U.S. patent application number 14/566946 was filed with the patent office on 2015-04-02 for electricity generating shock absorbers.
This patent application is currently assigned to THE RESEARCH FOUNDATION OF STATE UNIVERSITY OF NEW YORK. The applicant listed for this patent is THE RESEARCH FOUNDATION OF STATE UNIVERSITY OF NEW YORK. Invention is credited to Xiudong TANG, Pei Sheng ZHANG, Lei ZUO.
Application Number | 20150090545 14/566946 |
Document ID | / |
Family ID | 45530420 |
Filed Date | 2015-04-02 |
United States Patent
Application |
20150090545 |
Kind Code |
A1 |
ZUO; Lei ; et al. |
April 2, 2015 |
ELECTRICITY GENERATING SHOCK ABSORBERS
Abstract
An electricity generating shock absorber includes a coil
assembly having a length of electrically conducting material
wrapped around an outside perimeter, and along a length, of a
hollow tube formed of electrically resistant material; a magnet
unit formed of at least one annular axial magnet; a central shaft
having a magnetic reluctance on which a plurality of the magnet
units are mounted, the central shaft dimensioned for insertion
through a central opening of the at least one annular axial magnet,
the central shaft combined with the plurality of magnet units
forming a magnet assembly dimensioned to slideably insert into a
central cavity of the hollow tube; and a cylindrical shell having a
first end attached to a terminal end of the magnet assembly, the
cylindrical shell extending a length of the magnet assembly, the
cylindrical shell having an inner diameter sized to slideably
accommodate an outside diameter of the coil assembly.
Inventors: |
ZUO; Lei; (Nesconset,
NY) ; TANG; Xiudong; (Stony Brook, NY) ;
ZHANG; Pei Sheng; (Bayside, NY) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
THE RESEARCH FOUNDATION OF STATE UNIVERSITY OF NEW YORK |
Albany |
NY |
US |
|
|
Assignee: |
THE RESEARCH FOUNDATION OF STATE
UNIVERSITY OF NEW YORK
Albany
NY
|
Family ID: |
45530420 |
Appl. No.: |
14/566946 |
Filed: |
December 11, 2014 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
13812959 |
Jan 29, 2013 |
8941251 |
|
|
PCT/US2011/024699 |
Feb 14, 2011 |
|
|
|
14566946 |
|
|
|
|
61368846 |
Jul 29, 2010 |
|
|
|
Current U.S.
Class: |
188/267 ; 29/596;
310/17 |
Current CPC
Class: |
H02K 15/03 20130101;
B60G 13/14 20130101; B60G 2300/60 20130101; F16F 15/03 20130101;
H02K 41/02 20130101; Y10T 29/49009 20150115; F16F 6/00 20130101;
H02K 35/02 20130101; H02K 15/08 20130101; B60G 17/06 20130101 |
Class at
Publication: |
188/267 ; 310/17;
29/596 |
International
Class: |
H02K 35/02 20060101
H02K035/02; F16F 6/00 20060101 F16F006/00; B60G 13/14 20060101
B60G013/14; H02K 15/08 20060101 H02K015/08; H02K 15/03 20060101
H02K015/03 |
Claims
1. An electricity generating shock absorber comprising: a coil
assembly having a length of electrically conducting material
wrapped around an outside perimeter, and along a length, of a
hollow tube formed of electrically resistant material; a magnet
unit formed of at least one annular axial magnet; a central shaft
having a magnetic reluctance on which a plurality of the magnet
units are mounted, the central shaft dimensioned for insertion
through a central opening of the at least one annular axial magnet,
the central shaft combined with the plurality of magnet units
forming a magnet assembly dimensioned to slideably insert into a
central cavity of the hollow tube; and a cylindrical shell having a
first end attached to a terminal end of the magnet assembly, the
cylindrical shell extending a length of the magnet assembly, the
cylindrical shell having an inner diameter sized to slideably
accommodate an outside diameter of the coil assembly.
2. The electricity generating shock absorber of claim 1, wherein
adjacent magnet units disposed on the central shaft are oriented
with like poles facing each other, adjacent magnet units being
separated by an annular spacer formed of a material having a high
magnetic permeability.
3. The electricity generating shock absorber of claim 1, wherein
the magnet unit consists of an annular radial magnet and the at
least one annular axial magnet.
