Abstract: A decoupler having an input hub, an output member, a one-way clutch, and at least one isolation spring. Rotary power is transmitted in a predetermined rotational direction from the input hub, through the one-way clutch, through the isolation spring and to the output member. A method for forming a decoupler is also provided.

Abstract: In an aspect, a tensioner for tensioning an endless drive member on an engine, is provided, comprising a base that mounts to the engine, a tensioner arm that is pivotally connected to the base for pivotal movement about a tensioner arm axis, a pulley rotatably mounted to the tensioner arm for rotation about a pulley axis that is spaced from the tensioner arm axis, a tensioner spring and a damping member. The tensioner spring is positioned to urge the tensioner arm into an endless drive member. The spring has a first helical end and a second helical end. The first helical end is positioned to transfer force with a first spring end force transfer surface on the base and the second helical end is positioned to transfer force with a second spring end force transfer surface on the tensioner arm. The damping member is positioned in a surrounding relationship with the tensioner spring.

Abstract: In an aspect, the invention relates to a decoupler that is positionable between a shaft (eg. for an alternator) and an endless power transmitting element (eg. a belt) on an engine. The decoupler includes a hub that mounts to the shaft, and a pulley that engages the endless power transmitting element, an isolation spring between the hub and the shaft. The decoupler provides at least a selected damping torque between the hub and the pulley.

Abstract: In an aspect, a decoupler is provided, comprising a hub defining an axis, a pulley, a one way clutch and an isolation spring that act in series, a damping member that frictionally engages a friction surface the pulley or the hub, and a biasing member that urges the damping member into the friction surface. The biasing member has a mounting portion having an axially extending first mounting surface that is fixedly engaged with a second axially extending mounting surface on the other of the pulley and hub and an engagement portion resiliently connected to the mounting portion by a transition portion having at least one bend that urges the engagement portion into engagement with the damping member with a selected force. The at least one bend resiliently permits axial movement of the damping member engagement portion independent of the mounting portion.

Abstract: In an aspect, a tensioner is provided for tensioning a belt and includes first and second tensioner arms having first and second pulleys respectively. The first and second pulleys are configured for engagement with first and second belt spans, and are biased in first and second free arm directions respectively. A second tensioner arm stop is positioned to limit the movement of the second tensioner arm in a direction opposite the second free arm direction. The second tensioner arm stop is positioned such that, in use, the second pulley is engaged with the endless drive member while the second tensioner arm is engaged with the second tensioner arm stop throughout a first selected range of operating conditions.

Abstract: In an aspect, a clutch assembly is provided that uses an electromagnet to generate a magnetic circuit which drives an armature to a position whereat it engages the clutch to operatively connect a rotating member to a stationary member. In embodiments wherein the armature initially rotates with the rotating member, the magnetic circuit passes through the stationary member. In embodiments wherein the armature is initially stationary, the magnetic circuit extends through the rotating member.

Abstract: In an non-limiting embodiment, 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, a rotary drive member that is engageable with the endless drive member, a torsion spring that is positioned to transfer torque between the shaft adapter and the rotary drive member, and a torque limiting surface. The torsion spring has a first helical end, a second helical end and a plurality of coils between the first and second helical ends. The torque limiting surface has a selected non-zero spacing from the coils.

Abstract: A tensioner for an engine accessory drive system includes a tensioner arm pivotally mounted for movement between a free arm position and a load stop position. The tensioner arm includes a pulley which engages a belt. A piston, disposed in a cylinder, is pivotally linked to the tensioner arm. A spring urges the tensioner arm towards the free arm position. A moveable load stop member, controlled by an actuator, projects into the cylinder. The load stop member abuts the piston to thereby arrest movement of the tensioner arm and define the load stop position. The actuator may drive the load stop member against the piston to move the tensioner arm towards the free arm position so as to increase belt tension.

Abstract: A decoupler having an input member, an output member and a combination one-way clutch and torsional isolator that couples the input and output members. The combination one-way clutch and torsional isolator includes a single helical coil spring. The decoupler being designed to provide torsional damping through a range of torque transmitted through the decoupler, the range including a maximum rated torque for the decoupler.

Abstract: A driven accessory comprising a first rotary clutch portion, a second rotary clutch portion, a wrap spring and an actuator. The actuator is selectively operable for generating a force that is applied to a second end of the wrap spring. The actuator includes an actuator input member that is rotatable about a rotary axis relative to the first rotary clutch portion. The actuator input member is axially movable along the rotary axis between a first position, in which the actuator input member is drivingly engaged to the first rotary clutch portion to cause the wrap spring to uncoil against a clutch surface on the first rotary clutch portion such that rotary power is transmitted between the first rotary clutch portion and the second rotary clutch portion, and a second position in which the actuator input member is disengaged from first rotary clutch portion.

