A pulley device provides a pulley and a bearing. The pulley has at least one C-shaped pulley part having an inner portion mounted on the bearing, an outer portion having an outer cylindrical surface dedicated to interact with a belt or a chain, and an intermediate portion extending substantially radially between axial ends of inner and outer portions on one axial side of pulley device. The outer cylindrical surface of outer ring is provided with at least one material deformation forming an axial stop for the pulley.

A pulley device for supporting a belt of chain tensioning idler or a runner roller includes a bearing having an outer ring mounted for rotation relative to a coaxial inner ring and at least one pulley part that is C-shaped in cross section. The pulley part has an inner portion with a frustoconical inner surface mounted on an outer cylindrical surface of the outer ring, an outer cylindrical portion having an outer cylindrical surface configured to support a belt or a chain, and an intermediate portion extending radially inward from the cylindrical outer portion to the inner portion. The pulley part is integral and has an open end on an axial side opposite the intermediate portion. The frustoconical surface extends inwardly towards the outer ring, and the inner surface is force fitted onto the outer cylindrical surface of the outer ring.

A pulley device for supporting a belt of chain tensioning idler or a runner roller includes a bearing having an outer ring mounted for rotation relative to a coaxial inner ring and at least one pulley part that is C-shaped in cross section. The pulley part has an inner portion with a frustoconical inner surface mounted on an outer cylindrical surface of the outer ring, an outer cylindrical portion having an outer cylindrical surface configured to support a belt or a chain, and an intermediate portion extending radially inward from the cylindrical outer portion to the inner portion. The pulley part is integral and has an open end on an axial side opposite the intermediate portion. The frustoconical surface extends inwardly towards the outer ring, and the inner surface is force fitted onto the outer cylindrical surface of the outer ring.

A pulley device for a transmission element having a pulley, a bearing, and at least one sleeve mounted freely in the bore of the inner ring of the bearing. The pulley device includes at least one annular protection shield, the shield retained axially in a first element from the pulley and coming into immediate proximity with the other element, the other element having at least one shoulder projecting radially ensuring that it is axially retained with the shield.

A pulley device for a tensioner roller or winding roller for a transmission element, providing a bearing and a pulley. The pulley including two pulley elements that are C-shaped in axial section. At least one of the pulley elements has an axial through-opening, the other pulley element providing an axially protruding portion housed in the opening, a collar being formed by deformation of the protruding portion in order to provide axial retention with the opening. The at least one through-opening is provided at its periphery with at least one recessed zone formed in a substantially radially set-back manner with respect to the protrusion, which passes through the opening.

A pulley device for a tensioner roller or winding roller for a transmission element, providing a bearing and a pulley. The pulley including two pulley elements that are C-shaped in axial section. At least one of the pulley elements has an axial through-opening, the other pulley element providing an axially protruding portion housed in the opening, a collar being formed by deformation of the protruding portion in order to provide axial retention with the opening. The at least one through-opening is provided at its periphery with at least one recessed zone formed in a substantially radially set-back manner with respect to the protrusion, which passes through the opening.

A variety of transmission mechanisms are provided that include split pulleys nested within each other in order to reduce the size of the transmissions, to provide infinitely variable transmission ratios that include forward and reverse ratios, or to provide some other benefits. These transmissions includeW-shaped belts, having both contact surfaces that are directed outward from the belt and inward, toward a center-line of the belt, to contact the pulleys with respective different inward- and outward-directed contact surfaces. Accordingly, the surfaces at which the belt contacts the different pulleys may be substantially the same with respect to a hinge or other structure of the belt. This improvement may permit higher levels of power transmission, increased efficiency, and increased transmission lifetime. Additionally, variable-eccentricity variable transmissions are provided wherein the eccentricity of rotation of an inner, nested pulley varies with changes in the transmission ratio of the transmission.

A variety of transmission mechanisms are provided that include split pulleys nested within each other in order to reduce the size of the transmissions, to provide infinitely variable transmission ratios that include forward and reverse ratios, or to provide some other benefits. These transmissions include W-shaped belts, having both contact surfaces that are directed outward from the belt and inward, toward a center-line of the belt, to contact the pulleys with respective different inward- and outward-directed contact surfaces. Accordingly, the surfaces at which the belt contacts the different pulleys may be substantially the same with respect to a hinge or other structure of the belt. This improvement may permit higher levels of power transmission, increased efficiency, and increased transmission lifetime. Additionally, variable-eccentricity variable transmissions are provided wherein the eccentricity of rotation of an inner, nested pulley varies with changes in the transmission ratio of the transmission.

A friction pulley includes a rotary wheel having a groove on an outer periphery of the rotary wheel rotatable about an axis, the groove being recessed toward an inner periphery side, and a rubber ring having an annular shape and can be accommodated in the groove. The groove has a pair of annular side surfaces facing each other in a direction of the axis and extending from an inner peripheral side toward an outer peripheral side. The rubber ring has a contact surface at an outer periphery of the rubber ring and friction surfaces that are a pair of surfaces corresponding to the pair of side surfaces of the groove. At least in a power transmission state where the contact surface is in pressure contact with the rotary member to transmit power, the friction surfaces of the rubber ring are pushed against the side surfaces of the groove.

A chain made up of bush link plates, bushes fitted into bush fitting holes, and rollers fitted rotatably on an outer circumference of each of the bush. In order to make it possible to replace the roller without removing the bush from the bush link plates, in the chain made up of the bush link plates provided with bush fitting holes, the bushes fitted into the bush fitting holes, and the rollers fitted rotatably on the outer circumference of each of the bushes, the roller is formed from split rollers made by splitting the roller into two or more parts.