ELECTRICAL TO MECHANICAL ENERGY CONVERTER

• US 20090224633A1
• Filed: 02/27/2007
• Published: 09/10/2009
• Est. Priority Date: 12/20/2006
• Status: Active Grant

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Gravatt, Lynn M., Clingman, Dan J.
• Granted Patent: US 7,872,397 B2
• Time in Patent Office: Days
• US Class Current: 310/331
• CPC Class Codes: H02N 2/186 Vibration harvesters
• CPC Class Codes: H10N 30/304 Beam type

Abstract

An energy conversion apparatus having a pair of flexible beams that are supported at first ends thereof from a base. The beams each include at least one piezoelectric material layer. Second ends of each of the beams are operatively coupled to rigid links. The rigid links are in turn operatively coupled to a working element that may form, in one application, a drive member for a motor, or in a second application form a valve element for an electronic fuel injection system, or in a third application form a piston for a fluid pump. The working element is free to move linearly in a path generally parallel to the longitudinal axes of the flexible beams. As electrical signals are applied to and removed from the piezoelectric material layer(s) of each flexible beam, the beams flex repeatedly and uniformly over their full lengths. This causes a linear movement of the working element that can be used to help form a rotational motor output or a linearly moving fluid control element.

Claims

1. An electrical to mechanical energy conversion apparatus, comprising:

a flexible beam that flexes substantially over its full length in response to electrical signals applied thereto;

said flexible beam having a first end fixedly supported against movement, and a second end able to move to enable flexing of said flexible beam, and an electrically responsive material that flexes in response to said electrical signals;

a moment converting subsystem in communication with said second end of said flexible beam for translating a moment generated at said second end of said flexible beam into a linear motion; and

a working element operably associated with moment converting subsystem.

2. The apparatus of claim 1, further comprising:

a rotational motion generating subsystem coupled to said working element system for generating a rotational output from linear motion of said working element.

3. The apparatus of claim 1, wherein said second end of said flexible beam oscillates in an arcuate motion in response to the application of and removal of electrical signals from said electrically responsive material;

and

wherein said oscillating motion of said second end is converted to reciprocating linear motion of said working element by said moment converting subsystem.

4. The apparatus of claim 1, wherein said working element forms a valve.

5. The apparatus of claim 4, wherein said valve comprises a valve for controlling a flow of fuel in an electronic fuel injection system.

6. The apparatus of claim 1, wherein said working element forms a piston.

7. The apparatus of claim 1, wherein said flexible beam comprises a flexible substrate for supporting said electrically responsive material.

8. The apparatus of claim 7, wherein said flexible beam comprises:

a flexible substrate; and

a layer of electrically responsive material disposed on opposing surfaces of said flexible substrate.

9. The apparatus of claim 1, wherein said electrically responsive material comprises a piezoelectric material layer.

10. The apparatus of claim 1, further comprising:

a pair of said flexible beams arranged generally parallel to one another; and

a base for fixedly supporting said first end of said flexible beam.

11. The apparatus of claim 1, wherein said moment generating subsystem comprises:

a coupling component secured to said second end of said flexible beam;

a first flexure secured to said couple component; and

a link coupled to said first flexure at a first end thereof; and

a second flexure coupled to a second end of said link, said second flexure being coupled to said linkage system.

12. An electrical to mechanical energy conversion apparatus, comprising:

a pair of flexible beams supported adjacent one another,

each said flexible beam having a first end fixedly supported against movement, and a second end able to move to enable flexing of said flexible beam, and an electrically responsive material that flexes in response to an application of electrical signals thereto;

a moment converting subsystem in communication with said second ends of said flexible beams for translating a moment generated at each said second end into a linear motion; and

a working element operably associated with said moment converting subsystem.

13. The apparatus of claim 12, wherein said flexible beams are supported generally parallel to one another.

14. The apparatus of claim 12, wherein each said beam comprises a piezoelectric material layer one a surface thereof.

15. The apparatus of claim 12, wherein each said beam comprises a pair of piezoelectric material layers on opposing surfaces thereof.

16. The apparatus of claim 12, wherein said working element forms a valve.

17. The apparatus of claim 12, wherein said working element forms an input linkage assembly for converting linear motion provided by an output end of said moment converting subsystem into a rotational output.

18. A method for converting electrical energy to useful mechanical energy, comprising:

supporting a beam at a first end so that a second end of the beam is free to move, the beam having a layer of electrically responsive material thereon;

intermittently applying an electrical signal to said electrically responsive material, thus causing said beam to bend generally uniformly over substantially its full length and creating an oscillating arcuate motion at said second end;

converting said arcuate motion into linear motion; and

applying said linear motion to a working element.

19. The method of claim 18, wherein the operation of applying said linear motion to a working element comprises applying said linear motion to a valve to control a flow of a fluid flowing in a path in which said valve is disposed.

20. The method of claim 18, wherein the operation of applying said linear motion to a working element comprises applying said linear motion to a an input of a motor, wherein said input member assists in driving an output member of said motor rotationally.

21. The method of claim 18, wherein the operation of supporting a beam having an electrically responsive material thereon comprises supporting a beam having a piezoelectric material layer thereon.