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 hydraulic tensioner includes a tensioner housing having a bore extending a length, with a slot along the length of the bore. A hollow piston is slidably received within the bore and has an outer circumference with a chamfer adjacent a formed edge. An expandable circlip is received by the outer circumference of the piston. The circlip includes a substantially clover shaped body with a plurality of lobes connected to a first leg and a second leg through connecting portions. The expandable circlip has a free state, in which the lobes of the circlip are engaged with at least the chamfer of the piston, and an expanded state, in which the first leg and the second leg are moved away from each other, disengaged from the chamfer. When the expandable circlip is in the free state, the piston is prevented from being ejected from the bore of the housing.

A hydraulic tensioner includes piston retaining, anti-return, and anti-rotation functions. A ratchet clip for the tensioner preferably has straight sides or legs substantially perpendicular to a connecting portion. The ratchet clip preferably is substantially rectangular or U-shaped. The ends of the ratchet clip opposite the connecting portion are preferably bent inwards after the ratchet clip has been assembled on the tensioner. The ratchet clip performs the piston retaining function, the anti-rotation function and the anti-return functions. It is unnecessary for the user to remove the ratchet clip after the tensioner is assembled on the engine.

This invention pertains to the field of hydraulic tensioners. A hydraulic tensioner of this invention includes a tensioner body having a bore in fluid communication with a source of pressurized fluid through an inlet, a hollow piston slidably received within the bore and having an outer diameter, a hydraulic pressure chamber defined by the hollow piston and the bore of the tensioner body, a piston spring received within the hydraulic pressure chamber for biasing the piston away from the inlet, and a metallic band surrounding the outer diameter of the piston. The metallic band forms a seal between an outer surface of the piston and the tensioner body when pressure builds in the hydraulic pressure chamber, wherein metallic bands or seals are placed over a hydraulic tensioner piston in order to seal the high pressure chamber and prevent or reduce leakage through the clearance between the piston and the tensioner body.

The invention relates to a device for locking at least one belt (10) at predetermined belt tension, which belt (10) is arranged at a machine arrangement (1) with belt drive. The machine arrangement comprises a stand (3) having legs (2) placed on a base (4). At least one driving pulley (5) and at least one driven pulley (6) are aligned relative to each other. The legs (2) being articulately attached to at least one of the stand (3) or the base (4), and at least two of the legs (2) comprises longitudinally adjustable tension legs (20), which each comprises a first tension leg part (21) having a wedge box (30) arranged to receive a wedge (31) having a grooved surface (32) and a second tension leg part (22) having a grooved surface (23) directed towards said wedge box (30). The first (21) and second (22) tension leg parts are adapted to lock in relation to each other by cooperation between the grooved surface (32) of the wedge (31) and the grooved surface (23) of the second tension leg part (22) when the wedge (31) is adapted to wedge in wedge box (30).

The invention relates to a device for locking at least one belt (10) at predetermined belt tension, which belt (10) is arranged at a machine arrangement (1) with belt drive. The machine arrangement comprises a stand (3) having legs (2) placed on a base (4). At least one driving pulley (5) and at least one driven pulley (6) are aligned relative to each other. The legs (2) being articulately attached to at least one of the stand (3) or the base (4), and at least two of the legs (2) comprises longitudinally adjustable tension legs (20), which each comprises a first tension leg part (21) having a wedge box (30) arranged to receive a wedge (31) having a grooved surface (32) and a second tension leg part (22) having a grooved surface (23) directed towards said wedge box (30). The first (21) and second (22) tension leg parts are adapted to lock in relation to each other by cooperation between the grooved surface (32) of the wedge (31) and the grooved surface (23) of the second tension leg part (22) when the wedge (31) is adapted to wedge in wedge box (30).

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 tensioner (10) for an endless loop power transmission member can induce a piston (12) operably engageable with an endless loop power transmission member, and a cylinder (14) guiding include a piston (12) for sliding coaxial movement in a direction of the endless loop power transmission member. The piston (12) and cylinder (14) defining an oil reservoir or pressure chamber (26) for receiving hydraulic fluid. A bearing (28) has bearing balls (30) located in a counter bore (32) coaxial with cylinder bore (34). The counter bore (32) has a steep taper (36) on which the bearing balls (30) ride. As the cylinder (14) moves in an extending direction, the bearing balls (30) move out of the counter bore (32) allowing free extending movement of the cylinder (14). As the cylinder (14) moves in a retracting direction, the bearing balls (30) are driven down into the steep taper (36) preventing the cylinder (14) from retracting.