US 6,296,088 B1Granted

Magnetorheological fluid seismic damper

AssigneeLord Corporation

InventorJ. David Carlson

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Abstract

A seismic MR damper for providing controllable damping forces between a first structural member and a second structural member within large structures, such as buildings, bridges, etc. The seismic damper includes a damper body having a hollow cavity and at least one aperture, at least one piston rod slidably received within the aperture, a piston assembly attached to the at least one piston rod and axially moveable within, and subdividing, the said hollow cavity into a first fluid chamber and a second fluid chamber, a controllable passageway for controlling flow between the first fluid chamber and second fluid chamber, a magnetorheological fluid including soft-magnetic particles disbursed within a carrier liquid contained in said controllable passageway, first fluid chamber, and second fluid chamber, and a plurality of alternately-wound coils for generating a plurality of magnetic fields which are directed to act upon the magnetorheological fluid contained in said controllable passageway to generate rheology changes thereby restricting flow of the magnetorheological fluid through the controllable passageway.

Claims20

Dependent claims

A seismic damper for providing controllable damping forces between a first large structural member and a second large structural member during a seismic event, the seismic damper comprising:

(a) a damper body having at least one aperture formed therein, and an inner diameter forming a portion of a hollow cavity,
(b) means for attaching said damper body to the first large structural member,
(c) at least one piston rod slidably received within said at least one aperture,
(d) means for attaching said at least one piston rod to the second large structural member,
(e) a piston assembly including a piston core having a plurality of pole pieces formed thereon, a plurality of coils alternately wound about said piston core, said piston assembly having an outer periphery attached to said at least one piston rod and axially moveable within said hollow cavity thereby subdividing said hollow cavity into a first fluid chamber and a second fluid chamber,
(f) a controllable passageway formed between said inner diameter of said damper body and said outer periphery of said piston assembly,
(g) a magnetorheological fluid including soft-magnetic particles disbursed within a carrier liquid contained within said controllable passageway, said first fluid chamber, and said second fluid chamber, and
(h) discrete current generating means for providing current to a plurality of coils, said means adapted to be operable during a seismic event and non-operable between seismic events, said means for providing current to said coils for generating a plurality of magnetic fields which are directed by said plurality of pole pieces to act upon said magnetorheological fluid contained in said controllable passageway thereby generating rheology changes which restrict flow of said magnetorheological fluid through said controllable passageway.

5 more elements

Dependencies are inferred from the claim text.