Abstract: The present invention relates to a noise dampening assembly of a hydraulic machine and a drive motor, and provides for a structure comprising a block, in which the hydraulic machine is mounted by means of noise dampening elements.

Abstract: Closed loop control circuit for a variable hydraulic pump the output flow of the pump being variable by control means and the pump including at least two closed loop controllers actuating the control means, wherein at least one hydraulic switching element is provided which automatically connects to the control means the closed loop controller providing the highest or the lowest pressure.

Abstract: The present invention relates to a valve assembly for the supply of users in hydraulic control systems with pressurized fluid for the load pressure (LS) independent control of several simultaneously actuated hydraulic users wherein the ratio of the partial flows once set is maintained at undersupply of the system with the pressurized fluid. When the demand of the users exceeds the maximum output flow of the variable displacement pump, the (high) priority users receive the demanded quantity whereas the low priority users receive a reduced quantity by switching the control pressure for the low (i.e. no) priority users via a directional control valve and a pressure relief valve to a lower pressure level. Only when undersupply of the entire system occurs, i.e. when the maximum output flow of the variable displacement pump is no more sufficient despite the limitation of the control pressure for the low priority users, then the presently flowing partial flows of all users are reduced proportionally.

Abstract: The invention relates to a hydraulic system for hydraulic operators for delivering pressurized fluid to a blower drive means and to the hydraulic operators of a hydraulic machine, comprising a variable delivery pump, control valves connecting the hydraulic operators and the blower drive means to the pump, a temperature responsive pressure valve for setting a temperature-proportional control pressure in the pressure line between the blower drive means and the respective control valve, wherein the control valve is subjected to the pressure in the control line in a sense to open the control valve, and a flow volume regulator associated to the variable delivery pump which regulator is subjected via a load sensing line by the load pressure occuring at the hydraulic operators or in the blower drive means depending on which pressure is higher.

Abstract: A nozzle resistance controlled by a piezoelectric element comprises a housing having a longitudinal bore, a piezoelectric element located in the longitudinal bore, a baffle plate supported by the piezoelectric element, a nozzle body located in the longitudinal bore such, that the bore extending through the nozzle body ends with one end adjacent to the baffle plate, and a chamber defined by the longitudinal bore and connected to the other end of the bore. The chamber is connected to a fluid supply device.

Abstract: A valve arrangement for a hydraulic transmission circuit, in particular for a change-under-load transmission with a clutch valve arrangement for controlling at least one clutch and/or start-up clutch with the aid of a pressure-regulating valve whose normal position can be influenced mechanically by a clutch pedal. The pressure-measuring area of the pressureregulating valve is connected to a control valve whose piston, acted on by the clutch pedal, can be brought, against the force of a spring placed between the pressure-regulating valve and the control valve, first of all out of a position that relieves the pressure-measuring area of load into a floating position in which the pressure-measuring area is connected to the pressure-regulating valve outlet. Then, and after traversing a certain path, it can be brought into contact with the valve body of the pressure-regulating valve.

Abstract: An engine brake for a multicylinder internal combustion engine includes valves that can be periodically opened briefly, in each case outside the exhaust stroke. In the vicinity of the applicable valve drive, a hydraulic piston is provided that is triggered synchronously with the engine rpm via an associated control line by a hydraulic pressure distributor fed by a pump. To improve the accuracy of control over the entire engine rpm range, the various valves are assigned a central positive displacement pump that runs synchronously with the camshaft rpm and whose outlet line leads to the hydraulic pressure distributor, which has a distributor disk. In engine braking operation, an alternating connection of the applicable control line to either the pump outlet line or a low-pressure region of the hydraulic control circuit is effected synchronously with the engine rpm by means of the distributor disk.

Abstract: A digital electronic control apparatus for controlling at least one electronic control element comprises. The apparatus comprises first and second pulse width modulated output signal generators, the frequency of the second signal being different from the first. The second pulse width modulated signal is provided as a function of a digital value determined by at least one of a characteristic and operating condition of the at least one electronic control element. An AND-gate receives the first and second pulse width modulated signals and is capable of producing an output signal for controlling the at least one electronic control element a first and second pulse width modulated signal having a first frequency.

Abstract: In a device for stroke end cushioning and speed regulating the movement of a piston (3) in a fluid pressure cylinder (1,2) a common adjusting means (9) is arranged for simultaneous setting of the throttle means (7,8) for regulating the stroke end cushioning as well as the piston speed, for the purpose of avoiding very time consuming adjustment. In connection with the setting of the adjusting means (9) the ratio between the flow areas of the respective throttle means is held within the range of 10-60%. In the most uncomplicated embodiment the common adjusting means (9) may be comprised by a screw being fixed to the valve bodies of the respective throttle means.

Abstract: A pressure compensating hydraulic directional valve comprising: a body provided with a movable slide; a passage through the body for connecting a distribution chamber associated with the slide to working orifices, the distribution chamber being selectively connectable to an admission orifice by the slide when moved; a load sensing line channel combined with means for selecting the maximum pressure selected from the pressure in the channel and the pressure of the fluid in the valve; and pressure compensating means placed in the passage and responsive to the difference between the pressure in the passage and the pressure in the channel to generate a fixed pressure drop in the pressurized fluid flowing through the passage towards the working orifices, the pressure compensating means being combined with the maximum pressure selecting means in such a manner that if the pressure in the channel is greater than or equal to the pressure of the fluid from the slide, then no communication exists between the passage and

Abstract: A pressure control valve is provided comprising an inlet bore, an annular channel and a control spool. So as to obtain a low control deviation and good stability an annular channel is provided at the outlet side of the valve. The axial extension of said annular channel is smaller than the outlet flow area formed by said bores.

