Abstract: A method of determining the position of at least one opening (9, 10) in a casting chamber (6) of a die-casting machine (1), wherein a casting plunger (7) is contained in the casting chamber (8), The casting plunger (7) is movable into a position in which communication between the opening (9, 10) and the casting chamber (6) is no longer possible. It is determined, on the basis of the vacuum in the connecting line (14, 15), when the casting plunger (7) has reached the position in which communication, between the opening (9, 10) and the casting chamber (6), is no longer possible. A method of operating a vacuum die-casting machine, wherein a casting curve, for performing a casting cycle, is determined by specified and/or experimentally determined characteristic values of the die-casting machine by a computer program for operating the die-casting machine, and to a corresponding computer program product.

Abstract: A hydraulic tensioning device (1) for a flexible drive element, particularly for a chain or a belt, is provided, and includes a housing (2) that has a cylindrical inner surface (3) at least in some regions, a piston (4) is arranged in the housing (2) in an axially displaceable manner, and an inner chamber (5) is formed by the housing (2) and the piston (4) for receiving hydraulic fluid. At least one vent hole (6) is integrated in the housing (2) and/or in the piston (4) is in contact with the surroundings (U). In order to provide a reliably ventilated system that has a simple design and that can be implemented in a cost-effective manner, a sealing element (7) is arranged in a region of the vent hole (6), and the sealing element is permeable to gas but not to hydraulic fluid.

Abstract: A hydraulic tensioning system (1), which is used in traction mechanism drives, particularly chain drives of internal combustion engines, is provided. The tensioning system (1) includes a piston (3), which is designed in the shape of a crucible, subjected to a pressure by a pressure spring (8), guided in a linearly displaceable manner in a housing (2) and spring-loaded against a traction mechanism. Hydraulic fluid can flow out of a pressure chamber (5) depending on an actuating direction of the piston (3) via an overpressure valve (11) forming a damper and associated with the piston (3) or can enter via a one-way valve (7) of the housing (2) into the pressure chamber (5). The overpressure valve (11) encloses a valve plate (15) that is integrated in the piston (3), and a pressure spring (8) of the piston (3) surrounds an outside of the valve housing (12) of the overpressure valve (11).

Abstract: A belt drive is provided which includes a circulating belt (8) which is driven by at least one drive element (9) and which drives at least one driven element (10). At least one first tensioning device (20) acts upon the belt (8) in the slack strand and at least one second tensioning device acts in the tightened strand. To prevent or reduce jumps and/or transverse oscillations of the belt (8), the second device (21) guides the belt (8) and at least one third device (22) which is arranged radially inside the belt drive, which is suitable, optionally, limits deviations of the belt (8). The second device (30, 40, 50, 60, 70, 80, 90, 100) also tensions the belt (8) in such a manner that it is subjected to a force (F1) which is smaller than the force (F2) which is oriented counter thereto during the operation of the belt (8) on the second tensioning device (30, 40, 50, 60, 70, 80, 90, 100).

Abstract: A hydraulic tensioning device (1) for a flexible drive element, particularly for a chain or a belt, is provided, and includes a housing (2) that has a cylindrical inner surface (3) at least in some regions, a piston (4) is arranged in the housing (2) in an axially displaceable manner, and an inner chamber (5) is formed by the housing (2) and the piston (4) for receiving hydraulic fluid. At least one vent hole (6) is integrated in the housing (2) and/or in the piston (4) is in contact with the surroundings (U). In order to provide a reliably ventilated system that has a simple design and that can be implemented in a cost-effective manner, a sealing element (7) is arranged in a region of the vent hole (6), and the sealing element is permeable to gas but not to hydraulic fluid.

Abstract: A belt drive is provided which includes a circulating belt (8) which is driven by at least one drive element (9) and which drives at least one driven element (10). At least one first tensioning device (20) acts upon the belt (8) in the slack strand and at least one second tensioning device acts in the tightened strand. To prevent or reduce jumps and/or transverse oscillations of the belt (8), the second device (21) guides the belt (8) and at least one third device (22) which is arranged radially inside the belt drive, which is suitable, optionally, limits deviations of the belt (8). The second device (30, 40, 50, 60, 70, 80, 90, 100) also tensions the belt (8) in such a manner that it is subjected to a force (F1) which is smaller than the force (F2) which is oriented counter thereto during the operation of the belt (8) on the second tensioning device (30, 40, 50, 60, 70, 80, 90, 100).

