MULTI-LAYER MODULAR ENERGY HARVESTING APPARATUS, SYSTEM AND METHOD

• US 20100045111A1
• Filed: 07/27/2009
• Published: 02/25/2010
• Est. Priority Date: 08/21/2008
• Status: Active Grant

• Current Assignee: Innowattech Limited
• Original Assignee: Innowattech Limited
• Inventors: Abramovich, Haim, Edery Azulay, Lucy, Amit, Uri, Harash, Eugeny, Milgrom, Charles
• Granted Patent: US 8,278,800 B2
• Time in Patent Office: Days
• US Class Current: 307/43
• CPC Class Codes: E01B 26/00 Tracks or track components not covered by any one of the preceding groups
• CPC Class Codes: E01B 3/00 Transverse or longitudinal sleepers for switches or crossings E01B7/22; Other means resting directly on the ballastway for supporting rails
• CPC Class Codes: H02N 2/18 producing electrical output from mechanical input, e.g. generators for measurement devices G01

Abstract

A multilayer piezoelectric generator is disclosed comprising a round, rectangular or other shaped box having a cover. In the box are top and bottom electrodes and a plurality of electricity generating layers. Each Layer comprises a plurality of piezoelectric rods held in place by a matrix layer that fits snugly in the box and configured to accept shear strains developed in the rods when pressure is applied to the cover. The layers are separated by central electrode layers. The structure is configures such that pressure is evenly spreads among all the rods and causes the rods to make contacts with the electrodes. Rods in adjacent layers are oppositely poled, and the electrodes are configured and wired such that all the rods are connected parallel such that their generated charge is summed. Adaptation of the generator to its application is done by changing the number and thickness of the layers.

Claims

1. A multilayer generator comprising:

a box having a top cover;

a bottom electrode placed above the bottom of said box;

a top electrode placed below said top cover; and

a multilayer electricity generating structure positioned between said bottom electrode and top electrode, each layer of said multilayer electricity generating structure comprising a plurality of piezoelectric rods held in place by a matrix layers, wherein;

thickness of said matrix layer is smaller than length of said plurality of piezoelectric rods in the corresponding layer,

said piezoelectric rods are oppositely poled in alternating layers, adjacent layers are separated by a central electrode.

2. The multilayer generator of claim 1, wherein said box and said matrix layers are substantially cylindrical.

3. The multilayer generator of claim 2, wherein said box constructed of a round top cover, a round bottom cover and a cylindrical mid section.

4. The multilayer generator of claim 3, wherein said round top cover and said round bottom cover are substantially identical.

5. The multilayer generator of claim 1, wherein said matrix layers are shaped and sized to snugly fit inside said box.

6. The multilayer generator of claim 5, wherein said matrix layers are configured to withstand sheer stresses in said plurality of piezoelectric rods due to pressure applied on said cover.

7. The multilayer generator of claim 6, wherein said matrix layers are made of a non-conductive material selected from the group comprising:

glass;

Pertinex;

Plexiglas;

thermoplastics;

reinforced resin and concrete.

8. The multilayer generator of claim 1 and further configured such when pressure is applied to said cover, said applied pressure causes mechanical and electrical contact between ends of said piezoelectric rods and the nearest electrodes.

9. The multilayer generator of claim 8, wherein rods in each layer are poled in the same direction, and are electrically connected in parallel by two of said electrodes such that the charge generated by said layer is the sum of the charges generated by all the rods in said layer.

10. The multilayer generator of claim 9, wherein alternating electrode layers are joined such that the voltage generated by said entire multilayer generator is substantially equal to the voltage generated by one rod, and the charge generated by said entire multilayer generator is substantially equal to the sum of charges generated by all said rods.

11. The multilayer generator of claim 8 and further comprising fasteners, wherein said fasteners are configured to apply preloading force on said cover.

12. The multilayer generator of claim 8, wherein said cover is stiff and is configured to substantially evenly spread force applied to said cover among said piezoelectric rods.

13. The multilayer generator of claim 8 and further comprising a load spreading layer situated between said cover and said top electrode, said load spreading layer configured to receive force applied to said cover and to substantially evenly spread force among said piezoelectric rods.

14. The multilayer generator of claim 1, wherein said at least one of said box and said cover is made of concrete.

15. The multilayer generator of claim 1, wherein said box and said matrix layers are shaped as polygons.

16. The multilayer generator of claim 1 and further comprising a seal situated between said box and said cover.

17. A multilayer super-module generator comprising:

a box having a plurality of chambers; and

at least one top cover, wherein in each chamber;

a bottom electrode placed above the bottom of said chamber;

a top electrode placed below said top cover; and

a multilayer electricity generating structure positioned between said bottom electrode and top electrode, each layer of said multilayer electricity generating structure comprising a plurality of piezoelectric rods held in place by a matrix layers, wherein;

thickness of said matrix layer is smaller than length of said plurality of piezoelectric rods in the corresponding layer,

said piezoelectric rods are oppositely poled in alternating layers; and

adjacent layers are separated by a central electrode.

18. The multilayer super-module generator of claim 17, wherein each chamber has a separate top cover.

19. The multilayer super-module generator of claim 17, wherein all the chambers are covered by same top cover.

20. The multilayer super-module generator of claim 17, wherein:

rods in each layer in each chamber are poled in the same direction, and are electrically connected in parallel by two of said electrodes, alternating electrode layers in each chamber are joined such that the voltage generated by said entire multilayer generator in each chamber is substantially equal to the voltage generated by one rod, and the charge generated by said entire multilayer generator is substantially equal to the sum of charges generated by all said rods, and

said generators in said chambers are electrically joined in parallel.

21. Method of installing an energy harvesting system in a road comprising the steps of:

drilling an array of circular holes in said road;

cutting slots in said road, joining said circular holes;

placing a round piezoelectric energy generator in each of said drilled holes;

placing connecting cables in said cut slots; and

covering said connecting cables in said cut slots.

22. Method of installing an energy harvesting system of claim 21 and further comprising covering said round piezoelectric energy generators placed in said drilled holes.

23. Method of installing an energy harvesting system of claim 21, wherein said round piezoelectric energy generators are placed in said drilled holes such that upper surface of said round piezoelectric energy generators are flush with the surface of said road.

24. Method of installing an energy harvesting system of claim 21, wherein the step of drilling an array of circular holes in said road comprises using cup drill.

25. Method of installing an energy harvesting system of claim 21 and further comprising pouring a reinforcing layer at the bottom of said drilled hole before placing a round piezoelectric energy generator in each of said drilled holes.

26. A Method of installing an energy harvesting system in a railroad comprising the steps of:

providing a sleeper having a cavity under the track mount;

placing in said cavity a multilayer generator comprising;

a bottom electrode placed above the bottom of cavity;

a top electrode placed below said mount; and

a multilayer electricity generating structure positioned between said bottom electrode and top electrode, each layer of said multilayer electricity generating structure comprising a plurality of piezoelectric rods held in place by a matrix layers, wherein;

thickness of said matrix layer is smaller than length of said plurality of piezoelectric rods in the corresponding layer,

said piezoelectric rods are oppositely poled in alternating layers, and adjacent layers are separated by a central electrode, alternating electrode layers are joined such that said rods are electrically connected in parallel; and

attaching said mount and said track to said sleeper such that force applied by a train traveling over said track causes generation of electric energy in said piezoelectric rods.