Wave powered generation

• US 7,649,276 B2
• Filed: 07/30/2007
• Issued: 01/19/2010
• Est. Priority Date: 05/05/2006
• Status: Active Grant

• Current Assignee: SRI International, Inc.
• Original Assignee: SRI International, Inc.
• Inventors: Prahlad, Harsha, Low, Thomas, Stanford, Scott E., Pelrine, Ronald E., Chiba, Seiki, Chavez, Bryan, Kornbluh, Roy D., Eckerle, Joseph S.
• Primary Examiner(s): Ponomarenko, Nicholas
• Assistant Examiner(s): Cuevas, Pedro J
• Application Number:
  US11/830,722
• Publication Number:
  US 20080016860A1
• Time in Patent Office: 904 Days
• Field of Search: 290/53, 290/42
• US Class Current: 290/53
• CPC Class Codes: F03B 13/1845 and the wom slides relative to the rem
• CPC Class Codes: F03B 13/20 wherein both members , i.e. wom and rem are movable relative to the sea bed or shore
• CPC Class Codes: F05B 2250/44 one element moving inside another one, e.g. wave-operated member (wom) moving inside another member (rem)
• CPC Class Codes: F05B 2260/50 Kinematic linkage, i.e. transmission of position
• CPC Class Codes: Y02E 10/30 Energy from the sea, e.g. using wave energy or salinity gradient

Abstract

Described herein are marine devices and methods that convert mechanical energy in one or more waves to mechanical energy that is better suited for conversion into electrical energy. The marine devices employ a mechanical energy conversion system that harnesses wave energy and converts it into limited motion that is suitable for input to an electrical energy generator.

Claims

1. A marine device comprising:

a body, wherein the marine device is configured such that a portion of the body rests above a water surface level when the marine device floats and configured such that the water surface level change causes movement of the body relative to the water surface level;

a mechanical energy transmission system including an energy storage mass, slideably coupled to a linear axis, and configured to linearly translate relative to the portion of the body that rests above the surface level of water and at an angle relative to the water surface level in response to a water surface level change; and

a generator mechanically coupled to the moving portion and to the portion of the body that rests above the water surface level, said generator comprising a spring having a tunable stiffness that produces electrical energy using kinetic energy of the energy storage mass along the linear axis.

2. The marine device of claim 1 wherein the body is configured such that the water surface level change causes movement of the body relative to the water surface level.

3. The marine device of claim 2 wherein the moving portion is configured to linearly translate relative to the portion of the body that rests above the surface level of water.

4. The marine device of claim 1 wherein the mass is configured to displace in a direction substantially opposite to a direction of displacement for the body when the water surface level changes.

5. The marine device of claim 1 wherein the spring includes a stiffness that provides a resonant frequency for the mechanical energy transmission system within about 0.2 hertz of a resonant frequency for the marine device.

6. The marine device of claim 1 further comprising a second energy storage mass that is configured to move relative to the body in response to the water surface level change.

7. The marine device of claim 6 further comprising a second generator configured to produce electrical energy using kinetic energy of the second energy storage mass.

8. The marine device of claim 1 wherein the mechanical energy transmission system is configured to rest above the surface level of the water when the marine device floats in the water.

9. The marine device of claim 1 wherein the device is a floating electrical energy generation device and includes a tether configured to transport electrical energy from the floating generation device.

10. A marine device comprising;

a body, wherein the marine device is configured such that a portion of the body rests above a surface level of water when the marine device floats;

a mechanical energy transmission system including

a) a first energy storage mass that is configured to move relative to the body in response to a water surface level change that causes tilting of the body relative to the water surface level, wherein the first energy storage mass is configured to move at a first angle relative to a vertical center of the body when the portion of the body rests above the water surface level, and

b) a second energy storage mass that is configured to move relative to the body in response to the water surface level change that causes tilting of the body relative to the water surface level, wherein the second energy storage mass is configured to move at a second angle relative to a vertical center of the body when the portion of the body rests above the water surface level; and

at least one generator mechanically coupled to the first energy storage mass and to the second energy storage mass, said at least one generator comprising a spring having a tunable stiffness that produces electrical energy using kinetic energy of the first energy storage mass and the second energy storage mass.

11. The marine device of the claim 10 wherein the first energy storage mass is slideably coupled to a linear axis and the generator in configured to produce electrical energy using kinetic energy of the first energy storage mass along the linear axis.

12. The marine device of claim 10 further comprising a spring mechanically coupled to the first energy storage mass and mechanically coupled to the body.