Abstract: A hydraulic tensioning system (1) for a belt drive, including a cylinder (4) that is designed to receive a linearly displaceable piston (6), these elements together forming a piston-cylinder unit (3) and delimiting a pressure chamber (10) that is filled with hydraulic fluid. A relative movement between the piston (6) and the cylinder (4) causes the hydraulic fluid to be exchanged between the pressure chamber (10) and a storage chamber (12) or vice versa. At least one annular spring valve (14), which opens depending on the pressure, is positioned in an outflow section (17) for the hydraulic fluid between the pressure chamber (10) and the storage chamber (12) as a one-way valve.

Abstract: A hydraulic backlash compensating element for an internal combustion engine, which has a housing in which a pressure-actuated piston is mounted The piston has a check valve via which oil can flow into the housing, and the check valve has a valve seat and a valve element arranged movably therein. The valve element is a hollow ball.

Abstract: A tensioning device for the endless drive in a timing system on a motor vehicle, which has a tensioning piston that can move along a path axis in a housing, within which a pressure chamber is located which houses a working medium which brings about a movement of the tensioning piston in the housing and has a valve seat, connected to the exterior of the tensioning piston by an outlet and accommodating a valve body essentially matching the shape of the valve seat. The valve body is tapered along the axial path axis to the outlet, which allows for a large chamber between the valve body and the valve seat. The path that the working medium, on bleeding gas bubbles from the same, takes from the pressure chamber to the outlet is longer, which increases the hydraulic resistance and restricts and limits emptying of working medium from the tensioning piston.

Abstract: A plate valve designed as a hydraulic one-way valve, which has a valve plate, a one-piece valve spring and a holding element. The plate valve is integrated into a piston and is assigned to a feed opening. The rotationally symmetrical plate valve is inserted into a receptacle in the piston. The valve spring, which is positioned between the valve plate and the holding element, is designed as a perforated disk, on the inside of which at least two separate spring tongues of wound design arranged offset with respect to one another are provided, the spring tongues being supported in non-positive engagement against a valve plate.

Abstract: A hydraulic belt tensioner for a unit drive or control drive of a motor vehicle. The belt tensioner has a cylinder housing in which a damper piston with a piston rod is arranged to be axially retracted against the force of a compression spring. A damping valve is integrated into the damper piston which, when interacting with a pressure compartment in the cylinder housing, are a component of a hydraulic damping system that is effective in the direction of retraction of the piston rod. The damping piston is produced from a shaped metal sheet piece that is guided inside the cylinder housing with very little play. The interior of the damping piston forms a receptacle for the damping valve configured as a throttle-check valve.

Abstract: Traction element tensioner (1), which is preferably a hydraulic traction element tensioner for a chain drive, with a housing (2), which holds a tensioning piston (3) that can move axially and that is adjacent to a tensioner high-pressure space (4). The tensioner high-pressure space (4) is fed via a fluid supply opening (5) and also a non-return valve (6). The traction element tensioner (1) includes a valve assembly, which is constructed as a pressure-limiting valve (7) and limits a fluid pressure in the tensioner high-pressure space (4).