U.S. patent application number 13/804797 was filed with the patent office on 2014-02-27 for ganged single axis solar tracker and its drive system.
This patent application is currently assigned to Suzhou Jinshan Solar Science and Technologies Co., Ltd.. The applicant listed for this patent is Suzhou Jinshan Solar Science and Technologies Co., Ltd.. Invention is credited to Yin Zhou.
Application Number | 20140053825 13/804797 |
Document ID | / |
Family ID | 50146901 |
Filed Date | 2014-02-27 |
United States Patent
Application |
20140053825 |
Kind Code |
A1 |
Zhou; Yin |
February 27, 2014 |
GANGED SINGLE AXIS SOLAR TRACKER AND ITS DRIVE SYSTEM
Abstract
The present invention involves a ganged single axis solar
tracker and its drive system having at least two rows of solar
trackers and a drive mechanism. Each tracker row shares one common
rotation axis and the at least two tracker rows are placed in
parallel. At least one torque arm is rigidly and perpendicularly
connected to the each tracker rotation axis. The drive mechanism
has at least one rotary actuator, such as a slew drive, whose
rotation axis is parallel to the tracker rotation axes. At least
one drive torque arm is rigidly and perpendicularly connected to
the drive rotation axis. The drive torque arm and the tracker
torque arms are hinge connected with a series of rigid beams. The
linkage beams are perpendicular to the tracker and drive rotation
axes. The rotary drive rotates and creates a rotation movement. The
drive torque arm follows the rotation movement of the drive, which
consequently converts a linear push-pull movement in the linkage
beams. The linkage beams push and pull the tracker torque arms,
rocking the at least two rows of solar trackers to rotate about
their axes and to follow the sun's movement.
Inventors: |
Zhou; Yin; (Changsu,
CN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Co., Ltd.; Suzhou Jinshan Solar Science and Technologies |
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US |
|
|
Assignee: |
Suzhou Jinshan Solar Science and
Technologies Co., Ltd.
Changshu City
CN
|
Family ID: |
50146901 |
Appl. No.: |
13/804797 |
Filed: |
March 14, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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PCT/CN2012/080586 |
Aug 25, 2012 |
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13804797 |
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61699371 |
Sep 11, 2012 |
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Current U.S.
Class: |
126/606 |
Current CPC
Class: |
F24S 30/42 20180501;
F24S 2030/131 20180501; F24S 30/425 20180501; F24S 50/20 20180501;
F24S 2030/134 20180501; Y02E 10/47 20130101; F24S 2030/136
20180501; F24S 20/20 20180501 |
Class at
Publication: |
126/606 |
International
Class: |
F24J 2/54 20060101
F24J002/54 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 25, 2012 |
CN |
2012 1030 6130.9 |
Claims
1. A ganged single axis solar tracker system comprising at least
two rows of solar trackers and a drive mechanism, said solar
trackers have rotation axes and solar receivers; said solar
receivers being mounted onto the tracker rotation axes, said solar
trackers in one row being rotationally mounted on at least one
foundation and share one common rotation axis, at least two tracker
rows being placed in parallel with at least one torque arm being
rigidly and perpendicularly connected to the each tracker rotation
axis, a rotation center of the torque arm being coincident with the
tracker rotation axis onto which the torque arm is affixed; said
drive mechanism having at least one rotary actuator whose rotation
axis is parallel to the tracker rotation axes, wherein said at
least one drive torque arm is rigidly and perpendicularly connected
to the drive rotation axis, the rotation center of the torque arm
being coincident with the drive rotation axis, wherein the drive
torque arm and the tracker torque arms are hinge connected with a
series of rigid beams having linkage beams that are perpendicular
to the tracker and drive rotation axes.
2. A ganged single axis solar tracker system according to claim 1
wherein said rotary actuator is a slew drive, a worm gear, a
planetary gear, or a slew ring.
3. A ganged single axis solar tracker system according to claim 1
wherein said rotation axis of the rotary actuator is coincident
with the rotation axis of one tracker row within the tracker
array.
4. A ganged single axis solar tracker system according to claim 1
wherein said rotation axis of the rotary actuator is parallel to
and away from the rotation axis of any tracker row of the tracker
array.
5. A ganged single axis solar tracker system according to claim 4
wherein said rotation axis of the rotary actuator is located within
or outside of the tracker array.
6. A ganged single axis solar tracker system according to claim 1
wherein said rotation axes of the rotary actuator and trackers are
flat, tilted to the ground, or vertical.
7. A ganged single axis solar tracker system according to claim 1
wherein said tracker rotation beam is of round or square cross
section, or truss.
8. A ganged single axis solar tracker drive mechanism for linking
and driving at least two rows of solar trackers, wherein the solar
trackers have rotation axes and solar receivers that are mounted
onto the tracker rotation axes, and wherein solar trackers in one
row are rotatorily mounted onto at least one foundation and share
one common rotation axis with at least two tracker rows being
placed in parallel, the single axis solar tracker drive mechanism
comprising: a plurality of torque arms which are perpendicularly
and rigidly connected to each of the tracker rotation axes, a
rotation center of each torque arm being coincident with the
tracker rotation axis onto which each torque arm is affixed, said
single axis solar tracker drive mechanism further comprising of at
least one rotary actuator drive having one rotation axis which is
parallel to the tracker rotation axes, and at least one drive
torque arm which is rigidly and perpendicularly connected to the
drive rotation axis, wherein a rotation center of the drive torque
arm is coincident with the drive rotation axis, the at least one
drive torque arm and the tracker torque arms being hinge connected
with a series of rigid linkage beams, the linkage beams being
perpendicular to the tracker and arranged to drive rotation axes.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to solar energy production and more
particularly to an apparatus for driving a number of rows of solar
receivers to follow the motion of the sun relative to the
earth.
