One-way clutch

A one-way clutch comprising:

• a plurality of cams arranged between an outer ring and an inner ring and arrayed in a circumferential direction;
• a retainer that holds the cams;
• and
• an annular spring provided across an outer peripheral side of the cams, wherein
• each of the cams comprises
• an outer surface facing an outer side in a radial direction and facing the outer ring, and
• a groove portion in which the outer surface is cut away in the circumferential direction and the spring is housed, and
• an axial direction is defined as a direction parallel to a central axis of the outer ring,
• the retainer comprises a retainer body made of resin,
• the retainer body comprises
• an annular first side plate arranged on one side in the axial direction with respect to the cams, and
• a plurality of protrusions protruding from the first side plate to the other side in the axial direction and arrayed in the circumferential direction,
• the protrusions comprise
• a plurality of column portions, and
• at least one spring protrusion with the spring provided across the outer peripheral side,
• a window portion with the cam arranged is formed between two of the column portions adjacent to each other in the circumferential direction,
• one side in the axial direction of the window portion is closed by the first side plate, and the other side in the axial direction thereof is open,
• a hook portion protruding outward in the radial direction and arranged on the other side in the axial direction with respect to the spring is formed on the at least one spring protrusion, and
• the first side plate is provided with a cutaway formed by cutting away a portion facing the hook portion in the axial direction.