Abstract: The invention concerns a fully hydraulic steering with a steering member, a steering unit that can be activated by the steering member, said steering unit comprising a supply connection arrangement (P, T) with a pressure connection (P) and a tank connection (T), and a working connection arrangement (L, R) with two working connections (L, R), and a steering motor, which is connected with the working connection arrangement (L, R). It is endeavored to increase the possibilities of steering. For this purpose, it is ensured that an auxiliary force operated steering valve is arranged in parallel to the steering unit between the supply connection arrangement (P, T) and the working connection arrangement (L, R).

Abstract: The invention concerns a hydraulic valve arrangement (1) with a control valve module (2) comprising a supply connection arrangement with a high-pressure connection (P) and a low-pressure connection (T) and a working connection arrangement with two working connections (A, B) as well as a control valve (3) between the supply connection arrangement and the working connection arrangement. It is endeavoured to improve the control behaviour of the valve arrangement. For this purpose, it is ensured that the control valve module (2) has a return compensation valve (15, 16) between the control valve (3) and at least one working connection (A, B).

Abstract: The invention concerns a method and a hydromachine with a commutation device and with expanding and contracting pressure chambers passed by fluid and formed by displacement arrangements. With the method and the hydromachine, it is endeavoured to control a displacement in the hydromachine to keep pressure fluctuations small. For this purpose, the hydromachine has a group of devices, comprising a commutation device and at least two displacement devices, at least two of the devices being adjusted in relation to each other.

Abstract: The invention concerns a hydraulic steering with a steering initiator, a steering unit with feedback properties, which can be activated by the steering initiator, the steering unit having a supply connection arrangement with a pressure connection (P) and a tank connection (T) and a working connection arrangement with two working connections (L, R), an auxiliary-force operated steering valve, which is located in parallel with the steering unit between the supply connection arrangement (P, T) and the working connection arrangement (L, R), and a feedback suppressing device, which is active, when the steering valve is active. It is endeavoured to find a simple manner of ensuring the priority of the steering initiator over the steering valve. For this purpose, the steering initiator interacts with an activation sensor, which deactivates the feedback suppressing device on an activation of the steering initiator.

Abstract: The invention concerns a hydraulic machine with a set of teeth, having a toothed ring with an inner toothing and a gear wheel with an outer toothing, the gear wheel rotating and orbiting in the toothed ring, the inner toothing and the outer toothing touching each other in contact areas, thus separating pressure chambers, and with a valve arrangement controlling a connection between a connection arrangement having a high pressure connection and a low pressure connection, and the pressure chambers. It is endeavoured to achieve a stable operation, particularly with low speeds. For this purpose, each contact area is provided with an opening, which, at the time when a pressure chamber reaches an extreme value of its volume, produces a short-circuiting with the neighbouring pressure chamber.

Abstract: The invention concerns a control device for a hydraulic lifting arrangement with a drive in the form of a hydraulic motor, which has a first working connection and a second working connection, a pressure connection and a tank connection, and a control valve, which is connected with the pressure connection and the tank connection on the one side and with the first working connection via a first working pipe and with the second working connection via a second working pipe, each working pipe comprising a stop valve that can be opened.

Abstract: A rotary fluid pressure device has a first oil passage with relatively high pressure fluid therein surrounding the gear set; a plurality of second oil passageways connecting the first oil passageway to the expanding and contracting oil chambers; and fluid non-return valves in each of the second oil passageways to permit the flow of oil therethrough only in a direction from the oil chambers to the first oil passageway.

Abstract: The invention concerns a hydraulic valve arrangement with a working connection arrangement having a first working connection and a second working connection, both working connections being connectable with a hydraulic consumer, a supply connection arrangement having a pressure connection and a tank connection, a first valve arrangement, which closes the pressure connection or connects it in a controlled manner with the first working connection or the second working connection, a second valve arrangement, which closes the tank connection or connects it in a controlled manner with the first working connection or the second working connection, and a control device, which controls the first valve arrangement and the second valve arrangement. It is endeavoured to enable a simple manner of exact controlling the consumer.

Abstract: The invention concerns a pressure reduction valve (1) with a housing (2a, 2b), a valve element (6) being displaceable in the housing and acted upon in one direction by a pressure in a low-pressure chamber connected with an outlet (11) and in the opposite direction by the force of a spring (16), which is arranged in a spring chamber (17) in the housing (2a). It is endeavoured to improve the dynamic behaviour of the pressure reduction valve. For this purpose, a pilot flow path (7, 23, 21) connects the low-pressure chamber (5) and the spring chamber (17) with each other.

Abstract: A hydraulic control system (1) has a hydraulic motor (10), which is connected with a control valve (2) via two working lines (8, 9), the control valve (2) being connected with a low-pressure connection (T) and, via a compensation valve (4), with a high-pressure connection (P), to ensure that a return compensation valve (14, 15) is arranged in each working line, each return compensation valve (14, 15) having a nominal flow line (29), which extends unintersectedly in relation to the nominal flow line (28) of the compensation valve (4).

