Abstract: A hydraulic steering unit (1) is described comprising a supply port arrangement having a pressure port (P) connected to a main flow path (2) and a tank port (T) connected to a tank flow path (3), a first working port arrangement having a first left working port (L1) connected to a first left working flow path (4) and a first right working port (R1) connected to a first right working flow path (5), a variable first left orifice (A2L) connected to the main flow path (2) and to the first left working flow path (4), a variable first right orifice (A2R) connected to the main flow path (2) and to the first right working flow path (5), a variable second left orifice (A3L) connected to the first left working flow path (4) and to the tank flow path (3), a variable second right orifice (A3R) connected to the first right working flow path (5) and to the tank flow path (3), and a second working port arrangement having a second left working port (12) connected to a second left working flow path (9) and a second right work

Abstract: A steering wheel angle sensor is described comprising a first part and a second part, wherein the first part and the second part are moveable relative to each other in rotational direction and the first part comprises at least one first signal generating means (1, 2) generating a sine signal (x2, x5) in response to an angular position of the second part and at least one second signal generating means (3, 4) generating a cosine signal (y2, y5) in response to the angular position of the second part. Such a steering wheel angle sensor should allow a simple fault detection. To this end fault detecting means (9) are provided, wherein the fault detecting means (9) form a sum of the square of the sine signal (x2, x5) and the square of the cosine signal (y2, y5) and generates a fault signal, if the sum is not within a predetermined range.

Abstract: A hydraulic steering unit (1) is described comprising a supply port arrangement having a pressure port (P) connected to a main flow path (5) and a tank port (T) connected to a tank flow path (6), a working port arrangement having a left working port (L) connected to a left working flow path (7) and a right working port (R) connected to a right working flow path (8), a bridge arrangement (14) of variable neutral open orifices, said bridge arrangement (14) comprising a first left orifice (A2L) connected to a main flow path (5) and to the left working flow path (7), a first right orifice (A2R) connected to a main flow path (5) and to the right working flow path (8), a second left orifice (A3L) connected to the left working flow path (7) and to the tank flow path (6), and a second right orifice (A3R) connected to the right working flow path (8) and to the tank flow path (6). Such a steering unit has a good steering behavior but can function as a closed-center solution.

Abstract: A hydraulic steering unit (1) is described comprising a supply port arrangement having a pressure port (P) connected to a main flow path (2) and a tank port (T) connected to a tank flow path (3), a working port arrangement having a left working port (L) connected to a left working flow path (4) and a right working port (R) connected to a right working flow path (5), a bridge arrangement (21) of variable orifices (A2L, A3L, A2R, A3R) having a first left orifice (A2L) connected to the main flow path (2) and to the left working flow path (4), a first right orifice (A3R) connected to the main flow path (2) and to the right working flow path (5), a second left orifice (A3L) connected to the left working flow path (4) and to the tank flow path (3), and a second right orifice (A3R) connected to the right working flow path (5) and to the tank flow path (3). Such a steering unit allows steering a vehicle with low energy consumption.

Abstract: A hydraulic steering unit (1) is described comprising a supply port arrangement having a pressure port (8) connected to a main flow path (2) and a tank port (5) connected to a tank flow path (3), a working port arrangement having a left working port (L) connected to a left working flow path (4) and a right working port (R) connected to a right working flow path (5), a variable first left orifice (A2L) connected to the main flow path (2) and to the left working flow path (4), a variable first right orifice (A2R) connected to the main flow path (2) and to the right working flow path (5), a variable second left orifice (A3L) connected to the left working flow path (4) and to the tank flow path (3), and a variable second right orifice (A3R) connected to the right working flow path (5) and to the tank flow path (3). Such a steering unit should allow comfortable steering. To this end a measuring motor (15) is arranged in one of the working flow parts (4, 5).

