Electromagnetic control apparatus for varying the driver steering effort of a hydraulic power steering system

摘要

A hydraulic power steering system having conventional relatively rotatable spool and valve body elements for flow regulation, and an integral electromagnetic mechanism which effectively varies the centering force between the spool and valve body to adjust the level of steering assist provided for a given operator steering input. The electromagnetic mechanism comprises a rotary multipole permanent magnet supported for rotation with one of the spool and valve body elements, a rotary flux conducting element supported for rotation with the other of the spool and valve body elements, and a stationary exciting coil magnetically coupled thereto. The exciting coil is energized so as to produce a variable centering force between the spool and valve body with vehicle speed, which produces a corresponding variation in the driver steering effort.