Abstract: A one-way clutch is proposed which is low in surface pressures and durable. It includes an inner ring having a cylindrical outer surface, and an outer ring having a cylindrical inner surface defining a wedge-shaped space in cooperation with the cylindrical outer surface of the inner ring. A ring-shaped wedge member is disposed in the wedge-shaped space. The wedge member is formed with a cylindrical outer surface and a cylindrical inner surface having a center of curvature that is radially offset from the center of curvature of the cylindrical outer surface of the wedge member. A resilient member is provided between the inner ring and the wedge member to bias the wedge member in a direction to be wedged into the narrow portion of the wedge-shaped space. When the inner ring is rotated in one direction, the wedge member will be brought into wedging engagement with the cylindrical surfaces of the inner and outer rings. Torque is thus transferred from the inner ring to the outer ring.

Abstract: A one-way clutch is proposed which is low in surface pressures and durable. It includes an inner ring having a cylindrical outer surface, and an outer ring having a cylindrical inner surface defining a wedge-shaped space in cooperation with the cylindrical outer surface of the inner ring. A ring-shaped wedge member is disposed in the wedge-shaped space. The wedge member is formed with a cylindrical outer surface and a cylindrical inner surface having a center of curvature that is radially offset from the center of curvature of the cylindrical outer surface of the wedge member. A resilient member is provided between the inner ring and the wedge member to bias the wedge member in a direction to be wedged into the narrow portion of the wedge-shaped space. When the inner ring is rotated in one direction, the wedge member will be brought into wedging engagement with the cylindrical surfaces of the inner and outer rings. Torque is thus transferred from the inner ring to the outer ring.

Abstract: A two-way differential clutch is provided which can prevent the resilient ring for biasing a friction plate from expanding radially outwardly and getting out of the mounting position due to centrifugal force during high-speed rotation. Two retainers having different diameters are mounted between a rotary shaft and an input gear. The large-diameter retainer is fixed to the input gear. Sprags are mounted in pockets formed in the large-diameter retainer and the small-diameter retainer. A flange and a ring groove are formed at one end of the small-diameter retainer. A friction plate arranged on one side of the flange is pressed against the flange by a resilient ring mounted in the ring groove. A restricting portion for restricting the amount of radial expansion of the resilient ring is formed on the friction plate to prevent the resilient ring from radially expanding too much due to centrifugal force during high-speed rotation.