Active seal assemblies for sound isolation

• US 20050199440A1
• Filed: 03/08/2005
• Published: 09/15/2005
• Est. Priority Date: 03/12/2004
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations Incorporated (Motors Liquidation Co. GUC Trust)
• Inventors: Henry, Christopher P., Barvosa-Carter, William, Johnson, Nancy L., Keefe, Andrew C., Mc Knight, Geoffrey P., Herrera, Guillermo A.
• Granted Patent: US 7,594,359 B2
• Time in Patent Office: Days
• US Class Current: 181/284
• CPC Class Codes: F16J 15/064 the packing combining the sealing function with other functions

Abstract

Active seal assemblies employing active materials that can be controlled and remotely changed to alter the seal effectiveness, wherein the active seal assemblies actively change modulus properties such as stiffness, shape orientation, and the like. The active seal assemblies are generally configured to reduce the noise (sound waves) that is transmitted through the seal by measuring and actively canceling and/or absorbing the noise.

Claims

1. An active seal assembly for sound isolation, comprising:

a flexible hollow body comprising an interior wall defining a first chamber and a second chamber;

a sensor disposed in an exterior wall of the body and in operative communication with a controller, wherein the sensor is adapted to detect an amplitude and a phase of a noise vibration and forward a signal corresponding to the amplitude and the phase to the controller; and

an active material disposed within the interior wall and in operative communication with the controller, wherein the active material is adapted to cancel the signal corresponding to the amplitude and the phase in response to an activation signal from the controller.

2. The active seal assembly of claim 1, wherein the active material comprises an electroactive polymer, an ionic polymer metal composite, a piezoelectric polymer or ceramic, a magnetostrictive material, a thin film shape memory alloy, and combinations comprising at least one of the foregoing active materials.

3. The active seal assembly of claim 1, wherein the sensor and the active material are distributed along the length of the flexible hollow body.

4. The active seal assembly of claim 1, wherein the sensor comprises a piezoelectric polymer or ceramic.

5. The active seal assembly of claim 1, wherein the active material is adapted to generate anti-noise in response to the signal.

6. The active seal assembly of claim 1, wherein the controller is disposed in a base portion of the body.

7. The active seal assembly of claim 1, further comprising a dissipative circuit in operative communication with the active material, wherein the active material is selected to couple electrical or magnetic energy to the dissipative circuit.

8. The active seal assembly of claim 1, wherein the active material is selected to provide passive damping of incident sound and vibrational energy via internal elastic losses.

9. An active seal assembly for sound isolation, comprising:

a flexible hollow body comprising an interior wall defining a first chamber and a second chamber;

a normal force sensor disposed in an exterior wall of the body and in operative communication with a controller, wherein the normal force sensor is adapted to detect planar waves and forward a signal to the controller, wherein the controller is adapted to average the amplitudes and frequencies associated with planar waves; and

an active material disposed within the interior wall and in operative communication with the controller, wherein the active material is adapted to absorb the planar waves in response to an activation signal from the controller.

10. The active seal assembly of claim 9, wherein the active material is an electrorheological fluid, a magnetorheological fluid, and combinations comprising at least one on the foregoing active materials.

11. The active seal assembly of claim 9, wherein the controller averages an amplitude and frequency of the planar waves to provide the activation signal.

12. An active seal assembly for sound isolation, comprising:

a flexible hollow body defining an interior wall region;

a shear force sensor disposed in an exterior wall of the body and in operative communication with a controller, wherein the shear force sensor is adapted to detect a noise vibration and forward a signal to the controller; and

a plurality of planar membranes comprising an active material in operative communication with the controller, wherein the plurality of planar membranes are disposed in the interior wall region and are generally parallel to a base portion of the flexible hollow body, wherein the active material is adapted to cancel the signal in response to an activation signal from the controller.

13. The active seal assembly of claim 12, wherein the active material is adapted to cancel shear waves.

14. The active seal assembly of claim 12, wherein the active material is a magnetorheological elastomer, thin film shape memory alloys, piezoelectric ceramic or polymers, electroactive polymers, and, and combinations comprising at least one on the foregoing active materials.

15. The active seal assembly of claim 12, wherein the controller averages an amplitude and frequency of the planar waves to provide the activation signal.

16. An active seal assembly for sound isolation, comprising:

a flexible hollow body defining an interior wall region;

a shear force sensor disposed in an exterior wall of the body and in operative communication with a controller, wherein the shear force sensor is adapted to detect a noise vibration and forward a signal to the controller; and

a plurality of planar membranes disposed in the interior wall region and are generally parallel to a base portion of the flexible hollow body; and

an active material fluid intermediate each one of the plurality of planar membranes in operative communication with the controller, wherein the active material is adapted to cancel the signal in response to an activation signal from the controller.

17. The active seal assembly of claim 16, wherein the active material is adapted to cancel shear waves.

18. The active seal assembly of claim 16, wherein the active material fluid is an electrorheological fluid, a magnetorheological fluid, and combinations comprising at least one on the foregoing active materials.

19. The active seal assembly of claim 16, wherein the controller averages an amplitude and frequency of the planar waves to provide the activation signal.