A hydraulic tensioner having a piston sliding around an outside surface of a pin or rod, so that the high pressure chamber for chain control is created by the area between the piston internal diameter and the rod outside diameter. A spring around the outside of the rod presses against the bottom of the piston, biasing the piston outward during low oil pressure conditions. Preferably, the piston is steel and the rod is aluminum, the reverse of prior art designs, which means that as temperature increases, the piston to bore clearance reduces. This can offset the oil viscosity reduction and maintain the same performance over operating temperatures.

A tensioning device, more particularly a hydraulically actuated chain tensioner, for a chain drive of an internal combustion engine, having a tensioner housing, a tensioning piston which is displaceably guided in a piston bore of the tensioner housing and has a piston skirt, a transport securing means for fastening the tensioning piston in the tensioner housing, a adjustment apparatus for incrementally adjusting and limiting the working range of the tensioning piston, and a final position securing means for the captive arrangement of the tensioning piston in the piston bore. The transport securing means, the adjustment apparatus and the final position securing means together have a single securing ring for fastening the tensioning piston in the tensioner housing, the incremental adjustment and limiting of the working range of the tensioning piston and the captive arrangement of the tensioning piston. A chain drive, more particularly a control chain drive, of an internal combustion engine, having such a tensioning device is also provided.

A tensioning device, more particularly a hydraulically actuated chain tensioner, for a chain drive of an internal combustion engine, having a tensioner housing, a tensioning piston which is displaceably guided in a piston bore of the tensioner housing and has a piston skirt, a transport securing means for fastening the tensioning piston in the tensioner housing, a adjustment apparatus for incrementally adjusting and limiting the working range of the tensioning piston, and a final position securing means for the captive arrangement of the tensioning piston in the piston bore. The transport securing means, the adjustment apparatus and the final position securing means together have a single securing ring for fastening the tensioning piston in the tensioner housing, the incremental adjustment and limiting of the working range of the tensioning piston and the captive arrangement of the tensioning piston. A chain drive, more particularly a control chain drive, of an internal combustion engine, having such a tensioning device is also provided.

A variable force tensioner (VFT) system that includes a primary piston split into two chambers disposed within a primary bore. The two chambers including a first low pressure chamber having a primary reservoir therein that feeds fluid through a check valve into a second high pressure chamber to control a biasing force on the primary piston. A piston bore clearance path can extend along a groove in the primary bore to feed oil back to the primary reservoir from the high pressure chamber.

In one aspect, there is provided an isolation device, which includes a hub, a pulley and at least one isolation spring arrangement including first and second springs in series. The first spring rate is higher than the second spring rate. Initially during torque transfer from the first one to a second one of the hub and the pulley, the entire first isolation spring is slid along a friction surface towards the second one of the hub and the pulley during compression of the second isolation spring thereby generating a first frictional damping torque. During torque transfer the other way, at least a portion of the first isolation spring remains stationary relative to the friction surface, such that the first frictional damping torque is greater than the second frictional damping torque.

A chain guide is provided that can improve the work efficiency during assembly and transportability with a simple structure. The chain guide includes a bushing structure where a bushing member is attached to a guide body at least in one location. The guide body includes a cylindrical insertion hole through which a bushing cylindrical part is inserted, and a backside restricting part that restricts movement of a flange part to the back side in the guide width direction. The guide body is provided, in each bushing structure, with a front-side restricting portion that restricts movement of the flange part to the front side in the guide width direction only in one location on the outer circumference of the cylindrical insertion hole when viewed in the guide width direction.

A chain guide is provided that can improve the work efficiency during assembly and transportability with a simple structure. The chain guide includes a bushing structure where a bushing member is attached to a guide body at least in one location. The guide body includes a cylindrical insertion hole through which a bushing cylindrical part is inserted, and a backside restricting part that restricts movement of a flange part to the back side in the guide width direction. The guide body is provided, in each bushing structure, with a front-side restricting portion that restricts movement of the flange part to the front side in the guide width direction only in one location on the outer circumference of the cylindrical insertion hole when viewed in the guide width direction.

Provided is a crank sprocket that allows suppressing a transmission of vibration. The crank sprocket of the present disclosure is mounted to one end side in an axial direction of a crankshaft of an internal combustion engine, and a timing chain is wound around the crank sprocket. The crank sprocket includes a sprocket base body, and a vibration-damping resin layer formed on an inner peripheral surface or a tooth surface of the sprocket base body. The vibration-damping resin layer includes a heat-resistant resin and a vibration damping filler that converts vibration energy into thermal energy.

Provided is a crank sprocket that allows suppressing a transmission of vibration. The crank sprocket of the present disclosure is mounted to one end side in an axial direction of a crankshaft of an internal combustion engine, and a timing chain is wound around the crank sprocket. The crank sprocket includes a sprocket base body, and a vibration-damping resin layer formed on an inner peripheral surface or a tooth surface of the sprocket base body. The vibration-damping resin layer includes a heat-resistant resin and a vibration damping filler that converts vibration energy into thermal energy.

An object of the present invention is to provide a tensioner lever that can reduce vibration and noise when the chain runs, and realize smooth attachment into an engine with minimal deformation of the lever body with a simple configuration. A tensioner lever according to the present invention includes a lever body and a torsion coil spring pressed the lever body toward the chain. The lever body includes a stopper member mounting part where a stopper member by which the support arm of the torsion coil spring is locked and which retains the torsion coil spring in a compressed state is removably mounted. The stopper member mounting part is located closer to a distal end of the lever body than a center position in the longitudinal direction of the lever body, or a center of gravity position of the lever body.