Abstract: A hydraulic steering unit (1) is described comprising a supply port arrangement having a pressure port (8) 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 (L) connected to a left working flow path (9) and a right working port (R) connected to a right working flow path (10), a bridge arrangement (14) of variable orifices having a first left orifice (A2L) connected to the main flow path (6) and to the left working flow path (9), a first right orifice (A2R) connected to the main flow path (6) and to the right working flow path (10), a second left orifice (A3L) connected to the left working flow path (9) and to the tank flow path (7), and a second right orifice (A3R) connected to the right working flow path (10) and to the tank flow path (7). Such a hydraulic steering unit should allow comfortable steering.

Abstract: A hydraulic system (1) is provided comprising a group of at least two valves (2a, 2b, 2c) connected to a bus (8), each of said valves (2a, 2b, 2c) comprising a primary memory (9a, 9b, 9c) for storing a set of parameters of the valve (2a, 2b, 2c). The service work of such a hydraulic system should be facilitated. To this end each valve (2a, 2b, 2c) comprises a secondary memory (10a, 10b, 10c) storing said set of parameters of a different valve (2b, 2c, 2a) of said group.

Abstract: A hydraulic steering arrangement is shown having a steering unit and two working ports each of which being connected to the steering unit by a working line (3), wherein an anti jerk valve (9) is arranged in each working line (3), the anti jerk valve (9) having a valve element (12) being loaded in opening direction by the pressure in the working line (3) and in closing direction by restoring means (17). A vehicle equipped with such a steering arrangement should have a good comfort. To this end the valve element (12) is loaded in closing direction by the pressure in the working line (3) via delay means (21).

Abstract: A hydraulic steering arrangement (2) is described having a main flow path (8) with a flow meter (9) and an amplification flow path (10) opening into the main flow path (8) at a connecting point (11) located between the flow meter (9) and a working port arrangement (L, R). Such a steering arrangement should have in a simple way a large flow of the hydraulic fluid to the working port arrangement. To this end pressure increasing means (17) are arranged in the main flow path (8) upstream the connecting point (11).

Abstract: A shaft (1) is shown comprising a shaft section (2) having an axis (3), a tooth geometry (4) at least at one end of said shaft section, said tooth geometry (4) having a first end (5) opposite said shaft section (2) and a second end (6) adjacent said shaft section (2), a number of teeth (7) distributed in circumferential direction around said axis (3), a bottom curve (9) between adjacent teeth (7), and an outer tooth curve (12), said bottom curve (9) having a positive slope from said first end (5) towards said shaft section (2) and a negative slope (14) at said second end (6). In such a shaft wear should be made as small as possible. To this end said bottom curve (9) comprises a section having a concave bottom curvature (15) between said positive slope and said negative slope.

Abstract: A hydraulic steering unit (1) is described comprising a supply port arrangement having a pressure port (P) connected to a main flow path (2) and a tank port (T) connected to a tank flow path (3), a working port arrangement having a left working port (L) connected to a left working flow path (9) and a right working port (R) connected to a right working flow path (10), a bridge arrangement (15) of variable orifices having a first left orifice (A2L) connected to the main flow path (2) and to a left connecting point (16) at the left working flow path (9), a first right orifice (A2R) connected to the main flow path (2) and to a right connecting point (17) at the right working flow path (10), a second left orifice (A3L) connected to the left connecting point (16) at the left working flow path (9) and to the tank flow path (3), and a second right orifice (A3R) connected to the right connecting point (17) at the right working flow path (10) and to the tank flow path (3).

Abstract: Hydraulic steering (1) is disclosed comprising a high pressure port (P), a low pressure port (T), two working ports (CL, CR), a manual steering section (3), and a steering valve section having a steering valve 5 and a hydraulic driving arrangement (6) 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 (11) is provided, which is actuatable between a first position in which said driving arrangement (6) is supplied with hydraulic fluid under pressure, and a second position in which a supply of hydraulic fluid to said driving arrangement (6) is interrupted, wherein said switching valve (11) is hydraulically actuated into said second position by a pressure generated upon actuating of said manual steering section (3).

