Patent ID: 7618337
Filing Date: 2009-11-17
Classification: F02B,F16D,F16H

Abstract:
1. A decoupler assembly for transferring torque between a shaft and an endless power transmitting element, said decoupler assembly comprising: a hub that is adapted to be coupled to the shaft such that the shaft co-rotates with the hub about a rotational axis; a carrier that is rotatable relative to the hub; a torsion spring concentric with the rotational axis and extending between a hub end and a carrier end for transferring rotary power between the hub and carrier; a pulley rotatably coupled to the hub, the pulley having an outer periphery that is adapted to engage the endless power transmitting element, the pulley having an inner surface formed therein; a clutch spring formed only of wire, the clutch spring having a first end that is fixedly coupled to the carrier, a second end opposite the first end and a plurality of coils between the first and second ends, the clutch spring exiting the carrier and extending toward the inner surface of the pulley such that at least one of the plurality of coils is engaged against the inner surface of the pulley when rotary power is transmitted from the pulley to the hub, the plurality of coils contracting to at least reduce gripping engagement between the plurality of coils and the inner surface of the pulley in response to deceleration of the pulley relative to the carrier beyond a predetermined extent to permit the hub to rotate at a speed in excess of the pulley; a lubricant disposed on coils of the clutch spring, wherein the pulley and the hub cooperate to define an annular cavity in which the torsion spring and the clutch spring are disposed and wherein the torsion spring and the clutch spring are disposed axially between the carrier and the hub.