Abstract: A hydraulic steering arrangement (1) is disclosed. The hydraulic steering arrangement (1) includes 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) and at least one further orifice (A2, A3, A4) downstream the main orifice (A1), 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), a measuring motor (3), 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 (Adrain) is connected between the main flow path (2) down-stream the main orifice (A1) and the return flow path (4).

Abstract: A hydraulic steering system (1) includes a steering command device (2) having a steering sensor (3), a steering motor (6), a wheel sensor (9), a pressure source (P), and control means (12) controlling a fluid supply from the pressure source (P) to the steering motor (6), wherein the control means (12) has an open loop control (19). Such a steering system should have a good relationship between steering input from the operator and steering behaviour of the vehicle to be steered. To this end the control means (12) include in addition to the open loop control (19) a closed loop control (20), wherein cross-over transition means (21) are provided which are connected to the open loop control (19) and to the closed loop control (20) and control a transition between the open loop control (19) and the closed loop control (20).

Abstract: A steering command means (1) is described comprising a joystick (2) and an arm rest (3) having an arm support surface (4), wherein the joystick (2) comprises a handle member (5) and a grip surface (6) is located on a circumference of the handle member (5). A risk of unintended steering input in a vibrating environment should be minimized. To this end an axis (9) of rotation of the handle member (5) runs through a space surrounded by the grip surface (6).

Abstract: A hydraulic arrangement (1) including a supply port (P), a return port (T), a working port arrangement (L, R), and a valve (2) controlling a supply of hydraulic fluid from the supply port (P) to the working port arrangement (L, R), wherein the valve (2) includes a housing (4) and a spool (3) movable in lengthwise direction in the housing (4) and forming together with the housing (4) at least one flow path the resistance of which depends on the position of the spool (3) in the housing (4), and the spool (3) is actuated by a hydraulic pilot pressure (21, 22) in a pressure chamber (7, 8). In such a hydraulic arrangement a safety functionality should be achieved in a simple way. To this end the housing (4) includes a pilot pressure relief port (20) connected to the return port (T) via a shut-off valve (10) and the spool (3) after a predetermined stroke (13, 14) opens a connection between the pressure chamber (7, 8) and the pilot pressure relief port (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 number of pairs of commutation grooves (12, 13) 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 controlling together with a valve geometry 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 behaviour.

Abstract: A hydraulic steering arrangement (1) including a supply port (2), a return port (4), a working port arrangement having two working ports (5, 6), a main flow path (7) between the supply port (2) and one of the working ports (5) and a return flow path (8) between the other working port (6) and the return port (4), wherein the main flow path (7) includes a main orifice (A1), a flow meter (9), a first flow meter orifice (A2) upstream the flow meter (9), a second flow meter orifice (A3) downstream the flow meter (9), and a first working port orifice (A4), the return flow path (8) includes a second working port orifice (A5), a load sensing point (17) is arranged between the main orifice (A1) and the first flow meter orifice (A2), a drain orifice (Ad) is arranged between the load sensing point (17) and the return port (4), and a priority valve arrangement (10) is arranged between the supply port (2) and the main orifice (A1). Such a steering arrangement should enable a high steering speed without loss of comfort.

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.