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.

A torsion bar is provided that is easy, quick, and cost effective to manufacture. The torsion bar may extend along an axis and have a first end and a second end that is spaced from the first end. The torsion bar may have an active section positioned between the first and second ends. The active section may also have a length defined along the axis. A cross-section transverse to the axis may define a contour of the torsion bar where the contour may be uniform along the length of the active section. The contour may define at least one of a polygon and a polygon-like shape.

A brushless motor includes: a motor rotor; a stator coil section which has a plurality of energization phases, which includes a first stator coil and a second stator coil that are provided to each phase, and which is arranged to generate a magnetic field, and thereby rotate the motor rotor; and a connection switching section configured to switch a connection of the first stator coil and the second stator coil from a serial connection to a parallel connection, or from the parallel connection to the serial connection.

In a steering device of the present invention, an electric motor rotates a steering shaft through a reduction mechanism, and the reduction mechanism and a torque sensor are accommodated in an integrally-structured housing. With this, the present invention can provide a steering device that is capable of suppressing increase in size of the electric motor.

In a steering device of the present invention, an electric motor rotates a steering shaft through a reduction mechanism, and the reduction mechanism and a torque sensor are accommodated in an integrally-structured housing. With this, the present invention can provide a steering device that is capable of suppressing increase in size of the electric motor.

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.

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).

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. To this end at least one of the commutation grooves (12, 13) comprise a closed bottom and at least one of the commutation grooves (12, 13) comprise a throughgoing opening (10, 11) forming part of the valve geometry.

An improved steering shaft assembly is provided. The steering shaft assembly further includes an output shaft that is rotatable with respect to the input shaft. The output shaft includes a rotary valve portion and a longitudinal portion. The steering shaft assembly further includes a torsion bar coupled to the input shaft and coupled to the output shaft distal from the input shaft. The steering shaft assembly further includes a mid-coupler extending around about the longitudinal portion of the output shaft and adapted to cooperate with the rotary valve portion of the output shaft. The steering shaft assembly further includes a screw mechanism extending about the longitudinal portion of the output shaft and adapted to cooperate with the mid-coupler. The screw mechanism is adapted to move laterally relative to the output shaft to maintain transfer of power from between output shaft and the screw mechanism despite misalignments therebetween.

A quick response steering system with a steering device that steers a vehicle. An electro-hydraulic steering circuit couples to the steering device. The electro-hydraulic steering circuit includes a load sensing pump that pumps hydraulic fluid to a steering cylinder. The load sensing pump increases or decreases output from the load sensing pump in response to a pressure differential between a first fluid line and a second fluid line. A precharge valve diverts hydraulic fluid from the first fluid line to the second fluid line. A controller couples to the steering device and the precharge valve. The controller opens the precharge valve in response to input from the steering device to change a first pressure of the first fluid line to increase an output of the load sensing pump.