Research On Optimization Design Of Short Cup Harmonic Gear Structure And Tooth Profile Parameters For Robots

The harmonic drive with short cup-shaped flexspline has advantages of small size and compact structure,so it is more suitable for the field of robots.But there is big gap between the domestic product and the imported one,which is difficult to meet the requirements of modern robots.Therefore,this paper takes the harmonic drive with short cup-shaped flexspline for robot as the research object,and carries out optimum design of structure and teeth profile.First,according to the design criteria and technical specifications of the harmonic drive with short cup-shaped flexspline,the tooth number,modulus and structural parameters of flexspline were determined.Taking the normal double-circular-arc tooth profile of flexspline hobbing cutter as the reference profile,the tooth profile of flexspline could be obtained by tooth profile normal method.The optimum design of conjugate region of flexspline tooth profile was carried out,so the dual-conjugated meshing zone was maximized.Then the tooth profile of circular spline could be solved by envelope method,the meshing characteristics such as meshing backlash were analysed,so the rationality of tooth profile was verified.The tooth deflection of flexspline was analysed,and the three-dimensional profile of circular spline was designed to avoid meshing interference.Secondly,deformation function of flexspline could be solved by finite element method.The error between it and theoretical deformation function was analysed,and the difference between teeth profile of circular spline by two ways was prepared,which provides a reference for obtaining the accurate tooth profile of circular spline.At last,the stress analysis of flexspline was carried out,and the influence degree of structural parameters of flexspline on the maximum stress could be studied by orthogonal design.With the minimum optimization objective of maximum stress and length of cylinder,the optimum design of flexspline was carried out by Isight,which improved the bearing capacity and reduce the volume of flexspline.