Abstract: A decoupler that includes a hub, a drive member and a one-way clutch and torsionally resilient coupling. The drive member is configured to engage an endless power transmitting element. The one-way clutch and torsionally resilient coupling is disposed in series in a torque path and has a carrier and a wrap spring. The carrier defines a groove. The wrap spring is formed of wire and has an engagement end and a plurality of helical coils. The engagement end is being shorter in overall length than a length of one of the helical coils. The engagement end is received in the groove. The carrier is received in a pocket formed in a rotary member that can be the hub, the drive member, or a component in a torque path between the hub and the drive member. An axial end face of the wire that forms the wrap spring is abutted against an edge of the pocket.

Abstract: A tensioner assembly that includes a base, an arm, an opening spring (i.e., a torsion spring that opens or radially expands with increasing torque applied thereto), a spring reaction member, and a pivot bushing. The tensioner assembly is configured to orient various loads in predetermined directions. For example, a spring load can be oriented to counteract a hub load to reduce a bushing load that acts on the pivot bushing. As another example, a spring reaction force exerted by the spring reaction member can be employed by a damping mechanism to generate a grounding force that is parallel to the spring reaction force and is directed to intersect an axis about which the arm pivots relative to the base. A tensioner assembly having improved assembly characteristics is also provided.

Abstract: A driven accessory (10) is provided that includes a first rotary clutch portion (50), a second rotary clutch portion (52), a wrap spring (56) and an actuator (60). The wrap spring (56) is configured to transmit rotary power between the first and second rotary clutch portions (50, 52). The actuator (60) is selectively operable for generating a drag force that is applied to the wrap spring (56) to control torque transmission through the wrap spring (56). The actuator (60) includes an actuator input member (140), a brake shoe (144) and a motor (142) that is configured to translate the brake shoe (144) axially along the rotary axis (70). The drag force is generated when the motor (142) is operated in a first mode so that transmission of rotary power between the first rotary clutch portion (50) and the second rotary clutch portion (52) is interrupted.

Abstract: A tensioner having a closing-type torsion spring that is employed to bias a pivot arm about a pivot shaft. The tensioner includes a damper, which contacts an inside surface of the torsion spring to dampen torsional vibration transmitted through the torsion spring, and a one-way clutch that is configured to permit unencumbered rotation of the pivot shaft in one rotational direction but to resist rotation of the pivot shaft in an opposite direction.

Abstract: An engine starter apparatus having a clutch assembly and a ring gear or pulley. The clutch assembly has a plate structure, a drive hub and a clutch element for selectively coupling the drive hub to the plate structure. The ring gear or pulley is coupled to the plate structure.

Abstract: A clutched driven device (10) having a clutch assembly (16) with a first rotary clutch portion (50), a second rotary clutch portion (52), a bearing (54), a wrap spring (56) and an actuator (60). The first rotary clutch portion has an interior clutch surface (76). The first and second rotary clutch portions are rotatably disposed about a rotary axis (70) of the clutched driven device. The bearing is received between the first and second rotary clutch portions and supports the first rotary clutch portion for rotation on the second rotary clutch portion. The wrap spring is disposed radially inwardly of the bearing and has a plurality of helical coils (114) that are received against the interior clutch surface. The actuator is configured to selectively initiate coiling of the wrap spring to cause the helical coils of the wrap spring to disengage the interior clutch surface to a predetermined extent.

Abstract: A component, such as an engine accessory for an automotive engine, that has clutch with a helical clutch coil and an axially movable armature. The helical clutch coil is normally engaged so as to transmit rotary power between a driving member and a driven member. The armature can be moved to apply a force to a tang of the helical clutch coil that causes the helical clutch coil to disengage to an extent where full rotary power is not passed through the clutch to drive the component.

Abstract: In one aspect, the invention is directed to a decoupler assembly for between an endless drive element and a shaft. The endless drive element may be, for example, an accessory drive belt from a vehicular engine. The shaft may be, for example, the input shaft of a belt-driven accessory, such as an alternator or a compressor. The decoupler assembly includes a hub that mounts to the shaft, a pulley that is rotatable with respect to the hub, a dampening spring and a clutch member. A part of the pulley is supported on a pulley support surface on the hub. There is a gap between the pulley and the pulley support surface. The gap has lubricant therein to facilitate sliding between the pulley and the pulley support surface. By eliminating the use of a polymeric bushing between pulley and the hub, there are several advantages that are provided.

Abstract: An engine starter that employs a clutch between a flywheel or flex plate and a plate structure that is configured to receive rotary power from a starter motor through a transmission. The transmission may include ring and pinion gears or a belt that transmits rotary power between pulleys.

Abstract: A method for producing an over-running decoupler that is configured to transmit rotary power between a rotary member and a hub. The over-running decoupler includes a one-way clutch having a clutch spring, a carrier that is coupled to the clutch spring and at least one spring that resiliently couples the carrier to the hub. The method includes: establishing a desired fatigue life of the at least one spring; establishing a design deflection of the at least one spring during resonance, wherein deflection of the at least one spring at the design deflection during resonance does not reduce a fatigue life of the at least one spring below the desired fatigue life; and preventing resonance in the over-running decoupler by controlling a maximum deflection of the at least one spring such that the maximum deflection is less than or equal to the design deflection.