U.S. patent application number 12/592480 was filed with the patent office on 2010-06-10 for balanced support and solar tracking system for panels of photovoltaic cells.
This patent application is currently assigned to SUN-A-RAY, LLC.. Invention is credited to Sterling Holmes, Spencer Murphy, Gerald Whipple, Tom Willsey.
Application Number | 20100139645 12/592480 |
Document ID | / |
Family ID | 42229669 |
Filed Date | 2010-06-10 |
United States Patent
Application |
20100139645 |
Kind Code |
A1 |
Whipple; Gerald ; et
al. |
June 10, 2010 |
Balanced support and solar tracking system for panels of
photovoltaic cells
Abstract
A solar tracking mechanism and mounting platform for solar
panels is mounted with three or four legs attachable to a concrete
pad and includes a substantially vertically disposed axle and a
substantially horizontally disposed axle to which a plurality of
panel support members are mounted to form a panel support assembly.
The vertically disposed axle allows at least 240 degree rotation of
the panel support assembly to follow the daily East-West travel of
the Sun in the sky. The substantially horizontally disposed axle
allows declining or tilting of the panel support assembly for the
North-South adjustment of the panel support assembly to correspond
to the geographic latitude of the location where the solar tracking
mechanism and platform is used. The substantially horizontally
disposed axle is placed on the centroid or substantially on the
centroid location relative to the panel support members, including
solar panels so that, as a result, the assembly is completely or
substantially balanced and can be placed horizontally or in any
inclined position without the weight of the assembly, including
solar panels mounted thereon, causing it to precipitously drop or
fall.
Inventors: |
Whipple; Gerald; (Cedar
City, UT) ; Willsey; Tom; (Cedar City, UT) ;
Murphy; Spencer; (Cedar City, UT) ; Holmes;
Sterling; (Cedar City, UT) |
Correspondence
Address: |
GABOR L. SZEKERES
P.O. BOX 27938
ANAHEIM HILLS
CA
92809
US
|
Assignee: |
SUN-A-RAY, LLC.
|
Family ID: |
42229669 |
Appl. No.: |
12/592480 |
Filed: |
November 25, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61200550 |
Dec 1, 2008 |
|
|
|
Current U.S.
Class: |
126/576 |
Current CPC
Class: |
F24S 30/452 20180501;
F24S 2030/134 20180501; F24S 25/13 20180501; F24S 2030/135
20180501; Y02B 10/10 20130101; H02S 20/32 20141201; H02S 20/10
20141201; H02S 20/24 20141201; Y02E 10/50 20130101; F24S 2030/18
20180501; Y02E 10/47 20130101 |
Class at
Publication: |
126/576 |
International
Class: |
F24J 2/38 20060101
F24J002/38 |
Claims
1. A solar tracking mechanism and mounting platform adapted for
supporting a plurality of solar panels that comprise solar energy
collecting means and for adjusting said solar panels in an
East-West direction and for also adjusting the declination of said
panels relative to the horizontal, said adjustment being considered
adjustment for North-South location and in accordance to seasons,
the solar tracking mechanism and mounting platform comprising: a
plurality of legs; a solar panel mounting subassembly that forms a
frame adapted for receiving the plurality of solar panels, the
subassembly being mounted to the legs; first means mounted to the
legs for rotating the solar panel mounting subassembly around a
substantially vertically disposed axis for East to West adjustment;
second means mounted to the first means for pivoting the solar
panel mounting subassembly around a substantially horizontally
disposed axis for adjustment of North-South location and for
seasons; the second means holding the solar panel mounting
subassembly in a substantially weight balanced position at any
angle of declination that is practically used for North-South and
seasonal adjustment.
2. A solar tracking mechanism and mounting platform in accordance
with claim 1 wherein the substantially horizontally disposed axis
is located substantially in the weight centroid of the solar panel
mounting subassembly.
3. A solar tracking mechanism and mounting platform in accordance
with claim 2 additionally comprising an electric motor to power the
first means for rotating the solar panel mounting subassembly
around a substantially vertically disposed axis for East to West
adjustment and an electrically powered actuator to power the second
means for pivoting the solar panel mounting subassembly around a
substantially horizontally disposed axis for adjustment of
North-South location and for seasons.
4. A solar tracking mechanism and mounting platform in accordance
with claim 2 additionally comprising a first electric motor to
power the first means for rotating the solar panel mounting
subassembly around a substantially vertically disposed axis for
East to West adjustment and a second electric motor to power the
second means for pivoting the solar panel mounting subassembly
around a substantially horizontally disposed axis for adjustment of
North-South location and for seasons.
5. A solar tracking mechanism and mounting platform in accordance
with claim 4 additionally comprising switch means for limiting the
rotation of the solar panel mounting subassembly around a
substantially vertically disposed axis for East to West adjustment
of at least 240 degrees.
6. A solar tracking mechanism and mounting platform in accordance
with claim 5 additionally comprising second switch means for
limiting the pivoting the solar panel mounting subassembly around a
substantially horizontally disposed axis for adjustment of
North-South location and for seasons within a predetermined set
range of degrees.
7. A solar tracking mechanism and mounting platform in accordance
with claim 2 additionally comprising a plurality of solar panels
mounted to the solar panel mounting subassembly and wherein the
second means is adapted for holding the solar panel mounting
subassembly together with the plurality of solar panels in the
substantially weight balanced position.
8. A solar tracking mechanism and mounting platform in accordance
with claim 2 wherein the first and second means are powered
manually.
9. A solar tracking mechanism and mounting platform in accordance
with claim 2 that has no more than 3 legs.
10. A solar tracking mechanism and mounting platform adapted for
supporting a plurality of solar panels that comprise solar energy
collecting means and for adjusting said solar panels in an
East-West direction and for also adjusting the declination of said
panels relative to the horizontal, said adjustment being considered
adjustment for North-South location and in accordance to seasons,
the solar tracking mechanism and mounting platform comprising: a
plurality of legs; a solar panel mounting subassembly that forms a
frame adapted for receiving the plurality of solar panels, the
subassembly being mounted to the legs; first means mounted to the
legs for rotating the solar panel mounting subassembly around a
substantially vertically disposed axis for East to West adjustment,
said first means including a substantially vertically disposed axle
fixedly connected to the solar panel mounting subassembly, the
substantially vertically disposed axle including a smoothly
machined stainless steel outer surface, the first means further
including an oil impregnated nylon bushing in working engagement
with the stainless steel outer surface; second means mounted to the
first means for pivoting the solar panel mounting subassembly
around a substantially horizontally disposed axis for adjustment of
North-South location and for seasons; the second means holding the
solar panel mounting subassembly in a substantially weight balanced
position at any angle of declination that is practically used for
North-South and seasonal adjustment, the substantially horizontally
disposed axis being located substantially in the weight centroid of
the solar panel mounting subassembly.
