| 摘要 |
PURPOSE:To enable to establish selectively a speed change ratio of a back gear at a value larger sufficiently than a normal one, by a method wherein an auxiliary input shaft is provided concentrically on an input shaft to be driven by an engine through a reduction clutch, and a counter shaft is provided in parallel with the auxiliary input shaft. CONSTITUTION:A gear 7 is fixed to an input shaft 6 to be connected with a crank shaft 4 through a clutch 5 and an auxiliary input shaft 9 is provided beyond the gear 7 through a reduction clutch 8. The auxiliary input shaft 9 side of the clutch 8 supports a gear 11 rotatably to the same shaft 9 and the clutch 8 is connected with either of gears 11, 7 selectively. Gears 12-15 whose numbers of cogs are different to each other are fixed to the auxiliary input shaft 9, which are meshed with gears 17-19 supported by a countershaft 16 supported close to the auxiliary input shaft 9 appropriately. The titled device is enabled to obtain a far larger speed reduction ratio as compared with the ratio obtainable at the time of connection with a gear 7 side, when a back gear 21 is made selectively connectable on the countershaft 16 by providing a low speed clutch 20 and the clutch 8 is connected with a gear 11 side. |
