A traction mechanism tensioning unit (1) for a traction mechanism drive of a motor vehicle is provided. The traction mechanism tensioning unit (1) includes a housing (2) in which a hydraulic tensioner (3) is arranged, the hydraulic tensioner (3) has a cylinder element (4) connected rigidly to the housing (2), in which an axially moving piston (5) is arranged, a compression spring (18) is arranged for generating an axial tensioning force on the piston (5) in a compression chamber (6) formed between the cylinder element (4) and the piston (5), and the hydraulic tensioner (3) is fluidly connected to a pressurized medium supply line (8) via a pressure control valve (7) arranged in the housing (2) for realizing a constant pressurized medium pressure in the compression chamber (6).

A marine propulsion apparatus includes a first drive shaft, a lifting plate fixed relative to the first drive shaft, a midsection top collar. The apparatus includes a lower unit attached to the midsection top collar, the lower unit having a second drive shaft, wherein the midsection top collar is fixed relative to the second drive shaft. The apparatus includes a power transmission component rotatably coupling the first drive shaft to the second drive shaft, wherein the power transmission component is continuously disposed over the first drive shaft and the second drive shaft and configured to rotate about the first and second drive shafts. The apparatus includes one or more lifting screws coupling the lifting plate to the midsection top collar, wherein adjusting the one or more lifting screws changes a distance between the lifting plate and the midsection top collar, thereby adjusting a tension of the power transmission component.

An autonomous hydraulic expansion and contraction apparatus comprises a fixing unit, a cylinder unit, a support unit, a piston unit, a valve unit and oil supply parts. By controlling the expansion and contraction length of the support part by a simple manipulation of the valve part by moving the lever, the autonomous hydraulic expansion and contraction apparatus can be easily expanded and contracted to the combined length of the expansion and contraction equipment, and additionally, the convenience of use can be enhanced.

A drive arrangement is provided which includes: a first and second rotatable members; an endless loop member, extending around the first and second rotatable members, arranged to convey drive from the first rotatable member to the second rotatable member; a first support, arranged to support the first rotatable member and the second rotatable member, having at least one aperture therein; a guide member, defining at least part of a path of the endless loop member between the first rotatable member and the second rotatable member; and a second support, arranged to support the guide member, the second support being connected to the guide member through the at least one aperture in the first support such that guide member is movable, via the at least one aperture, to engage and disengage drive from the first rotatable member to the second rotatable member.

A tensioner which adjusts the mean tensioner force to keep the chain tension as low as possible without sacrificing chain control, significantly improving drive efficiency as the chain wears and is subject to low dynamic loads.

A traction tensioning device which has one or more upper chain assemblies driven by an upper sprocket pulley and one or more lower chain assemblies driven by a lower sprocket pulley. Each of the upper and lower chain assemblies has a plurality of pads mounted to the chain assemblies. The upper chain assembly is mounted to a movable platen. The lower chain assembly is mounted to a fixed platen. The upper chain assembly and the movable platen are raised and lowered with respect to the lower chain assembly thereby creating a tension on a strip of material passing between the upper and lower chain assemblies.

A hydraulic auto-tensioner includes a sleeve; a rod vertically movable relative to the sleeve; a spring seat fixed to the portion of the rod protruding beyond the sleeve; a return spring configured to bias the spring seat upwardly; oil passages through which a pressure chamber communicate with a reservoir chamber; a check valve mounted to the oil passages; a tubular plunger vertically movably mounted between the outer periphery of the rod and the inner periphery of the sleeve; a first leakage gap defined between the inner periphery of the tubular plunger and the outer periphery of the rod; an upper stopper configured to restrict the upwardly movable range of the tubular plunger; and a pressure regulating spring disposed above the tubular plunger so as to surround the outer periphery of the rod.

A chain tensioner is provided which is configured such that the air remaining in a pressure chamber can be discharged to the outside through a helical gap defined between a screw and a threaded hole, and through between circumferentially separate radial ends of a spring washer mounted between the screw and a housing. The chain tensioner includes an air discharge groove or grooves formed in the seat surface of the head of the screw such that an annular space defined between the neck of the screw and the inner diameter surface of the spring washer communicates with the outside through the air discharge groove or grooves. Even if foreign objects clog the space between the separate radial ends so as to hinder air from being discharged through between the separate radial ends, the air remaining in the pressure chamber can be discharged to the outside through the air discharge groove or grooves.

An actuating device for orthosis including a housing, a motor, a transmission disposed in the housing, and an actuating arm. The transmission is operatively connected to the motor such that the motor provides power to the transmission. The transmission includes a first stage, a second stage, and a third stage. The first stage has a first sprocket, a second sprocket, and a first drive belt tensioned between the first sprocket and the second sprocket. The first sprocket is attached to a shaft of the motor. The second stage has a third sprocket, a fourth sprocket, and a second drive belt tensioned by the third sprocket and the fourth sprocket. The third sprocket is attached to the second sprocket of the first stage. The third stage has a fifth sprocket, a sixth sprocket, and a third drive belt tensioned by the fifth sprocket and the sixth sprocket. The fifth sprocket is attached to the fourth sprocket of the second stage. The transmission additionally includes a first shaft and a second shaft. The second sprocket, the third sprocket, and the sixth sprocket are attached to the first shaft, and the fourth sprocket and the fifth sprocket are attached to the second shaft. The actuating arm is operatively connected to the sixth sprocket of the third stage of the transmission such that the power provided to the transmission by the motor causes the actuating arm to provide an output torque.

The belt drive assembly includes a frame having a first plate including an inner surface, an outer surface, a first end, and a second end, a second plate including an inner surface, an outer surface, a first end, and a second end, and a shaft disposed between the first plate and the second plate. The belt drive assembly also includes a first pair of idler pulley wheels positioned coaxially at one end of the first plate, a second pair of idler pulley wheels positioned coaxially at one end of the second plate, a drive pulley wheel rotatably mounted onto the outer surface of the first plate, a driven pulley wheel rotatably mounted onto the outer surface of the second plate, and an endless belt trained on the drive pulley wheel, on each idler pulley wheel, and on the driven pulley wheel.