IP Library Granted Patent US 7,051,849
Granted Patent B2
US 7,051,849 · App. 10/691,365 · Granted May 30, 2006

Magnetorheological fluid damper

Assignee: General Motors Corporation
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Quick Facts
Patent No.
US 7,051,849
App. No.
10/691,365
Filed
Oct 22, 2003
Granted
May 30, 2006
Kind
B2
Art Unit
3683
USPC
188/267.2
Abstract

A magnetorheological damper device is provided having an increased shear interface area per unit volume of the device, which enhances the stroking force of the damper. The damper generally includes a cylindrically shaped housing; a magnetorheological fluid disposed in the cylindrically shaped housing; a piston assembly disposed within the cylindrically shaped housing in sliding engagement with the cylindrically shaped housing defining a first chamber and a second chamber, wherein the piston assembly comprises a plurality of cylindrically shaped fluid passageways extending from the first chamber to the second chamber, and an electromagnet; and a power supply in electrical communication with the electromagnet.

Claims (20)

1. A magnetorheological damper, the damper comprising:

a cylindrically shaped housing;

a magnetorheological fluid disposed in the cylindrically shaped housing;

a piston assembly disposed within the cylindrically shaped housing in sliding engagement with the cylindrically shaped housing defining a first chamber and a second chamber, wherein the piston assembly comprises a plurality of cylindrically shaped fluid passageways extending from the first chamber to the second chamber, and at least one electromagnet, wherein the cylindrically shaped fluid passageways are formed from a plurality of annular plates stackedly arranged, wherein each one of the plurality of annular plates comprise a plurality of circular openings that when aligned with the other ones of the plurality of annular plates form the cylindrically shaped fluid passageways; and

a power supply in electrical communication with the at least one electromagnet.

2. The magnetorheological damper of claim 1 , wherein the plurality of cylindrically shaped fluid passageways defines a cross sectional area of the piston assembly of at least about 30 to about 70 percent.

3. The magnetorheological damper of claim 1 , wherein the cylindrically shaped fluid passageway has a diameter that increases from the first chamber to the second chamber.

4. The magnetorheological damper of claim 1 , wherein the cylindrically shaped fluid passageway has a diameter that decreases from the first chamber to the second chamber.

5. The magnetorheological damper of claim 1 , further comprising a third chamber defined by a second floating piston and an end of the housing, wherein the third chamber is filled with an inert gas.

6. A magnetorheological damper, the damper comprising:

a cylindrically shaped housing;

a magnetorheological fluid disposed in the cylindrically shaped housing;

a piston assembly disposed within the cylindrically shaped housing in sliding engagement with the cylindrically shaped housing defining a first chamber and a second chamber, wherein the piston assembly comprises an open cell porous media comprising a plurality of fluid passageways in fluid communication with a plurality of opening in a top surface and in a bottom surface of the piston assembly, and at least one electromagnet centrally disposed in the piston assembly; and

a power supply in electrical communication with the at least one electromagnet.

7. The magnetorheological damper of claim 6 , wherein the fluid passageways have circular or polygon shaped cross sectional openings.

8. The magnetorheological damper of claim 6 , wherein the open cell porous media comprises a plurality of stackedly arranged sheets, wherein each sheet of the plurality of stackedly arranged sheets is a rigid lattice network of nonmetallic material having hexagonally shaped openings.

9. The magnetorheological damper of claim 6 , wherein the fluid passageways formed in the open cell porous media have a cross sectional area of about 30 to about 70 percent.

10. The magnetorheological damper of claim 6 , wherein the open cell porous media comprises a rigid foam comprising a plurality of irregularly shaped fluid passageways extending from the first chamber to the second chamber.

11. The magnetorheological damper of claim 6 , wherein the fluid passageways have different size and/or shaped openings.

12. The magnetorheological damper of claim 6 , further comprising a third chamber defined by a floating piston and an end of the housing, wherein the third chamber is filled with an inert gas.

Assignments (13)
RELEASE OF SECURITY INTEREST Recorded Nov 7, 2014
From: WILMINGTON TRUST COMPANY
To: GM GLOBAL TECHNOLOGY OPERATIONS LLC
Reel/Frame 034371/0676 →
CHANGE OF NAME Recorded Feb 10, 2011
From: GM GLOBAL TECHNOLOGY OPERATIONS, INC.
To: GM GLOBAL TECHNOLOGY OPERATIONS LLC
Reel/Frame 025780/0902 →
SECURITY AGREEMENT Recorded Nov 8, 2010
From: GM GLOBAL TECHNOLOGY OPERATIONS, INC.
To: WILMINGTON TRUST COMPANY
Reel/Frame 025327/0262 →
RELEASE OF SECURITY INTEREST Recorded Nov 4, 2010
From: UNITED STATES DEPARTMENT OF THE TREASURY
To: GM GLOBAL TECHNOLOGY OPERATIONS, INC.
Reel/Frame 025245/0347 →
RELEASE OF SECURITY INTEREST Recorded Nov 4, 2010
From: UAW RETIREE MEDICAL BENEFITS TRUST
To: GM GLOBAL TECHNOLOGY OPERATIONS, INC.
Reel/Frame 025311/0725 →
SECURITY AGREEMENT Recorded Aug 28, 2009
From: GM GLOBAL TECHNOLOGY OPERATIONS, INC.
To: UAW RETIREE MEDICAL BENEFITS TRUST
Reel/Frame 023161/0911 →
SECURITY AGREEMENT Recorded Aug 27, 2009
From: GM GLOBAL TECHNOLOGY OPERATIONS, INC.
To: UNITED STATES DEPARTMENT OF THE TREASURY
Reel/Frame 023156/0001 →
RELEASE OF SECURITY INTEREST Recorded Aug 21, 2009
From: CITICORP USA, INC. AS AGENT FOR BANK PRIORITY SECURED PARTIES; CITICORP USA, INC. AS AGENT FOR HEDGE PRIORITY SECURED PARTIES
To: GM GLOBAL TECHNOLOGY OPERATIONS, INC.
Reel/Frame 023127/0273 →
RELEASE OF SECURITY INTEREST Recorded Aug 20, 2009
From: UNITED STATES DEPARTMENT OF THE TREASURY
To: GM GLOBAL TECHNOLOGY OPERATIONS, INC.
Reel/Frame 023124/0470 →
SECURITY AGREEMENT Recorded Apr 16, 2009
From: GM GLOBAL TECHNOLOGY OPERATIONS, INC.
To: CITICORP USA, INC. AS AGENT FOR BANK PRIORITY SECURED PARTIES; CITICORP USA, INC. AS AGENT FOR HEDGE PRIORITY SECURED PARTIES
Reel/Frame 022553/0399 →
SECURITY AGREEMENT Recorded Feb 4, 2009
From: GM GLOBAL TECHNOLOGY OPERATIONS, INC.
To: UNITED STATES DEPARTMENT OF THE TREASURY
Reel/Frame 022201/0547 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jan 14, 2009
From: GENERAL MOTORS CORPORATION
To: GM GLOBAL TECHNOLOGY OPERATIONS, INC.
Reel/Frame 022117/0047 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Feb 2, 2004
From: BROWNE, ALAN L.; JOHNSON, NANCY L.; NAMUDURI, CHANDRA S.
To: GENERAL MOTORS CORPORATION
Reel/Frame 014297/0547 →
Continuity (1)
Related Publication 20050087409A1 · Apr 28, 2005