Patent ID: 7686143
Filing Date: 2010-03-30
Classification: B60G,F16F

Abstract:
1. A suspension damping system for a vehicle having a body and a wheel, comprising: a magnetorheological (MR) strut connected to a suspension spring and the body of the vehicle at one end, and to a support of the vehicle wheel at an opposite end; and an electronic control system responsive to a vehicle operating characteristic and in signal communication with the MR strut; wherein the MR strut is responsive to a control signal from the electronic control system for changing the damping characteristic of the MR strut; wherein the MR strut comprises: first, second and third portions, the first portion being disposed at the one end, the second portion being disposed at the opposite end; the first and second portions having a translational degree of freedom therebetween; a bearing disposed between the first and second portions for supporting a side load therebetween; the third portion having a rotational degree of freedom with respect to the first and second portions; the first and third portions coupled via a translation-to-rotation converter; the second and third portions coupled via a magnetorheological fluid (MRF); a magnetic field generator in field communication with the magnetorheological fluid; and a signal path in signal communication with the magnetic field generator; wherein: the third portion is rotationally responsive to translational motion between the first and second portions, the shear stress characteristic of the magnetorheological fluid is responsive to the magnetic field generator, and the magnetic field generator is controllably responsive to an excitation signal from the signal path; the magnetic field generator comprises a magnetic core and an excitation coil, the magnetic core defining a first cylindrical surface; the second portion comprises magnetic stator defining a second cylindrical surface concentric with the first cylindrical surface, the first and second cylindrical surfaces defining an annular space therebetween, the magnetorheological fluid being disposed within the annular space; and the third portion comprises a cylindrical magnetic rotor ring disposed within the fluid within the annular space, the rotor ring comprising a substantially non-magnetic section radially disposed with respect to the coil.