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 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 an isolation device is provided, comprising a hub that is connectable to a shaft; a pulley that is rotatable relative to the hub; at least one isolation spring positioned to transfer torque between the hub and the pulley, wherein each of the at least one isolation spring is an arcuate helical compression spring having an isolation spring axis that is arcuate; and a spring shell that is monolithic and that receives the at least one isolation spring and transfers torque between the at least one isolation spring and the pulley. The spring shell surrounds more than 180 degrees of the at least one isolation spring in a plane that is perpendicular to the isolation spring axis.

Abstract: 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.

Abstract: A synchronous drive is provided in which a non-circular rotor generates a fluctuating corrective torque to counteract a fluctuating load torque on a driven rotor. The angular orientation of the non-circular rotor can vary relative to the driven rotor so as to change the phase angle of the fluctuating corrective torque relative to the driving rotor. The arrangement may be applied in internal combustion engines with variable valve timing (VVT) systems, wherein the phase angle of a fluctuating load torque presented on a cam rotor, due to forces arising from actuation of intake and/or exhaust valves by the camshaft, varies relative to the crankshaft. The phase angle of the fluctuating corrective torque is also varied relative to the crankshaft to maintain phase relationship with the fluctuating load torque and thereby maintain reduced cam torsional vibrations and span tensions provided by the non-circular rotor during operation.

Abstract: In an aspect, a clutched device is provided, and includes an input member, an output member, a one-way clutch that can operatively connect the input member to the output member, and a motor including a stator and a rotor. The rotor is connected for rotation with a portion of the one-way clutch. The stator is operable to apply a first magnetic driving force to cause movement of the portion of the one-way clutch in a first rotational direction to increase a force of engagement between the input and output members. The stator is operable to apply a second magnetic driving force to cause movement of the portion of the one-way clutch to disengage the input and output members from each other.

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 clutched device is provided, including a hub, a pulley and a roller clutch. The roller clutch includes at least one roller and a cage. The roller is engageable with a first engagement surface operatively associated with the hub and is engageable with a second engagement surface operatively associated with the pulley. The cage is movable between a first position in which torque is transferrable from one of the hub and the pulley to the other of the hub and the pulley through the roller clutch and the isolation spring. The other of the hub and the pulley is permitted to overrun said one of the hub and the pulley, and a second position in which torque is transferred from said other of the hub and the pulley to the one of the hub and the pulley through the roller clutch.

Abstract: In an aspect, a tensioner is provided for tensioning an endless drive member that is engaged with a rotary drive member on a shaft of a motive device. The tensioner includes a base that is mountable to the motive device, a ring that is rotatably supported by the base in surrounding relationship with the shaft of the motive device and which is rotatable about a ring axis, a tensioner arm pivotally mounted to the ring for pivotal movement about an arm pivot axis, and first and second tensioner pulleys. The first tensioner pulley is rotatably mounted to the tensioner arm. The tensioner arm is biased towards a first span of the endless drive member on one side of the rotary drive member. The second tensioner pulley is rotatably mounted at least indirectly to the ring and is biased towards a second span of the endless drive member on another side of the rotary drive member.

Abstract: In an aspect, there is provided a pump impeller assembly that includes a first impeller portion arranged to drive a fluid through a fluid conduit, a second impeller portion movable between a more-rotationally engaged position in which the second impeller portion has a first amount of rotational engagement with the first impeller portion, and a less-rotationally engaged position in which the second impeller portion has a second amount of rotational engagement with the first impeller portion that is less than the first amount of rotational engagement, and an actuator operatively connected to the second impeller portion and configured to drive movement of the second impeller portion between the more-rotationally engaged position and the less-rotationally engaged position based on a fluid property.

Abstract: In an aspect, a decoupler includes a hub, a pulley, a torsion spring, a first spring driver fixed to the pulley, and having a first stop feature for the spring; a second spring driver mounted about the hub and not fixed to the pulley, and having a second stop feature for the spring, a driving clutch shaft mounted connected to the second spring driver, a driven clutch shaft mounted concentrically with the driving clutch shaft and drivingly connected to the hub, a one-way wrap spring clutch mounted about the hub and disposed to interconnect the driving and driven clutch shafts, and configured to transfer torque in a first direction between the driving and driven clutch shafts, and an axial biasing member acting between one of (i) the pulley and the driving clutch shaft and (ii) the hub and driven clutch shaft, to urge the driving and driven clutch shafts together.

Abstract: In an aspect a tensioner is provided for a belt drive and includes a base, an arm with a pulley pivotally mounted to the base, and a biasing member. The pulley is rotatably mounted to the arm. The belt applies a hub load on the pulley and thereby applies a hub load moment on the arm along a first moment arm. The biasing member applies a biasing member moment on the arm along a second moment arm that is at least about 50 percent of the length of the first moment arm. The tensioner is mountable to an accessory frame via fasteners that each have a center distance from an accessory pulley axis, wherein the center distance is a value that is less than about 25 mm greater than the frame body diameter.

Abstract: In an aspect, a tensioner is provided for tensioning an endless drive member that is engaged with a rotary drive member on a shaft of a motive device. The tensioner includes a base that is mountable to the motive device, a ring that is rotatably supported by the base in surrounding relationship with the shaft of the motive device and which is rotatable about a ring axis, a tensioner arm pivotally mounted to the ring for pivotal movement about an arm pivot axis, and first and second tensioner pulleys. The first tensioner pulley is rotatably mounted to the tensioner arm. The tensioner arm is biased towards a first span of the endless drive member on one side of the rotary drive member. The second tensioner pulley is rotatably mounted at least indirectly to the ring and is biased towards a second span of the endless drive member on another side of the rotary drive member.

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: 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.

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.