Abstract: A pressure relief valve system is provided that makes it possible to provide numerous varied pressure relief functions with a minimum of structural changes. For this purpose, a standard distributing valve housing is equipped with a valve core that makes it possible to construct a double-acting pressure relief valve with an individually adjustable pressure system on each valve side. However, there is also the possibility of completely shutting off the pressure system on one side. The valve core and/or the valve elements are preferably exchangeable, and the valve elements can be separately controlled by an adjusting device, for example in the form of a proportional magnet, to generate a pressure output signal corresponding to an input signal in each of the independent pressure systems independent of one another.

Abstract: A hydraulic remote control distributor valve device comprises a flat body (1) having two main assembly faces (3) to enable a multiple hydraulic remote control block to be built up, and two side faces and a bottom face (5) that are narrow and on which orifices are located for receiving link couplings for hydraulic connection with a source of hydraulic fluid under pressure and with a component to be controlled. Two outlet orifices (A, B) are situated on the bottom face of the body (5) and the width e of the bottom face (5) is less than the diameter d of the link couplings suitable for fixing on the outlet orifices. The two outlet orifices (A, B) are disposed asymmetrically relative to the median plane (M) of the body (1) that extends perpendicularly to the main faces and to the bottom face (5), said orifices being offset relative to the plane (M) by an offset 1 that is equal to or greater than 1/2.sqroot.(d.sup.2 -e.sup.2).

Abstract: Electric connecting device for electrically controlled, so called pilot valves (21-25) connected to a corresponding number of valves (1-5) in a modular valve array. Each pilot valve has equally placed contact pins (26,27,28), which are connected to a common, flexible connecting cable (29) with a plurality of conductors (29) over an electric connecting module (30). Each connecting module (30) is constituted by a coupling plate (32) provided with on the one hand contact sockets (33,34,35) for connection to said contact pins (26,27,28) of the respective pilot valve, and on the other hand a multipolar contact means (37), which is connectable to a corresponding cable contact means (38), which is connected to conductors of the common connecting cable (29). The coupling plate (32) is provided with an array of preferably controllable electrical connections (36) for the desired connection between said multipolar cable contact means (37) and said contact sockets (33,34,35).

Abstract: The invention relates to a valve system for supplying fluid from a pair of fluid pressure sources to a load. A feed valve is provided which feeds--when required--a partial flow of the second fluid pressure source into the feed line of the load which is connected to the first fluid pressure source through a directional control valve. The feed valve comprises a pressure-compensating valve to control the volume of the partial flow and a switching valve to automatically open the pressure-compensating valve when required.

Abstract: An engine brake for a multicylinder internal combustion engine includes valves that can be periodically opened briefly, in each case outside the exhaust stroke. In the vicinity of the applicable valve drive, a hydraulic piston is provided that is triggered synchronously with the engine rpm via an associated control line by a hydraulic pressure distributor fed by a pump. To improve the accuracy of control over the entire engine rpm range, the various valves are assigned a central positive displacement pump that runs synchronously with the camshaft rpm and whose outlet line leads to the hydraulic pressure distributor, which has a distributor disk. In engine braking operation, an alternating connection of the applicable control line to either the pump outlet line or a low-pressure region of the hydraulic control circuit is effected synchronously with the engine rpm by means of the distributor disk.

Abstract: A multi-stage hydraulic actuator including a cylinder body having an outer cylinder and an inner cylinder provided in the outer cylinder, first and second pistons inserted in the outer cylinder to independently move and provided with first and second working members, and third and fourth pistons inserted in the inner cylinder to independently move and provided with third and fourth working members.

Abstract: A hydraulic control circuit for building machinery includes a hydraulic cylinder to operate a tool. To stabilize vibrations of the tool around the pitch axis, a hydraulic accumulator is provided to be connected to a pressure source via a fill line. A shut-off valve is disposed in the fill line, which valve is subjected to the pressure in the accumulator such that in operating the cylinder the accumulator is loaded to a pressure corresponding to the load pressure. The system is very simple in structure and fluid losses are eliminated.

Abstract: A circuit for limiting a static and/or dynamic pressure load in a hydraulically actuated use device which is controlled in a closed control circuit by means of a directional control valve and a mechanically or hydraulically releasable blocking device. Aa pressure control valve is arranged between the use device and the pressure relief valve and being adapted to discharge a hydraulic fluid from the use device to a tank when a predetermined hydraulic pressure in the use device is exceeded. The output port of the pressure relief valve is connected to a hydraulic control line is adapted to hydraulically connect the pressure relief valve to a control side of the control valve.

Abstract: A vane pump or a vane motor is here specified, having a variable displacement volume. The vane pump has a vane rotor and an annular stator that surrounds the rotor eccentrically and that is stabilized by means of a piston arrangement for adjusting the eccentricity that determines the displacement volume. The piston arrangement includes at least one pendulum piston that is acted upon by a pressure medium, the pendulum piston being guided in a sealed manner in a housing bore by a piston head that delimits a control space. To simplify the assembly and to decrease manufacturing costs while simultaneously improving the sealing action and increasing the peripheral life of the guide surfaces, plastic rings, which are composed of wear resistant, sliding material, or are prestressed radially, to guide the piston in the piston bore and to seal the control space are embedded, inserted or emplaced in the piston head.