4. The electricity generating shock absorber of claim 3, wherein
adjacent magnet units disposed on the central shaft are disposed
with a reflected orientation with respect to each other.
5. The electricity generating shock absorber of claim 1, wherein
the shaft is at least partially composed of aluminum, the coil is
wound around the hollow tube less than 301 times and at least
partially composed of copper and the tube is at least partially
composed of polyoxymethylene.
6. The electricity generating shock absorber of claim 1, wherein
the electrically conducting material of the coil assembly is
operably connected to a rectifier.
7. The electricity generating shock absorber of claim 6, wherein
the rectifier is operably connected to an energy storage
device.
8. The electricity generating shock absorber of claim 1, wherein
the cylinder is at least partially composed of a
magnetically-permeable material.
9. The electricity generating shock absorber of claim 1, wherein an
outer surface of the cylinder is at least partially composed of
magnetically-permeable material and an inner surface of the
cylinder having a second plurality of annular magnet units aligned
with like-poles.
10. The electricity generating shock absorber of claim 1, wherein
the terminal end of the magnet assembly is securely attached to a
first mounting ring connectable to a vehicle axle.
11. The electricity generating shock absorber of claim 10, wherein
the hollow tube includes a second mounting ring securely attached
to a terminal end of the hollow tube opposite the magnet assembly
insertion end, the second mounting ring being connectable to a
vehicle frame.
12. The electricity generating shock absorber of claim 1, wherein
electromotive voltage is generated as the magnet assembly is moved
in relation to the coil assembly during a compression and extension
cycles, the electromotive voltage serving as a damping force to
reduce vibration.
13. A method of manufacturing an electricity generating shock
absorber, the method comprising: winding a coil at least once
around a hollow tube having an electrical resistance; stacking a
first pair of permanent magnets on a shaft having a magnetic
reluctance; adapting the stacked shaft to be moveable in relation
to a hollow cavity of the hollow tube; attaching the shaft to a
first base; separating the first pair of magnets between each other
on the shaft by a first magnetically-permeable spacer; aligning the
first pair of magnets with like-poles facing each other; and
encapsulating at least a part of the wound coil via a concentric
outer cylinder attached at one end to the first base.
14. The method of claim 13, wherein the shaft is at least partially
composed of aluminum, the coil is wound around the hollow tube less
than 301 times, the coil is at least partially composed of copper
and the tube is at least partially composed of
polyoxymethylene.
15. The method of claim 13, further comprising connecting the coil
to a rectifier, wherein the first pair of magnets comprises a
radial magnet and an axial magnet and the cylinder is at least
partially composed of a magnetically-permeable material and the
first pair of magnets and the first spacer are ring-shaped.
16. The method of claim 15, wherein an outer surface of the
cylinder is at least partially composed of magnetically-permeable
material, an inner surface of the cylinder comprises a second pair
of ring-shaped permanent magnets aligned with like-poles facing
each other to redirect a magnetic flux in a clockwise and a
counter-clockwise directions, the second pair of magnets separated
between each other by a second ring-shaped magnetically-permeably
spacer, the second pair further comprising a radial magnet and an
axial magnet and the wound coil movable in relation to and between
the first and the second pairs of magnets.
17. The method of claim 13, further comprising attaching the first
base to a first mounting ring connectable to a vehicle axle,
wherein the tube includes a second base at one end of the tube and
a second mounting ring securely attached to the second base, the
second mounting ring connectable to a vehicle frame.
18. A method for generating electricity from mechanical vibrations,
the method comprising: providing an electricity generating shock
absorber having a magnet assembly including a first pair of magnets
stacked horizontally along a shaft constructed of magnetic
reluctant material and a coil assembly including a coil wound
around a hollow tube having an electrical resistance, the first
pair of magnets aligned with like-poles facing each other, the
first pair of magnets, an insertion end of the magnet assembly
being slidably inserted into an open end of the hollow tube of the
coil assembly, a concentric outer cylinder encapsulating at least a
part of the coil assembly, the cylinder attached at a base end of
the magnet assembly opposite the insertion end; coupling a closed
end of the hollow tube to a first mass; coupling the base end of
the magnet assembly to a second mass, the electricity generating
shock absorber providing vibration dampening between the first mass
and the second mass; inducing relative motion between the magnet
assembly and the coil assembly to generate electromotive voltage in
the coil; and capturing the electromotive voltage.