11. A solar tracking mechanism and mounting platform in accordance
with claim 10 additionally comprising an electric motor having an
out-put gear, the substantially vertically disposed axle being
fixedly connected to a gear that is in meshing engagement with the
out-put gear of the electric motor, the electric motor rotating the
solar panel mounting subassembly around a substantially vertically
disposed axis for East to West adjustment.
12. A solar tracking mechanism and mounting platform in accordance
with claim 11 additionally comprising switch means for limiting the
rotation of the solar panel mounting subassembly around a
substantially vertically disposed axis for East to West adjustment
of at least 240 degrees.
13. A solar tracking mechanism and mounting platform in accordance
with claim 11 additionally comprising a second electric motor to
power the second means for pivoting the solar panel mounting
subassembly around a substantially horizontally disposed axis for
adjustment of North-South location and for seasons.
14. A solar tracking mechanism and mounting platform in accordance
with claim 13 additionally comprising second switch means for
limiting the pivoting the solar panel mounting subassembly around a
substantially horizontally disposed axis for adjustment of
North-South location and for seasons within a predetermined set
range of degrees.
15. A solar tracking mechanism and mounting platform in accordance
with claim 11 additionally comprising a plurality of solar panels
mounted to the solar panel mounting subassembly and wherein the
second means is adapted for holding the solar panel mounting
subassembly together with the plurality of solar panels in the
substantially weight balanced position.
16. A solar tracking mechanism and mounting platform in accordance
with claim 11 that has no more than 3 legs.
17. A solar tracking mechanism and mounting platform including a
plurality of solar panels that comprise solar energy collecting
means and for adjusting said solar panels in an East-West direction
and for also adjusting the declination of said panels relative to
the horizontal, said adjustment being considered adjustment for
North-South location and in accordance to seasons, the solar
tracking mechanism and mounting platform comprising: a plurality of
legs; a solar panel mounting subassembly that forms a frame adapted
for supporting the plurality of solar panels, the subassembly being
mounted to the legs; first means mounted to the legs for rotating
the solar panel mounting subassembly around a substantially
vertically disposed axis for East to West adjustment, said first
means including a substantially vertically disposed axle fixedly
connected to the solar panel mounting subassembly, the
substantially vertically disposed axle including a smoothly
machined stainless steel outer surface, the first means further
including an oil impregnated nylon bushing in working engagement
with the stainless steel outer surface; the first means still
further including a first electric motor having an out-put gear,
the substantially vertically disclosed axle being fixedly connected
to a gear that is in meshing engagement with the out-put gear of
the first electric motor, the first means yet additionally
including switch means for limiting the rotation of the solar panel
mounting subassembly around a substantially vertically disposed
axis for East to West adjustment of at least 240 degrees; second
means mounted to the first means for pivoting the solar panel
mounting subassembly and the supported solar panels around a
substantially horizontally disposed axis for adjustment of
North-South location and for seasons; the second means holding the
solar panel mounting subassembly and solar panels in a
substantially weight balanced position at any angle of declination
that is practically used for North-South and seasonal adjustment,
the second means comprising a second electric motor, the
substantially horizontally disposed axis being located
substantially in the weight centroid of the solar panel mounting
subassembly and solar panels, and the second means additionally
including switch means for limiting the pivoting the solar panel
mounting subassembly around a substantially horizontally disposed
axis for adjustment of North-South location and for seasons within
a predetermined set range of degrees.
18. A solar tracking mechanism and mounting platform in accordance
with claim 17 that has no more than 3 legs.
19. A solar tracking mechanism and mounting platform in accordance
with claim 17 additionally including a rechargeable battery, said
battery capable of powering the first and second electric motors.
Description
CLAIM OF PRIORITY OF PROVISIONAL APPLICATION
[0001] The applicants claims priority of provisional application
Ser. No. 61/200,550, filed on Dec. 1, 2008.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention is in the field of support and
tracking systems for an array of photovoltaic cells. More
particularly, the present invention relates to a support and
tracking system for an array of photovoltaic cells that is well
balanced in the North-South declination sense and has numerous
additional improvements over the state-of-the-art.
[0004] 2. Brief Description of the Prior Art
[0005] The need to obtain reliable and renewable energy sources
alternative to fossil fuels is greater at the present time than
perhaps in any previous time in history. Electrical power generated
from solar irradiation is a well known alternative and renewable
energy source and the technology to exploit this source has been
advancing rapidly during the last few decades. In the present state
of the art photovoltaic cells are available that are capable of
supplying very substantial electrical energy. Because photovoltaic
cells are typically arranged in substantially flat panels, the
terms "photovoltaic cells" and "solar panels" can be used
interchangeably for the purposes of describing the state-of-the-art
pertinent to the present invention, and for describing the
invention itself.
[0006] Photovoltaic cells or solar panels are typically permanently
mounted on flat surfaces such as roofs, or on stands, poles, frames
or other mounting apparatus or mechanism. It is well known in the
art, that better performance is obtained from solar panels when the
panels continuously face the sun, that is, when they follow the Sun
on its East to West daily track in the sky. This type of movement
of the panels is commonly known as East-West movement or
adjustment. It is also known in the art that still further improved
performance is obtained from solar panels if the panels are
inclined or tilted relative to the horizontal as a function of the
geographical latitude of the location where the panels are, and
still further if periodic adjustment of the panels' inclination or
tilt is made during the seasons when the position of the Sun in the
sky changes. This type of adjustment of the position of the solar
panels is referred to as a North-South adjustment.
[0007] Photoelectric devices and associated electronic circuitry
are available in the state-of-the-art to detect the position of the
Sun in the sky and to control an electric motor or like device to
cause the panels to move East-West to follow the daily track of the
Sun in the sky, provided the mounting apparatus or mechanism allows
such movement.