Abstract: A hydraulic tensioning system (1), which is used in traction mechanism drives, particularly chain drives of internal combustion engines, is provided. The tensioning system (1) includes a piston (3), which is designed in the shape of a crucible, subjected to a pressure by a pressure spring (8), guided in a linearly displaceable manner in a housing (2) and spring-loaded against a traction mechanism. Hydraulic fluid can flow out of a pressure chamber (5) depending on an actuating direction of the piston (3) via an overpressure valve (11) forming a damping device (22) and associated with the piston (3) or can enter via a one-way valve (7) of the housing (2) into the pressure chamber (5). The overpressure valve (11) encloses a plate valve (21) that is integrated in the piston (3), and a pressure spring (8) of the piston (3) surrounds an outside of the valve housing (12) of the overpressure valve (11).

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 hydraulic tensioner intended for use in chain drives of internal combustion engines. The hydraulic tensioner has a pot-shaped housing in which a piston is elastically suspended against a traction element and guided for longitudinal displacement. A damping device forms a leak gap which serves to damp adjusting movements of the piston. The leak gap is defined by a bushing which is inserted into the housing and, at the same time, guides the piston. During an adjusting movement of the piston towards a pressure chamber filled with a hydraulic fluid, a fractional quantity of the hydraulic fluid is displaced via the leak gap. An adjusting movement of the piston in the opposite direction causes a re-flow of the hydraulic fluid via a one-way valve arranged in the housing.

Abstract: The configuration of teeth (20) and spacewidths (22) of a rotary disc (10) which is rotatable about a rotational axis (12) are provided. Here, the spacewidths (22) are in each case arranged symmetrically with respect to a spacewidth axis of symmetry (30), with a rotary disc radius being dependent on a rotational angle and a certain mean radius. The spacewidth axes of symmetry (30) of the rotary disc (10) are aligned towards the local centers of curvature, that is to say towards the center of curvature of the curve at the point at which the spacewidth axis of symmetry (30) intersects the peripheral line of the rotary disc (10). Formed around the rotational axis (12) is a circle axis (14) which is not intersected by any of the spacewidth axes of symmetry (30).

Abstract: A belt drive (1) including a belt drive element (4) such as a belt or a chain and a plurality of wheels (1, 6, 7, 8) seated on shafts and integrated into the drive, around which the belt drive element is wound. Parasitic oscillations are introduced into the belt drive (1) by at least one shaft. For the purpose of generating a counter-oscillation, at least one wheel (3) has a non-circular shape. The non-circular wheel (3) is configured, in terms of its shape, in such a manner that it is adapted to generate a counter-oscillation which compensates at least two different main oscillation orders of the parasitic oscillation.

Abstract: A belt drive is provided which includes a circulating belt (8) which is driven by at least one drive element (9) and which drives at least one driven element (10). At least one first tensioning device (20) acts upon the belt (8) in the slack strand and at least one second tensioning device acts in the tightened strand. To prevent or reduce jumps and/or transverse oscillations of the belt (8), the second device (21) guides the belt (8) and at least one third device (22) which is arranged radially inside the belt drive, which is suitable, optionally, limits deviations of the belt (8). The second device (30, 40, 50, 60, 70, 80, 90, 100) also tensions the belt (8) in such a manner that it is subjected to a force (F1) which is smaller than the force (F2) which is oriented counter thereto during the operation of the belt (8) on the second tensioning device (30, 40, 50, 60, 70, 80, 90, 100).

Abstract: A rotating disk is provided, which can rotate by a rotational angle about a rotational axis (12) and has a number of teeth (20) arranged on a periphery of the rotating disk (10) and tooth spaces (22) located between the teeth, through whose middle runs a tooth-space middle line (30), and the rotating disk (10) has a periodically changing tooth-space geometry. The rotating disk (10) has a tip circle radius (24) that is constant. In addition, a drive device and a belt drive with a rotating disk (10) are provided.

Abstract: A tensioning system (18) is provided, which interacts with a traction element of a traction element drive via a tensioning rail. The construction of the tensioning system (18) includes a pot-shaped housing (19), which forms a pressure space (20), in which a piston (21) is guided so that it can move longitudinally. For an adjustment movement of the piston (21) in a direction of the pressure space (20), the hydraulic fluid enclosed in the pressure space (20) is regulated by a leakage gap (24). An opposite adjustment movement of the piston (21) causes a return flow of the hydraulic fluid into the pressure space (20) via a one-way valve (1a) integrated in the piston (21). The construction of the one-way valve (1a) includes a cage (2), in which a valve body (3a) constructed as a disk is inserted captively and is guided between a valve seat (5) and a rim (8) so that it can move axially.

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).