19. The method of claim 18, wherein the shaft is at least partially
composed of aluminum, the coil is wound around the hollow tube less
than 301 times, the coil is at least partially composed of copper
and the tube is at least partially composed of
polyoxymethylene.
20. The method of claim 18, wherein the coil is operably connected
to a rectifier, the first pair of magnets comprises a radial magnet
and an axial magnet and the cylinder is at least partially composed
of magnetically-permeable material and the first pair of magnets
and the first spacer are annular.
21. The method of claim 20, wherein an outer surface of the
cylinder is at least partially composed of magnetically-permeable
material, an inner surface of the cylinder comprises a second pair
of ring-shaped permanent magnets aligned with like-poles facing
each other to redirect a magnetic flux in a clockwise and a
counter-clockwise directions, the second pair of magnets separated
between each other by a second ring-shaped magnetically-permeably
spacer, the second pair of magnets further comprising a radial
magnet and an axial magnet and the wound coil movable in relation
to and between the first and the second pairs of magnets.
22. The method of claim 18, wherein the base end is securely
attached to a first mounting ring connectable to a vehicle axle,
and the closed end of the hollow tube is securely attached to a
second mounting ring connectable to a vehicle frame, electromotive
voltage, serving as a damping force to reduce a vehicle vibration,
is generated during compression and extension cycles of the
electricity generating shock absorber.
Description
PRIORITY CLAIM
[0001] The present disclosure claims benefit of U.S. Provisional
Application No. 61/368,846 filed on Jul. 29, 2010, PCT Application
No. PCT/US2011/024699 filed on Feb. 14, 2011 and is a continuation
of U.S. patent application Ser. No. 13/812,959 filed on Jan. 29,
2013, for "ELECTRICITY GENERATING SHOCK ABSORBERS," the entire
contents and disclosure of which, are expressly incorporated by
reference herein as if fully set forth herein.
TECHNICAL FIELD
[0002] The present disclosure is generally related to energy
recovery. Specifically, the present disclosure is related to
regenerative suspension systems.
BACKGROUND
[0003] Among all the sources of pollutants in the atmosphere, the
transportation industry generally is a significant contributor. For
example, in the United States, the transportation industry consumes
a majority of the crude oil, much of which is used by automobiles.
Hence, any advances in energy efficiency, especially in the
transportation industry, may correspondingly lead to reduction in
energy consumption, which not only cumulatively decreases energy
costs, but also cumulatively contributes to a greener environment
and greater energy independence and security.
[0004] Increasing demand for better fuel economy has led to
improvements and developments in hybrid vehicles, electric vehicles
and vehicles powered by fuel cells or diesel fuel. Efforts on the
part of the automotive industry to increase fuel economy have
included, but are not limited to, reductions in vehicle mass,
improved aerodynamics, active fuel management, direct injection
engines, homogeneous charge compression ignition engines and hybrid
engines. Still, other mechanisms, techniques and energy sources
that will improve fuel economy are continually being sought.
[0005] Currently, about 10 to 16% of the available fuel energy is
used to drive an automobile, overcoming the friction and drag force
from the road and wind. Besides engine cycle efficiency, one
important mechanism of energy loss in automobiles is the
dissipation of kinetic energy during vehicle vibration and motion.
In the past hundred years, the automotive industry has been working
hard to dissipate the motion and vibration energy into waste heat
by optimal design of braking and suspension systems and by
employing active controls, such as anti-lock braking systems or
active suspensions. During the past ten years, energy recovery from
braking has achieved great commercial success in hybrid vehicles.
However, regenerative vehicle suspensions, which have the advantage
of continuous energy recovery, have generally not come into
practice due to various factors, such as insufficient vibration
control, unsatisfactory energy harvesting, prohibitive costs, high
complexity, practical incompatibility and relative
inefficiency.
[0006] In view of the foregoing, it would be desirable to provide a
regenerative vehicle suspension technology that takes into account
the aforementioned factors.
