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. A grip surface portion is provided to one surface among the outer cylindrical surface of the outer ring and the inner cylindrical surface of the inner cylindrical portion of the pulley part, the grip surface portion including a plurality of indentations and recesses.

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. A grip surface portion is provided to one surface among the outer cylindrical surface of the outer ring and the inner cylindrical surface of the inner cylindrical portion of the pulley part, the grip surface portion including a plurality of indentations and recesses.

A pulley device for a tensioner roller or winding roller of a transmission element, providing a pulley, and a bearing. The bearing includes a rotating outer ring mounted to the pulley, a fixed inner ring, and at least one row of rolling elements arranged between the rings. The inner ring of the bearing has at least one end portion protruding axially with respect to the outer ring. The pulley is provided with at least one pulley element that is C-shaped in axial section. One of the at least one pulley elements is provided with a lateral portion extending substantially radially to pass into the immediate vicinity of an outer surface of the axially protruding end portion of the inner ring.

A Pulley device for a tensioning or winding roller for a transmission element including a pulley, and a rolling bearing provided with a rotating outer ring, the pulley being mounted on an outer surface of the outer ring, a fixed inner ring, the rings being coaxial and forming a radial space between them, and at least one row of rolling elements arranged in the radial space. The pulley device further includes at least one annular protection flange with a radial body. The flange is fixed to the rotating outer ring by crimping an axially protruding portion of the pulley towards an outer edge of the flange.

A Pulley device for a tensioning or winding roller for a transmission element including a pulley, and a rolling bearing provided with a rotating outer ring, the pulley being mounted on an outer surface of the outer ring, a fixed inner ring, the rings being coaxial and forming a radial space between them, and at least one row of rolling elements arranged in the radial space. The pulley device further includes at least one annular protection flange with a radial body. The flange is fixed to the rotating outer ring by crimping an axially protruding portion of the pulley towards an outer edge of the flange.

A press-fit-interlocking connection of an inner part to an outer part which is fastened to the inner part includes a cylindrical press joint (3) between the outer part and the inner part. The interlocking connection is formed by an axial stop having contacting stop parts (18, 19) on the inner part and on the outer part. The connection has an edge support in contact with the stop parts which contact one another, in a first main plane of curvature (E.sub.1) to which the cylinder axis of the press joint is perpendicular, with equal radii of curvature (r.sub.a1, r.sub.a2), and in a second main plane of curvature (E.sub.2) in which the cylinder axis of the press joint lies, with different radii of curvature (r.sub.a2, r.sub.i2).

In an aspect, an isolation device is provided for a belt and a component shaft in an engine. The device includes a hub, a pulley, an isolation spring and a damping member that is fixed rotationally relative to the hub and is engageable frictionally with the pulley. Torque transmission through the spring below a selected non-zero torque, irrespective of hub load on the pulley, drives a change in radius of the helical coils of the spring that is sufficiently small that the spring avoids pressing the damping member against the pulley. Torque transmission through the spring above the selected non-zero torque, irrespective of hub load on the pulley, drives a change in radius of the helical coils that is sufficiently large that the isolation spring applies a radial force to press the damping member against the pulley so as to generate frictional damping.

In an aspect, a power transfer device, such as a decoupler, is provided for transferring torque between a shaft and a belt. The device includes: a hub configured to couple to the shaft, a pulley rotatably coupled to the hub that includes a power transmitting surface configured to engage the belt, an isolation spring to transfer a rotational load from one of the pulley and the hub to the other of the pulley and the hub, optionally a one-way clutch to permit overrunning of one of the pulley and the hub relative to the other of the pulley and the hub in a first direction, and a damping member positioned to be driven into frictional engagement with a friction surface by a force from the isolation spring acting on the damping member that varies based on the rotational load transferred by the isolation spring.

In an aspect, a power transfer device, such as a decoupler, is provided for transferring torque between a shaft and a belt. The device includes: a hub configured to couple to the shaft, a pulley rotatably coupled to the hub that includes a power transmitting surface configured to engage the belt, an isolation spring to transfer a rotational load from one of the pulley and the hub to the other of the pulley and the hub, optionally a one-way clutch to permit overrunning of one of the pulley and the hub relative to the other of the pulley and the hub in a first direction, and a damping member positioned to be driven into frictional engagement with a friction surface by a force from the isolation spring acting on the damping member that varies based on the rotational load transferred by the isolation spring.

In an aspect, an assembly is provided and includes a pulley device and a drive shaft. The pulley device includes a pulley and has a shaft adapter. A selected amount of combined resistance in the first and second connections to relative rotation in the second direction is generated by a threaded first connection and a second connection between the shaft adapter and the shaft at least some of which is provided by a compression force between them.