Patent ID: 10876615

Abstract:
A V surface of a pulley with which a metal element comes in contact includes first grooves extending spirally from a side of a rotation axis of the pulley to an outer side in a radial direction and one side in a circumferential direction, second grooves extending spirally to the outer side in the radial direction and the other side in the circumferential direction, and rhomboid protrusions surrounded thereby. An average circumferential width of the protrusions is smaller at a position on the inner side in the radial direction than at a position on the outer side in the radial direction. Therefore, at a position on the inner side in the radial direction of the V surface in which cracks easily occur, the average circumferential width of the protrusions is lower, such that cracks occurring on the protrusions are prevented by the grooves, and further extension of cracks is prevented.