[0008] When the mounting apparatus allows adjustment of the
North-South inclination or tilt of the panels, then this is
typically performed periodically, but not necessarily daily, as the
seasons change. A good practical rule to be followed in this regard
is that during the summer the panels should be declined relative to
the horizontal at an angle that is approximately 15 degrees less
than the latitude-in-degrees of the location where the panels are,
and during winter at an angle of 15 degrees greater than the
latitude-in-degrees of the location where the panels are.
Optimally, the declination of the panels can also be periodically
changed between the above-noted two extremes as the seasons
change.
[0009] The solar panels have substantial weight and because they
are typically arranged in arrays of multiple panels, their combined
weight can amount to several hundred or with wind loads to even
several thousand pounds. It should already be apparent from the
foregoing that the mounting mechanism that is capable of supporting
this much weight and is also capable of reliably allowing the
North-South adjustment of panels and reliably performing or
allowing the East-West daily movement of the panels is relatively
complex itself. In fact, the prior art has produced a large number
of such mounting and tracking mechanisms as evidenced by the
numerous United States and foreign patents, published patent
applications and catalogs and advertisements in this field of
technology.
[0010] More specifically, such mounting devices or mechanisms are
described, for example, in U.S. Pat. Nos. 6,046,400; 4,280,853;
4,457,297; 6,563,040; 6,848,442; 6,302,099; 6,239,353; 7,240,674;
7,202,457; 4,225,781; 4,266,530; 4,302,710; 4,476,854; 4,202,321;
6,248,968; and in 4,172,739; in Published Patent Applications Nos.
US 2004/0238025; US 2007/0227574; EP 1 241 416 A2; WO 92/11496; and
WO 2005/026628.
[0011] Additional disclosures of interest to the present invention
and pertaining to mounting mechanisms of various devices such as
panels, solar cameras, weathering test apparatus and the like are
found in U.S. Pat. Nos. 3,889,531; 70,09; 931,692; 6,572,061;
6,305,653; 4,378,100; 6,766,623; and 6,563,040.
[0012] In spite of the relatively large number of such disclosures
of mounting and tracking apparatus for solar panels the mounting
apparatus known in the present state-of-the-art still have some
serious disadvantages in terms of the cost of installing them to a
permanent location, their durability, particularly the durability
of their East-West tracking and North-South tilting mechanism, and
their ability to withstand wind pressures which can be very
substantial. The present invention provides improvements in terms
of all these problems of the prior art.
[0013] Another serious problem in the prior art relates to the
weight of the solar panels when a North-South declination or
tilting is adjusted or maintained. More specifically, whenever
North-South declination or tilting and its periodic adjustment are
enabled, the array of panels is mounted on an axis that allows such
tilting relative to the horizontal. In all prior art mounting
apparatus known to the present inventors whenever such North South
tilting is enabled, the weight of the panels would normally cause
the array to precipitously drop or fall relative to the horizontal
axis until the maximum angle allowed is reached. This uncontrolled
drop or can seriously injure or even kill a person who may be hit
by the combined weight of the panels and the may damage the entire
mounting device and the panels themselves. The state-of-the-art is
aware that seriousness of this problem increases with the size and
therefore with the weight of the array of panels. Because such
rapid uncontrolled drop of the array of panels must be prevented to
avoid injury and damage in the present state-of-the art usually at
least two persons are needed to install the solar tracking
apparatus. Usually two persons are needed also when the periodic
adjustment of the North-South declination is performed. Even then,
the installing persons are not free of danger, and sometimes other
mechanical assistance is needed to avoid the damage or injury. One
principal feature of the present invention is to eliminate the
just-described serious problem.
OBJECTS AND SUMMARY OF THE INVENTION
[0014] It is an object of the present invention to provide a solar
tracking mechanism and mounting platform that can be installed on a
concrete foundation instead of attached to a pole affixed in the
ground.
[0015] It is another object of the present invention to provide a
solar tracking mechanism and mounting platform having an array of
panels that is less subject to wind pressure than similar size
panels mounted in accordance with the prior art.
[0016] It is still another object of the present invention to
provide a solar tracking mechanism and mounting platform that has
long useful life and requires a minimum of repairs or maintenance
procedures.
[0017] It is a further advantage of the present invention to
provide a solar tracking mechanism and mounting platform that is
completely or substantially completely balanced relative to a
horizontal axis of declination or tilting whereby the danger of
damage and injury to persons is eliminated or minimized during
installation and during adjustment of the North-South declination
of panels.
[0018] These and other objects and advantages are attained by a
solar tracking mechanism and mounting platform for solar panels
that is mounted with three or four legs attachable to a concrete
pad and includes a substantially vertically disposed axle and a
substantially horizontally disposed axle to which a plurality of
panel support members are mounted to form a panel support assembly.
The vertically disposed axle allows at least approximately 240
degree rotation of the panel support assembly to follow the daily
East-West travel of the Sun in the sky. The substantially
horizontally disposed axle allows declining or tilting of the panel
support assembly for the North-South adjustment of the panel
support assembly to correspond to the geographic latitude of the
location where the solar tracking mechanism and platform is
used.
[0019] The substantially horizontally disposed axle is placed on
the centroid or substantially on the centroid location relative to
the panel support members, including solar panels so that, as a
result, the assembly is completely or substantially balanced and
can be placed horizontally or in any inclined position without the
weight of the assembly, including solar panels mounted thereon,
causing it to precipitously drop or fall.
[0020] The objects and features of the present invention are set
forth with particularity in the appended claims. The invention may
be best understood by reference to the following description, taken
in connection with the accompanying drawings wherein like numerals
indicate like parts.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
[0021] FIG. 1 is a perspective view of a preferred embodiment of
the solar tracking assembly and mounting platform for solar
panels.
[0022] FIG. 2 is a partial front view showing an actuator that can
be used to adjust the declination or tilt of the panel support
assembly and mounted solar panels for North-South adjustment and a
motor that allows the rotation of the panel support assembly and
mounted solar panels for East-West tracking of the Sun's daily
travel in the sky.
[0023] FIG. 3 is a cross-sectional view of the motor and gear taken
on lines 3,3 of FIG. 2.
[0024] FIG. 4 is a partial side view showing the actuator and the
pivot axle for declination or tilting.
[0025] FIG. 5 is a cross-sectional view taken on line 5,5 of FIG.
2.
