Pulley unit having one-way clutch

摘要

A pulley is concentrically disposed around a hollow shaft (3), and a one-way clutch is disposed between the hollow shaft and the pulley. At least one bearing (7) is provided between the shaft and the pulley. In the one-way clutch, a roller (5) as a meshing member and a coil spring (14) as a biasing member are integrally rotated together with an outer ring (4). The roller moves in a meshing-releasing direction by a centrifugal force when a rotation speed of the outer ring (4) becomes equal to or higher than a predetermined speed, and a biasing force of the coil spring (14) has enough magnitude for permitting this movement. The pulley is provided at its inner periphery with a cam surface, and the pulley and the outer ring of the one-way clutch are integrally formed. <IMAGE>