In an aspect, a tensioner for an endless drive member, comprising a shaft and base that are mountable to be stationary relative to an engine, a tensioner arm that is pivotable relative to the shaft about a tensioner arm axis, a pulley on the tensioner arm rotatable about a pulley axis that is offset from the tensioner arm axis, and that is engageable with an endless drive member, a bushing that is positioned radially between the pulley and the tensioner arm to support the pulley radially during relative rotation between the pulley and the tensioner arm, a tensioner spring that is positioned to urge the tensioner arm towards a free arm position, a damping element that engages the tensioner arm and that is engaged by a plurality of axially spaced segments of the tensioner spring.

A belt tensioner having a tensioner base and a tensioning arm axially aligned about a pivot shaft defining a pivot axis, the tensioning arm pivotal in relation to the tensioner base about the pivot axis. The tensioner has a bearing positioned around and sealed against the pivot shaft, with the tensioning arm positioned around the bearing. The bearing forms a radial seal between the bearing and the tensioning arm and between the bearing and the pivot shaft. A torsion spring is positioned externally around a portion of the tensioning arm.

A pattern for application to the face of the tensioner arm, guide or snubber in contact with a chain to intentionally break up the chain contact force between the back of the chain links and the tensioner arm, guide or snubber face. This is done to prevent alignment with the chain related orders which are causing NVH within the chain system or to increase overall NVH to obscure chain related orders.

In an aspect, a tensioner includes a shaft and base unit that is mountable to an engine, an arm pivotable about the shaft and base unit, a pulley on the arm engageable with a belt, a spring urging the arm in a free arm direction, a first damping member fixed on the shaft and base unit, which receives a first radial force from a first segment of the spring causing a first amount of frictional force between the first damping member and a surface that moves with the tensioner arm, and a second damping member on the arm, which receives a second radial force from a second segment of the tensioner spring that is spaced axially from the first segment of the spring, causing a second amount of frictional force between the second damping member and a surface that is stationary with the shaft and base unit.

A tensioner includes a power spring, and a backup member being in contact with the power spring and supporting the power spring by acting an urging force in a direction opposite to a radial shift of the power spring in a direction in which the power spring is wound. The power spring is unwound in a condition in which an inter-plate frictional force of the power spring is small in a case where an urging force acting from a power spring to a tension member is greater than a load acting from the tensioner arm to the power spring and the power spring is wound in a condition in which the inter-plate frictional force of the power spring is large in a case where the urging force acting from the power spring to the tension member is smaller than the load acting from the tension member to the power spring.

A tensioner moves the flow restriction controlling the tensioner tuning to the nose of the piston through a hole ranging in cross sectional area from 0.01 mm.sup.2 to 1.1 mm.sup.2. It also eliminates a component from the design of the tensioner. The piston hole geometry is one or a plurality of holes.

A belt tensioner for a belt drive of a motor vehicle engine, comprising: a fixed part configured to be fixed with respect to the engine and provided with a pivot defining a rotation axis; an arm having a connection portion hinged to the pivot and rotatable about the rotation axis and an opposite portion rotatably supporting a pulley configured to cooperate with a belt of the drive; a main spring interposed between the fixed part and the arm to exert thrust on the arm such as to rotate said arm towards the belt; and at least one rolling bearing interposed between the arm and the pivot to support the arm and ensure the alignment thereof.

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 includes a power spring, and a backup member being in contact with the power spring and supporting the power spring by acting an urging force in a direction opposite to a radial shift of the power spring in a direction in which the power spring is wound. The power spring is unwound in a condition in which an inter-plate frictional force of the power spring is small in a case where an urging force acting from a power spring to a tension member is greater than a load acting from the tensioner arm to the power spring and the power spring is wound in a condition in which the inter-plate frictional force of the power spring is large in a case where the urging force acting from the power spring to the tension member is smaller than the load acting from the tension member to the power spring.

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.