[0026] FIG. 6 is a cross-sectional view taken on line 6,6 of FIG.
5.
[0027] FIG. 7 is a cross-sectional view taken similar to FIG. 5 but
showing adjustable rollers.
[0028] FIG. 8 is a cross-sectional view taken on line 8,8 of FIG.
7.
[0029] FIG. 9 is a cross-sectional view taken on line 9,9 of FIG.
8.
[0030] FIG. 10 is a top plan view taken on line 10,10 of FIG.
1.
[0031] FIG. 11 is a cross-sectional view taken on line 11 of FIG.
10.
[0032] FIG. 12 is a partial front view of a preferred embodiment
that lacks a motor and is manually rotatable in the East-West
direction.
[0033] FIG. 13 is a cross-sectional view taken on line 13,13 of
FIG. 12.
[0034] FIG. 14 is a partial side view of a preferred embodiment
that lacks an actuator and can be tilted manually to adjust for
Nort-South location and season.
[0035] FIG. 15 is a side view taken on line 15,15 of FIG. 1.
[0036] FIG. 16 is a top plan view taken on lines 16,16 of FIG.
15.
[0037] FIG. 17 is a cross-sectional view of taken on line 17,17 of
FIG. 16.
[0038] FIG. 18 is a cross-sectional view of taken on line 18,18 of
FIG. 16.
[0039] FIG. 19 is a partial top plan view of the solar tracking
assembly and mounting platform with solar panels mounted
thereon.
[0040] FIG. 20 is a cross-sectional view of taken on line 20,20 of
FIG. 19.
[0041] FIG. 21 is a view in elevation, taken on lines 21,21 of FIG.
19.
[0042] FIG. 22 is a view in elevation taken on line 22,22 of FIG.
19.
[0043] FIG. 23 is a diagrammatic view of the pivot axle that allows
balanced positioning of the panel support members, including the
solar panels.
[0044] FIG. 24 is a diagrammatic side view of solar tracking
assembly and mounting platform with 30 solar panels mounted
thereon.
[0045] FIG. 25 is a diagrammatic side view of solar tracking
assembly and mounting platform showing maximum North-South
declination and ground clearance.
[0046] FIG. 26 is a perspective view of the presently most
preferred embodiment of the solar tracking assembly and mounting
platform for solar panels.
[0047] FIG. 27 is a partial front view analogous to the partial
front view of FIG. 2, thus showing a motor that can be used to
adjust the declination or tilt of the panel support assembly and
mounted solar panels for North-South adjustment and a motor that
allows the rotation of the panel support assembly and mounted solar
panels for East-West tracking of the Sun's daily travel in the
sky.
[0048] FIG. 28 is a cross-sectional view taken on lines 28,28 of
FIG. 27.
[0049] FIG. 29 is a cross-sectional view taken on lines 29,29 of
FIG. 28.
[0050] FIG. 30 is a cross-sectional view taken on lines 30,30 of
FIG. 29.
[0051] FIG. 31 is a partial side view taken on lines 31,31 of FIG.
27.
DETAILED DESCRIPTION OF THE INVENTION
Preferred Embodiments
[0052] The following specification, taken in conjunction with the
drawings, sets forth the preferred embodiments of the present
invention. The embodiments of the invention disclosed herein are
the best modes contemplated by the inventors for carrying out their
invention in a commercial environment, although it should be
understood that various modifications can be accomplished within
the parameters of the present invention.
[0053] A perspective view of a preferred embodiment of the solar
tracking assembly and mounting platform 40 is provided in FIG. 1 of
the attached drawings. For the sake of brevity the solar tracking
and mounting assembly may also be referred to simply as the
"mounting apparatus", "mounting platform", "solar tracking
apparatus" or the like. The first described two preferred
embodiments have substantially the same construction with the
difference being primarily that the first preferred embodiment
includes equipment for automatically following the daily track of
the Sun in the sky, and an actuator that allows the periodic
North-South adjustment of the array of solar panels without using
human muscle power. The second preferred embodiment lacks the
automatic East-West tracking apparatus, however still enables the
at least approximately 240 degrees East West tracking of the Sun by
manual power, and also the periodic adjustment of North-South
inclination of the panels, by manual power also. The presently most
preferred embodiment is described last. This embodiment also
includes equipment for automatically following the daily track of
the Sun in the sky, and a motor that allows the periodic
North-South adjustment of the array of solar panels without using
human muscle power, and has additional useful features.
[0054] It should be noted at the outset that photosensor apparatus
and associated electronic or electric circuitry, electric motors
capable of performing the East-West tracking of the Sun when
controlled by the photosensor apparatus and electrically powered
actuators per se are well known in the art, are commercially
available, and need not be described here further.
[0055] Referring still primarily to FIG. 1, the solar tracking
assembly and mounting platform 40 includes four legs 42 which are
preferably placed on and attached to a concrete pad 44. A concrete
pad adequate to support the solar tracking assembly and mounting
platform 40 together with a plurality of solar panels mounted
thereon is typically four (4) inches thick. This arrangement of
placing the solar tracking apparatus 40 to a fixed location with
four legs 42, or with three legs as in the last described preferred
embodiment, is itself a novel and advantageous feature of the
present invention. This is because, unless mounted on a flat
surface such as a roof, tracking apparatus and solar panels in the
prior art are normally mounted on a pole (not shown) that must be
deeply embedded in a concrete reinforced hole in the ground.
Providing a typically four (4) inches thick concrete pad 44 and
attaching each of the legs 42 to the concrete pad 44 is considered
less time consuming, less costly and gives better attachment than
the previously used mounting poles (not shown). FIGS. 10 and 11
show attachment of the legs 42 in detail. Each of the legs 42
include a flat plate like member 46 that is attached by a plurality
of bolts 48 to the concrete pad 44. FIG. 11 also shows the ground
50.
[0056] Before describing several of the principal novel features of
the present invention the solar panel mounting subassembly 52 of
the solar tacking apparatus is described briefly. This description
is provided for the purpose of providing a complete description and
enabling disclosure and in order to be able to refer to and
identify certain components of the subassembly 52 when novel
features of the invention are described. The solar panel mounting
subassembly 52 is shown in perspective view in FIG. 1. It includes
two long main support members 54 and 56 made of steel, aluminum or
other strong material capable of supporting substantial weight. The
two main support members 54 and 56 are shown substantially
horizontally disposed in FIG. 1. The two main support members 54
and 56 are interconnected by a plurality of main cross-support
members. The herein described preferred embodiment has four (4)
main cross support members 58, 60, 62 and 64. The main support
members 54 and 56 and the main cross support members 58, 60, 62 and
64 are affixed to each other by welding or equivalent mechanical
means.
