Abstract: A valve arrangement includes a housing arrangement (12), (18), a first spool valve (1a, 1b) having a first spool (3a, 3b) and a second spool valve (2a, 2b) having a second spool (4a, 4b), wherein the first spool valve (1a, 1b) and the second spool valve (2a, 2b) each includes a supply channel arrangement having a pump channel (5) and a tank channel (6), and a working port arrangement having two working ports (8, 9), wherein the spools (3a, 3b; 4a, 4b) control a flow path between the supply channel arrangement (5, 6) and the working port arrangements (7, 8). In such a valve arrangement, it should be possible to simply adapt the control behaviour to different purposes. To this end, the working port arrangement (7, 8) is arranged in a flange (16a, 16b) connected to the housing arrangement (13, 14; 19, 20).

Abstract: A fluid controller (1), in particular as part of a hydraulic steering unit, is described said controller (1) comprising a housing (2) having a supply port arrangement, a sleeve (4) arranged rotatably in a bore of the housing (2), a spool (3) arranged rotatably in the sleeve (4), and a measuring motor, wherein the measuring motor comprises a plurality of working chambers, each working chamber being connected to the bore, wherein the sleeve (4) comprises a commutation geometry (7) having a first partition and controlling together with a housing geometry (5) of the housing (2) a flow of hydraulic fluid into and out of the working chambers and the spool (3) comprises a spool geometry (14) controlling together with a valve geometry (10, 11) of the sleeve (4) a flow of hydraulic fluid between the supply port arrangement and the commutation geometry. Such a fluid controller should have a stable control behavior. To this end the valve geometry (10,11) comprises a second partition different from the first partition.

Abstract: A thermal relief device (1) is described comprising a housing (2) having an inlet (3) and an outlet (4) connected by a relief channel (5). Such a thermal relief device should have a simple construction. To this end a microporous structure (10) is arranged between inlet (3) and outlet (4).

Abstract: A hydraulic steering arrangement includes a supply port arrangement having at least a supply port, a return port arrangement having at least a return port, a working port arrangement having two working ports, a first valve arrangement having a first supply side connected to the supply port arrangement and a first output side connected to the working port arrangement, a second valve arrangement having a second supply side connected to the supply port arrangement and a second output side connected to the working port arrangement, and a steering command device. In a neutral steering angle, the second valve arrangement connects the first output side to the return port arrangement and the first valve arrangement connects the second output side to the return port arrangement.

Abstract: A steering wheel arrangement 1 is described comprising a steering wheel (2) having a rim (3) and a steering column 4 rotatably supported in the housing (5) and connected to the rim (3), wherein an electric machine (9, 13, 14) is operatively connected to the steering wheel (2). Such a steering wheel arrangement should be able to produce a force feedback to a traditional steering wheel in a reliable low-cost solution with a high functional safety rating. To this end electric machine (9, 13, 14) is integrated in the rim (3).

Abstract: The invention relates to a hydraulic steering unit (1) including a housing (3), a spool, a sleeve (12) arranged between spool and housing (3), and a measuring motor (14) having a number of working chambers (15), wherein a first commutation geometry (18) and a second commutation geometry (19) are arranged between the sleeve (12) and the housing (3), wherein the commutation geometries (18, 19) are connected to the working chambers (15) of the measuring motor (14) and the housing includes a first direction port (4), a second direction port (5), a pressure port (6), and a return port (7). The object is to have a good steering behavior. To this end one of the commutation geometries (18) is directly connected to the first direction port (4).

Abstract: A hydraulic steering arrangement (1) comprising a supply port arrangement having a pressure port and a tank port, a working port arrangement having two working ports (L, R), a mechanical steering unit (3) connected to a steering wheel (2) and being arranged between the supply port arrangement and the working port arrangement (L, R), supply valve means (12) having a connection to the pressure port and to the working port arrangement (L, R) and being controlled by a controller (10), and a steering wheel sensor (9) connected to the controller (10) is described. Such a steering arrangement could allow a comfortable feeling for the driver.

Abstract: A piston ring (10) for forming a seal between a piston (26) and piston housing (28). The piston ring (10) has first and second orthogonal axes (12, 14) and a body portion (18) which is resiliently deformable in the direction of the first axis (12) and is substantially rigid in the direction of the second axis (14).

Abstract: A hydraulic steering unit includes a pressure port connected to a main flow path and a tank port connected to a tank flow path, and a working port arrangement having left and right working flow paths. A first bridge arrangement has first left and first right orifices connected to the main flow path and to first left or first right connecting points, respectively, each connecting point associated respectively with the left or right working flow paths, and second left and second right orifices connected to the tank flow path and to the first left or first right connecting points, respectively. A second bridge arrangement has a similar orifice arrangement connected to second left or second right connecting points. The first and second bridge arrangements have different steering characteristics. Selection means for connecting one of the bridge arrangements between the pressure port and the working port arrangement are provided.

Abstract: A hydraulic steering arrangement 1 is described comprising a supply port arrangement having a pressure port (4) and a tank port (5), a working port arrangement having two working ports (6, 7), a steering unit (2) arranged in a flow path (9) between the supply port arrangement (4, 5) and the working port arrangement (6, 7), and a second flow path (13) in form of an amplification flow path bridging the steering unit (2) and having an amplification orifice (AU1) which is controlled as function of the steering unit (2). Such a steering arrangement should have a possibility to change the steering behaviour. To this end at least a third flow path (14) in form of an amplification flow path is arranged in parallel to the second flow path (13), wherein the second/or the third flow path (13, 14) comprise an valve (15).

