| 摘要 |
PURPOSE:To make it possible to miniaturize a driven gear on a counter shaft to suppress the beat sound generation in a primary transmission system by transmitting the rotation of a crank shaft to an idle shaft arranged on an output shaft by means of a chane or a belt while jumping the counter shaft. CONSTITUTION:Revolutions of a crank shaft 1 is transmitted to a counter shaft 2 via a drive sprocket gear 4, a driven sprocket gear 5, a driven gear 7, and a driven gear 8. The reduction ratio of the primary transmission is provided as R.r while assuming the gear ratio of the both sprocket gears 4, 5 as R and the gear ratio of the both gears 7, 8 as r. In order to make the reduction ratio 1/3, if R=1/1.5, r=1/2 is provided. Accordingly, it is possible to set small the diameter of the driven gear 8, enabling the diameter of the driven gear 8 to be reduced to approximately 2/3 compared with a conventional direct primary transmission driven gear. |
