Patent ID: 7225905

Claim:
A screw-type magnetorheological damper, comprising: a thrust shaft comprising an external threaded surface in threaded communication with a sealed housing, wherein at least one end of the thrust shaft extends from the housing; at least one rotor disposed in the housing comprising a planar surface with a centrally located aperture, wherein the at least one rotor is in direct contact and rotatably engaged with the threaded surface of the thrust shaft; at least one stator spaced apart from and adjacent to the at least one rotor, wherein the at least one stator is fixedly attached to the housing and comprises a centrally located aperture dimensioned to accommodate vertical movement of the thrust shaft and a planar surface substantially parallel to the planar surface of the at least one rotor; at least one alignment bearing disposed on a free end of the planar surface of the at least one rotor to maintain a clearance between the at least one rotor and the at least on stator and to carry a thrust load; a magnetorheological fluid disposed in a space defined by the at least one rotor and the at least one stator; and means for applying a substantially perpendicular magnetic field to the magnetorheological fluid relative to the planar surface of the at least one stator.