BRIEF SUMMARY
[0007] An exemplary embodiment of the disclosed technology is
directed to an electricity generating shock absorber comprising: a
coil assembly having a length of electrically conducting material
wrapped around an outside perimeter, and along a length, of a
hollow tube formed of electrically resistant material; a magnet
unit formed of at least one annular axial magnet; a central shaft
having a magnetic reluctance on which a plurality of the magnet
units are mounted, the central shaft dimensioned for insertion
through a central opening of the at least one annular axial magnet,
the central shaft combined with the plurality of magnet units
forming a magnet assembly dimensioned to slideably insert into a
central cavity of the hollow tube; and a cylindrical shell having a
first end attached to a terminal end of the magnet assembly, the
cylindrical shell extending a length of the magnet assembly, the
cylindrical shell having an inner diameter sized to slideably
accommodate an outside diameter of the coil assembly.
[0008] An exemplary embodiment of the disclosed technology is
directed to a method of manufacturing an electricity generating
shock absorber, the method comprising: at least once, winding a
coil around a hollow tube having an electrical resistance; stacking
a first pair of permanent magnets on a shaft having a magnetic
reluctance; adapting the stacked shaft to be moveable in relation
to a hollow cavity of the hollow tube; attaching the shaft to a
first base; separating the first pair of magnets between each other
on the shaft by a first magnetically-permeable spacer; aligning the
first pair of magnets with like-poles facing each other; and
encapsulating at least a part of the wound coil via a concentric
outer cylinder attached at one end to the first base.
[0009] An exemplary embodiment of the disclosed technology is
directed to a method of using an electricity generating shock
absorber for generating electricity, the method comprising: moving
a magnet assembly in relation to a coil assembly, the coil assembly
comprising: a coil at least once wound around a hollow tube having
an electrical resistance and a hollow cavity, the magnet assembly
comprising: a first pair of permanent magnets stacked on a shaft
having a magnetic reluctance, the shaft attached to a first base,
the first pair of magnets separated between each other on the shaft
by a first magnetically-permeable spacer, the first pair of magnets
aligned with like-poles facing each other; and a concentric outer
cylinder encapsulating at least a part of the coil assembly, the
cylinder attached at one end to the first base.
[0010] An exemplary embodiment of the disclosed technology is
directed to electricity generating shock absorber comprising: a
first case comprising: a rack attached to the inner surface of the
first case; and a second case comprising: a pinion in contact with
the rack and attached to the inner surface of the second case via a
first shaft mounted on a first base, a bevel gear box comprising a
first and second bevel gear in contact with each other, the first
bevel gear mounted on the first shaft, the second gear mounted on a
second shaft coupled via a coupler to a rotational motor attached
to the inner surface of the second case.
[0011] An exemplary embodiment of the present invention is directed
to a method for generating electricity from mechanical vibrations,
the method comprising: providing an electricity generating shock
absorber having a magnet assembly including a first pair of magnets
stacked horizontally along a shaft constructed of magnetic
reluctant material and a coil assembly including a coil wound
around a hollow tube having an electrical resistance, the first
pair of magnets aligned with like-poles facing each other, the
first pair of magnets, an insertion end of the magnet assembly
being slidably inserted into an open end of the hollow tube of the
coil assembly, a concentric outer cylinder encapsulating at least a
part of the coil assembly, the cylinder attached at a base end of
the magnet assembly opposite the insertion end; coupling a closed
end of the hollow tube to a first mass; coupling the base end of
the magnet assembly to a second mass, the electricity generating
shock absorber providing vibration dampening between the first mass
and the second mass; inducing relative motion between the magnet
assembly and the coil assembly to generate electromotive voltage in
the coil; and capturing the electromotive voltage.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The objects, features and advantages of the disclosed
technology will become apparent to a skilled artisan in view of the
following detailed description taken in combination with the
attached drawings, in which:
[0013] FIG. 1a symbolically illustrates an exemplary embodiment of
a linear electromagnetic shock absorber;
[0014] FIG. 1b symbolically illustrates a cross-section view of an
exemplary embodiment of a magnet assembly;
[0015] FIG. 2 symbolically illustrates an exemplary embodiment of a
single layer electricity generating shock absorber with radial
magnets;
[0016] FIG. 3 symbolically illustrates an exemplary embodiment of a
double layer electricity generating shock absorber;
[0017] FIG. 4 symbolically illustrates an exemplary embodiment of a
gear-based electricity generating shock absorber; and
[0018] FIG. 5 symbolically illustrates an alternative arrangement
of the magnets of the electromagnetic embodiments of the present
invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0019] As used herein, a vehicle is a device that is designed or
used to transport people or cargo. Vehicles may be land-based, such
as automobiles, buses, trucks, trains, or marine-based, such as
ships, boats, or aeronautical, such as airplane, helicopter,
spacecraft.
