Ring tensioners having a plurality of rungs that extend from a first side to an opposite second side of the ring tensioner, in use, the rungs engaging between the teeth of a toothed belt. Both the first side and the second side of the ring tensioner are not continuous but have gaps. The gaps on the first side alternate with the gaps on the second side. The ring tensioners may be formed from a single length of wire.

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.

A tensioner comprising a base, a pivot arm pivotally engaged with the base, a pulley journalled to the pivot arm, a torsion spring urging the pivot arm, the torsion spring loaded in the unwinding direction, the torsion spring engaged with a damping shoe, the damping shoe frictionally engaging the base, and the damping shoe having a damping shoe portion comprising PTFE mixed within a plastic matrix material, the PTFE comprising between 2% and 4% of the plastic matrix material by weight.

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.

A tensioner comprising a base, a pivot arm pivotally engaged with the base, a pulley journalled to the pivot arm, a torsion spring urging the pivot arm, the torsion spring loaded in the unwinding direction, the torsion spring engaged with a damping shoe, the damping shoe frictionally engaging the base, and the damping shoe having a damping shoe portion comprising PTFE mixed within a plastic matrix material, the PTFE comprising between 2% and 4% of the plastic matrix material by weight.

Ring tensioners having a plurality of rungs that extend from a first side to an opposite second side of the ring tensioner, in use, the rungs engaging between the teeth of a toothed belt. Both the first side and the second side of the ring tensioner are not continuous but have gaps. The gaps on the first side alternate with the gaps on the second side. The ring tensioners may be formed from a single length of wire.

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.

A tensioning and damping element for endless chain drives, especially for roller chain drives, can be used for endless chain drives, which are to be tensioned diametrically. The material is an elastic plastic. All told, the known tensioning and damping elements, in conjunction with the wear of the chain, the load changing phases, as well as the reversing according to the degree of deformation, have the disadvantage of a phased running irregularity, an increased running noise and of wear-intensive areas in the toothed rim. An element with a ring part and a toothed rim of arc-shaped teeth with, in each case, axially opposite bulges in the roller-seating and, between these, roller-seating depressions, grooves, which are disposed peripherally between the ring part and the bulges, an extended pitch and extended roller-seatings with the advantageous profile shape similar to a semielliptical curve lying on the root circle.