Mercedes-benz Aktiengesellschaft

Daimler Chrysler Ag

Daimler-benz Ag

Hogo Benzing Gmbh & Co. Kg

Aydogan Cakmaz

Arno Roehringer

Reinhold Abt

Jaromir Bordovsky

Hubert Heck

Claus Gall

Karl-Hans Koehler

Rainer Strauss

Wolfgang Joerg

Arno Rohringer

Ulrich Asbrand

Wolfgang Jorg

Horst Gutscher

Juergen Class

Jurgen Class

Karl-Hans Kohler

Wolfgang Mockel

Wolgang Joerg

Rainer Strass

The invention relates to a damper valve arrangement, which can be combined with a servomotor of a hydraulic power steering system to form a steering damper. For calibration purposes, the damper valve arrangement has a bypass duct with a calibratable throttling resistance.

Damper valve arrangement

In a damper valve for use in a steering damper arrangement of a motor vehicle having a hydrostatic displacement motor for operating the vehicle steering mechanism wherein hydraulic fluid lines extending between the hydraulic motor and a servo-valve include the damper valve, the damper valve has a throttling arrangement which permits fluid flow in one direction and limits fluid flow in the opposite direction but permits essentially unlimited fluid flow in both directions as long as the pressure difference across the damper valve is below a predetermined threshold value so as to permit unrestricted normal steering movements of the vehicle steering system, but dampen shock movements thereof.

Damper valve

A servo control has an electromechanical or electrohydraulic support of setting strokes of a handle. A constantly running electric motor is coupled to a control member of the servo control by power flux which can be controlled by the handle. By way of an electronic load recognition, the load which is variable in dependence on the power flux and against which the electric motor has to operate is utilized to control the output of the electric motor. That is, the electric motor is switched to greatly increased output in the case of increased load.

Power steering system/servo control

A rack-and-pinion steering system has a rack which is toothed on two sides and cooperates with two pinions. At least one of the pinions can be axially translated in dependence on forces acting between the rack and that pinion. This axial translation controls a clutch arrangement so that a servomotor continuously rotating in one direction can in each case be nonpositively coupled to one of the pinions or uncoupled from both pinions.

Rack-and-pinion steering system

A rack-and-pinion steering or control system with a servomotor, especially an electric motor, which can be coupled to the rack by way of a mechanical transmission and runs continuously in one direction is provided. The rack is designed over a certain area as a screw which interacts with a recirculating ball sleeve which can be driven in two directions of rotation by the motor. To control the direction of rotation, use is made of normally disengaged clutches which can be controlled as a function of a small displacement of the recirculating ball sleeve.

Servomotor assisted rack-and-pinion steering or control system

The invention relates to a servo-assisted rack-and-pinion steering system having a helical-toothed rack and an axially movable pinion which interacts therewith and the axial movement of which controls the servomotor. The pinion is mounted on an input shaft in such a manner as to be incapable of rotation with respect to the shaft but axially movable thereon, in order to suppress the transmission of axial forces between the input shaft and the pinion.

Servo-assisted rack-and-pinion steering system

A servo-assisted rack-and-pinion steering system in which the rack is drive-coupled to a pinion which is mounted to move between two end positions in the longitudinal direction of the rack so that its movements control the servo motor. The end positions of the pinion are defined by two friction wheels which are driven continuously in opposite directions by the servo motor, in each case allowing an auxiliary force to be transmitted to the pinion.

Servo-assisted rack-and-pinion system

A servo-assisted rack-and-pinion steering system is provided in which the rack cooperates with a rotatable pinion. The pinion is supported in an eccentrically located opening in a circular disk rotatably mounted by rolling elements on its periphery. Pivoting movement of the pinion controls an hydraulic oil actuated servo motor. The rolling contact bearing of the disk lies in the path of flow of the hydraulic oil for the servo motor. The pinion is supported in a bearing in the opening in the disk and another bearing at an opposite side of the rack and separate from the disk.

A servo-assisted rack-and-pinion steering system includes a rack which cooperates with a pinion which is capable of limited movement transversely or, in particular, parallel to the longitudinal axis of the rack. The movements actuate the servomotor or its control elements.

A servo valve arrangement with a high-pressure, low-pressure and motor connection and with a pressure control valve arranged between the high-pressure connection and motor connection and a return control valve arranged between the motor connection and low-pressure connection is provided. The pressure control valve normally is closed and the return control valve normally is open. The pressure control valve can be opened by a common actuating member whilst closing the return control valve. The valve arrangement is suitable, in particular, for hydraulic power steering systems of motor vehicles with a so-called closed center.

Servo valve arrangement

In a drive unit which includes an electric motor and a cooling fan as well as a hydraulic power steering pump to be driven by the electric motor, the cooling fan is operatively connected to the motor by a clutch and a control circuit is provided for operating the clutch so as to disengage the cooling fan whenever the power steering unit needs hydraulic fluid for steering assistance, whereby both, the cooling fan and the hydraulic pump, are never operated at the same time so that the motor may be relatively small, light and inexpensive.

Drive unit having an electric motor

A slide valve, having a pump port, a reservoir port and at least one consumer port is described, which comprises a slide which is spring-loaded into a first position and can be moved into a second position counter to the spring force by means of an adjusting assembly. At least one of the consumer ports is connected to the reservoir port in the first slide position and to the pump port in the second slide position. Arranged between the adjusting assembly and the slide is a seat-controlled safety valve which, in the closed position, shuts off the adjacent open end of a longitudinal duct formed in the slide which, on the one hand, is connected to the consumer port and, on the other hand, to the reservoir port via the opened safety valve when the slide is possibly blocked and not loaded by the adjusting assembly. The longitudinal duct is closed off at the other end by an additional pressure relief valve which limits the pressure in the longitudinal duct with the safety valve usually being closed.

Slide valve

As a result of an appropriate displacement of the control member, a connection of a fluid unit can, for pressure relief, be connected to a line leading to a low-pressure reservoir or be isolated from this line and/or, for the exertion of pressure, connected to a connection of a pressure source. Should the control member jam and be incapable of following an appropriate actuating stroke of a servomotor into the pressure-relieving position, a safety relief valve is opened by means of the actuating stroke.

Growing community of inventors

Stuttgart, Germany

Aydogan Cakmaz