A chain tensioner includes a housing that forms a cylindrical receptacle. A piston is surrounded at least in part by the receptacle. The inner surface of the receptacle axially guides the piston when the piston travels into and out of the housing. The chain tensioner further includes a locking unit which limits the inward travel of the piston. The locking unit includes a stop facing the housing, and a mating stop facing the piston. A locking element establishes a force-transmitting connection between the stop and the mating stop. At a location of the stop facing the housing, the housing axially forms a locking section that is located between the locking element and the piston. The locking section includes at least one recess, allowing the locking element to establish the force-transmitting connection between the stop and the mating stop.

A belt-type continuously variable transmission capable of continuously changing a speed reduction ratio of a driven pulley to a drive pulley, has a speed reduction ratio regulation mechanism that regulates a minimum speed reduction ratio of the driven pulley to the drive pulley. The driven pulley includes a fixed sheave, a movable sheave displaceable in an axial direction with respect to the fixed sheave, and a coil spring that urges the movable sheave toward the fixed sheave. The speed reduction ratio regulation mechanism has a swing arm that adjusts an allowable range in which moving away in an axial direction of the movable sheave with respect to the fixed sheave is possible, and a regulation drive section that drives the swing distal end portion of the swing arm to swing continuously.

A hydraulic auto-tensioner is provided which includes a cylinder, a valve sleeve, a rod, a spring seat, and a plunger slidably fitted on the outer diameter surface of the rod. A first leakage gap is defined between the fitting surfaces of the plunger and the rod. A second leakage gap is defined between the fitting surfaces of the plunger and the valve sleeve such that the resistance to oil flowing in the second leakage gap is larger than the resistance to oil flowing in the first leakage gap. With the engine running normally, when the tension of the belt increases, and thus a pushing force is applied to the hydraulic auto-tensioner such that the cylinder and the spring seat are pushed toward each other, oil in a pressure chamber leaks through the first leakage gap into a reservoir chamber.

The invention provides a simple-structured tensioner lever capable of suppressing deflection of a stopper member and allows smooth assembly of the tensioner lever into an engine. The tensioner lever includes a stopper member for locking a coil spring, this stopper member including: a stopper pin portion inserted into a pin hole; a stopper front side extension portion continuous with one end of the stopper pin portion and protruding toward a base front surface; a stopper rear side extension portion continuous with the other end of the stopper pin portion and protruding toward a base rear surface; a spring lock portion formed in the stopper rear side extension portion and making engagement with a spring support arm; and a stopper movement restricting portion making engagement with the spring support arm to restrict movement of the spring support arm in a direction away from the base rear surface.

A belt-type continuously variable transmission capable of continuously changing a speed reduction ratio of a driven pulley to a drive pulley, has a speed reduction ratio regulation mechanism that regulates a minimum speed reduction ratio of the driven pulley to the drive pulley. The driven pulley includes a fixed sheave, a movable sheave displaceable in an axial direction with respect to the fixed sheave, and a coil spring that urges the movable sheave toward the fixed sheave. The speed reduction ratio regulation mechanism has a swing arm that adjusts an allowable range in which moving away in an axial direction of the movable sheave with respect to the fixed sheave is possible, and a regulation drive section that drives the swing distal end portion of the swing arm to swing continuously.

A tensioner is disclosed. The tensioner includes an arm, a tong, and a clutch. The arm is rotatable about a first axis in an opposite direction. The arm includes at least one stopping element. The tong is selectively engaged with the at least one stopping element of the arm. The arm is substantially prevented from rotating in the opposite direction if the tong is engaged with the at least one stopping element. The clutch is operatively coupled to the arm. The clutch includes an engaged and a disengaged position. If the clutch is in the engaged position, then the tong is engaged with the at least one stopping element of the arm.

In an aspect, a tensioner is provided for an endless drive arrangement. The tensioner includes a base, an arm movably mounted to the base, and which has a pulley thereon for engagement with a belt. The tensioner further includes an arm biasing member to bias the arm in a free arm direction, and a tensioner lock, including a locking feature on one of the arm and the base, and a projection that is movably mounted to the other of the arm and the base, and is movable between a locking position and a release position. The projection includes first and second parts. The second part is engageable with the locking feature. The first part has a first projection-withdrawal limit surface thereon that is engageable with a second projection-withdrawal limit surface on the other of the arm and the base to prevent complete withdrawal of the projection.

An auto tensioner is supported on one side surface of a cylinder block (the outer surface of a front wall part) via a bracket. The auto tensioner includes: a tension pulley that is pressed against a belt; an arm that rotatably supports the tension pulley and is swingably supported to the bracket; and a hydraulic actuator that is supported by the arm and bracket to adjust the pressing force of the tension pulley to the belt using a predetermined position of the arm as a supporting point. The hydraulic actuator is disposed outside the water pump on the front wall part of the cylinder block.

A crusher belt tensioning apparatus is arranged for being mounting on a crusher having a driven crusher pulley to actuate a crusher, a drive pulley drivable by a power unit, a belt extending between the crusher pulley and the drive pulley to transfer drive from the power unit to the crusher, and a tension drum mounted on a tension arm for applying a tension force to the belt. The tension arm includes a first relatively short arm portion and a second relatively long arm portion connected to the first relatively short arm portion. The tension drum is movable by a hydraulic cylinder, attached to the relatively short arm portion, between a first belt tensioning operating position in which the tension drum applies tension to the belt and a second belt non-tensioning maintenance position in which the belt is removable from the tensioning apparatus.

In an aspect, a tensioner is provided for an endless drive arrangement. The tensioner includes a base, an arm movably mounted to the base, and which has a pulley thereon for engagement with a belt. The tensioner further includes an arm biasing member to bias the arm in a free arm direction, and a tensioner lock, including a locking feature on one of the arm and the base, and a projection that is movably mounted to the other of the arm and the base, and is movable between a locking position and a release position. The projection includes first and second parts. The second part is engageable with the locking feature. The first part has a first projection-withdrawal limit surface thereon that is engageable with a second projection-withdrawal limit surface on the other of the arm and the base to prevent complete withdrawal of the projection.