| 摘要 |
<p>A multi-stage transmission has driving gears m and driven gears n supported on a hollow driven gear shaft 12. The driven gears n are individually engageable with and disengageable from the hollow driven gear shaft 12. The driving and driven gears m, n mesh constantly. The multi-stage transmission is intended to reduce friction loss between the hollow driven gear shaft 12 and cam rods 21,22 provided within the driven gear shaft 12 for engagement and disengagement between the driven gears n and the driven gear shaft 12. There are provided swing pawl members 24, 25 for controlling engagement and disengagement between each of the driven gears n and the driven gear shaft 12, and cam rods 21, 22 inserted in the driven gear shaft 12 to slide relative to the internal surface of the shaft 12 to operate the swing pawl members 24, 25. Gear shift driving means 50 includes a shift drum 65, a conrol rod 51 in sliding contact with the inner surface of the cam rods 21, 22 to axially move the cam rods 21, 22, and a control rod operating element 70 responsive to rotation of the shift drum 65 to move the control rod 51. The control rod 51 and the driven gear shaft 12 are prevented from relative rotation by an anti-rotation mechanism 12ss,51s,55 and 51v.</p> |
