Pressurized gas to electrical energy conversion for low-power field devices

• US 6,975,043 B2
• Filed: 12/22/2003
• Issued: 12/13/2005
• Est. Priority Date: 12/22/2003
• Status: Active Grant

• Current Assignee: Rosemount Incorporated (Emerson Electric Company)
• Original Assignee: Rosemount Incorporated (Emerson Electric Company)
• Inventors: Schumacher, Mark S., Brown, Gregory C.
• Primary Examiner(s): Waks, Joseph
• Application Number:
  US10/745,310
• Publication Number:
  US 20050134047A1
• Time in Patent Office: 722 Days
• Field of Search: 290/1.R, 310/15, 310/314
• US Class Current: 290/1.00R
• CPC Class Codes: H02K 7/1892 Generators with parts oscillating or vibrating about an axis
• CPC Class Codes: H02N 2/185 using fluid streams
• CPC Class Codes: H05K 7/1462 for programmable logic controllers [PLC] for automation or industrial process control

Abstract

An industrial process field device with improved power generation is provided. The process device can be a process variable transmitter, process actuator, or any other suitable field device. The field device includes a wireless transceiver that transceives information related to the process via a wireless medium. A power supply within the field device is couplable to a source of pressurized gas and generates motion within the power supply that is translated into electrical energy. This electrical energy is then used to operate the field device.

Claims

1. A power supply module for generating electricity in a field device, the module comprising:

a support structure coupleable to a source of pressurized gas, the support structure adapted to direct the pressurized gas;

a flexure mounted relative to the support structure, the flexure including a cantilever structure having one end that oscillates in response to gas flow;

an electrical conductor positioned on the flexure proximate the cantilever end and being electrically couplable to components within the field device;

a magnetic field disposed proximate the cantilever end such that oscillation of the cantilever end generates electricity in the conductor; and

an energy storage device electrically coupled to a trace, wherein both, the energy storage device and the trace are located within the module.

2. The module of claim 1, wherein the flexure further includes a bluff body.

3. The module of claim 2, wherein the bluff body has a triangular cross-section.

4. The module of claim 2, wherein the bluff body has an air foil-shaped cross-section.

5. The module of claim 2, wherein the bluff body has an elliptically shaped cross-section.

6. The module of claim 2, wherein the bluff body has a cylindrical shape.

7. The module of claim 2, wherein the bluff body has a spherical shape.

8. The module of claim 1, wherein the magnetic field is generated by a permanent magnet disposed proximate the flexure.

9. The module of claim 1, wherein the energy storage device is a battery.

10. The module of claim 1, wherein the energy storage device is a capacitor.

11. The module of claim 1, wherein the gas is air.

12. The module of claim 1, wherein the gas is natural gas.

13. The module of claim 1, and further comprising a nozzle disposed relative to the support structure to direct the pressurized gas, and to increase the velocity of the gas.

14. The module of claim 1, wherein the field device is a transmitter for measuring a process variable.

15. The module of claim 14, wherein the source of pressurized gas is the process fluid to be measured by the transmitter.

16. The module of claim 1, wherein the field device is an actuator.

17. The module of claim 1, wherein the module is a MEMS power supply module.

18. The module of claim 1, wherein the energy storage device is a battery.

19. The module of claim 1, wherein the energy storage device is a capacitor.

20. A power supply module for generating electricity in a field device, the module comprising:

a support structure coupleable to a source of pressurized gas, the support structure adapted to direct the pressurized gas;

a flexure mounted relative to the support structure, the flexure including a cantilever structure having one end that oscillates in response to the directed pressurized gas flow; and

a piezoelectric material mounted relative to the cantilever end such that oscillation of the cantilever end generates electricity from the piezoelectric material, the piezoelectric material being electrically coupleable to components within the field device; and

an energy storage device coupled to the piezoelectric material, wherein both, the energy storage device and the piezoelectric material are located within the module.

21. The module of claim 20, wherein the flexure further includes a bluff body.

22. The module of claim 21, wherein the bluff body has a triangular cross-section.

23. The module of claim 21, wherein the bluff body has an air foil-shaped cross-section.

24. The module of claim 21, wherein the bluff body has an elliptically shaped cross-section.

25. The module of claim 21, wherein the bluff body has a cylindrical shape.

26. The module of claim 21, wherein the bluff body has a spherical shape.

27. The module of claim 20, wherein the gas is air.

28. The module of claim 20, wherein the gas is natural gas.

29. The module of claim 20, wherein the field device is a transmitter for measuring a process variable.

30. The module of claim 29, wherein the source of pressurized gas is the process fluid to be measured by the transmitter.

31. The module of claim 20, wherein the field device is an actuator.

32. The module of claim 20, and further comprising a nozzle disposed relative to the support structure to direct the pressurized gas, and to increase the velocity of the gas.

33. The module of claim 20, wherein the module is a MEMS power supply module.