[0057] Referring still primarily to FIG. 1, a plurality of solar
panel support members (shown on FIG. 19) are to be attached on top
of the interconnected main support members 54 and 56 and the main
cross support members 58, 60, 62 and 64. The presently preferred
embodiment of the invention includes up to eight (8) solar panel
support members, the two lateral ones of these bear the reference
numerals 66 and 68.
[0058] Continuing to describe the solar panel mounting subassembly
52, primary reference is made to FIGS. 15 through 18. These drawing
figures disclose in detail how the solar panel support members such
as 66 and 68 are affixed to the interconnected main support members
54 and 56 and main cross support members 58, 60, 62 and 64. The
solar panel support members, such as 66 and 68, are usually not
affixed by welding to the interconnected main support members 54
and 56 and main cross support members 58, 60, 62 and 64 because the
number of solar panel support members depends on the number of
solar panels that are ultimately affixed to and carried by the
solar panel mounting subassembly 52. Thus, a spacer 70, a fastening
plate 72 and a plurality of carriage bolts 74 and nuts 76 are used
to removably but nevertheless strongly affix the solar panel
support members to the interconnected main support members 54 and
56 and main cross support members 58, 60, 62 and 64, as is best
shown in the cross-sectional views of FIGS. 17 and 18.
[0059] FIG. 19 is a partial top plan view of solar panels 78 that
are mounted on the above-described solar panel mounting subassembly
52. As is noted before, solar panels per se are well known in the
art and are commercially available. They usually come in the size
of 3 feet by 5 feet. Such typical size panel usually weighs 35 lbs.
Its maximum output of electricity when receiving sunlight varies
between 165 and 186 watts, depending on the manufacture and model.
It is well known that the maximum possible output of electricity
has rapidly grown in the recent past with improved design and
manufacturing technology.
[0060] The cross-sectional view of FIG. 20 discloses in detail the
manner of affixing solar panels 78 to the underlying solar panel
mounting subassembly 52 in locations where solar panels 78 abut
each other and are not on the edge of the solar panel mounting
subassembly 52. This is shown in FIG. 19 where the cross-section of
FIG. 20 is taken. A plurality of carriage bolts 80, plates 82 and a
plurality of nuts 84 are provided for this purpose. FIG. 20 show
attachment of two solar panels to the solar panel support member
66.
[0061] FIG. 22 discloses in detail the manner of affixing solar
panels 78 to the underlying solar panel mounting subassembly 52 in
locations where solar panels 78 abut each other and are in the
corner of the solar panel mounting subassembly 52. A plurality of
carriage bolts 80, a plate 86 and a plurality of nuts 84, an
additional top plate 88 and a spacer bolt 90 are used here as shown
in the drawing figure.
[0062] It should be readily apparent to those skilled in the art
that numerous modifications can be made to the above described
solar panel mounting subassembly 52 in terms of the number of main
support members, such as 54 and 56, in terms of the number of main
cross support members 58, 60, 62 and 64, in the manner of affixing
these to one another, and further in the manner of affixing the
solar panels 78 to the subassembly 52. Such modifications in terms
of the number of the respective support members and the mechanical
means, including welding, using nuts, bolts, carriage bolts or like
means should be considered equivalent to the above described
presently preferred construction and structure of the solar panel
mounting subassembly 52 and of the attachment of the solar panels
78 to it.
[0063] Having described the solar panel mounting subassembly 52 to
which the plurality of solar panels 78 are mounted, reference is
now made primarily to FIGS. 2 through 14 together with the
perspective view of FIG. 1, where several novel aspects and
features of the present invention are disclosed. The solar tracking
assembly and mounting platform 40 includes a substantially
vertically disposed axle 92 enclosed in an axle housing 94 that
forms the basis of East-West rotation of the solar panel mounting
subassembly 52 and of the solar panels 78 mounted thereon.
[0064] As is shown in FIG. 8, the axle housing 94 terminates on its
bottom in a plate 96 that closes the housing and is welded to it.
The part shown by reference numeral 98 is a leg stop plate also
shown in FIG. 5. A bearing housing or hub 102 is mounted to the
plate 96 with bolts 104 and nuts 106. The bearing housing or hub
102 includes tapered bearings 108 into which the vertical axle 92
is mounted. More specifically described in detail, the vertical
axle 92 itself terminates in a block 110 that continues in a pin
112 that is mounted in the tapered bearings 108. A nut 114 is
placed on the threaded end of the pin 112 to keep the assembly in
place. A significant advantage of the just described placement of
the vertical axle 92 into the bearing housing or hub 102 is that
the assembly can be readily removed for maintenance or repair.
[0065] Referring still primarily to FIG. 8, the vertical axle 92
continues upward as a hollow cylindrical member and is further
supported by four bearings 116 all four of which, or at least two
of which, are adjustable. The vertical axle 92 and the adjustable
bearings 116 are also shown in detail in the cross-sectional views
of FIGS. 7 and 9. A bearing housing 118 is attached to the axle
housing 94 and a pin 120 is held therein to provide the axis of
rotation of each bearing 116. Bolts 121 are provided in threaded
openings and abut the pin 120 and can move the pin 120 closer to or
further away from the vertical axle 92 to provide optimal
conditions and support for its rotation. The just described
assembly of the adjustable bearings 116 is an advantageous feature
of the present invention because it stabilizes the vertical axle
92, and enables it to resist bending under substantial wind
pressures that occur frequently when the solar panels 78 are
mounted on the tracking apparatus 40. Thus, this feature prolongs
the useful life of the apparatus 40. FIGS. 5 and 6 show similar
structures but without the bearings being adjustable.