Abstract: A hydraulic steering arrangement (1) is described comprising a supply port arrangement (P, T) having a pressure port (P) and a tank port (T), a working port arrangement having two working ports (L, R), a main flow path (2) having a main orifice (A1), at least one further orifice (A2, A3, A4) downstream the main orifice (A1), and a measuring motor (3), the main flow path (2) being arranged between the pressure port (P) and the working port arrangement (L, R), a return flow path (4) arranged between the working port arrangement (L, R) and the tank port (T), an amplification flow path (6) having an amplification orifice (AU) and being arranged between the pressure port (P) and the working port arrangement (L, R), and an adjustable pressure source (9) connected to the pressure port (P) and having a load sensing port (18), wherein a main drain orifice (Amd) is connected between the main flow path (2) downstream the main orifice (A1) and the return flow path (4).

Abstract: A method for controlling a hydraulic actuator (2) of a system (1) by means of a valve having a valve element is described. A position of the valve element determines a pressure supplied to a hydraulic actuator (2). In such a method a variable dead band should be minimized. To this end a start position of the valve element is preadjusted as a function of at least one parameter outside the hydraulic actuator (2).

Abstract: A fluid power system comprises a pump with multiple independently variable outlets, each of which is capable of delivering fluid in individually controllable volume units and a plurality of hydraulic loads. A system of switching valves is configured to create fluid connections between the pump outlets and the loads. A control system commands both the pump and the switching valves, so as to create valve state combinations to satisfy load conditions as demanded by an operator. The number of pump outlets connected to one or more of the loads is changeable to satisfy the flow required of the load due to the operator demand, each pump outlet being commanded to produce a flow depending on the status of other outlets connected a load to which the outlet is connected and the operator demand for that load.

Abstract: A hydraulic steering unit includes a pressure port connected to a main flow path and a tank port connected to a tank flow path, left and right working ports connected to left and right working flow paths, respectively, a bridge arrangement of variable orifices having a first left orifice connected to the main flow path and to the left working flow path, a first right orifice connected to the main flow path and to the right working flow path, a second left orifice connected to the left working flow path and to the tank flow path, and a second right orifice connected to the right working flow path and to the tank flow path. A variable diagonal orifice is connected to the main flow path and to the tank flow path. The bridge arrangement orifices being closed in neutral position and the diagonal orifice being open in neutral position.

Abstract: A control arrangement (5) of a hydraulic system (1) is provided, said control arrangement (5) comprising a supply port arrangement having a high pressure port (6) and a low pressure port (7), a working port arrangement having two working ports (8, 9), a first valve (10) arranged between said high pressure port (6) and said working port arrangement (8, 9), a second valve (11) arranged between said low pressure port (7) and said working port arrangement (8, 9). Such a control arrangement should enhance the control of a hydraulic system.

Abstract: A hydraulic steering arrangement (1) is described comprising a supply port arrangement having a pressure port (P) and tank port (T), a working port arrangement having two working ports (L, R), a steering unit (2) arranged between the supply port arrangement and the working port arrangement and a steering valve (3) arranged between the supply port arrangement and the working port arrangement. Such a steering arrangement should have a safety means. To this end in a manual steering mode the steering valve (3) is connected to the working port arrangement through the steering unit (2).

Abstract: A hydraulic steering unit (1) is described, said hydraulic steering unit (1) comprising a supply port arrangement having a pressure port (P) connected to a main flow path (3) and a tank port (T) connected to a tank flow path (4), a working port arrangement having a left working port (L) connected to a left working flow path (5) and a right working port (R) connected to a right working flow path (6), a bridge arrangement (14) of variable orifices having a first left orifice (A2L) connected to the main flow path (3) and to the left working flow path (5), a first right orifice (A2R) connected to the main flow path (3) and to the right working flow path (6), a second left orifice (A3L) connected to the left working flow path (5) and to the tank flow path (4), and a second right orifice (A3R) connected to the right working flow path (6) and to the tank flow path (4). Such a hydraulic steering unit should be operated together with a pressure source of fixed displacements.

Abstract: A hydraulic steering unit (1) is described comprising a supply port arrangement having a pressure port (P) connected to a main flow path (6) and a tank port (T) connected to a tank flow path (7), a working port arrangement having a left working port connected to a left working flow path (8) and a right working port (R) connected to a right working flow path (9), a bridge arrangement (14) of variable orifices (A2L, A2R, A3L, A3R) having a first left orifice (A2L) connected to the main flow path (6) and to the left working flow path (8), a first right orifice (A2R) connected to the main flow path (6) and to the right working flow path (9), a second left orifice (A3L) connected to the left working flow path (8) and to the tank flow path (7), and a second right orifice (A3R) connected to the right working flow path (9) and to the tank flow path (7). Such a steering unit should make steering comfortable.

Abstract: A hydraulic steering unit is described comprising a housing (1) and a non-return valve (2) having a ball (3) and a valve seat (4) at an end of a channel (5) in the housing (1), wherein a movement of the ball (3) away from the valve seat (4) is limited by an abutment (7) in the channel (5). Such a steering unit should have a non-return valve which can be produced with low costs. To this end the abutment (7) extends transversely through the channel.

Abstract: A hydraulic steering arrangement is described comprising a steering unit (1), a steering wheel and a steering wheel angle sensor (3) detecting an angle of rotation between the steering wheel and the steering unit (1). Such a steering arrangement should have a simple construction. To this end the steering wheel angle sensor (3) comprises a transmitter/receiver arrangement fixed to the steering unit (1) and a target assembly (4) which is rotateably fixed to the steering wheel by means of a connection geometry (9) and comprises a passive reaction arrangement.