Electrically assisted automotive power steering system

US6250420A · kind A · utility

Assignee

• ZF FRIEDRICHSHAFEN AG · DE

Inventors

• Peter Brenner · Friedrichshafen, DE
• Martin Budaker · Heubach, DE
• Willi Nagel · Biberach an der Riß, DE
• Uwe Loreit · Wetzlar, DE

Key dates

• Filing date: May 1, 2000
• Grant date: Jun 26, 2001
• Expiry date: May 1, 2020

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B62D15/0215
• WIPO field: Transport
• WIPO sector: Mechanical engineering

Abstract

An electrically assisted power steering system for motor vehicles includes an input shaft (5), which is operatively connected to a steering wheel, for transmitting a steering torque required to steer the vehicle wheels that are to be steered. An output member is operatively connected to the wheels to be steered. A servomotor (7), by which an auxiliary force can be exerted on the input shaft (5) or the output member, is disposed in the power steering system. The input shaft (5) and the output member are connected to one another via a torsion bar (4). A detection unit for detecting a steering torque acting on the input shaft (5) includes one magnetic ring (12, 14) each, connected to the input shaft (5) and the output member, and one associated sensor (13, 15) each. Each magnetic ring (12, 14) has the same number of magnetic pole pairs. Each magnetic ring (12, 14) is assigned a sensor (13, 15), structurally connected to the housing, by which both the steering torque and the rotary speed of the input shaft (5) are detected.