PULLEY TYPE SPEED-SHIFTING DEVICE

摘要

In a pulley type speed-shifting device with a belt trained between a pair of variable speed pulleys, a movable sheave of each pulley is driven by a cam mechanism. Each cam mechanism has a cylindrical cam arranged concentrically with a rotary shaft and a cam follower which is arranged concentrically with a rotary shaft and carries a rolling body which makes contact with the cam as it is rolling on a cam face. The movable sheave is driven in axial direction by either the cylindrical cam or the cam follower rotating around the rotary shaft and rotating relatively to the other. As the cam follower makes contact with the cam face through the medium of the rolling body, resistance is small and the transmission ratio can be shifted with light handling force.