Abstract: The invention concerns a valve arrangement for controlling a hydraulic drive, the supply to and the outflow from the hydraulic drive being separately controllable. It is endeavoured to realise separate controls of the speed and the hydraulic pressure of the hydraulic drive. For this purpose, a pump pipe is connected with a first control valve, the first control valve is connected through a pipe with a first working connection and a second working connection of the hydraulic drive, and the first working connection is connected with a second control valve and the second working connection is connected with a third control valve, the second control valve and the third control valve opening into a tank (T).

Abstract: The invention concerns a valve arrangement for controlling a hydraulic drive having a first working connection (A) and a second working connection (B), and being connectable with or separable from a pressure source (P), the supply and the outflow of the hydraulic drive being separately controllable. It is endeavoured to improve the energetic efficiency of the valve arrangement. For this purpose, the first working connection (A) is connected with a first control valve and the second working connection (B) is connected with a second control valve, the first and the second control valves being connected with each other and with a third control valve, which is connected with a tank.

Abstract: The invention concerns a valve arrangement for controlling a hydraulic drive, the supply and the outflow of the hydraulic drive being separately controllable. It is endeavoured to improve the valve arrangement in such a manner that it is intrinsically tight, at the same time having a relatively simple design. For this purpose, a pump pipe and a tank pipe are connected with a first control valve, the first control valve being connected by separate pipes with a second control valve and a third control valve connected in parallel with the second control valve, the second control valve being connected with a first working connection of the hydraulic drive and the third control valve being connected with a second working connection of the hydraulic drive, backflow preventers for preventing the flow from the hydraulic drive in the direction of the tank being connected in parallel with the second control valve and/or the third control valve.

Abstract: A hydraulic valve system (1) has a supply connection arrangement having a high-pressure connection (P) and a low-pressure connection (T), a working connection arrangement, having two working connections (A, B) connectable with a motor (2), with a directional valve (4), which is arranged between the supply connection arrangement (P, T) and the working connection arrangement (A, B), and with a compensation valve (8), which is acted upon in a first operation direction by a spring (22) and a pressure in a pressure chamber (23), which is connected with a load-sensing line (LS), and in a second operation direction, which is opposite to the first operation direction, by a pressure at the directional valve (4).

Abstract: The invention concerns a hydraulic steering arrangement with a steering motor, a supply path between a pressure source and the steering motor, in which supply path a throttling device and a measuring motor are located, a return path between the steering motor and a pressure sink, in which return path a return throttle is located, and a bypass path, which connects the supply path and the return path on the pressure source end or the pressure sink end, respectively, and which has a bypass throttle. It is endeavoured to make such steering arrangements suitable for fast motorboats. For this purpose it is ensured that with a load on the steering motor the pressure drop over the bypass throttle is larger than the sum of the pressure drops between a point before the first throttle and a point after the last throttle of the throttling device.

Abstract: A valve member includes an axially movable spool valve rotatably mounted in the valve member to cause the way that fluid is communicated between the inlet and outlet ports of the device and the volume chambers thereof. An outer surface of the spool has a configuration to react to fluid pressure to effect the timing between the gear set and the valving of valve member and that the timing therebetween will be adjusted when the spool valve is moved axially. A valve actuator comprising a spring loaded plunger controlled by fluid pressure at the inlet and outlet ports is in physical contact with one end of the valve spool.

Abstract: A hydraulic steering arrangement includes a steering valve, a steering motor, connected with a high-pressure connection and a low-pressure connection via the steering valve, and with a steering unit, connected via the steering valve with a pilot pressure valve, whose outlet is connected with the low-pressure connection. It is endeavoured to improve the steering behaviour. For this purpose, the pilot pressure valve is opened, before the steering valve creates a connection between the high-pressure connection and the steering motor.

Abstract: A hydraulic steering system (1) with a supply connection arrangement, having a high-pressure connection (P) and a low-pressure connection (T), and with a working connection arrangement (L, R), a directional valve (2) and a metering pump unit (3, 4) being arranged between the supply connection arrangement and the working connection arrangement, the metering pump arrangement having at least two hydraulically parallel-connected and mechanically parallel-operated metering pumps (3, 4) with a shut-off valve (6) in a hydraulic connection between the two metering pumps (3, 4), said shut-off valve (6) having a return spring (16) and a first control inlet (15) that is connected with the high-pressure connection (P).

Abstract: A hydraulic valve system (1) has a supply connection arrangement, having a high-pressure connection (P) and a low-pressure connection (T), a working connection arrangement, having two working connections (A, B), which can be connected with a hydraulic motor (2), and a directional valve (4) between the supply connection arrangement (P, T) and the working connection arrangement (A, B), which is connected with the working connection arrangement (A, B) via working lines (17, 18), in which are arranged check valves (21, 22), which can be opened by means of pressure.