| 摘要 |
PURPOSE:To realize arbitrary setting of characteristics in speed change zone by a structure wherein the movable face of a driving side pulley is fitted onto a driving shaft so as to be able to shift in both the directions of rotation and of axis relative to the driving shaft and yet the shifting is performed through the engagement of a pin with a guide groove. CONSTITUTION:When the rotational frequency of an engine is raised from the running state at low speed, the centrifugal force acting on a weight roller 20 increases, resulting in increasing an axial force F directed towards the driving fixed face 11 of a driving side pulley. When the tension acting on a V-belt 34 increases due to said increase of the force F, the distance between the fixed and movable faces (not shown) of a driven side pulley is widened, while the distance between the fixed and movable faces 11 and 13 of the driving side pulley is narrowed, resulting in starting to reduce the transmission ratio. In addition, at this time, because of the fitting of a pin 14, which is protrudedly provided on a boss 10 fitted onto a crankshaft 8, in a guide groove 13b arranged on the movable face 13, an axial force Q acts on the movable face 13 and consequently the change of the transmission ratio is performed smoothly. |
