Tooth profile of one of circular splines of flat-shaped strain wave gearing

摘要

A strain wave gearing comprising a circular spline, flexspline inside the circular spline, a wave generator for deforming the flexspline into, for example, an ellipsoid and a motor for rotating the wave generator to produce a relative rotation between the flexspline and the circular spline. The strain wave gearing is sometimes termed a harmonic drive transmission, and there is a type of gearing called flat-shaped strain wave gearing which is composed of two circular splines juxtaposed with each other, a flexspline in the circular splines having the same number of teeth as the first circular spline, a wave generator for deforming the flexspline into an ellipsoid and a motor for rotating the wave generator. In the flat-shaped gearing, each tooth of the flexspline is provided with a convex tooth face and a concave tooth flank. The tooth profile of the first circular spline is given by such a locus curve that the tooth face of the flexspline plots when the deformed configuration of the flexspline is rotated by the wave generator, and the tooth depth of the first circular spline is made equal to or larger than the working depth of the flexspline. Thus, the teeth of the flexspline engage with those of the first circular spline in the broad extent of the engagement region.