Abstract: In an aspect, an isolator is provided for isolating torsional vibration between a crankshaft of an engine and an endless drive member. The isolator includes a driver drivable by the crankshaft, a pulley that is engageable with an endless drive member, at least one isolation spring that is positioned to transfer forces between the driver and the pulley and to isolate torsional vibrations in the driver and the pulley from one another, and a damping structure configured to frictionally resist relative movement between the driver and the pulley beyond a selected relative threshold angle, and to permit relative movement between the driver and the pulley within the selected relative threshold angle without frictional resistance from the damping structure.

Abstract: In an aspect, a tensioner includes a pulley, a main piston chamber, a reservoir, and first and second fluid passageways connecting the main piston chamber and reservoir, a main piston that is movable in the main piston chamber, a check valve, a control valve, and a movable reservoir member. The check valve prevents flow in one direction through the second passageway and permits flow in an opposing direction through the second passageway. The control valve is movable between to provide a first flow resistance, or a second flow resistance. The movable reservoir member is movable based on the amount of fluid in the reservoir in such a way as to change the volume of the reservoir, such that the reservoir, the main piston chamber and the first and second passageways together are included in a fluid circuit that is substantially free of any compressible fluids.

Abstract: In an aspect, an isolator is provided, comprising a hub, a pulley, an isolation spring and a transition spring. The hub defines an axis and is connectable to a rotatable shaft of a rotary device. The pulley is rotatably mounted to the hub. The isolation spring and transition spring act in series in a torque path between the pulley and the hub. The isolation spring has a first spring rate. The transition spring has a second spring rate that is lower than the first spring rate.

Abstract: In an aspect, an electromechanical apparatus is provided, comprising an electromagnet, a magnetically permeable rotor, a drive, a current source, a current sensor and processing logic. The electromagnet includes a magnetically permeable housing and a wire coil disposed therein. The rotor spins and is disposed in the path of a magnetic circuit generated by the electromagnet. The drive rotates the rotor relative to the electromagnet housing. The rotor and electromagnet housing vary the reluctance therebetween as the rotor rotates. The current source applies a current to the electromagnet coil, wherein, during rotation of the rotor, fluctuations in the current result in the electromagnet coil due to the aforementioned varying reluctance are superimposed on the applied current. The current sensor senses fluctuations in current in the electromagnet coil. The processing logic reads the sensed current and determines the frequency of the fluctuations, which are correlated to rotor speed.

Abstract: An isolator includes a driver that is connectable with a shaft of a device, a rotary drive member that is engageable with an endless drive member; and a first isolation spring and a second isolation spring. The first and second isolation springs are positioned such that during rotation of the driver in a first direction torque is transferred from the driver to the first rotary drive member through the first isolation spring and not through the second isolation spring, and such that during rotation of the first rotary drive member in the first direction torque is transferred from the first rotary drive member to the driver through the second isolation spring and not through the first isolation spring.

Abstract: In an aspect, a spring assembly is provided for an isolator, and includes first and second helical compression springs, a retainer and a spring housing. The first helical compression spring has a central aperture and has a first end and a second end. The second helical compression spring having a central aperture and having a first end and a second end, wherein the second spring is coaxial with and nested within the first spring. The retainer has a base and a post that extends from the base into the central aperture at the first end of the second helical spring. The spring housing that has an interior space in which the first and second springs are positioned, and further includes a base-engaging aperture that holds the base of the retainer. The spring housing includes a drive wall that is engaged with the first ends of the first and second springs.

Abstract: In one aspect the invention relates to a tensioner that is capable of precognitively anticipating when it is desirable to increase the tension in a belt or other endless drive element so as to prevent belt slip prior to events that would raise the risk of it.

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, 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 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, 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, 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 first isolation spring arrangement that is positioned to transfer torque between the shaft adapter and the rotary drive member, and a position-based damping structure. The damping structure is positioned to transfer torque via a frictional damping force between the rotary drive member and the shaft adapter at a selected amount of relative movement therebetween. The selected amount of relative movement is selected to be less than a maximum permitted amount of flexure of the first isolation spring arrangement.

Abstract: In an aspect, a tensioner is provided for maintaining tension in an endless drive member in a belt-in-oil drive system. The tensioner includes a base that is mountable to a stationary structure and that has a circumferential wall that defines an arm pivot axis, an arm having a radially inner arm surface, and an endless drive member engagement surface that is engageable with an endless drive member, a bushing positioned between the radially inner arm surface and the circumferential wall of the base cup, and a tensioning spring. The arm is supported on the base cup via the bushing. The tensioning spring is positioned to bias the arm in a first direction about the arm pivot axis.

Abstract: An isolator is provided for use with an engine and in particular an engine that is assisted or started by MGU (Motor-Generator Unit) or a motor through an endless drive member. It comprises a double acting spring system for isolating crankshaft pulley from torsion vibration at the crankshaft, and in extreme conditions, such as during engine startup and accelerations or decelerations of the engine crankshaft relative to the pulley and when isolator operates in an “engine-driven” mode with the engine crankshaft is driven by the belt.

Abstract: In an aspect, a tensioner for an endless drive member, comprising a shaft and base that are mountable to be stationary relative to an engine, a tensioner arm that is pivotable relative to the shaft about a tensioner arm axis, a pulley on the tensioner arm rotatable about a pulley axis that is offset from the tensioner arm axis, and that is engageable with an endless drive member, a tensioner spring that is positioned to urge the tensioner arm towards a free arm position, a damping element that engages the tensioner arm and that is engaged by a plurality of axially spaced segments of the tensioner spring.

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 aspect, a tensioner for an endless drive member, comprising a shaft and base that are mountable to be stationary relative to an engine, a tensioner arm that is pivotable relative to the shaft about a tensioner arm axis, a pulley on the tensioner arm rotatable about a pulley axis that is offset from the tensioner arm axis, and that is engageable with an endless drive member, a bushing that is positioned radially between the pulley and the tensioner arm to support the pulley radially during relative rotation between the pulley and the tensioner arm, a tensioner spring that is positioned to urge the tensioner arm towards a free arm position, a damping element that engages the tensioner arm and that is engaged by a plurality of axially spaced segments of the tensioner spring.

Abstract: A decoupler assembly that includes a hub, a pulley and a mechanism for transmitting rotary power between the hub and the pulley. The mechanism includes a torsion spring and a one-way clutch. The torsion spring is configured to dampen vibration in the rotary power that is transmitted from the pulley to the hub. The one-way clutch has a wrap spring that is smaller in diameter than the torsion spring.

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.