| 摘要 |
<p>In the provided multi-stage transmission, engagement protrusions (31) are formed on inner ridges (30C) that protrude annularly from the inner surface of a gear. A ring member (35) is situated, in a manner allowing relative rotation, near the side surfaces of said inner ridges (30C) on which the engagement protrusions (31) of the gear are formed. Abutting protrusions (36) are formed on the inner surface of the ring member in the circumferential direction, said abutting protrusions having inclined surfaces capable of abutting against an engagement prong (Rp) that is part of an engagement means. At least the sections of said abutting protrusions (36) other than the sections formed into inclined surfaces are positioned by a return spring (38) so as to overlap, as viewed from the axial direction, with the engagement protrusions (31). The inclined surfaces of the abutting protrusions (36) comprise: base-section inclined surfaces (36pb) inclined at an angle that allows engagement with the engagement prong (Rp); and tip-section inclined surfaces (36ps) inclined at an angle such that the engagement prong makes sliding contact but cannot engage. This configuration prevents an excessive load from being applied to part of the engagement prong when the engagement prong engages with the engagement protrusions on the gear.</p> |
