The present invention provides a chain tensioner that while being free from an increase in its size, reduces the number of processing parts and the number of assembling steps and reduces the outflow of oil to an outside. Inside a plunger, an inner sleeve including a check valve unit provided on a side of a pressure oil chamber and a pressure regulating unit provided on an outer periphery thereof is arranged. The inner sleeve has a cylinder part and a movement restricting part provided on the side of the pressure oil chamber, and the pressure regulating unit has an annular relief valve slidably fitted onto an outer surface of the cylinder part and slidably contacting on an inner surface of the plunger and a relief spring urging the relief valve to a side of the movement restricting part.

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.

A belt tensioner for a belt system having a compression spring internal to the tensioning arm, the tensioning arm pivotable in relation to the pivot shaft and the tensioner base. The compression spring provides an axial force against an axially slidable hub bearing, which moves to accommodate variations in spring force and/or dimensional changes.

A linear tensioner is provided for tensioning a traction mechanism provided in a drive system with a first adjustment element that has a hollow-cylindrical construction and a second adjustment element that is guided so that it can be moved longitudinally on this first element, wherein contact surfaces are formed on facing end surfaces of the adjustment elements, on which a compression spring actuating at least one of the adjustment elements in the tensioning direction is supported. A transport securing device is provided that prevents, in a specified locked position, a movement of the adjustment elements relative to each other by at least one locking element.

An accessory drive system for an engine 1 includes: a drive shaft (a crankshaft 21); a driven shaft (an oil pump drive shaft 31); an endless transmission member (a drive chain 33); a first tensioner disposed on a slack side of the endless transmission member (a first hydraulic tensioner 41); and a second tensioner disposed on a tight side of the endless transmission member (a second hydraulic tensioner 43). The second tensioner has a damping function to damp pushing force applied to the second tensioner by the endless transmission member in a direction opposite to a biasing direction.

The present disclosure provides an automatic belt tensioner for an engine which automatically adjusts the tension of a belt for transmitting rotational force between an engine and an auxiliary machinery component. The automatic belt tensioner includes: a tensioner body mounted at the engine side and having an internal space; a tension spring installed in the internal space of the tensioner body; first and second damping shoes coupled by the tension spring; a first arm having a hinge portion coupled to the first damping shoe; a second arm having a hinge portion coupled to the second damping shoe; and idlers rotatably mounted on the first and second arms, respectively, and also supporting the belt. The first hinge portion which is a rotation center of the first arm and the second hinge portion which is a rotation center of the second arm are rotatably coupled to the tensioner body.

A belt drive system for rotatably coupling an internal combustion engine to an electric machine is described. The belt drive system includes a serpentine belt and a hydraulic strut tensioner, wherein the hydraulic strut tensioner is disposed to exert a tension force on the serpentine belt. A controller is operatively connected to the electric machine and includes an instruction set that is executable to periodically induce a reduction in torque output of the electric machine.

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.

In an aspect, a tensioner for tensioning an endless drive member on an engine, is provided, comprising a base that mounts to the engine, a tensioner arm that is pivotally connected to the base for pivotal movement about a tensioner arm axis, a pulley rotatably mounted to the tensioner arm for rotation about a pulley axis that is spaced from the tensioner arm axis, a tensioner spring and a damping member. The tensioner spring is positioned to urge the tensioner arm into an endless drive member. The spring has a first helical end and a second helical end. The first helical end is positioned to transfer force with a first spring end force transfer surface on the base and the second helical end is positioned to transfer force with a second spring end force transfer surface on the tensioner arm. The damping member is positioned in a surrounding relationship with the tensioner spring. The damping member includes a spring force adjustment member having a first end face and a second end face spaced from the first end face by a selected angular spacing. The damping member includes a first portion that contains the spring force adjustment member and that is generally rigid, and at least one second portion that is adjacent the first member and that is flexibly joined to the first member. The spring force adjustment member is positioned between one of the spring ends and one of the spring end force transfer surfaces on one of the base and the tensioner arm. The damping member is frictionally engaged with the other of the base and the tensioner arm during pivotal movement of the tensioner arm relative to the base.

A tensioning system including a magnetic stop is provided. The tensioning system includes a tensioner arm and a support. The tensioner arm is mounted on the support for pivoting movement. The support includes a support magnetic or ferromagnetic element on at least a first surface thereof. The tensioner arm includes a tensioner arm magnet on at least a second surface thereof that faces the first surface of the support.