An object of the present invention is to provide a chain and a chain transmission device capable of reducing sliding resistance of the chain to a guide lip portion and stably maintaining an oil film between the guide lip portion and an outer plate. Provided is a chain 20 wherein a plurality of link plates 40 and 60 include outer plates 60, each of the outer plates 60 has a pair of front and rear pin holes 61 into which connecting pins 50 are inserted, a guide-side end surface 62 that faces a traveling guide surface 81a side of a chain guide 80, and a contact convex portion 63 that protrudes from an outer surface of the outer plate 60, and the contact convex portion 63 is formed in an area between the pin holes 61 and the guide-side end surface 62 in a plate height direction.

A clip lock for securing an expandable clip of a chain tensioner includes an elongated member having a first surface configured to engage an exterior surface of the chain tensioner and a second surface, spaced apart from the first surface, that is configured to engage the expandable clip and maintain the expandable clip in contact with an annular groove of a chain tensioner component preventing radially-outward expansion and axial movement of the expandable clip with respect to the chain tensioner component while the first surface engages that exterior surface of the hydraulic tensioner and the second surface engages the expandable clip.

A tensioner capable of keeping oil pressure in an oil pressure chamber stable is provided. In the tensioner, a flow amount control mechanism includes a flow amount control member set inside a control space so as to be able to approach and separate from the oil pressure chamber, a control biasing unit, a first restricting part and a second restricting part. The flow amount control member and the inner wall of the control space are provided such that the flow resistance of a first control flow passage, which is exhibited when the flow amount control member contacts the first restricting part, is larger than the flow resistance of a second control flow passage, which is exhibited when the flow amount control member contacts the second restricting part.

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.

The problem to be solved is to provide a tensioner lever that inhibits friction-induced wear or seizure on a surface of a pivoting support boss contacting a shoulder bolt so that high durability is achieved, and that is easily producible and enables cost reduction. As a solution to the problem noted above, the tensioner lever includes a shoe having a traveling surface, a lever body, and a pivotal support boss provided at a proximal end of the lever body to allow a distal end thereof to swing. The shoe and the lever body are integrally formed and assembled together by double injection molding. The lever body includes a slide bearing member, and a connecting part that connects the slide bearing member and the shoe. The slide bearing member, the connecting part, and the shoe are made of the same synthetic resin, and configured as a continuous one-piece component.

A hydraulic tensioning device, comprising a tensioning piston receptacle, a tension piston that includes a piston compartment and is movably guided in the tensioning piston receptacle, a high-pressure chamber that can be connected to an inlet connection using an inlet passage secured by a non-return valve, a low-pressure chamber between the inlet connection and the inlet passage, and a balance piston located in the low-pressure chamber.

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 the inner sleeve facing a pressure oil chamber and a pressure regulating unit provided on an outer periphery of the inner sleeve is arranged. The inner sleeve has a cylinder part and a movement restricting part provided on the side of the inner sleeve facing 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 tensioner includes a power spring, and a backup member being in contact with the power spring and supporting the power spring by acting an urging force in a direction opposite to a radial shift of the power spring in a direction in which the power spring is wound. The power spring is unwound in a condition in which an inter-plate frictional force of the power spring is small in a case where an urging force acting from a power spring to a tension member is greater than a load acting from the tensioner arm to the power spring and the power spring is wound in a condition in which the inter-plate frictional force of the power spring is large in a case where the urging force acting from the power spring to the tension member is smaller than the load acting from the tension member to the power spring.

To provide a tensioner that improves, with a simple structure, maintenance operation efficiency, as well as enhances the sealing performance and the degree of freedom of check valve design. Either a plunger or a housing has a valve setting hole for disposing a check valve therein, and a valve movement restricting part that restricts movement of the check valve, disposed in the valve setting hole, toward an oil supply passage. A coil spring includes a small-diameter part and a large-diameter part continuous with the small-diameter part and disposed in contact with the check valve. The coil spring is disposed so as to urge the check valve toward the oil supply passage. The largest diameter of the large-diameter part is set larger than the inner diameter of the valve setting hole.

A device for tensioning a roller chain in a chain drive system is disclosed. The device includes a floating shoe with a surface upon which the chain may slide and a housing. A tension force provided by a tension mechanism is directed from the housing to the floating shoe in an outward direction with respect to the path of the roller chain. A retention feature limits the distance the floating shoe may travel with respect to the housing.