SPANNUNGSWELLENGETRIEBE

A strain wave gearing 10 comprises two circular splines 11,12 juxtaposed with each other, a flexspline 13 in the circular splines having the same number of teeth as the first circular spline 11, a wave generator 14 for deforming the flexspline into for example an ellipsoid and a motor for rotating the wave generator. In this flat-shaped gearing, each tooth of the flexspline 13 is provided with a convex tooth face and a concave tooth flank. The tooth profile of the first circular spline 11 is given by such a locus curve L that the tooth face of the flexspline plots when the deformed configuration of the flexspline is rotated by the wave generator 14, and the tooth depth GI of the first circular spline 11 is made equal to or larger than the working depth of the flexspline 13. Thus, the teeth of the flexspline engage with those of the first circular spline to give an engagement region of broader extent than hitherto.