[0020] As used herein, a shock absorber is an energy dissipating
device generally used in parallel with the suspension spring to
reduce the vibration generated by surface irregularities or during
acceleration and braking
[0021] While, for simplicity and clarity, the following description
of the figures is described in reference to land-based vehicles,
the disclosed technology is not limited to land-based vehicles.
Rather, the disclosed technology may be implemented and used with
any device that is designed or used to transport people or
cargo.
[0022] FIG. 1a symbolically illustrates an exemplary embodiment of
a linear electromagnetic shock absorber and FIG. 1b symbolically
illustrates a cross section view of an exemplary embodiment of a
magnet assembly.
[0023] As shown in FIG. 1a, a regenerative shock absorber 100 is in
a configuration of a linear induction generator. In an exemplary
embodiment, shock absorber 100 includes a magnet assembly 110
moveable in relation to a coil assembly 120. In an exemplary
embodiment, shock absorber 100 includes a coil assembly 120 movable
in relation to a magnet assembly 110. In an exemplary embodiment,
magnet assembly 110 and coil assembly 120 are both movable in
relation to each other.
[0024] In an exemplary embodiment, shock absorber 100 works in two
cycles--a compression cycle and an extension cycle. In an exemplary
automotive implementation where coil assembly 120 is attached to an
automobile's frame and magnet assembly 110 is attached to the
automobile's suspension system, the compression cycle occurs as
coil assembly 120 moves downward and the extension cycle occurs as
magnet assembly 110 moves upward (the relative movement of the coil
and magnet assemblies 110 and 120 may be different upon a different
configuration). Thus, if the compression cycle controls the motion
of the vehicle's unsprung weight, then extension controls the
motion of the heavier, sprung weight. Consequently, via alternation
of cycles, due to, for example, road irregularities or during
acceleration and braking, shock absorber 100 converts a kinetic
energy of suspension vibration between an automobile wheel and a
sprung mass into useful electrical power, as further described
below.
[0025] In an exemplary embodiment, magnet assembly 110 is composed
of ring-shaped, i.e. annular, permanent magnets 111 separated by
ring-shaped high magnetically permeable spacers 114 stacked on a
shaft 113 of high reluctance material. In an exemplary embodiment,
the material is aluminum. In an exemplary embodiment, magnets 111
are rare-earth permanent magnets. In an exemplary embodiment,
spacers 114 are steel spacers. In an exemplary embodiment, magnet
assembly includes 12 magnets 111 and 13 spacers 114.
[0026] As illustrated in FIG. 1b, magnets 111 are arranged with
like-poles of adjacent magnets 111 facing each other to redirect a
magnetic flux in a radial direction. A concentric outer cylinder
112 made of high magnetically permeable material is used to protect
the coils and reduce the reluctance of magnetic loops, to further
increase magnetic flux density in the coils i.e. in order to
further "pull" the magnetic flux outward.
[0027] Coil assembly 120 is composed of coils 121 wound around a
tube 122 having a high electrical resistance. In an exemplary
embodiment, coils 121 are composed of copper and tube 122 is
composed of polyoxymethylene. In an exemplary embodiment, the
height of one coil is equal to half of the total height of magnet
111 and spacer 114. In an exemplary embodiment, coils 121 align
with magnet assembly 110. In an exemplary embodiment, the total
number of coils 121 is 16. In an exemplary embodiment, coils 121
are connected to a rectifier set-up.
[0028] In an exemplary embodiment, power generated in shock
absorber 100 is related to the total volume of coils 121. However,
voltage is related with the winding of coils 121 around tube 122.
In an exemplary embodiment where the total volume of coils 121 is
constant and coils 121 with a small diameter are used, then more
windings of coils 121 are expected, thus generating a higher
voltage. In an exemplary embodiment, coils 121 are wound in a range
between 250 and 300 turns, which generates about 10V of output
voltage.
