A method of fabricating a chain tensioner includes bending a sheet metal blank to form a connector portion perpendicular to a flat base. The connector portion has an arm extending beyond the base. The method further includes stamping an end of the arm to curl the end into a hollow cylinder having an axis perpendicular the flat base. Curling the end into a hollow cylinder may be performed in a series of stamping operations. The blank may define a gap which extends around a narrower portion of the arm after the end is curled into the hollow cylinder.

A hydraulic tensioning device for a chain device, having a housing and having a clamping piston guided displaceably in a housing bore of the housing, the clamping piston having a piston cavity with a hardened inner circumferential surface, and also having a pressure relief valve unit arranged in the piston cavity. The pressure relief valve unit (12) is a preassemblable unit and includes a spring (18), a closing body (17) and a valve seat (16) and also a receptacle (15, 26) at least partially enclosing the valve seat (16), wherein the valve seat (16) is made of a metal material, has an at least partially hardened surface and wherein the receptacle (15, 26) forms a press-fit with the inner circumferential surface of the clamping piston (3).

An object of the present invention is to provide a tensioner lever that allows for reduction of the number of components and the weight, while being able to prevent vibration and noise during the running of the chain. The tensioner lever according to the present invention is configured such that a lever body rotatably supported on an attachment surface is urged to rotate toward the chain by the resilient force of a coil spring. The coil spring includes a pressing arm extending from one end of a helical part and contacting the lever body, and a support arm extending from another end of the helical part and supported by the attachment surface. The lever body includes an engagement portion configured to allow the support arm of the coil spring to be hooked thereon by resilient deformation, and to removably engage therewith by rebound resilience of the coil spring.

Described embodiments include a reconfigurable belt tensioner that can be used to add, remove, and/or reposition peripheral accessories of an engine installation, for example, in an automobile or another vehicle. The tensioner has a housing, an arm with an axle, and a spring installed in the housing. The axle is inserted into and fastened to the housing. The arm rotates around the axle. When the arm is rotated, the spring provides the force that tends to return the arm and the housing to the original position. The tensioner can be reconfigured by repositioning the spring relative to the housing and/or the arm, changing the angle between the housing and the arm. The tensioner may be used, for example, on an LS-based GM small-block engine, and allow operation with and without the air conditioning compressor or other accessories.

An orbital tensioner comprising an annular base, a ring journalled to the annular base on a ball bearing, said ring having a ring axis of rotation (A-A), a first pulley journalled to the ring, a first pulley axis of rotation (B-B) offset from the ring axis of rotation (A-A), a pivot arm pivotally mounted to the ring, a pivot arm pivot axis (C-C) offset from the ring axis of rotation (A-A), a second pulley journalled to the pivot arm, a torsion spring biasing the pivot arm in a first direction, the ball bearing having a first race and a second race, the ring fixed to the first race, the annular base fixed to the second race, and a damping mechanism frictionally disposed between the ring and the base.

An object of the present invention is to provide a tensioner lever that allows for reduction of the number of components and the weight, while being able to prevent vibration and noise during the running of the chain. The tensioner lever according to the present invention is configured such that a lever body rotatably supported on an attachment surface is urged to rotate toward the chain by the resilient force of a coil spring. The coil spring includes a pressing arm extending from one end of a helical part and contacting the lever body, and a support arm extending from another end of the helical part and supported by the attachment surface. The lever body includes an engagement portion configured to allow the support arm of the coil spring to be hooked thereon by resilient deformation, and to removably engage therewith by rebound resilience of the coil spring.

A method of fabricating a chain tensioner includes bending a sheet metal blank to form a connector portion perpendicular to a flat base. The connector portion has an arm extending beyond the base. The method further includes stamping an end of the arm to curl the end into a hollow cylinder having an axis perpendicular the flat base. Curling the end into a hollow cylinder may be performed in a series of stamping operations. The blank may define a gap which extends around a narrower portion of the arm after the end is curled into the hollow cylinder.

An orbital tensioner comprising an annular base, a ring journalled to the annular base on a ball bearing, said ring having a ring axis of rotation (A-A), a first pulley journalled to the ring, a first pulley axis of rotation (B-B) offset from the ring axis of rotation (A-A), a pivot arm pivotally mounted to the ring, a pivot arm pivot axis (C-C) offset from the ring axis of rotation (A-A), a second pulley journalled to the pivot arm, a torsion spring biasing the pivot arm in a first direction, the ball bearing having a first race and a second race, the ring fixed to the first race, the annular base fixed to the second race, and a damping mechanism frictionally disposed between the ring and the base.

To provide a tensioner that has a simple structure and is easy to assemble, and is configured to smoothly relieve pressure during oil release with reduced flow resistance so that the oil pressure in an oil pressure chamber is kept stable in a favorable manner. A relief valve unit includes a cap member that fits with a seat member to retain a stopper member inside the seat member. An external relief hole, which causes a relief-side space in a plunger hole to communicate with the outside of a plunger, opens radially in an outer circumferential surface of the plunger.

A tensioner includes a movable section, a fixed section, a flat spiral spring, and a back-up spring. The movable section receives load from an entrained transmission body through a tension member. The fixed section supports the movable section so as to be capable of displacing. The flat spiral spring biases the movable section so as to resist the tension member. The flat spiral spring unwinds in a state in which there is a small inter-plate friction force in cases in which there is a large biasing force applied to the tension member to counter load acting from the tension member. The flat spiral spring winds-up in a state in which there is a large inter-plate friction force in cases in which there is a small biasing force applied to the tension member to counter load acting from the tension member. The back-up spring limits wind-up of the flat spiral spring.