Rotary shift valve for servo-assisted steering systems of motor vehicles

US6612336B1 · kind B1 · utility

Assignee

• ZF Lenksysteme GmbH · DE

Inventors

• Jens-Uwe Hafermalz · Lorch, DE
• Peter Ertle · Durlangen, DE
• Karl-Heinz Urban · Spraitbach, DE

Key dates

• Filing date: Mar 5, 2001
• Grant date: Sep 2, 2003
• Expiry date: Mar 5, 2021

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T137/86654
• WIPO field: Transport
• WIPO sector: Mechanical engineering

Abstract

A rotary disk valve for motor vehicle power steering systems includes rotary disk which is connected non-rotatably to a valve inlet element. A control bushing is connected non-rotatably to a valve outlet element. These two valve elements are disposed so that they are coaxially movable into one another and are rotatable by at most the amount of torsion of a dead travel coupling. The two valve elements have longitudinal control grooves, which interact with one another for controlling a pressure medium to and from two working areas of a servo motor and to a return connection for a pressure medium container. The rotary disk is connected via a torsion bar spring to the valve outlet element. The longitudinal control grooves of the radially internal valve element connected to the return connection are connected to an internal space of the radially internal valve element. The torsion bar spring is supported in this internal space via a roller bearing. The return from the inner space of the radially internal valve element to the return connection occurs through the roller bearing and through the dead travel coupling.