[0029] In an exemplary embodiment, all the coils together will form
a four-phase design where the 0 degree and 180 degree phases
generate maximum positive and negative voltages and the 90 degree
and 270 degree phases have zero voltage. Although the voltage or
power of each phase may depend on the relative position of coil
assembly 120 in the magnetic field, the total power generation does
not. As coils 121 vibrate in relation to the magnetic field created
by magnet assembly 110, an electromotive force is generated, thus
producing electricity. Also, the electromotive force serves as a
damping force to reduce the vehicle vibration. In an exemplary
embodiment, shock absorber 100 maintains a constant performance of
power generation for movement (compression and extension cycles)
between about 2 to about 4 inches.
[0030] For example, when shock absorber 100 is placed in an
automobile suspension system, vibrations in the suspension system,
due to road irregularities or during acceleration and braking,
cause the coil assembly 120 to move in relation to the magnetic
assembly 110 i.e. compression and extension cycles, thus generating
an electromotive force, which can then be used to recharge the
automobile's battery. In an exemplary embodiment, the peak output
voltage is inversely proportional to the square of coils 121
diameter and the peak power depends on the total volume of
conducting material in the coils.
[0031] FIG. 2 symbolically illustrates an exemplary embodiment of a
single layer electricity generating shock absorber, where radial
magnets are used to increase the magnetic flux density.
[0032] In an exemplary automotive implementation, shock absorber
200 converts a kinetic energy of suspension vibration between a
wheel and a sprung mass into useful electrical power. In an
exemplary embodiment, shock absorber 200 includes a magnet assembly
210 movable in relation to a coil assembly 220 in direction V. In
an exemplary embodiment, shock absorber 200 includes a coil
assembly 220 movable in relation a magnet assembly 210 in direction
V. In an exemplary embodiment, magnet assembly 210 and coil
assembly 220 are both movable in relation to each other.
[0033] In an exemplary embodiment, magnet assembly 210 is composed
of radial magnets 211.a and axial magnets 211.b stacked on a shaft
213 of high reluctance material. In an exemplary embodiment, the
material is aluminum. In an exemplary embodiment, the magnets are
rare-earth permanent magnets. In an exemplary embodiment, shaft 213
is attached to a first base 224. In an exemplary embodiment, a
first mounting ring 215 is attached to first base 224. In an
exemplary embodiment, mounting ring 215 connects to an axle, near
an automotive wheel, i.e., the unsprung weight.
[0034] As further exemplarily illustrated in FIG. 2, radial magnets
211.a and axial magnets 211.b are arranged with like-poles of
adjacent magnets 211.a and 211.b facing each other to redirect a
magnetic flux in clockwise and counter-clockwise directions 216. In
an exemplary embodiment, a concentric outer cylinder 212 made of
high magnetically permeable material is used to protect the coils
and reduce the reluctance of magnetic loops, to further increase
magnetic flux density in the coils i.e. in order to further "pull"
the magnetic flux outward.
[0035] Coil assembly 220 is composed of coils 221 wound around a
tube 222 having a high electrical resistance. In an exemplary
embodiment, coils 221 are composed of copper and tube 222 is
composed of polyoxymethylene. In an exemplary embodiment, tube 222
is connected to a second base 225. In an exemplary embodiment, a
second mounting ring 223 is attached to second base 225. In an
exemplary embodiment, second mounting ring 223 connects to an
automobile frame, i.e., the sprung weight. In an exemplary
embodiment, coils 221 are connected to a rectifier set-up.
[0036] For example, when shock absorber 200 is placed in an
automobile suspension system, vibrations in the suspension system,
due to road irregularities or during acceleration and braking,
cause the coil assembly 220 to move in relation to the magnetic
assembly 210 i.e. compression and extension cycles, thus generating
an electromotive force, which can then be used to recharge the
automobile's battery. In an exemplary embodiment, the relative
motion generates alternating current ("AC"). The generated AC
passes through a rectifier and via a rectification process gets
converted to direct current ("DC"). Subsequently, a power
converter, such as a DC to DC converter, is used to maintain a
suitable voltage for charging a typical automobile battery. In an
exemplary embodiment, shock absorber 200 harvests between about 2
to about 8 W of energy at 0.25-0.5 m/s RMS suspension velocity,
which charges a typical car battery in about 7.5 hours.
