Abstract: A hydraulic servo-steering device includes a pump and a pump drive motor. At least one defined high power stage (C) and one defined low power stage (B) are provided in which the motor is selectively operated. Moreover, a defined additional power stage (A) is provided for the motor, in which the speed of the motor is reduced with respect to the low power stage (B). According to a method for controlling the pump drive motor of the hydraulic servo-steering device, the motor is operated in the additional power stage (A) under certain conditions which rule out an impairment to driving safety.

Abstract: An assembly consists of a valve shaft, a valve member and an adjusting device which can alter the angle alignment of the valve member relative to the valve shaft.

Abstract: An assembly consists of a valve shaft, a valve member and an adjusting device which can alter the angle alignment of the valve member relative to the valve shaft.

Abstract: A steering valve (30) directs hydraulic fluid from a hydraulic fluid source to a hydraulic cylinder of a steering system in a vehicle. The steering valve includes a rotatable first shaft (32) having a first face valve member (36) on an end portion of the first shaft and a rotatable second shaft (34) having a second face valve member (50) on an end portion of the second shaft. The first face valve member (36) includes a plurality of channels (40, 42) fluidly connected with the hydraulic cylinder and the second face valve member (50) includes a plurality of passages (54, 56) fluidly connected with the hydraulic fluid source. A rotatable intermediate disk (70) is located between the first and second face valve members (36, 50). The intermediate disk (70) includes a plurality of axially extending bores (80a-80d) for fluidly connecting the plurality of channels (40, 42) with the plurality of passages (54, 56).

Abstract: A rotary slide steering valve (1) for supplying an actuator with hydraulic pressure, has an input shaft (2), an output shaft (3), a centering spring element (4) connected to the input shaft (2) and to the output shaft (3) and a valve element. The valve element comprises at least two elements that can be turned relative to one another and comprise control bores for supplying and returning a hydraulic medium as well as a hydraulic medium line to and a hydraulic medium return line from both sides of the actuator. All control bores of the valve element which are assigned to one another are exclusively arranged within a region of opposing end faces of the input shaft (2) and the output shaft (3) and directly connected to pressure medium connections on a housing side of the rotary slide steering valve. The input shaft (2) and the output shaft (3) comprise a disk-shaped widening (11, 12) within the region of the opposing end faces. Control recesses (15, 16, 17, 18) are arranged on the opposing end faces.

Abstract: A vehicle steering gear for transferring rotational movement of a pinion (6) associated with a vehicle steering mechanism into axial movement of a tie rod connected with steerable wheels in the vehicle. The steering gear comprises a piston (1), first and second piston rods (2), a cylinder (3) encircling the piston and partially defining first and second chambers which are separated by the piston. A piston ring (17) seals the piston (1) inside the cylinder (3). First and second bushings (4) seal the ends of the cylinder (3) around the piston rods (2). A rack member comprising an arcuate segment (5) is fixedly attached to the cylinder (3) and has a toothed surface portion and a threaded opening for receiving a tie rod fastener (16). A tubular housing (7) encircles the cylinder (3) and the arcuate segment (5). The pinion (6) is engageable with the toothed surface portion of the arcuate segment (5) within the housing (7).

Abstract: The invention proposes a rapid, safe, and economic device for assembling a servo valve with an input shaft, an output shaft and a valve sleeve in a hydraulically centered position by:a) Forming a preassembled unit consisting of the output shaft and the input shaft;b) Clamping the valve sleeve into a rotatable position, however a position in which it is fixed in the axial direction;c) Inserting the preassembled unit into the valve sleeve, with said preassembled unit being axially movable, but positioned in a nonrotatable fashion such that the valve sleeve and the output shaft adjoin one another and can be turned relative to one another;d) Charging the preassembled servo valve with hydraulic pressure;e) Centering the servo valve by turning the valve sleeve; andf) Pressing the preassembled unit into the valve sleeve such that the output shaft and the valve sleeve are pressed together within the overlapping region.

Abstract: In order to be able to more simply manufacture and center a steering valve consisting of an input shaft, an output shaft, a valve sleeve surrounding the input shaft, and a reaction arrangement to which pressure can be applied to generate a centering moment, where the steering valve can simultaneously be of a shorter configuration than a conventional steering valve, it is proposed that the hydraulic lines for the system or operating pressure, as well as for tank return, be formed between the input shaft (2) and valve sleeve (5) and that the reaction arrangement (6) exerts a radial pressure acting between the input shaft (2) and the valve sleeve (5).