A tensioner comprising a base having a base aperture, the base aperture disposed to receive a driven component, a rotary arm pivotally engaged with the base, an axis of rotation of the rotary arm aligned with a base aperture center, a first pulley journalled to the rotary arm, a swing arm pivotally engaged with the rotary arm about a shaft, the shaft and swing arm each having cooperating frustoconical portions, a torsion spring biasing the pivot arm, a second pulley journalled to the swing arm, a bushing having a frustoconical portion in frictional engagement with the swing arm frustoconical portion, the bushing in fixed relation to the shaft or pivot arm, and a first damping ring frictionally engaged between the rotary arm and the base, a Belleville spring in pressing engagement whereby a normal force is applied to the first damping ring.

A coupling system can include an energy transfer device and a load mitigation system. The energy transfer device can include a shaft, gear, chain or piston-cylinder arrangement to transfer the energy from a power supply to an object to be moved. The load mitigation system can be used to limit or prevent the transfer of forces from the object to the drive unit as a result of external loads being applied to the object. The load mitigation system can be pre-loaded such that external loads on the object having an excessive impulsive or resonant cyclic force greater than the pre-load force on the load mitigation system are reduced and only partially transferred to the energy transfer device and power supply. The load mitigation system can dampen both resonant loads and impulsive impact loads occurring at the object thereby preventing damage and extending life.

A tensioner system may be replaced by selecting replacement components. Components such as a housing, roller arm, pulley, and index plate locating pin may be selected from a group of housings, roller arms, pulleys, and index plate locating pins, respectively. The selection of the components allows a user to assemble multiple variations of tensioner that are commercially available. The location of the index plate locating pin on the index plate allows for proper orientation of the tensioner in the vehicle in order to apply the proper tension to a belt. The selection of the components may be based on current tensioner model, or based on dimensions measured from the current tensioner.

An orbital tensioner comprising an annular base, a ring journalled to the annular base on a ball bearing, said ring having a ring axis of rotation (A-A), a first pulley journalled to the ring, a first pulley axis of rotation (B-B) offset from the ring axis of rotation (A-A), a pivot arm pivotally mounted to the ring, a pivot arm pivot axis (C-C) offset from the ring axis of rotation (A-A), a second pulley journalled to the pivot arm, a torsion spring biasing the pivot arm in a first direction, the ball bearing having a first race and a second race, the ring fixed to the first race, the annular base fixed to the second race, and a damping mechanism frictionally disposed between the ring and the base.

A tensioner for an accessory drive of an internal combustion engine has a belt on a first pulley connected to a drive shaft of the engine and a second pulley connected to an electric machine. The tensioner has a base configured to be fixed to a casing of the electric machine, a first ring rotating with respect to the base about a first axis, a second ring rotating with respect to the first ring about a second axis distinct from the first axis, a first tensioning pulley carried by the first ring and rotating with respect to it about its own axis, a second tensioning pulley carried by the second ring and rotating with respect to it about its own axis and elastic means acting on the first and on the second ring to push the first and the second pulleys into contact with respective spans of the belt.

In an aspect, a tensioner is provided for tensioning a belt on an engine, and includes a base mountable to a stationary member, and a first tensioner arm pivotably connected to the base. The first tensioner arm is biased in a first pivot direction. The tensioner includes a first bumper on one of the base and the first tensioner arm, which is engageable with a first travel limiter on the other of the base and the first tensioner arm to limit travel of the first tensioner arm in a second pivot direction, and a first pulley rotatably mounted to the first tensioner arm and positioned to engage a first section of the belt. The first bumper and the first travel limiter together have a selected first combined spring rate during engagement. The first combined spring rate increases progressively with compression between the first bumper and the first travel limiter.

In an aspect, a V tensioner is provided and includes a first arm and a second arm. A damping structure and a damping system biasing member are provided. The damping system biasing member is positioned axially in between the first and second arms.

An orbital tensioner comprising an annular base, a ring journalled to the annular base on a ball bearing, said ring having a ring axis of rotation (A-A), a first pulley journalled to the ring, a first pulley axis of rotation (B-B) offset from the ring axis of rotation (A-A), a pivot arm pivotally mounted to the ring, a pivot arm pivot axis (C-C) offset from the ring axis of rotation (A-A), a second pulley journalled to the pivot arm, a torsion spring biasing the pivot arm in a first direction, the ball bearing having a first race and a second race, the ring fixed to the first race, the annular base fixed to the second race, and a damping mechanism frictionally disposed between the ring and the base.

An electromechanical transmission and/or clutch actuator includes an electric motor for generating a driving rotational movement of a motor shaft, and elements for transmitting the driving rotational movement via a flexible drive from the electric motor to a spindle drive configured to convert the rotational movement to an axial actuation movement. The elements for transmitting the driving rotational movement may include a driving element such as a driving pulley or gear connected coaxially to the motor shaft, a driven element wheel such as a driven pulley or gear connected to the spindle drive, and a flexible element such as a drive belt which transfers the driving rotational movement from the motor shaft to the spindle drive.

A coupling system can include an energy transfer device and a load mitigation system. The energy transfer device can include a shaft, gear, chain or piston-cylinder arrangement to transfer the energy from a power supply to an object to be moved. The load mitigation system can be used to limit or prevent the transfer of forces from the object to the drive unit as a result of external loads being applied to the object. The load mitigation system can be pre-loaded such that external loads on the object having an excessive impulsive or resonant cyclic force greater than the pre-load force on the load mitigation system are reduced and only partially transferred to the energy transfer device and power supply. The load mitigation system can dampen both resonant loads and impulsive impact loads occurring at the object thereby preventing damage and extending life.