| 摘要 |
<p>An elastic gear (30) and a drive ring (40) are superposed on each other in the direction of the center axis of their rotation. A circular arc groove (32) is formed in the elastic gear (30) so as to extend along a tooth row section (33) of the elastic gear (30). The circular arc groove (32) facilitates elastic deformation of the elastic gear (30), particularly that in a radial direction. Further, the tips (331a) of teeth (33a) project radially outward from the tips (431a) of teeth (43a). The construction reduces operation noise caused by backlash.</p> |
