Danfoss Power Solutions Aps

Thomas Bauer

Svend Erik Thomsen

Niels Bjarne Hansen

Morten Hoeck Petersen

Soeren Moeller Hansen

Poul Ennemark

Soren Pedersen

Jeroen Hinse

Thomas Træger Hansen

Oktay Goece

A hydraulic arrangement () including a supply port (P), a return port (T), a working port arrangement (L, R), and a valve () controlling a supply of hydraulic fluid from the supply port (P) to the working port arrangement (L, R), wherein the valve () includes a housing () and a spool () movable in lengthwise direction in the housing () and forming together with the housing () at least one flow path the resistance of which depends on the position of the spool () in the housing (), and the spool () is actuated by a hydraulic pilot pressure () in a pressure chamber (). In such a hydraulic arrangement a safety functionality should be achieved in a simple way. To this end the housing () includes a pilot pressure relief port () connected to the return port (T) via a shut-off valve () and the spool () after a predetermined stroke () opens a connection between the pressure chamber () and the pilot pressure relief port ().

Hydraulic arrangement

Hydraulic steering () is disclosed comprising a high pressure port (P), a low pressure port (T), two working ports (CL, CR), a manual steering section (), and a steering valve section having a steering valveand a hydraulic driving arrangement () adjusting hydraulically a position of said steering valve. A change from automatic steering to manual steering should be reliably ensured when the manual steering section is directly influenced by a driver. To this end, a switching valve () is provided, which is actuatable between a first position in which said driving arrangement () is supplied with hydraulic fluid under pressure, and a second position in which a supply of hydraulic fluid to said driving arrangement () is interrupted, wherein said switching valve () is hydraulically actuated into said second position by a pressure generated upon actuating of said manual steering section ().

Hydraulic steering

The invention provides a steering system comprising a controlled element which is movable in a neutral area comprising a neutral position and in areas on opposite sides of the neutral area based on a steering input and a handle for requesting a desired position for the controlled element. The handle is movable between set-points in a center zone comprising a center set-point and set-points on opposite sides of the center zone. Furthermore, a steering unit is arranged to receive set-points from the handle, to determine a corresponding controlled position of the controlled element, and to move the controlled element to said controlled position. In order to prevent or reduce jerks, the steering unit is adapted to vary a speed by which the controlled element is moved to the controlled position. The speed is variable in dependence of the received set-point.

Steering system

The invention concerns a hydraulic steering () comprising a supply connection arrangement, a steering motor (), a high pressure supply (P), and a steering unit () arranged between the supply connection arrangement (S) and the steering motor (), the supply connection arrangement comprising a steering valve (), and a valve arrangement (). The task of the hydraulic steering is to improve the safety and faults detection over the state of the art. For this purpose, the steering valve () is only deflectable if the valve arrangement () is deflected.

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Sydals, Denmark

Thomas Bauer