Abstract: The invention relates to a hold-down device for a joining drive and joining drive with a hold-down device. The hold-down device includes a hold-down cylinder, wherein the hold-down cylinder provides a hold-down force by means of a pressurized chamber. The pressure chamber consists of the hold-down cylinder and a punch of the joining drive. The pressurization required for the provision of the hold-down force is provided by a hydraulic circuit of the joining drive. In the joining mode, the pressure chamber of the hold-down device is connected to a pressure accumulator of the hold-down device, so that a change in volume in the pressure chamber of the hold-down device has no noticeable influence on the pressure in the pressure chamber.

Abstract: A hydrostatic system has a pressure source and a hydraulic motor or a consumer. An additional hydraulic motor/pump unit is furnished for controlling the volumetric flow for the consumer or the power output of the hydraulic motor.

Abstract: A method for regulating output pressure of a hydraulic drive system by using a rotational speed as the actuating variable. The method includes determining a setpoint rotational speed main component of motor drive as a pilot control signal, determining an error rotational speed as a regulating deviation from a comparison of an actual pressure value of the hydraulic drive system and a setpoint pressure value of the hydraulic drive system and adjoining regulating amplifier, adding the determined setpoint rotational speed main component to the determined error rotational speed to create the setpoint rotational speed as the actuating variable, and converting the created setpoint rotational speed into an input rotational speed of the motor drive to drive the hydraulic drive system at the converted rotational speed in order to generate regulated output pressure of the hydraulic drive system which represents actual pressure value.

Abstract: A pumping station for a pipeline, in particular an oil or gas pipeline, has a feed pump for delivering a fluid through the pipeline and a combustion engine for driving the feed pump. A hydrostatic system has a hydraulic motor for driving the combustion engine, in order to accelerate same to start-up. The hydraulic system also has a hydraulic pressure accumulator of limited volume which can be filled with a pressurized hydraulic medium to be admitted to the first hydraulic motor, thereby powering the latter. A pressure differential in the hydrostatic system prevailing over the hydraulic motor is variably adjustable, in order to accelerate the combustion engine to a predefined firing speed.

Abstract: A hydraulic drive including at least one hydraulic cylinder that includes a piston chamber, an annulus, and a piston that separates the piston chamber from the annulus. The hydraulic drive also includes a first hydraulic pump hydraulically connected with the piston chamber, a second hydraulic pump hydraulically connected with the annulus, a third hydraulic pump, and a directional control valve that has a first switching position and a second switching position. The third hydraulic pump in the first switching position of the directional control valve is hydraulically connected with the piston chamber, and the third hydraulic pump in the second switching position of the directional control valve is not hydraulically connected with the piston chamber.

Abstract: A method for regulating output pressure of a hydraulic drive system by using a rotational speed as the actuating variable. The method includes determining a setpoint rotational speed main component of motor drive as a pilot control signal, determining an error rotational speed as a regulating deviation from a comparison of an actual pressure value of the hydraulic drive system and a setpoint pressure value of the hydraulic drive system and adjoining regulating amplifier, adding the determined setpoint rotational speed main component to the determined error rotational speed to create the setpoint rotational speed as the actuating variable, and converting the created setpoint rotational speed into an input rotational speed of the motor drive to drive the hydraulic drive system at the converted rotational speed in order to generate regulated output pressure of the hydraulic drive system which represents actual pressure value.

Abstract: A hydrostatic system has a pressure source and a hydraulic motor or a consumer. An additional hydraulic motor/pump unit is furnished for controlling the volumetric flow for the consumer or the power output of the hydraulic motor.

Abstract: A pumping station for a pipeline, in particular an oil or gas pipeline, has a feed pump for delivering a fluid through the pipeline and a combustion engine for driving the feed pump. A hydrostatic system has a hydraulic motor for driving the combustion engine, in order to accelerate same to start-up. The hydraulic system also has a hydraulic pressure accumulator of limited volume which can be filled with a pressurized hydraulic medium to be admitted to the first hydraulic motor, thereby powering the latter. A pressure differential in the hydrostatic system prevailing over the hydraulic motor is variably adjustable, in order to accelerate the combustion engine to a predefined firing speed.

Abstract: A hydraulic drive including at least one hydraulic cylinder that includes a piston chamber, an annulus, and a piston that separates the piston chamber from the annulus. The hydraulic drive also includes a first hydraulic pump hydraulically connected with the piston chamber, a second hydraulic pump hydraulically connected with the annulus, a third hydraulic pump, and a directional control valve that has a first switching position and a second switching position. The third hydraulic pump in the first switching position of the directional control valve is hydraulically connected with the piston chamber, and the third hydraulic pump in the second switching position of the directional control valve is not hydraulically connected with the piston chamber.

