A flex spline 1 used for a meshing type gear device includes an attachment portion 1a, a thin-thickness tubular portion 1b continuing to the attachment portion and capable of being elastically deformed, and external teeth 1c formed at the tip end portion of the tubular portion away from the attachment portion. The thin-thickness tubular portion 1b is formed in a conical shape with an opening angle θ which is tapered in a direction from the attachment portion 1a toward the external teeth 1c before inserting a wave generator 3.
展开▼
