A chain tensioner includes a sleeve fixedly disposed in a cylinder, with a first end of the sleeve inserted in a plunger and a second end of the sleeve protruding out of the plunger. A cylindrical space is defined between an outer periphery of the sleeve and an inner periphery of the cylinder. An oil supply passage opens to the cylindrical space. A communication passage is defined in the sleeve and provides communication between the cylindrical space and a reservoir chamber.

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.

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.

An object of the present invention is to provide a chain guide that can reduce vibration and noise while maintaining necessary strength, rigidity, and durability. The chain guide has a support wall extending forward from a boss part, which constitutes a circumferential wall of a pivot shaft, along a plane perpendicular to a pivot axis line. The support wall includes a base part that is provided with a running surface-side rib, and a connecting portion with a cross-sectional area thereof reducing toward the boss part. The running surface-side rib is not in contact with the boss part. The chain guide does not include a connecting portion that has a larger width than the thickness of the support wall and extends in a pivoting direction on a back side of the running surface-side rib in a region at a pivot shaft side end thereof.

A tensioner including a support member, a thrust member supported so as to be capable of reciprocating movement in a straight line along a first direction with respect to the support member, and a contact-type flat spiral spring. The flat spiral spring is disposed adjacent to the thrust member in a second direction orthogonal to the first direction. The flat spiral spring has a coil axis direction running in a third direction orthogonal to both the first direction and the second direction and includes an inner-end portion anchored to the support member and an outer-end portion anchored to the thrust member so as to bias the thrust member in a forward-direction and so as to be wound-up by movement of the thrust member in a retraction-direction.

To provide a universal design chain guide that can provide a position, track, and length of contact between the chain guide and the chain for optimal performance even when used with different types of chains. The chain guide includes a guide surface slidably guiding a running chain and at least one mounting part. The guide surface includes a first guide surface extending along a longitudinal direction and a second guide surface parallel to and protruding more than the first guide surface. The second guide surface protrudes from the first guide surface with varying heights along the longitudinal direction.

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.

An integrated valve for a hydraulic tensioner includes a pressure relief valve with an integrated band, which is preferably made of metal, placed around the outside of a pressure relief valve body. A hydraulic tensioner includes a housing with a bore and a hollow piston slidably received within the bore. A piston spring biases the piston in a direction toward a power transmission device. The tensioner also includes an integrated check valve in a body of the housing. The integrated check valve includes a pressure relief valve mechanism and a band check valve mechanism surrounding a circumference of the pressure relief valve mechanism. The pressure relief valve mechanism permits transfer of pressurized fluid from a piston chamber formed by the hollow piston to the source of pressurized fluid and the check valve mechanism permits transfer of pressurized fluid from the source of pressurized fluid to the piston chamber.

A chain guide and tensioning apparatus is disclosed that is configured for engagement (contact) with a driven chain (e.g., in an automotive engine). The chain guide and tensioning apparatus includes a guide body and a guide face overlying the guide body. The guide face defines an inner surface and an opposite outer surface that is configured to guide and tension the driven chain. The guide face includes a plurality of spacers that extend therefrom into engagement (contact) with the guide body so as to define at least one channel that is configured to facilitate air and/or lubricant circulation between the guide body and the guide face to reduce heat and friction generated by engagement of the driven chain with the guide face.

An orifice member is disposed in a plunger including a plunger hole that forms a hydraulic chamber in conjunction with a plunger housing hole in a housing. The orifice member includes a deformed fitting section deformed to fit on the inner circumferential surface of the plunger hole, a communication section that causes a surface in contact with the top surface on the front side of the plunger hole and a surface on the hydraulic chamber side to communicate, and an orifice groove that communicates with the communication section and an external relief hole provided in the plunger on the surface in contact with the top surface on the front side of the plunger hole to constitute an orifice.