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).

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).

The self-propelled construction machine according to the invention has a braking device which comprises at least one hydraulically actuated braking device actuating device 8 which has a pressure chamber 10A, 11A that can be acted upon with a hydraulic fluid. The braking device actuating device 8 is formed in such a way that, in a locking position, the running gear 3B, to which the braking device actuating device 8 is assigned, is braked, and, in an operating position, the running gear is unbraked. In addition, the construction machine according to the invention has a hydrostatic steering device 9, which comprises at least one hydraulic steering device actuating device 22. In the event of a malfunction in the supply of hydraulic fluid to the braking device actuating device 10, 11, the hydraulic system has a manually actuated emergency-operation valve arrangement 16 which is formed in such a way that, after the manual actuation thereof, a fluid connection is created between the steering device actuating device 22 and the pressure chamber 10A, 11A of the braking device actuating device 10, 11. The emergency-operation valve arrangement 16 has a valve block 27 in which flow paths are formed which can be shut off by means of shut-off screws 31, 32.

The self-propelled construction machine according to the invention has a braking device which comprises at least one hydraulically actuated braking device actuating device 8 which has a pressure chamber 10A, 11A that can be acted upon with a hydraulic fluid. The braking device actuating device 8 is formed in such a way that, in a locking position, the running gear 3B, to which the braking device actuating device 8 is assigned, is braked, and, in an operating position, the running gear is unbraked. In addition, the construction machine according to the invention has a hydrostatic steering device 9, which comprises at least one hydraulic steering device actuating device 22. In the event of a malfunction in the supply of hydraulic fluid to the braking device actuating device 10, 11, the hydraulic system has a manually actuated emergency-operation valve arrangement 16 which is formed in such a way that, after the manual actuation thereof, a fluid connection is created between the steering device actuating device 22 and the pressure chamber 10A, 11A of the braking device actuating device 10, 11. The emergency-operation valve arrangement 16 has a valve block 27 in which flow paths are formed which can be shut off by means of shut-off screws 31, 32.

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. To this end an idle flow path (15) branches off the main flow path (3), wherein a variable idle orifice (An) is arranged in the idle flow path (15), the idle orifice (An) being open in neutral position and closing out of neutral position.

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. To this end a measuring motor (15) a measuring motor (15) is arranged in one of the left working flow path (8) and the right working flow path (9) and an amplification flow path (16) is connected to the one working flow path (8, 9) downstream the measuring motor (15).

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. To this end a measuring motor (15) a measuring motor (15) is arranged in one of the left working flow path (8) and the right working flow path (9) and an amplification flow path (16) is connected to the one working flow path (8, 9) downstream the measuring motor (15).

The invention relates to a hydraulic steering facility for mobile systems, with a steering circuit for a steering facility and a working circuit for a working hydraulic system, whereby the steering circuit and the working hydraulic system are connected to a supply pump via a shared flow dividing valve and the flow dividing valve is connected to a load signal connection of the steering device. It is provided that the steering facility has an adjustable input choke that is connected via an inflow connection of the steering facility to the flow dividing valve, between the load signal connection and downstream of the input choke, a parallel circuit consisting of a choke and an adjustable second load signal choke is arranged, and the load signal connection is further connected via an adjustable first load signal choke to a return flow connection of the steering facility.

The invention relates to a hydraulic steering facility for mobile systems, with a steering circuit for a steering facility and a working circuit for a working hydraulic system, whereby the steering circuit and the working hydraulic system are connected to a supply pump via a shared flow dividing valve and the flow dividing valve is connected to a load signal connection of the steering device. It is provided that the steering facility has an adjustable input choke that is connected via an inflow connection of the steering facility to the flow dividing valve, between the load signal connection and downstream of the input choke, a parallel circuit consisting of a choke and an adjustable second load signal choke is arranged, and the load signal connection is further connected via an adjustable first load signal choke to a return flow connection of the steering facility.

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 first bridge arrangement (15a, 15b) of variable orifices having a first left orifice (A2L) connected to the main flow path (2) and to a first 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 first right connecting point (17) at the right working flow path (10), a second left orifice (A3L) connected to the first 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 first right connecting point (17) at the right working flow path (10) and to the tank flow path (3). It should be possible to change the steering characteristics of such a steering unit. This is achieved by at least a second bridge arrangement (20a, 20b) of variable orifices having a third left orifice (A2L) connected to the main flow path (2) and to a second left connecting point (21) at the left working flow path (9), a third right orifice (A2R) connected to the main flow path (2) and to a second right connecting point (22) at the right working flow path (10), a fourth left orifice (A3L) connected to the second left connecting point (21) at the left working flow path (9) and to the tank flow path (3), and a fourth right orifice (A3R) connected to the second right connecting point (22) at the right working flow path (10) and to the tank flow path (3), wherein the first bridge arrangement (15a, 15b) and the second bridge arrangement (20a, 20b) have different steering characteristics, and by selection means (23) connecting at least one of the bridge arrangements (15a, 15b; 20a, 20b) between the pressure port (P) and the working port arrangement.