A belt tensioning device comprises a base member having an attachment portion and an opening for a drive shaft; first and second tensioning arms that are pivotably supported by first and second bearings on the base member around first and second pivot axes and have first and second tensioning rollers 5, 7. A spring arrangement pretensions the two tensioning arms in a circumferential direction towards each other; wherein the spring arrangement has at least one bow-shaped spring that has a circumferential extension of less than 360° around the first and the second pivot axis; wherein the at least one bow-shaped spring has first and second support portions that are supported on the first and second tensioning arm as well as a spring portion extending between the first and second support portion; wherein the at least one bow-shaped spring has an axial length in the area of the first and the second support portion which is axially shorter than a total axial length of the bow-shaped spring.

A chain tensioning device which combats natural build-up of chain slack. In controlling the chain slack, the torque at which a chain jumps occurs is delayed resulting in a higher jump torque performance.

A toothed CVT using a Cone with One Torque Transmitting Member that is coupled by a Transmission Belt to another Cone with One Torque Transmitting Member for which teeth re-engagement between the Torque Transmitting Members and their Transmission Belt is improved. Said CVT uses a slack-side Tensioning Pulley in order to maintain the tension in the slack-side of the Transmission Belt almost constant so as to ensure smooth re-engagement of the Driven Cone; and a Transmission Diameter Compensating Mechanism, which increases the Transmission Diameter of the Driving Cone when the torque being pulled by the Driving Cone is increased, in order to compensate for an increase in “Transmission Belt Teeth Compression” and an increase in “stretching of the tense-side of the Transmission Belt”, due to an increase in tension in the tense-side of the Transmission Belt when an increased torque is transmitted; to ensure smooth re-engagement of the Driving Cone.

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.

A belt tensioner for an engine accessory drive is installed over a pulley such that rollers extend toward the engine. Due the belt being between the tensioner and the engine, installation of the belt on the pulley is difficult. To simplify installation, a removable belt guide is included in the belt tensioner. Two methods of installing the belt and tensioner are envisioned. In a first method, the belt is first installed on the pulley and the belt guide holds the belt toward the pulley radially as the tensioner is installed over the pulley. In a second method, the belt is first installed to the tensioner and the guide holds the belt radially away from the pulley as the tensioner is installed over the pulley. In both methods, the belt guide is removed after the belt and tensioner are installed.

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.

A belt tensioning device includes a base body. A first tensioning arm is mounted on the base body such that it can pivot about a first pivot axis and which has a rotatable first tensioning roller. A second tensioning arm is pivotably mounted relative to the base body about a second pivot axis and which has a rotatable second tensioning roller. A spring arrangement is arranged between the first tensioning arm and the second tensioning arm and via which the first tensioning arm and the second tensioning arm are resiliently supported against one another in the circumferential direction.

A damping mechanism is operatively arranged between the base body and the first tensioning arm for damping relative rotational movement between the first tensioning arm and the base body.

The damping mechanism generates a varying damping torque dependent on the rotational position and/or rotational direction of the first tensioning arm relative to the base body upon pivoting of the first tensioning arm relative to the base body.

A chain tensioning device which combats natural build-up of chain slack. In controlling the chain slack, the torque at which a chain jumps occurs is delayed resulting in a higher jump torque performance.

A belt tensioner for an engine accessory drive is installed over a pulley such that rollers extend toward the engine. Due the belt being between the tensioner and the engine, installation of the belt on the pulley is difficult. To simplify installation, a removable belt guide is included in the belt tensioner. Two methods of installing the belt and tensioner are envisioned. In a first method, the belt is first installed on the pulley and the belt guide holds the belt toward the pulley radially as the tensioner is installed over the pulley. In a second method, the belt is first installed to the tensioner and the guide holds the belt radially away from the pulley as the tensioner is installed over the pulley. In both methods, the belt guide is removed after the belt and tensioner are installed.