Parameters Optimization And Dynamic Simulation For Harmonic Gear Drive With Involute Tooth Profile

The paper optimizes the involute tooth profile parameters of flexspline and circular spline based on the elastic conjugation theory of harmonic gear drive. The involute tooth profile of flexspine is revised after analyzing the characteristic of the theoretical spatial conjugation tooth profile of flexspline. Then, the dynamic working process of harmonic gear is simulated with finite element method, and the meshing performance of optimal tooth profile is studied.The spatial elastic conjugation motion model that based on the deformation function of flexspline is set up after researching the transmission principle of harmonic gear. The solution equation of conjugation tooth profile is deduced according to the centrode theory of planar rigid-body motion. Thus, the optimization model of tooth profile parameters is established and its objective is to make the involute profile approaching the theoretical conjugation profile as much as possible. Then the optimal modification coefficient of flexspline tooth and circular spline tooth can be obtained. The tooth profile of flexspline is revised by reversing all conjugation profiles in different cross-section of flexspline and studying their spatial characteristics.The parameterized finite element model is constructed by manual programming aiming at the tedious repeater modeling and the mesh quality requirement of dynamic simulation solution. A new node numbering algorithm and mesh generation algorithm are presented, and the program interface is set up easy to modify parameters and control mesh quality. The program can generate the solution file for the solver of ABAQUS to compute.The assembly process of wave generator is simulated. The deformation function and stress distribution of flexspline in the state of assembly are analyzed. Furthermore, the simulation of dynamic working process of harmonic gear under loads condition is conducted taking the deformation and stress of flexspline as preload. The time-variant characteristics of flexspline stress and the influence of loads on deformation function of flexspline are investigated, and the contact forces of harmonic gear drive on tooth direction and circumferential direction are studied. A comparison of meshing performance is made between optimal tooth profile and un-optimized tooth profile. The research results have practical significance on improving the meshing performance of harmonic gear drive and reference value for the tooth shape which is suitable for dynamic transmission with loads.