Vibrational energy harvester

Patent metadata

Field	Value
Publication number	US-2022166300-A1
Application number	US-202017622745-A
Country	US
Kind code	A1
Filing date	Jun 29, 2020
Priority date	Jun 27, 2019
Publication date	May 26, 2022
Grant date	—

Abstract

A vibrational energy harvester ( 100, 200, 300, 400 ) comprises a first mass ( 101, 201, 301 ) comprising a first internal cavity ( 102, 202, 302 ) and a second mass ( 103, 203 ) disposed within and configured to move within the first internal cavity. Movement of the second mass relative to the first mass induces an electrical current in one of the first mass and the second mass. The vibrational energy harvester also comprises a housing ( 104, 204, 404 ) comprising a second internal cavity ( 105, 405 ). The first mass is disposed within and configured to move within the second internal cavity. An adjustment mechanism ( 419 ) is also provided, configured to adjust a size of the second internal cavity.

First claim

1 . A vibrational energy harvester comprising:
a first mass comprising a first internal cavity; a second mass disposed within and configured to move within the first internal cavity;
wherein movement of the second mass relative to the first mass induces an electrical current in one of the first mass and the second mass;
a housing comprising a second internal cavity;
wherein the first mass is disposed within and configured to move within the second internal cavity; and
an adjustment mechanism configured to adjust a size of the second internal cavity.

2 . The vibrational energy harvester of claim 1 , wherein the adjustment mechanism is configured to adjust the size of the second internal cavity without adjusting an external size of the vibrational energy harvester.

3 . The vibrational energy harvester of claim 1 , wherein the housing comprises a plurality of portions, wherein at least one of the portions of the housing is movable relative to one or more of the other portions of the housing.

4 . The vibrational energy harvester of claim 3 , further comprising a cam coupled to the at least one movable portion of the housing.

5 . The vibrational energy harvester of claim 4 , wherein an axial position of the cam relative to the one or more other portions of the housing is adjustable in response to movement of the at least one movable portion of the housing relative to the one or more other portions of the housing.

6 . The vibrational energy harvester of claim 4 , wherein the cam and the at least one movable portion of the housing are coupled via corresponding male and female connectors, and optionally, wherein the cam comprises one or more grooves and the at least one movable portion of the housing comprises one or more protrusions configured to engage with the one of more grooves, and further optionally wherein the cam comprises helical grooves.

7 . (canceled)

8 . The vibrational energy harvester of claim 1 , wherein the second mass is configured to move along a first fixed axis within the first internal cavity.

9 . The vibrational energy harvester of claim 1 , further comprising one or more elements disposed at each end of the first internal cavity, wherein the elements are configured to control oscillation of the second mass in the first internal cavity, and optionally wherein the one or more elements are or comprise one of magnetic springs and mechanical springs.

10 . The vibrational energy harvester of claim 1 , further comprising one or more elements disposed at each end of the second internal cavity, wherein the elements are configured to control oscillation of the first mass in the second internal cavity, and optionally wherein the one or more elements are or comprise one of magnetic springs and mechanical springs.

11 . The vibrational energy harvester of claim 1 , wherein the first mass is configured to move along a second fixed axis within the second internal cavity.

12 . The vibrational energy harvester of claim 10 , wherein the first fixed axis and the second fixed axis are coaxial or are the same.

13 . The vibrational energy harvester of claim 1 , wherein the first mass has a greater mass than the second mass.

14 . The vibrational energy harvester of claim 1 , wherein the first mass is or comprises a conductive material.

15 . The vibrational energy harvester of claim 13 , wherein the first mass is or comprises a plurality of coils, and optionally wherein the coils are wound using a single wire or using multiple wires, and further optionally wherein the coils are wound such that adjacent coils alternate between being wound clockwise and being wound anti-clockwise.

16 . (canceled)

17 . The vibrational energy harvester of claim 1 , wherein the second mass comprises a stack of magnets, and optionally wherein the stack of magnets comprises one or more of a Halbach stack, a stack of oppositely axially polarised magnets and a stack of axially polarised magnets.

18 . The vibrational energy harvester of claim 1 , further comprising an electrical output portion electrically connected via one or more conductive springs to the one of the first mass and the second mass in which an electrical current is induced.

19 . The vibrational energy harvester of claim 16 , wherein an elastic constant of the one or more conductive springs is lower than an elastic constant of the one or more elements.

20 . The vibrational energy harvester of claim 1 , wherein:
i) a size of the second internal cavity is adjustable in increments of between substantially 0.25 mm and 1.0 mm, and optionally in increments of substantially 0.5 mm; and/or ii) a size of the second internal cavity is adjustable between a length of substantially 80 mm and a length of substantially 45 mm, and optionally between a length of substantially 70 mm and a length of substantially 50 mm, and further optionally between a length of substantially 64 mm and a length of substantially 53 mm.

21 . The vibrational energy harvester of claim 1 , wherein a resonant frequency of the vibrational energy harvester is adjustable by substantially 40 Hz by adjusting a size of the second internal cavity, and optionally is adjustable by substantially 30 Hz, and further optionally is adjustable by substantially 20 Hz.

22 . The vibrational energy harvester of claim 1 , wherein a resonant frequency of the vibrational energy harvester is adjustable between substantially 5 Hz and substantially 45 Hz by adjusting a size of the second internal cavity, and optionally is adjustable between substantially 10 Hz and substantially 30 Hz, and further optionally is adjustable between substantially 15 Hz and substantially 35 Hz.

Assignees

• Univ Limerick

Inventors

• Nico Valeria
• Punch Jeff

Classifications

• H02K35/02 Primary

  with moving magnets and stationary coil systems · CPC title

• H02K7/1876 Primary

  with reciprocating, linearly oscillating or vibrating parts · CPC title