Abstract: A cooling device includes a cooling unit (10) through which a fluid to be cooled, especially hydraulic oil, can flow and a filter unit (12) for filtering fluid. The cooling unit (10) and the filter unit (12) are joined together as one piece. The filter unit (12) is placed together with the cooling unit (10) inside a device housing (14). The cooling device can be constructed in a manner that is considerably more compact and lighter, while having an output that is comparable to that of prior art solutions.

Abstract: The invention relates to a valve that comprises at least one pump connection (10), one tank connection (14) and one consumer connection (18), and a valve piston (22) that is displaced within the valve box (12). Said valve piston separates the pump connection (10) from the tank connection (14) in at least one blocked position and interacts with an energy accumulator (24). A fluid stream that flows between the consumer connection (18) and the tank connection (14) is controlled by means of a control device (26). The control device (26) is configured as a fluid stream control that is integrated in the valve piston (22) and that allows, contrary to known valves which use a diaphragm construction, reduction, by a constant value, of the volume flow to the consumer in a load-independent manner, thereby allowing for a proportional load-independent control.

Abstract: A device for pumping fluid has a hydraulic pump (10) and a drive (12). The hydraulic pump (12) is produced as an independent component with different types of drive devices (12) as additional components that can be coupled in the form of a modular system, and is configured as a coupling piece (14) for this purpose. Hydraulic tanks (16) having different volumes represent a third, different type of component. Each hydraulic tank (16) can be connected on one side to the coupling piece (14). The corresponding drive device (12) can be connected on the opposite or same side of the coupling piece (14). The coupling piece (14) is built as a single component and embodied in the form of a base plate. The hydraulic pump (10) is an external gear pump (20), whose toothed wheels (22) are received or integrated into the base plate. A compact, modularly constructed building block system is achieved which is functionally reliable and easy to maintain.

Abstract: A control device for hydraulically operated hoisting mechanisms used to raise and lower loads includes an electrically controllable throttle valve connected to a return line of the hoisting mechanism, and a pressure scale with at least one blocking position and one control position. The pressure scale operates in conjunction with an unblocking mechanism. When in its normal position, the pressure scale blocks the return line. The pressure scale assumes its control position in lowering of a load as a result of triggering of the unblocking mechanism. In the event of failure of the throttle valve, the pressure scale may be moved to its blocking position by the unblocking mechanism. In the event of failure of the pressure scale, the throttle valve assumes its blocking position. The load retention function is performed by two series-connected closed hydraulic actuators which can be electrically controlled individually.

Abstract: A valve, especially a pressure control valve, includes a housing (10) with a pump connection (P), an appliance connection (A) and a tank connection (T). A piston (16) controlled by a magnet armature (26) is guided inside the housing (10) of the valve. The vavle is provided with a hydraulic damping device (34) having a damping chamber (36) in fluid communication with appliance connection (A) through a throttle (38). The pump connection (P) or the tank connection (T) is selectively joined to the appliance connection (A) via a connecting line (40) according to the position of the piston (16). This valve improves upon known control valves so that the control valve remains stable in terms of behavior, especially with regard to permanent oscilliations.

Abstract: A fluid cooling device has a cooler, filter and pump combined in a building unit. Fluid conveyed by the pump can be filtered in a fluid circuit by the filter and can be cooled in the circuit by the cooler. The filter is provided with at least one filter element that can be exchanged when the filter is clogged. A controllable unit is provided in the fluid circuit for exchanging the filter element. The filter can be separated from the pump by the controllable unit in such a way that the cooler is still supplied with the fluid to be cooled. The filter element can be exchanged without entailing further difficulties, even when the downstream supply of lubricating oil is not stopped.

Abstract: A switching device for a machine, especially a digger, has at least one supply connection and one useful connection in addition to at least one hydraulic accumulator. An on-off valve is arranged between the supply connection and the useful connection, and separates the supply connection at least partially from the useful connection in one of its switching positions, in addition to ensuring that the hydraulic accumulator is charged on the fluid side via the supply connection. In another switching position, the supply connection is connected to the useful connection. A substantial improvement relative to conventional switching devices is attained by being able to guarantee an emergency function before the machine is used to perform work.

Abstract: A control device for hydraulically operated hoisting mechanisms used to raise and lower loads includes an electrically controllable throttle valve connected to a return line of the hoisting mechanism, and a pressure scale with at least one blocking position and one control position. The pressure scale operates in conjunction with an unblocking mechanism. When in its normal position, the pressure scale blocks the return line. The pressure scale assumes its control position in lowering of a load as a result of triggering of the unblocking mechanism. In the event of failure of the throttle valve, the pressure scale may be moved to its blocking position by the unblocking mechanism. In the event of failure of the pressure scale, the throttle valve assumes its blocking position. The load retention function is performed by two series-connected closed hydraulic actuators which can be electrically controlled individually.

Abstract: The invention relates to a pressure control valve (1) comprising a control piston (3) which is able to slide in a valve hole (4). Under the effect of an energy accumulator (5) said piston in one direction of displacement connects a pump connection (23) with a consumer connection (24) and in the other direction of displacement connects the consumer connection (24) with a tank connection (21) such that the pump connection (23) is closed off. The aim of the invention is to provide a pressure control valve which functions reliably and in a stable manner even in case of elevated control dynamics. To this end, independently of the direction of displacement of the control piston (3) a minimum volume flow present between the piston and the valve hole (4) dampens the displacement of the control piston (3).