Study On Deformation Function Of Flexspline And Tooth Profile Of Tooth-locked-output Harmonic Drive

Supported by the National Natural Science Foundation of China (No.50975038), and based on the study of the harmonic drive by our research group, the kinematic model of tooth-locked-output harmonic drive is established and simulated in this paper. The nodal displacements of neutral-layer are picked up using ABAQUS which is a finite element analysis software. With the deformation discipline, the deformation function under load is fitted by fourier function. On this basis, the conjugate profiles are modified. And propose a new tooth profile.Firstly, based on the no-load deformation function under wave generator and as the research object to the tooth-locked-output harmonic drive, the kinematic model of harmonic drive is established. Taking an example of ring flexspline harmonic drive whose drive ratio is 120, the involute tooth profile of flexspline is given, the wave generator's rotation angle corresponding to conjugate area and conjugate circular spline profile are calculated by the no-load deformation function and the basic meshing equation of the harmonic drive. The program, written by MATLAB, realizes the kinematic simulation of tooth-locked-output harmonic drive and checks the interference of the profiles to determine the parameters of addendum.Based on ABAQUS, the ring model is developed. It makes entity assembly simulation of harmonic drive with general module, ABAQUS/Standard, picks up the nodal displacements of neutral-layer under no load, and compares with the theoretical deformation function. Then simulates the load motion with the explicit analysis module, ABAQUS/Explicit, with the deformation discipline, the deformation function under load is fitted by fourier function and the conjugate tooth profile of involute tooth profile is modified on this basis, then studies the effect of modified profile to the deformation.This paper proposes a new tooth profile, CA-B tooth profile, whose conjugate area is obviously superior than the involute tooth profile, and does kinematical simulation. The finite element model of tooth-locked-output harmonic drive with CA-B tooth profile is simulated in ABAQUS. It found that the load has little effect to this tooth profile's deformation function, the deformation function is stable, and that is the evidence of CA-B tooth profile's superiority. The methods and results can be used to search the relationship among tooth profile and deformation, load and deformation. It has significant theoretical significance and practical value to the study of the performance of high-power harmonic drive's meshing performance and fatigue life.