[0037] FIG. 3 symbolically illustrates an exemplary embodiment of a
double layer electricity generating shock absorber.
[0038] In an exemplary automotive implementation of the disclosed
technology, shock absorber 300 converts a kinetic energy of
suspension vibration between a wheel and a sprung mass into useful
electrical power. In an exemplary embodiment, shock absorber 300
includes a magnet assembly 310 moveable in relation to a coil
assembly 320 in direction V. In an exemplary embodiment, shock
absorber 300 includes a coil assembly 320 movable in relation to a
magnet assembly 310 in direction V. In an exemplary embodiment,
magnet assembly 310 and coil assembly 320 are both movable in
relation to each other.
[0039] In an exemplary embodiment, magnet assembly 310 is composed
of double layers (inner and outer) of radial magnets 311.a and
axial magnets 311.b stacked on a shaft 313 of high reluctance
material. In an exemplary embodiment, the material is aluminum. In
an exemplary embodiment, the magnets are rare-earth permanent
magnets. In an exemplary embodiment, shaft 313 is attached to a
first base 324. In an exemplary embodiment, a first mounting ring
315 is attached to first base 324. In an exemplary embodiment,
mounting ring 315 connects to an axle, near an automotive wheel,
i.e., the unsprung weight.
[0040] Double layers of radial magnets 311.a and axial magnets
311.b are arranged with like-poles of adjacent magnets 311.a and
311.b facing each other to redirect a magnetic flux in clockwise
and counter-clockwise directions 316. In an exemplary embodiment,
as coils 321 vibrate in relation to and between double layers of
radial magnets 311.a and axial magnets 311.b, a magnetic flux,
which has increased power density over an exemplary embodiment
described in FIGS. 2a and 2b, is generated. In an exemplary
embodiment, a concentric outer cylinder 312 made of high
magnetically permeable material is used to protect the coils and
reduce the reluctance of magnetic loops, to further increase
magnetic flux density in the coils i.e. in order to further "pull"
the magnetic flux outward.
[0041] Coil assembly 320 is composed of coils 321 wound around a
tube 322 having a high electrical resistance. In an exemplary
embodiment, coils 321 are composed of copper and tube 322 is
composed of polyoxymethylene. In an exemplary embodiment, the
polyoxymethylene tube is connected to a second base 325. In an
exemplary embodiment, a second mounting ring 323 is attached to
second base 325. In an exemplary embodiment, second mounting ring
323 connects to an automobile frame, i.e., the sprung weight. In an
exemplary embodiment, coils 321 are connected to a rectifier
set-up.
[0042] For example, when shock absorber 300 is placed in an
automobile suspension system, vibrations in the suspension system,
due to road irregularities or during acceleration and braking,
cause the coil assembly 320 to move in relation to the magnetic
assembly 310 i.e. compression and extension cycles, thus generating
an electromotive force, which can then be used to recharge the
automobile's battery.
[0043] Alternatively, the arrangement of radial and axial magnets,
shown in FIGS. 2a, 2b and 3, are arranged as shown in FIG. 5.
Specifically, radial rare-earth magnets 502 are dimensioned to be
thinner than the radial magnets disclosed above with respect to
FIGS. 2a, 2b and 3. Spacers 504, constructed of a material having
high magnetic permeability such as iron, are stacked onto the
radial rare-earth magnets 502 so that the stacked assembly of the
radial rare-earth magnet 502 and the spacer 504 has the same height
as adjacent axial magnets 506. In other words, the annular radial
magnet 502 includes an inlayed spacer 504, having an annular shape.
The cross-sectional aspect of the combination of radial magnet 502
and spacer 504 is identical to the cross-sectional aspect of the
axial magnet 506 in that the central opening diameter and the
outside diameter of the combined radial magnet 502 and spacer 504
is the same as the respective diameters of the axial magnet.
[0044] The radial rare-earth magnets 502, Axial magnets 506 and
spacers 504 are positioned between an aluminum shaft 508 and
linearly disposed coils 510 similar to the arrangement shown in
FIGS. 2a and 2b. Moreover, in the double layer embodiment of FIG.
3, the radial rare-earth magnets in both layers can be replaced
with the stacked assembly shown in FIG. 5.
