspline and rigid spline is evaluated according to the experimental engaging force formula. The stress and deformation of the flexspline are solved by precondition conjugate gradient method, and the relationship with varying loads are analyzed. It is found that the deformation and stress increments on the flexspline ring cross section increase geometrically with heightened load, and the distributions of the deformation and stress increments remain unchanged. The conclusions are compatible with the cases of unloaded flexspline deformation, flexspline destruction and axial stress distribution under load.