Driving-side pulley

A driving-side pulley forming one component of a belt-type continuously variable transmission that transmits a rotational power from a driving shaft to a driven shaft while continuously changing a speed of the rotational power that is transmitted to the driven shaft in accordance with a rotational speed of the driving shaft, the driving-side pulley comprising:

• a fixed sheave immovable along an axis line and non-rotatable around the axis line with respect to the driving shafts;
• a movable sheave movable along the axis line and non-rotatable around the axis line with respect to the driving shaft;
• a return spring pressing the movable sheave in a direction away from the fixed sheave;
• and
• a flyweight mechanism pressing the movable sheave in a direction toward the fixed sheave with a force having an amount corresponding to the rotational speed of the driving shaft against a pressing force of the return spring,
• wherein the fixed sheave is provided with a fixed sheave-side engagement surface capable of engaging with a first side surface of a belt while the movable sheave is provided with a movable sheave-side engagement surface that is capable of engaging with a second side surface of the belt and forms, in cooperation with the fixed sheave-side engagement surface, a V-shaped groove into which the belt is engaged,
• wherein the driving-side pulley includes a movable sleeve inserted around an axis-line-direction fixed member, which is formed by the driving shaft or the fixed sheave, in a movable manner along the axis line and in a rotatable manner around the axis line with respect thereto, and a one-way clutch inserted around the movable sleeve in such a manner as to form a bottom surface of the V-shaped groove,
• wherein the movable sleeve includes a tubular portion inserted around the axis-line-direction fixed member and a flange portion extending outward in a radial direction from the tubular portion,
• wherein the one-way clutch includes an inner ring body inserted around the tubular portion in a non-rotatable manner with respect thereto and an outer ring body surrounding the inner ring body and forming the bottom surface of the V-shaped groove, and is configured so that only a rotational power generated by a rotation of the outer ring body in a normal direction is transmitted to the inner ring body,
• wherein the flange portion is provided with a pressing surface capable of engaging with one of the first and second side surfaces of the belt in a state where the inner circumferential surface of the belt engages with the outer ring body,
• wherein the driving-side pulley further includes a cam mechanism that presses the movable sleeve in a first direction by utilizing a relative rotation of the movable sleeve in the normal direction with respect to the axis-line-direction fixed member, the first direction being a direction that has the pressing surface pressed against a corresponding side surface of the belt, and
• wherein the cam mechanism includes a convex-like member provided at one of the axis-line-direction fixed member and the tubular portion so as to be arranged at a position different from the one-way clutch in the axial line direction, and a spiral groove provided at the other one of the axis-line-direction fixed member and the tubular portion in such a manner as that the convex-like member can be engaged into the spiral groove.