Patent ID: 7143881

Claim:
A pulley unit having a one-way clutch comprising a one-way clutch which has an inner ring fitted to a rotation shaft of a starter motor, an outer ring fitted to a pulley, a meshing member disposed between both the rings, and a biasing member for biasing the meshing member in a meshing direction wherein at least one bearing is provided between the shaft and the pulley, in the one-way clutch, the meshing member and the biasing member are rotated integrally with the outer ring, and wherein the biasing member is oriented such that when a centrifugal force is applied, the biasing member is deformed due to a mass of the biasing member in a direction reducing a biasing force with respect to the meshing member so that when the rotation speed of the outer ring becomes equal to or greater than a predetermined speed, the meshing member moves in the meshing-releasing direction to a free condition to allow only the pulley being rotated and when the rotation speed of the outer ring becomes smaller than the predetermined speed, the meshing member moves in the meshing direction to a lock condition and a the biasing force of the biasing member has enough magnitude to allow these meshing member movements.