Abstract: A pulley assembly for a flexible motor vehicle transmission, comprising a supporting member rotatable about an axis, a pulley adapted to cooperate with a belt and connected to the supporting member to be rotatable about said axis with respect to the supporting member, elastic spiral means interposed between the supporting element and the pulley and comprising a sliding portion elastically loaded in radial direction against a sliding wall carried by one of either the supporting members or the pulley for tangential force drive coupling pulley to the supporting member. In particular, the elastic spiral means comprise a supporting element and sliding portion comprising at least one runner carried by the supporting element and sliding along the sliding walls.

Abstract: A device for driving a piece of equipment from a driving shaft has a torsional vibration damper and comprises a primary element for connection to the driving shaft and a secondary element for connection to the piece of equipment. A first elastic member surrounds the primary element and an inertia ring surrounds the first elastic member. The secondary element has a rim extending parallel to the longitudinal axis of the device, and the rim partly covers the inertia ring. A cylindrical ring is located between the rim and the inertia ring for providing friction and a radial guide bearing. The secondary element has a transverse covering integral with the rim extending radially inwardly toward the longitudinal axis of the driving shaft. A second elastic member is located between the transverse covering and the primary element.