Daimler-benz Ag

Mercedes-benz Aktiengesellschaft

Daimler Chrysler Ag

Arno Rohringer

Gunter Worner

Reinhold Abt

Aydogan Cakmaz

Wolfgang Jorg

Manfred Rombold

Manfred Link

Jaromir Bordovsky

Hubert Heck

Bernd Langkamp

Claus Gall

Jurgen Frank

Heiko Bublitz

Werner Walter

Werner Weiler

Ernst-Heinrich Fasse

Karl-Hans Kohler

Bernd Schick

Peter Lindeckert

Ernst Fasse

Rainer Strass

In a steering reaction force control arrangement for a hydraulic servo valve of a power steering system including a rotary spool rotatable received in a control sleeve and having a portion with axially extending V-shaped grooves disposed within a sleeve structure connected, by a conical engagement structure, to the control sleeve, the sleeve structure has radial bores receiving force transmitting balls which are pressed into the V-shaped grooves by a controllable hydraulic pressure so that the rotary spool can be moved relative to the control sleeve only upon the transmission of a torque sufficient to lift the force transmitting balls against the force of the hydraulic fluid by which they are pressed into the grooves.

Steering reaction force control arrangement for a power steering servo

In a hydraulic power steering for a motor vehicle with a hydraulic servomotor and a servovalve arrangement in communication with opposite servomotor actuating chambers by way of separate communication conduits through which the actuating chambers can be pressurized or depressurized for the operation of the servomotor depending on a force applied by an operator to a steering means, the communication conduits include valve arrangements permitting, when they are open, the release of hydraulic fluid from the actuating chambers but blocking the release of hydraulic fluid when they are closed thereby hydraulically locking the power steering.

Hydraulic power steering

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

In a servo valve arrangement for hydraulic power assisted steering systems in motor vehicles comprising a rotary spool connected to a steering shaft and a control sleeve receiving the rotary spool so as to permit some relative rotation between the control sleeve and the rotary spool, an axial endpiece is coupled to the rotary sleeve for rotation therewith by an articulated joint structure so as to accommodate any misalignment in the steering system.

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 hydraulic flow control apparatus has shape memory alloy springs which develop substantial actuating forces only at relatively high temperature. As a result of these forces, an only relatively slightly throttled connecting path between delivery side and intake side of a pump is opened directly or indirectly.

Hydraulic flow control with temperature sensitive spring biased bypass

A rear wheel steering is operated by a mechanical gear, which is connected on an input side to a front wheel steering. The gear has a controllable transmission ratio, a control element controlling the transmission being adjusted against spring force by a self locking free positioning motor. In the event of failure of a control unit operating the positioning motor as a function of the travelling speed, a maximum transmission ratio for deflection in the same direction of the front wheels and rear wheels is set by spring force.

All-wheel steering for motor vehicles

A servo control for power-assisted steering for motor vehicles having two coaxial shaft parts that are positively coupled to each other, but with play. The shaft parts are coupled such that limited relative rotations between these shaft parts are possible against the resistance of a pretensioned spring arranged in between. These relative rotations cause a pivoting stroke of a lever arranged between the shaft parts, this lever thereby actuating the control spool of a servo valve.

Hydraulic auxiliary-force control of steering

In a vehicle with a permanently active rear-axle drive train and with a front-axle drive train which can be connected via an electrohydraulically controllable clutch and a power take-off gear, and which is connected each time for a specific period of a few seconds when the drive slip in the rear-axle drive train exceeds a predetermined threshold value. A torque direction sensor responds to pulling and pushing stresses in the front-axle drive train and which generates electrical output signals characteristic of such stresses. These output signals are used with the output signals from a forward-reverse motion sensor in a logic circuit, in such a way that the clutch is released when admissibly high stresses occur in the front-axle drive train within the connection period, and the clutch is engaged again when these stresses have diminished. The torque direction sensor comprises a rotary-slide reversing valve, the piston of which is connected fixedly in terms of rotation to the cardan shaft of the connectable drive train, on the one hand, and to the output gear wheel of the power take-off gear via a torsion rod, on the other hand. For alternative directions of the torque in the connectable drive train, this valve assumes alternative through-flow positions, in each of which a dynamic pressure in one of two flow branches is produced. The monitoring of the pressures in the two flow branches by a pressure/voltage converter device generates the torque direction signals necessary for logic circuit.

Intermittent change-over control from two-wheel drive to four-wheel drive

A device for the shifting of a multi-disk clutch for the locking of a transfer differntial for the drive of two vehicle axles of a motor vehicle, wherein the multi-disk clutch is engaged by means of the force of a spring and is released by means of an axial piston that can be acted upon by working pressure. The axial piston acts upon the set of disks via a pressure ring that, with respect to the disk carrier of one half of the clutch, is fixed in the direction of the clutch axis pointing away from a first counterbearing of the set of disks by a second counterbearing. The first counterbearing of the set of disks is coupled with the disk carrier by means of an adjusting arrangement that works toward displacing the first counterbearing by an additional spring force toward the pressure ring along the clutch axis. In a position of a control valve that brings the disk clutch into the engaged position, the working pressure chamber used for the admission of pressure to the axial piston is connected with a pressure-relieved storage tank via a hydraulic throttling arrangement.

Arrangement for the shifting of a multi-disk clutch for the locking of a

A steering wheel end shaft part and a gear end shaft part are connected together elastically by means of a mechanism located between the shaft parts, the relative rotation between the shaft parts being converted into a large-stroke pivoting movement of a setting lever which actuates a control valve unit of the power steering system.

Servo-control for power steering arrangement

A shifting arrangement for the shifting between a single-axle standard drive and an all-wheel drive having a first clutch for the locking of a central differential gear and a second clutch for the connecting and disconnecting of one vehicle axle actuated by first and second pressure medium control element respectively against the force of a spring having first and second shift valve respectively controlled by an electronic control unit, to either supply working pressure or relieve from pressure respective control elements. The improvement including a hydraulic identifying valve for bringing the control elements into a mutual interaction. The identifying valve operates, as a function of the working pressure of at least one of the control elements and exclusively during the simultaneous controlling of both shift valves, in such a way that the clutch torque at both clutches increases and decreases approximately to the same extent. As a result, when shifting into a shift step with a balanced all-wheel drive from standard drive, a shifting can first take place for a short time into an intermediate step with a longitudinally locked all-wheel drive for securing the driving stability.

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Ditzingen, Germany

Arno Rohringer