US 5,509,493 AGranted

Control device for steering-rack equipped auxiliary power steering

AssigneeZF Friedrichshafen AG

InventorsArmin Lang, Helmut Knodler

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Abstract

In a steering-rack-equipped auxiliary power steering which is intended particularly for motor vehicles, a pinion (2), positioned in a steering housing (1), engages a steering rack (6). A servomotor (11) is operationally connected with steering rack (6) for auxiliary power support. Pinion (2) is positioned swingably in a fixed bearing (3) and a loose bearing (4). In the area of loose bearing (4), there are arranged two control valves (26, 27) whose axes are essentially perpendicular to the axis of pinion (2). Loose bearing (4) is guided in a movable fashion in steering housing (1), perpendicularly with respect to its axis only in the direction of the axes of the two control valves (26, 27). In this steering-rack-equipped auxiliary power steering, one can make sure that to activate the control valves, one will not use the axial forces that act upon pinion (2) but rather the lateral forces. As a result, the activation of the control valves is independent of the helix angle or slope angle of the pinion gearing.

Claims6

Dependent claims

Steering-rack-equipped auxiliary power steering suitable for use in motor vehicles including a steering housing, a pinion having an axis which is connected to a manual steering wheel spindle and positioned rotatably in the steering housing, a steering rack mounted for axial movement in the steering housing and positioned in engagement with the pinion by a spring-loaded thrust piece, a control device responsive to the movement of the pinion, and a servomotor operated by the control device and associated with the steering rack to provide auxiliary power support to the steering rack, wherein the improvement comprises:

providing a fixed bearing and a movable bearing in the steering housing, swingably positioning the pinion in the fixed bearing and the movable bearing such that rotation of the pinion causes movement of the movable bearing, wherein the control device includes two control seat valves mounted in said steering housing, each control seat valve having an axis which is substantially perpendicular to the axis of the pinion, and wherein the movable bearing is operably engaged with the control seat valves such that the movement of the movable bearing opens and closes the control seat valves to operate the servomotor.

Dependencies are inferred from the claim text.