[0066] FIGS. 2 through 6 in conjunction with FIG. 1 and the rest of
the drawings, as applicable, further disclose the preferred
embodiment where the daily East-West tracking of the Sun is
performed by an electric motor 122 controlled by a photosensor 124
that is shown only in FIG. 1. The electric motor 122 and
photosensor 124 are commercially available. In this embodiment, a
housing 126 for the electric motor 122 and other parts (to be
described immediately below) is mounted to the legs 42 and encloses
non-adjustable bearings 128 for the vertical axle 92. The
cross-sectional view of FIG. 5 shows all four of the non-adjustable
bearings 128. Each of the non-adjustable bearings 128 is fixedly
mounted to the axle housing 94 and rotates on a fixedly mounted pin
130.
[0067] The vertical axle 92 has a fixedly attached gear 132 with
cogwheel type teeth 136 on its periphery that is in meshing
engagement with an output gear 138 of the electric motor 122. The
housing 126 is mounted to the legs 42 with plates 140 and bolts
142, as is best shown in FIG. 2. It should be readily apparent from
the foregoing description that the electric motor 122 controlled by
the photosensor 124 causes slow rotation of the solar panel
mounting subassembly 52 together with the solar panels 78 to follow
the daily East to West track of the Sun in the sky. Sometime
between sunset and sunrise the motor 122 causes the solar panel
mounting subassembly 52 and the solar panels 78 to rotate back
again to the most eastwardly position. To accomplish this the gear
132 has the cogwheel type teeth 136 on at least approximately 240,
preferably on approximately 270 degrees around its periphery.
Optionally the gear 132 may be teethed on its entire periphery.
[0068] In the just described preferred embodiment a battery 144 is
mounted to the legs 42 and provides or contributes to the electric
power needed to rotate the solar panel mounting subassembly 52 with
the solar panels 78. The battery 144 is shown only in FIG. 1. The
battery 144 is charged by the solar panels 78 or may be charged
from inside the facility (not shown) to where the solar panels' 78
power is sent. The battery 144 is an optional feature of the
present invention because the power to rotate the solar panel
mounting subassembly 52 with the solar panels 78 may be provided
from another power source, as noted above.
[0069] FIGS. 2 and 4 show in detail the construction of the
just-described preferred embodiment that also includes the ability
to incline the solar panel mounting subassembly 52 together with
the solar panels 78 to adjust for the geographic latitude of the
location where the tracking apparatus 40 is used, and further to
periodically adjust for the change of the position of the Sun in
the sky due to change of seasons. Thus, the solar panel mounting
subassembly 52 is mounted on a substantially horizontally disposed
axle 146. The herein described preferred embodiment has the axle
146 in two parts 146a and 146b as is best shown in FIG. 2. Having
the axle 146 in two parts provides an advantage in construction,
maintenance and when repair is needed. The detailed drawing of FIG.
2 discloses a member 148 (also shown in FIG. 1) that is fixedly
attached to the upper end of the vertical axle 92. Plates 150 are
mounted to project upwardly from the member 148 into which the
axles 146a and 146b are respectively mounted for possible rotating
movement therein. The mounting of the axles 146a and 146b in the
upwardly projecting plates 150 is reinforced by additional plates
152 mounted on the upward plates by bolts and nuts 154 holding
bearings 156.
[0070] An arm 158 is affixed on one side of the member 148 to hold
an actuator 160 the output rod 162 of which is attached to the one
of the main cross support members 60 of the solar panel mounting
subassembly 52, as is best shown in FIG. 4. Electrically powered
actutarors per se are well known in the art and are commercially
available. The actuator 160 of the preferred embodiment includes a
switch (not shown) that causes the output rod 162 to move in or
out, as wanted, to adjust the inclination or tilting of the solar
panel mounting subassembly 52 together with the solar panels 78
mounted thereon. Electric power to the actuator 160 is provided by
the battery 144, or may be provided by another power source
similarly to the manner of providing power to the electric motor
122.
[0071] The location of the substantially horizontally disposed axle
146 in such a manner that it causes the solar panel mounting
subassembly 52, together with the assembled solar panels 78 to be
weight-balanced against precipitous and dangerous drop is a highly
important feature of the invention and is described below in
detail.
[0072] It was found in accordance with the present invention that
the desired weight balancing of the solar panel mounting
subassembly 52 can be accomplished only when the axis of horizontal
pivoting movement or rotation represented by the axles 146a and
146b is in the centroid or substantially in the centroid of the
combined weight solar panel mounting subassembly 52 and solar
panels 78. The concept of centroid per se is well known in
mathematics and engineering and is described here for the sake of
completeness only by including description from readily available
sources, such that may readily accessed by searching on the
Internet. Thus, as it can be found by searching for "centroids" in
GOOGLE, the free encyclopedia, Wikipedia, describes centroid as
follows:
[0073] In geometry, the centroid or barycenter of an object X in
n-dimensional space is the intersection of all hyperplaness that
divide X into two parts of equal moment about the hyperplane.
Informally, it is the "averagee" of all points of X. The centroid
of an object coincides with its center of mass if the object has
uniform density, or if the object's shape and density have a
symmetry which fully determines the centroid. These conditions are
sufficient but not necessary. The centroid of a finite set of
points can be computed as the arithmetic mean of each coordinate of
the points. The centroid of a convex object always lies in the
object. A non-convex object might have a centroid that is outside
the figure itself. The centroid of a ring or a bowl, for example,
lies in the object's central void.
[0074] More specifically with regard to "center of gravity" and
"moment of inertia" as is well known and can be found by searching
on the Internet the following is noted for the sake of complete
description of the present invention. The centroid, or center of
gravity, of any object is the point within that object from which
the force of gravity appears to act. An object will remain at rest
if it is balanced on any point along a vertical line passing
through its center of gravity. In terms of moments, the center of
gravity of any object is the point around which the moments of the
gravitational forces completely cancel one another.
The center of gravity of a rock (or any other three dimensional
object) can be found by hanging it from a string. The line of
action of the string will always pass through the center of gravity
of the rock. The precise location of the center of gravity could be
determined if one would tie the string around the rock a number of
times and note each time the line of action of the string. Since a
rock is a three dimensional object, the point of intersection would
most likely lie somewhere within the rock and out of sight. The
centroid of a two dimensional surface (such as the cross-section of
a structural shape) is a point that corresponds to the center of
gravity of a very thin homogeneous plate of the same area and
shape. The planar surface (or figure) may represent an actual area
(like a tributary floor area or the cross-section of a beam) or a
figurative diagram (like a load or a bending moment diagram). It is
often useful for the centroid of the area to be determined in
either case. Symmetry can be very useful to help determine the
location of the centroid of an area. If the area (or section or
body) has one line of symmetry, the centroid will lie somewhere
along the line of symmetry. This means that if it were required to
balance the area (or body or section) in a horizontal position by
placing a pencil or edge underneath it, the pencil would be best
laid directly under the line of symmetry.
