Patent ID: 7147091

Claim:
A one-way clutch which transmits relative rotation between inner and outer races in one direction only, and which runs idle in another direction, wherein said one-way clutch comprises: said inner race in which two plate-like members overlay each other, a ball raceway surface is formed by curved portions that are formed in outer edges or radially intermediate portions of said plate-like members, and an air gap is formed by a step portion disposed on an inner periphery of said raceway surface; said outer race which is configured by a plate-like member that is disposed in said air gap, between said two plate-like members of said inner race to be relatively rotatable with respect to said inner race, and in which a plurality of windows are formed in a circumferential direction; a plurality of balls which are accommodated in said windows of said outer race, respectively; and urging means for urging said balls in a constant direction along a circumferential direction, and a cam surface is formed on an inner face of each of said windows on a side of an outer periphery of said outer race, a distance between said cam surface and said ball raceway surface of said inner race being gradually reduced in said direction.