谐波齿轮传动双圆弧齿形双向共轭设计方法

A novel bidirectional conjugate design method is proposed to solve the uncertain problem of the conjugated convex circular-arc tooth profile of circular spline existing in the widely used unidirectional conjugate design method of double-circular-arc tooth profile. The proposed method is based on the combined conjugate calculation of the tooth profiles of flexspline and circular spline. The double-circular-arc tooth profile of a circular spline is obtained through conjugate calculation and fitting via presetting parameters of the convex circular arc of the flexspline. The concave circular arc of the flexspline is obtained through a reverse conjugate calculation of the convex circular arc profile of the circular spline. The whole tooth profile of the flexspline is obtained by combining the fitted concave arc with the preset convex arc of the flexspline. The method ensures that the convex arc of the circular spline is conjugated with both arcs of the flexspline. Meshing backlash analysis and finite element contact analysis of a double-circular-arc tooth profile are carried out. Results and a comparison with the unidirectional conjugate method show that the tooth profile designed by the bidirectional conjugate method is able to engage on whole tooth profile, has multi-point meshing property, and possesses larger tooth contact area and smaller contact stress on the tooth surface. It is concluded that the proposed method improves the meshing performance of harmonic drives.