Abstract: An electrohydraulic control valve (1) comprising a control valve element (2) displaceable in a first direction by a pressure in a first pressure chamber (5) and in a second direction by a pressure in a second pressure chamber (6). Each pressure chamber (5, 6) is connected to a line between a high pressure port (PP) and a low pressure port (PT) via a magnetic valve (11, 12). Each magnetic valve (11, 12) is a three-way valve and comprises a first valve seat (17) and a second valve seat (18). A space (19) between the first valve seat (17) and the second valve seat (18) is connected to the pressure chamber (5, 6) and a first valve element (20) positioned outside the space (19) cooperates with the first valve seat (17) and a second valve element (21) positioned outside the space (19) cooperates with the second valve seat (18).

Abstract: A hydraulic overpressure valve (1) is provided comprising a valve housing (2), a valve seat (3) located in said valve housing and having a seat center and a seat center axis (4), a cone element (5) movable relatively to said valve seat (3), said cone element (5) having a cone (6) protruding at least partly into said valve seat (3) and having a cone center axis (4), and force generating means acting on said cone element (5) in a direction towards said valve seat (3). Such a hydraulic overpressure valve should be operated with low noise. To this end said cone (6) is movable along a path of movement in which said cone center axis is kept outside said seat center axis (4).

Abstract: A hydraulic steering system (1) is provided having a steering device (2) and a symmetrically acting steering motor (3), said steering device (2) comprising a supply port arrangement having a high pressure port (P) and a low pressure port (T), a working port arrangement having two working ports (L, R), a control valve (14), two working lines (18, 19) each connecting said control valve (14) with one of said working ports (L, R), and a measuring motor (23). Such a hydraulic steering system should show a comfortable steering behavior. To this end said measuring motor (23) is arranged in one of said working lines (18, 19).

Abstract: A hydraulic system (1) is disclosed comprising a pressure source (2), at least a hydraulic consumer (12, 13), and a pressure booster (16) arranged between the pressure source (2) and the hydraulic consumer (12, 13), wherein inactivating means (17) are provided inactivating or activating said pressure booster (16), said pressure booster (16) and said inactivating means (17) being part of a booster module (11). The operational possibilities of such a hydraulic system (1) should be extended. To this end the booster module (11) is part of a valve block (3), said valve block (3) comprising said booster module (11) and at least one valve module (9, 10) controlling said hydraulic consumer (12, 13).

Abstract: It is intended to provide a vehicle comprising a fluid working machine which can reduce wear of parts and be produced at low cost. The fluid working machine 11, 12 is provided with an eccentric cam 17, a piston 18A to 18F, a cylinder 19A to 19F, a drive rod 20A-20F having an engaging part 24 engaging with the piston and a contact part 25 contacting the eccentric cam 17, a holding member 34A to 34F surrounding the drive rod, a pressing member 40A to 40F for pressing up the holding member in a radially outward direction, and at least one holding ring 41 for holding the holding member from the outside.

Abstract: A hydraulic system (1) is provided comprising a group of at least two valves (2a, 2b, 2c) connected to a bus (8), each of said valves (2a, 2b, 2c) comprising a primary memory (9a, 9b, 9c) for storing a set of parameters of the valve (2a, 2b, 2c). The service work of such a hydraulic system should be facilitated. To this end each valve (2a, 2b, 2c) comprises a secondary memory (10a, 10b, 10c) storing said set of parameters of a different valve (2b, 2c, 2a) of said group.

Abstract: A hydraulic steering system (1) is described comprising a first steering circuit (2a) and a second steering circuit (2b), each of said steering circuits (2a, 2b) comprising a steering device (3a, 3b) and a steering motor (4a, 4b) connected to said steering device (3a, 3b), each of said steering devices (3a, 3b) comprising a supply port arrangement having a high pressure port (Pa, Pb) and a low pressure port (Ta, Tb), a working port arrangement having two working ports (La, Ra; Lb, Rb) connected to said steering motor (4a, 4b), a control valve (5a, 5b), and a measuring motor (6a, 6b). Such a steering system should have a comfortable steering behavior. To this end in each of said steering devices (3a, 3b) said measuring motor (6a, 6b) is arranged in a working line (19a, 20b) between said control valve (5a, 5b) and one of said working ports (La, Ra; Lb, Rb).