Abstract: The pulley structure includes a ventilation path that is formed at a position shifted in a radial direction from a rotating axis of a first rotating body and allows a spring accommodation space, formed between the first rotating body and a second rotating body, and the outside to communicate with each other. At least a part of the ventilation path is formed in an end cap that blocks an opening portion on one side of the first rotating body in a rotating axis direction. The end cap blocks the opening portion of the first rotating body such that the spring accommodation space does not communicate with the outside toward the one side in the rotating axis direction other than the ventilation path.

Abstract: A spring (11b) for a one-way clutch is provided that can suppress skewing of rollers and can restrain to a low level the stress generated due to bending of elastic pressure sections (23b1, 23b2). The spring (11b) is formed by subjecting an elastic metal plate to a bending process and comprises: a base section (22b) comprising a flat base-plate section (25); and a pair of elastic pressure sections (23b1, 23b2) formed by bending to an acute angle the both ends in the length direction of the base-plate section (25) towards the one side in the thickness direction of the base-plate section (25); and a pair of elbow sections (24a) located on the portions connecting the elastic pressure sections (23b1, 23b2) and the base-plate section (25). In particular, the elastic pressure sections (23b1, 23b2) cross each other in the middle sections in the length direction thereof.

Abstract: A length of each pocket of a cage in a circumferential direction is smaller than the sum of an outer diameter of a roller and a free length of a coil spring. The cage can rotate relative to an inner ring having cam surfaces in accordance with revolution of the rollers in an overload-applied condition, and the cage can not rotate in a direction opposite to a direction of revolution of the rollers in the overload-applied condition.