Abstract: A hydraulic control arrangement (1) is described having a directional valve (2), a metering pump unit which has at least two metering pumps (3, 4) which are connected hydraulically in parallel and are operable mechanically in parallel, and a shut-off valve (6) in hydraulic connection between two of the at least two metering pumps (3, 4), a pump connection (P) and a tank connection (T) which are connected to said metering pump unit by way of the directional valve (2), and two working connections (L, R) connected to the directional valve (2), a control input (8) of the shut-off valve (6) being connected to the pump connection (P) by means of a control valve. Such a control arrangement should be operated at a high hydraulic pressure and at the same time it should be made sure that the shut-off valve is actuated only when the required high pressure is available.

Abstract: A hydraulic steering device (1) is described comprising a supply port arrangement having a supply port (P) and a tank port (T), a working port arrangement having two working ports (L, R), a main flow path (14) between the supply port (P) and the working port arrangement, a return flow path (16) between the working port arrangement and the tank port (T), flow meter means (15) being arranged in said main flow path (14), said flow meter means (15) comprising at least two flow meters (27, 28) and a flow meter valve means (30), said flow meter valve means (30) in a first operation mode connecting at least two flow meters (27, 28) in parallel and in a second operation mode making inactive at least one flow meter (27). Such a steering device should be operated comfortable for a driver.

Abstract: In open-circuit hydraulic systems (1), the cross-sections of the supply lines (6) and input valves of the hydraulic pump (3) have to be large, so that sufficient flow flux can be provided. This hinders a reduction of the size of the pump and the whole hydraulic system. It is suggested that the supply flow (7) of a hydraulic pump (3) is charged by a second, charging pump (2), to a mid-pressure level (7). The cross-sections of the supply flow areas can thus be decreased.

Abstract: The invention provides a method and a system for moving an element, e.g. a rudder of a ship or a wheel of a vehicle. The element is moved by a hydraulic fluid. According to the invention, an operator indicates a desired movement, and in accordance with the desired movement, at fluid is provided from at least three fluid providers each providing a share of the fluid in parallel streams and only considering the desired movement not the shares provided by the other fluid providers. The invention allows continuation of a steering task even if one fluid provider is disabled, and the invention allows the continuation even without having to notice that one provider is disabled. Accordingly, the invention provides an improvement and simplification relative to the known hydraulic steering systems.

Abstract: The invention concerns a fluid rotary machine (1) with a housing (2), a shaft (3) projecting from the housing (2), and being rotatable around an axis (4) and forming part of a movement chain, and a sensor arrangement (10) comprising a transmitter (12) and a receiver (15). It is endeavored to find a simple solution for detecting the rotation of the shaft with a relatively high accuracy. For this purpose, a channel (21) is provided in the movement chain, and the transmitter (12) is connected to a transfer element (19) transferring a torque that is led through said channel (21) to a section of the movement chain that is farther away from the transmitter (12) than a transmitter-side end of the movement chain.

Abstract: The invention concerns a hydraulic steering arrangement with a hydraulically actuated steering valve arrangement, steering motor connections (CL, CR), which are connected to supply connections (HP, T) via the steering valve arrangement, and a steering unit. It is endeavored to equalize in a simple manner the steering behavior in both directions. For this purpose, it is ensured that the steering valve arrangement has a directional valve and a flow control valve.

Abstract: In usual hydraulic pumps, a separate assembly opening is provided for every valve of the hydraulic pump. This design causes sealing problems. It is proposed, that the fluid inlet valve and the fluid outlet valve can be assembled through a common assembly access port. Further, the fluid inlet valve and the fluid outlet valve can be arranged around a common cavity, or even within the same cavity, via the common assembly access port in the fluid working machine's body.

Abstract: The invention concerns a fluid rotary machine (1) with a housing (2), a shaft (3) led out of the housing (2) and a sensor arrangement (10) comprising a transmitter (12) in active connection with the shaft (3), and a receiver (15). It is endeavored to arrange the sensor arrangement in an advantageous manner on the fluid rotary machine. For this purpose, the sensor arrangement (10) comprises an accommodation area, in which the transmitter (12) is arranged, the accommodation area being in fluid connection with the inside of the housing (2) and sealed towards the outside, and the receiver (15) is arranged outside the housing (2) and the accommodation area.