[0045] The stacked assembly of the radial rare-earth magnet 502 and
the spacer 504, shown in FIG. 5, advantageously similar or even
higher magnetic density than a full height radial rare-earth magnet
at a significantly reduced cost. The advantages are obtained
because iron has a greater permeability than rare-earth materials,
such as NdFeB, used for rare-earth permanent magnets. Moreover,
iron is significantly less expensive than rare-earth permanent
magnets. Thus, a cost savings can be realized by using smaller
dimensioned radial rare-earth magnets 502 with the spacers 504 over
using full height radial rare-earth magnets in the configurations
shown in FIGS. 2a, 2b and 3.
[0046] FIG. 4 symbolically illustrates an exemplary embodiment of a
gear-based electricity generating shock absorber. Shock absorber
400 includes an outer case 410 and an inner case 410.
[0047] In an exemplary embodiment, outer case 410 includes a
toothed rack 413 attached to inner surface of outer case 410 via a
first base 412. A first mounting ring 411 is attached to an outer
surface of outer case 410.
[0048] In an exemplary embodiment, inner case 420 includes a
toothed pinion 424, which is mounted near a first end of a first
shaft 423, engaging rack 413 for converting linear motion into
rotational motion. Hence, since vehicle vibration is periodic
linear motion, the vibration is converted into rotational motion
via the movement of rack 413 up to the limit of its travel, against
pinion 424, causing pinion 424 to rotate on its axis. First end of
first shaft 423 is attached to a base 422 mounted on inner surface
of inner case 420.
[0049] In an exemplary embodiment, a bevel gear 425.a engages a
bevel gear 425.b within a bevel gearbox 429. Bevel gear 425.a is
mounted on a second end of first shaft 423. Bevel gear 425.b is
mounted on a second end of a second shaft 426 attached to a
rotational motor 428. As bevel gear 425.a transfers rotational
motion from rack 413 and pinion 424 to bevel gear 426.b, rotational
motor 428 is driven via a rotation of second shaft 426 about its
axis. A coupler 427 attaches motor 428 to second shaft 426. A
second mounting ring 421 is attached to an outer surface of inner
case 420.
[0050] In an exemplary embodiment, when rotational motor 428 is
driven by rack 413 and pinion 424 via bevel gear 425.a and 425.b,
rotational motor 428 generates a back electromotive force, thus
producing electricity. While in the typical shock absorber, the
electromotive force acts as the damping force as the vibration is
mitigated by dissipating the vibration energy into heat, shock
absorber 400 vibration is mitigated by dissipating the vibration
energy into electric energy.
[0051] Exemplary embodiments of electricity generating shock
absorbers maintain or enhance the required suspension damping
performance and provide an effective way to adjust the suspension
damping according to driver need or road conditions. Furthermore,
the vibration mitigation performance is maintained or enhanced
since the electricity-generating shock absorbers can provide back
electromagnetic force, acting as the damping or control force.
Also, exemplary embodiments of electricity generating shock
absorbers enable energy harvesting in a typical passenger vehicle
estimated to be on the same order of scale as a vehicle alternator
as under normal driving conditions. Moreover, the generated power
can be used to charge a battery, power the electrical accessories,
such as lights or radio, or drive the wheels of a hybrid
vehicle.
[0052] Further, exemplary embodiments of electricity generating
shock absorbers enable an easy implementation of regenerative
active suspension: a combination of energy harvesting and active
suspension control. Additionally, exemplary embodiments of
electricity generating shock absorbers are retrofittable, which
means it can be used for new cars, or just to replace the
traditional viscous shock absorber in the existing cars.
[0053] It should further be known that the present invention is not
limited to application in motor vehicles. Rather, the electricity
generating shock absorber can be advantageously utilized in any
application where sufficient vibrational forces are present to
operate the shock absorbers. In all embodiments, the electricity
generating shock absorbers of the present invention are intended to
be properly sized to accommodate the loads and forces experienced
by the electricity generating shock absorbers in the particular
application. Thus, any specific values provided in the disclosure
above, are intended for illustrative convenience only and should
not be taken as the full range of values acceptable for
implementing the present invention.
[0054] In contrast to other regenerative shock absorbers, exemplary
embodiments of electricity generating shock absorbers have high
energy density, low weight and good compactness. Unlike ball-screw
based systems, exemplary embodiments of electricity generating
shock absorber also have little interference with vehicle
dynamics.
* * * * *