A belt pulley decoupler is provided for transmitting drive torque from belts of an auxiliary unit belt drive to the shaft of one of the auxiliary units, including: a belt pulley, a hub secured to the shaft, and a series circuit arranged in the drive torque flow between the belt pulley and the hub and including a decoupler spring and a wrap-around band that extends in the direction of the rotational axis of the belt pulley decoupler and is arranged radially between the belt pulley and the decoupler spring. Both ends of the wrap-around band open out radially when the drive torque is transmitted, the first end of the wrap-around band is braced against the inner surface of a first sleeve rotationally fixed in the belt pulley, and the second end of the wrap-around band is braced against the inner surface of a second sleeve rotationally mounted in the first sleeve.

Pulley-torsional damper integrated group comprising a hub adapted to be rigidly connected to a drive member and a pulley connected to the hub. The hub comprises an inner tubular wall and an outer tubular wall. The pulley is angularly coupled to said hub by means of the ring made of elastomeric material. The elastomeric ring has an outer surface towards the pulley and an inner surface towards the hub, and an adhesive is arranged on at least one of the outer or inner surfaces.

The invention relates to a drive system (1) for an engine arrangement (2), the drive system comprising an epicyclical gear reduction mechanism (20) having a main axis (15) and comprising: a first main gear (123), a second main gear (121) arranged to rotate about main axis (15) in the same direction as the first main gear (123), a first set of planet gears with planet gears (23) meshing with the first main gear (123), a second set of planet gears with planet gears (21) meshing with the second main gear (121), a planet carrier (25), supporting planet gears (23, 21) of the first and second planet gears (23, 21), the planet carrier (25) being located, along the main axis (15), between the first main gear (123) and the second main gear (22, 121). Each planet gear (23) of the first set of planet gears (23) is coupled to a planet gear (21) of the second set of planet gears (21) such that no relative rotation is possible between them. In the mounted position: the first main gear (123) is connected to an engine crankshaft (5), the planet carrier (25) is connected to an accessory pulley (9) which is drivingly connected to an electric machine (6) and at least one accessory (7). The drive system further comprises a free wheel (30) which is connected to a non-rotating part (16) of the engine arrangement in the mounted position. The second main gear (121) is configured to be coupled, preferably via an intermediate junction element (22) of the drive system, to the free wheel (30) in a first operating phase of the drive system (1). In the first operating phase, the free wheel (30) is configured such that when the second main gear (22, 121) exerts torque on the free wheel in one direction, the free wheel is in an engaged state and stops the rotation of the second main gear (22, 121), and when the second main gear (22, 121) exerts torque on the free wheel in the opposite direction, the free wheel is in a free state and allows rotation of the second main gear (22, 121).

In an aspect, an isolator is provided for isolating a device driven by an engine via an endless drive member. The isolator includes a shaft adapter that is connectable with a shaft of the device and that defines an isolator axis, a rotary drive member that is engageable with the endless drive member, a first isolation spring arrangement that includes a first torsion spring, and that is positioned to transfer torque between the shaft adapter and an intermediate drive member, and a second isolation spring arrangement that is positioned to transfer torque between the intermediate member and the rotary drive member.

A filtering pulley for an accessory transmission of an internal combustion engine that has a hub, a crown, a filtering unit for transmitting the torque interposed between the hub and the crown, a torsion spring, a carrier, and a torque limiting joint. The torque limiting joint has an open-loop strip spring and is configured to slide with respect to said surface when the torque transmitted between the crown and the hub reaches a predetermined level.

A filtering pulley having a hub adapted to be fixed to a rotating shaft, a pulley ring mounted coaxial and rotationally free on said hub, and at least one elastic assembly interposed between the hub and the pulley ring and a damper for damping the relative oscillations between the hub and the pulley ring is disclosed. The damper has a first damping level for relative rotations between the hub and the pulley ring which are smaller than a predetermined angle and a second damping level, which is greater than the first level, for relative rotations between the hub and the pulley ring which are larger than the predetermined angle.

The present invention relates to a decoupler with free wheel system and comprising a vibration damping pulley, a shaft actionable by the pulley, hub pieces having a first hub piece and a second hub piece, hub pieces being mounted between the inner race of the pulley and the outer surface of the shaft, at least one journal element between the shaft and pulley, along with a torsion spring, and a clutch spring, with the first hub piece being mounted on the shaft and the second hub piece being mounted around the shaft and can rotate relative to it, the torsion spring being disposed between the outer race of the hub pieces and the inner race of pulley, having a first end operatively attachable to the pulley and a second end operatively attachable to the second hub piece and the clutch spring being disposed internally in relation to the torsion spring and which is frictionally engaged with the hub pieces for transmission of torque to the shaft.

An isolator for isolating a device driven by an engine via an endless drive member is described. The isolator comprises a shaft adapter that is connectable with a shaft of the device, defining a shaft adapter axis, a rotary drive member that is rotatable relative to the shaft adapter and has an endless drive member engagement surface that is engageable with the endless drive member, and an isolation spring arrangement positioned to transfer torque between the shaft adapter and the rotary drive member. The isolation spring arrangement has at least one isolation spring that is axially offset from the endless drive member engagement surface. The at least one isolation spring has an outer edge that is radially outside the endless drive member engagement surface.

A belt pulley structure of an engine is provided to prevent abnormal noise from generating between a belt pulley and a torsional vibration damper. The belt pulley structure includes a stepped portion that is formed in a shape that blocks a cavity in a radial direction thereof. The cavity is formed at a portion where a belt pulley and a torsional vibration damper face each other.

A filtering pulley having a hub adapted to be fixed to a rotating shaft, a pulley ring mounted coaxial and rotationally free on the hub, and a plurality of elastic assemblies arranged circumferentially with respect to the hub and the pulley ring and each interposed between a pair of first elements integral with the hub and between a pair of second elements integral with the pulley ring is disclosed. Each elastic element forms with the first elements and with the second elements respective angular clearances, and the pulley ring and the hub have a free angle of relative rotation equal to the sum of the above-mentioned angular clearances.