Extended contact harmonic drive devices

摘要

The present invention relates to an extended tooth contact harmonic drive gearing apparatus for transmitting rotary motion from an input drive to an output drive through mating contact between the gear teeth of a flexspline and a rigid circular spline, the flexspline being rotated into non-circular shape by a wave generator. The profile of the flexspline teeth are generated to cause the teeth of the flexspline to contact more than one tooth of the circular spline by forming a face profile on the flexspline teeth in accordance with a predetermined equation while the flank tooth profile of the circular spline is formed of a known arc segment, such as, a circle, ellipse or parabola.