[0075] If a body (or area or section) has two (or more) lines of
symmetry, the centroid must lie somewhere along each of the lines.
Thus, the centroid is at the point where the lines intersect. This
means that if it were required to balance the area (or body or
section) in a horizontal position by placing a nail underneath it,
the point of the nail would best be placed directly below the point
where the lines of symmetry meet. This might seem obvious, but the
concept of the centroid is very important to understand both
graphically and numerically. The position of the center of gravity
for some simple shapes is easily determined by inspection. One
knows that the centroid of a circle is at its center and that of a
square is at the intersection of two lines drawn connecting the
midpoints of the parallel sides.
[0076] For further description and explanation of the concept of
centroid and how to find it on a given object, reference is made to
standard handbooks of mathematics, geometry and engineering.
[0077] Solar panels are usually of rectangular shape and therefore
have a symmetry of the type described above that would render the
determination of the centroid of each panel easy. Each of the solar
panels used in the same assembly have practically the same weight
and density distribution on their respective surfaces. Moreover, in
accordance with the present invention the plurality of solar panels
are preferably placed in a symmetrical pattern on the solar panel
mounting subassembly 52. It is important that it was found in
accordance with the present invention that the centroid is usually
high in, or relative to the solar panel mounting subassembly 52,
and can be found by routine experimentation that is sufficiently
simple so as not to constitute undue experimentation. For this
reason a mathematical or geometrical determination of the centroid
is usually not necessary in the practice of the invention, although
it can be performed. As noted before, the axis of rotation, namely
the axle 144 (or as in the preferred embodiment of the axles 146a
and 146b) is placed in the centroid, or substantially in the
centroid in accordance with the present invention.
[0078] The herein shown preferred embodiments of the invention
accomplish well the goal of weight balancing by utilizing the
described mechanical construction. It should be noted that in the
preferred embodiments the position of the horizontal axle 146 is as
specifically shown in FIG. 4 in relation to member 62.
[0079] FIGS. 12 through 14 are directed to a preferred embodiment
that is identical or substantially similar in construction with the
just described embodiment but requires manual adjustment for
East-West tracking and also for North-South declination. The
component parts of this embodiment are described only to the extent
they are different from or additional to the parts of the first and
above described preferred embodiment.
[0080] Thus, the just noted preferred embodiment may lack the
photosensor 124 of the first preferred embodiment. It lacks the
electric motor 122 and lacks the electrically powered actuator 160
of the first preferred embodiment. Nevertheless, to enable manual
tracking of the Sun, or to place the solar panel mounting
subassembly 52 together with the assembled solar panels 78 into a
desired East-West position a disk 164 is fixedly attached to the
vertical axle 92 above the non-adjustable bearings 128. The disk
164 has a plurality of apertures or holes 166 close to its
periphery. Similarly to the teeth 136 of the gear 132 of the first
preferred embodiment, in this embodiment the apertures 166 are
placed at least approximately 240, preferably at approximately 270
degrees around the periphery of the disk 164. Optionally, and as is
shown for the presently described preferred embodiment, the disk
164 may have the apertures 166 around its entire periphery. A plate
168 is affixed to the axle housing 94 below the disk 164. The plate
168 includes an aperture that can be aligned with one of the
plurality of apertures 166 on the disk 164. A bolt and nut
combination 170 is normally used to secure the vertical axle 92,
together with the solar panel mounting subassembly 52 and assembled
solar panels 78 to remain stationary in any desired East-West
position. When the bolt 170 is removed, then the vertical axle 92,
the subassembly 52 with the solar panels 78 can be manually rotated
to any desired new position.
[0081] FIG. 14 discloses a disk 172 that is fixedly attached to the
horizontal axle 146 and rotates with it. The disk 172 also has
apertures 174 capable of receiving a bolt 176. An elongated member
178 shown in FIG. 12 and by phantom lines in FIG. 14 is fixedly
attached to one of the main cross support members 60 and has an
aperture (not shown) that can be aligned with one of the plurality
of apertures 174 of the disk 172. This can also receive the bolt
176 that can be secured with a nut (not shown). The apertures 174
are positioned around the periphery of the disk 172 so that any
inclination or tilting of the subassembly 52 and solar panels 78
can be accomplished to the extent that it is practical for
North-South adjustment of the solar panels 78. In this regard it
should be noted that in virtually any location of planet Earth
(except during the summer and winter solistice on the Equator or
close to the Equator) ideal position of the solar panels 78 is at
an angle to the horizontal. The just described structure enables
the periodic adjustment of the inclination of the solar panels 78
by manual power.
[0082] FIG. 23 is a diagrammatic representation of the important
feature of the present invention that the horizontal axis
(corresponding to axle 146) for the tilting of the solar panel
mounting subassembly 52 together with the assembled solar panels 78
is likely to be high relative to the main cross support members
represented by 60 in this drawing figures. As noted above this is
usually the necessary construction to have the axis of rotation in
the centroid or substantially in the centroid.
[0083] FIG. 24 is a diagrammatic representation to show that the
solar tracking assembly and mounting platform 40 of the present
invention is capable of having a relatively large number of solar
panels 78. A presently contemplated practical limit is
approximately thirty (30) solar panels. However this practical
limitation is not one of the invention per se, but rather is a
matter of practical weight and size limitations which could be
overcome with further improvement in technology, such as less heavy
solar panels and stronger support materials.
[0084] Exemplary dimensions of the solar tracking assembly and
mounting platform 40 of the present invention, designed and
constructed to mount state-of-the-art commercially available solar
panels are as follows. The solar panel mounting subassembly 52
(that can also be called "the frame") is approximately 10.times.12
feet when designed to hold eight (8) solar panels of 3 feet by 5
feet. A frame that is designed to hold up to thirty (30) solar
panels is 18.times.25 feet. Thirty state-of-the-art panels may
provide up to 5 KW power.