Abstract: A hydraulic drive including at least one hydraulic cylinder that includes a piston chamber, an annulus and a piston that separates the piston chamber from the annulus. The hydraulic drive further includes a first hydraulic pump that has a pump intake and a pump outlet, a directional control valve that has a first and a second switching position, and a second hydraulic pump. The second hydraulic pump has a direction of delivery that is consistent with the direction of delivery of the first hydraulic pump at the pump outlet, wherein the second hydraulic pump in the first switching position of the directional control valve is hydraulically connected with the piston chamber and the second hydraulic pump in the second switching position of the directional control valve is not hydraulically connected with the piston chamber.

Abstract: A hydraulic drive including at least one hydraulic cylinder that includes a piston chamber, an annulus and a piston that separates the piston chamber from the annulus. The hydraulic drive further includes a first hydraulic pump that has a pump intake and a pump outlet, a directional control valve that has a first and a second switching position, and a second hydraulic pump. The second hydraulic pump has a direction of delivery that is consistent with the direction of delivery of the first hydraulic pump at the pump outlet, wherein the second hydraulic pump in the first switching position of the directional control valve is hydraulically connected with the piston chamber and the second hydraulic pump in the second switching position of the directional control valve is not hydraulically connected with the piston chamber.

Abstract: A device for cutting shock damping of work machines, for example, for presses and stamping or nibbling machines, and a method for cutting shock damping. Embodiments of the invention are employed in work machines that have a machine frame and a working drive for moving a working tool along a working direction, and in which the machine frame is deformed elastically by a working force exerted by the working drive for machining a workpiece. The working drive provides a control variable for determining the working force of the work machine.

Abstract: Provided is a hydraulic drive including a double-acting work cylinder with a piston having a first working surface effective in a retracting direction and a second working surface effective in an extending direction, wherein the first working surface delimits a first pressure chamber and the second working surface delimits a second pressure chamber, at least two different pressures being applicable to at least one of the first working surface and the second working surface for retracting or extending the piston into and out of the work cylinder, an actuator unit which optionally enables a throttled return flow of a hydraulic medium from the first pressure chamber delimited by the first working surface, and control means for triggering the actuator unit in such a way prior to a sudden acceleration of the piston due to a sudden force release.

Abstract: A stamping and/or nibbling machine, with a Z-axis drive for driving a tool, which is movable in the vertical direction and can be held by a tool holder, for the machining of sheet metal workpieces, with a first CNC control unit for actuating the Z-axis drive, wherein the first CNC control unit provides an interface for a data channel to a primary control unit or to a second CNC control unit of an X/Y-axis drive for moving the sheet metal workpieces relative to the tool in horizontal directions (X, Y), wherein the tool holder, during a vertical movement during the machining of sheet metal workpieces, is rotatable around its vertical longitudinal axis by a C-drive which is actuated by the second CNC control unit, as a result of which an angle sensor is provided for detecting the angle information of the C-drive and the first CNC control unit is designed in such a way that from the angle information it determines a Z-setpoint value as a reference variable of the Z-axis drive.

Abstract: The invention relates to a method for operating a hydraulic drive device comprising a hydraulic piston-cylinder unit having a working piston that can be moved in a working direction between an upper dead point and a lower dead point, a set point for the position of the working piston in the working direction being predefined, and an actual value of the position of the working piston in the working direction being interrogated, and the movement of the working piston being regulated as a function of the set point and the actual value. The invention additionally relates to a hydraulic drive device.

Abstract: The invention relates to a device (2) for the cutting shock damping of work machines (1), in particular presses, stamping or nibbling machines, comprising a machine frame (3) and a work drive (5) for moving a work tool (10) along a work direction. The machine frame (3) is elastically deformed by a work force exerted by the work drive (5) for machining a work piece (W). The work drive (5) provides for a control variable for determining the work force, wherein the device (2) for cutting shock damping provides for a support cylinder (16, 16?) having a support piston (18) that can be moved along the work direction and delimits a support pressure chamber (20), on which pressure fluid can act for moving the support piston (18). The invention further relates to a method for cutting shock damping.

Abstract: The invention relates to a hydraulic drive, especially for a press, punching or nibbling machine, comprising a double-acting work cylinder whose piston comprises a first working surface effective in the retracting direction and a second working surface effective in the extending direction, which each delimit one pressure chamber; with at least two different pressures being applicable to at least one of the working surfaces by means of an actuator for retracting or extending the piston into and out of the work cylinder; with the hydraulic drive comprising an actuator unit which optionally enables a throttled return flow of hydraulic medium from the first pressure chamber delimited by the first working surface.