Abstract: In view of the influence of tooth profile parameters on the fatigue life of flexspline without considering the tooth profile parameters in the design specifications, the enveloping method is used to design the double tangent conjugate tooth profile without common tangent, and the multi-body contact finite element analysis is carried out. The response surface model of tooth profile parameter and flexspline stress is established, and the influence law of each tooth profile parameter on the flexspline stress is analyzed. The results show that the flexspline stress is more sensitive to the change of tooth profile parameters due to the deforming of the flexspline caused by the meshing teeth between the circular spline and the flexspline; the harmonic drive is more tooth meshing transmission, so the single contact tooth is less loaded and the load has less effect on the stress of the flexspline. The ratio of tooth thickness has the greatest effect on the flexspline stress. The teeth height coefficient and the root fillet radius have the second impact, and the dedendum high coefficient has the least impact. The flexspline stress decreases with the increase of root radius and root height coefficient and then increases, and the other factors are inversely proportional to the stress of the flexspline.

Key words: harmonic gear drive; double arc tooth profile; finite element method; response surface model; tooth profile parameter