摘要 |
Provided is a strain wave gear device in which a main section of the addendum tooth profile in an external tooth (24) of a rigid internal gear in a cross section that is perpendicular to the axis of said strain wave gear device is defined using a semicircle (26) that is centered on the tooth ridge center line of said main section. A main section of the addendum tooth profile of an external tooth (34) of an external gear is defined using a parallel curved line (38) that is at a distance equivalent to the radius (r1) of the semicircle (26) from a curved line part Ma(A, B) in a predetermined range in a movement trajectory Ma that results from rack approximation of the external tooth (34) with respect to the internal tooth (24). The present invention makes it possible to achieve continuous intermeshing of addendum tooth profiles in a wide range between the external tooth (34) and the internal tooth (24), thereby making it possible to increase the torque capacity of the strain wave gear device. |