[0085] In summary, several advantages of the above-described solar
tracking assembly and mounting platform 40 of the present invention
include the advantage of being weight balanced whereby the tilting
of the subassembly 52 and solar panels 78 can be readily
accomplished manually without major hazard to workmen and
substantially decreased chance of property damage due to
precipitous drop of the subassembly 52 and panels 78 around the
horizontal axis. Having the subassembly 52 and the panels 78 weight
balanced renders it easier for the electric motor 122 of the first
preferred embodiment to function and prolongs the useful life of
the equipment. Having the subassembly 52 and the panels 78 weight
balanced also renders manual East-West rotation or adjustment
easier.
[0086] Another important advantage is the ability to mount the
solar tracking assembly and mounting platform 40 on a concrete pad
44 at a substantially lesser cost and effort than the usual
mounting on poles as in the prior art. Still another advantage is
that by utilizing three or four legs the solar panels can be at a
relatively low height above the ground 50 whereby exposure of the
solar panels 78 to wind pressure is substantially decreased. All of
the foregoing contributes to the prolonged useful life and less
requirement for maintenance and repair.
[0087] FIG. 25 is a diagrammatic representation of the height to
which the subassembly 52 with the solar panels 78 is mounted under
actual circumstances. The assembly 52 should be mounted at such
height that even at the maximum desired inclination it still does
not touch the ground 50. Moreover, at locations where there is
substantial snow-cover during winter, the subassembly or frame 52
should not reach the snow (not shown) at its maximum desired
inclination. Thus, it will be readily apparent to those skilled in
the art that the practical minimum height of mounting of the
subassembly 52 depends on the geographic location and climate
conditions where the solar tracking assembly and mounting platform
40 is used and also depends on its actual size. Generally speaking,
if no substantial snow-cover of ground is expected the edge of the
solar panels 78 should be about 2 to 3 feet above the ground at the
maximum desired tilt angle. If substantial snow-cover is expected
the height of the snow-cover should be added to the above noted 2
or 3 feet of desired ground clearance.
[0088] As a practical example the following is noted. At a latitude
of approximately 37 degrees North (where Cedar City, Utah) is
located an exemplary solar tracking assembly and mounting platform
40 that has 24 panels (each panel being 3 feet by 5 feet) the
horizontal axis of the subsassembly 52 is at approximately eight
(8) feet above the ground. At this latitude the practical maximum
inclination for the winter is about 55 degrees relative to the
horizontal. The same height is also appropriate when thirty (30)
such solar panels are included.
[0089] Referring now primarily to FIGS. 26 through 31 the presently
most preferred embodiment of the solar tracking assembly and
mounting platform 40 is disclosed. It is noted at the outset of the
description of this presently most preferred embodiment that in
many aspects of its construction it is identical or substantially
identical with the previously described embodiments, and for this
reason its description will focus on the parts, features and
advantages that are either different or additional to the
previously described embodiments.
[0090] FIG. 26 is a perspective view of the presently most
preferred embodiment. The solar panel mounting subassembly 52 is
constructed in the same or substantially the same manner as for the
previously described two embodiments. This embodiment, however, is
supported by three legs 42, and each of the legs terminates in a
flat plate 46 that is positioned to point inward, toward the center
of the triangle formed by the legs 42, as is shown in the drawing
figure. The legs 42 are attachable to a concrete pad 44 as in the
previously described embodiments. This embodiment includes
cross-members or braces 200 attached to a plate 202 that is itself
attached to the bottom of the vertical axle housing 94. It was
found in experience that the braces 200 substantially stabilize the
entire solar tracking assembly and mounting platform 40, make it
more resistant to wind and lengthen its working life. As in the
previously described embodiments in the axle housing 94 is the axle
92 that rotates the solar panel mounting subassembly 52 in the
East-West direction. The axle 92 has a fixedly attached gear 132
that is in meshing engagement with the output gear 138 of the
electric motor 122. Inasmuch as rotation in the East-West sense is
not required beyond approximately 240 degrees this embodiment
includes a limit switch 204 that is triggered by the limit switch
trigger 206 mounted to the gear 132. In order to further stabilize
the axle 92 and thereby the entire solar tracking assembly and
mounting platform 40 a stainless steel sleeve 208 having a smoothly
machined outer surface is welded to the axle 92. A bushing support
ring 210 is supported by the legs 42 and an oil impregnated nylon
bushing 212 is affixed by a plurality of bolts 214 to the bushing
support ring 210. The bushing 212 is further supported and held in
place by metal retainers 215a that are held with bolts 215b (FIG.
8). The nylon bushing 212 interfaces with the smoothly machined
outer surface of the sleeve 208. This is best shown in FIGS. 27
through 30.
[0091] In order to accomplish the North-South declination or
tilting of the solar panel mounting subassembly 52 an electric
motor or tilt motor 216 is mounted to a plate 218 that is itself
mounted to an arm 220 (shown at an approximately 45 degree angle in
FIG. 27) so that the motor 216 moves in the East-West direction
together with the rotating axle 92. The tilt motor 216 includes an
output gear 222. The solar panel mounting subassembly 52 includes a
gear 224 in meshing engagement with the output gear 222 of the tilt
motor 216. This embodiment also includes a tilt limit switch 226
and a tilt limit switch trigger 228. These parts and features are
best shown in FIGS. 27 and 31.
[0092] In the presently most preferred embodiment also, like in the
previously described embodiments, the horizontally disposed axle
146 (shown only schematically in FIG. 31)on which the solar panel
mounting subassembly 52 tilts in the North-South sense is also
placed in the centroid or substantially in the centroid of the
combined weight solar panel mounting subassembly 52 and solar
panels 78. This accomplishes such balancing of the combined solar
panel mounting subassembly 52 and solar panels 78 that a
precipitous and dangerous drop is avoided, and if necessary the
tilting can be readily accomplished by human force without undue
danger. Perhaps just as importantly such weight balancing makes it
possible to use a tilt motor 216 of much lesser power than what
would be otherwise required if the combined solar panel mounting
subassembly 52 and solar panels 78 were not weight balanced and
such motor will have a long working life. It should also be readily
apparent from the foregoing description that the just described
most preferred embodiment includes all of the advantages of the
present invention, is capable of virtually automatic operation by
following in the East-West direction the daily route of the Sun in
the sky, and also by tilting, as controlled by a computer or
otherwise programmed, the combined solar panel mounting subassembly
52 and solar panels 78 in the North-South sense to adjust for
seasonal changes of the position of the Sun in the sky.
* * * * *