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 and that defines an isolator axis, a rotary drive member that is engageable with the endless drive member, a first isolation spring arrangement that includes a first torsion spring, and that is positioned to transfer torque between the shaft adapter and an intermediate drive member, and a second isolation spring arrangement that is positioned to transfer torque between the intermediate member and the rotary drive member.

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: 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, 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 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 and that defines an isolator axis, a rotary drive member that is engageable with the endless drive member, a first isolation spring arrangement that includes a first torsion spring, and that is positioned to transfer torque between the shaft adapter and an intermediate drive member, and a second isolation spring arrangement that is positioned to transfer torque between the intermediate member and the rotary drive member.

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, 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: 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: In an aspect, an assembly is provided and includes a pulley device and a drive shaft. The pulley device includes a pulley and has a shaft adapter. A selected amount of combined resistance in the first and second connections to relative rotation in the second direction is generated by a threaded first connection and a second connection between the shaft adapter and the shaft at least some of which is provided by a compression force between them.

Abstract: In an aspect, a system is provided for controlling tension in an endless drive member, and including an isolation device and a tensioning system. The isolation device is positioned on an accessory drive shaft and has a pulley and a biasing member to transfer force from the pulley to the accessory drive shaft. The isolation device pulley is engaged with the endless drive member, such that a first span of the endless drive member is on a first side of the isolation device pulley and a second span of the endless drive member is on a second side of the isolation device pulley. The tensioning system has a first tensioner pulley engaged with the first span and a second tensioner pulley engaged with the second span. The first and second tensioner pulleys are urged by first and second tensioner pulley biasing forces towards the first and second spans respectively.

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 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: 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 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 one aspect, a tensioner is provided, comprising, a first tensioner arm and a second tensioner arm, a first wheel and a second wheel. The first tensioner arm is pivotable about a first pivot axis. The second tensioner arm is pivotally connected to the first arm so as to be pivotable about a second pivot axis located at a selected distance from the first pivot axis. The first wheel is rotationally connected to the first tensioner arm about a first rotation axis. The second wheel is rotationally connected to the second tensioner arm about a second rotation axis. The first and second wheels are configured to engage an endless drive member. The first and second wheels are biased in respective first and second free arm directions.

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 crank shaft is driven by the belt.

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: 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 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: In one aspect, a tensioner is provided, comprising, a first tensioner arm and a second tensioner arm, a first wheel and a second wheel. The first tensioner arm is pivotable about a first pivot axis. The second tensioner arm is pivotally connected to the first arm so as to be pivotable about a second pivot axis located at a selected distance from the first pivot axis. The first wheel is rotationally connected to the first tensioner arm about a first rotation axis. The second wheel is rotationally connected to the second tensioner arm about a second rotation axis. The first and second wheels are configured to engage an endless drive member. The first and second wheels are biased in respective first and second free arm directions.