[0003] 2. Description of the Related Art
[0004] Solar energy has gradually become an important alternative
power resource to help achieve the goal of sustainable development.
Solar power has a few unique advantages such as it is clean,
abundant, and it produces when the consumption is high. The biggest
challenge the solar energy is currently facing is its relatively
high cost. Solar tracking systems can improve incident angles of
solar receivers such as solar thermal or photovoltaic modules (PV).
These tracking devices have been successfully used to improve power
production efficiency, and thus to reduce solar power generation
costs.
[0005] The prior art single axis trackers typically have one
motor/drive per tracker row, thus limiting the total area of solar
receivers driven by each motor/drive. Solar tracker array using
this technology will have high costs due to generally increased
material usage, field construction work, as well as maintenance
requirements. In order to reduce costs associated with tracking,
U.S. Pat. No. 6,058,930, to Shingleton, described a ganged single
axis solar tracker system. In this system, multiple solar trackers
are linked together with a linear motion linkage and operated by a
single linear actuator, such as a hydraulic or screw jack, attached
to a separate foundation located away from the solar tracker array.
The advantage of such a system is clear since the costs of motor
and drive system have been shared by multiple tracker rows, thus
the tracking costs per PV module have been substantially reduced.
The system has also limitations. Firstly, the first linkage member
close to the drive has to withstand wind loads on the entire
tracker array, thus it becomes less economy when the tracker array
increases in size. Secondly, the linear actuator produces large up
and down forces onto the foundations and tracker beams near the
drive, increasing costs for these affected members. Thirdly, the
drive has to be located away from the tracker array, thus requiring
extra land.
SUMMARY OF THE INVENTION
[0006] In accordance with an aspect of the present invention, a
ganged single axis solar tracker array has at least two rows of
solar trackers and a drive mechanism. The said solar trackers have
rotation axes; solar receivers are mounted onto the tracker
rotation axes. Solar trackers in one row are rotatorily mounted
onto at least one foundation and share one common rotation axis.
The at least two tracker rows are placed in parallel. At least one
torque arm is rigidly and perpendicularly connected to the each
tracker rotation axis. The rotation center of the torque arm is
coincident with the tracker rotation axis onto which the torque arm
is affixed. The driver mechanism has at least one rotary actuator,
such as a slew drive, whose rotation axis is parallel to the
tracker rotation axes. At least one drive torque arm is rigidly and
perpendicularly connected to the drive rotation axis. The rotation
center of the drive torque arm is coincident with the drive
rotation axis. The drive torque arm and the tracker torque arms are
hinge linked with a series of rigid beams. The linkage beams are
perpendicular to the tracker and drive rotation axes. The rotary
drive rotates to create a rotation movement. The drive torque arm
follows the rotation movement of the drive, which consequently
converts a linear push-pull movement in the linkage beams. The
linkage beams push and pull the tracker torque arms, rocking the
tracker rows to rotate about their axes and to follow the sun's
movement.
[0007] The rotation centers of the two torque arms on any two
adjacent tracker rows, and the two connecting joints between the
two torque arms and the linkage beam, form the four corner points
of a quadrilateral. Similarly, the rotation center of the drive
torque arm, the rotation center of an adjacent torque arm, and the
two connecting joints between the two torque arms and the linkage
beam, form the four corner points of a quadrilateral.
[0008] In one embodiment, a ganged single axis solar tracker system
has at least two rows of solar trackers and a drive mechanism. The
solar trackers have rotation axes; solar receivers are mounted onto
the tracker rotation axes. Solar trackers in one row are
rotationally mounted on at least one foundation and share one
common rotation axis. At least two tracker rows are placed in
parallel. At least one torque arm is rigidly and perpendicularly
connected to the each tracker rotation axis. The rotation center of
the torque arm is coincident with the tracker rotation axis onto
which the torque arm is affixed.
[0009] In one embodiment, the drive mechanism has at least one
rotary actuator whose rotation axis is parallel to the tracker
rotation axes. The rotary actuator may be a slew drive, a worm
gear, a planetary gear, or a slew ring. At least one drive torque
arm is rigidly and perpendicularly connected to the drive rotation
axis. The rotation center of the drive torque arm is coincident
with the drive rotation axis. The drive torque arm and the tracker
torque arms are hinge connected with a series of rigid beams. The
linkage beams are perpendicular to the tracker and drive rotation
axes.
[0010] In one embodiment, the rotation axis of the rotary actuator
may be coincident with the rotation axis of one tracker row within
the tracker array, and may also be parallel to and away from the
rotation axis of any tracker row of the tracker array. The rotation
axis of the rotary actuator may further be located within or
outside of the tracker array, and may be flat, tilted to the
ground, or vertical.
[0011] In one embodiment, the tracker rotation beam may be of round
or square cross section, or truss. The ganged single axis solar
tracker drive mechanism links and drives at least two rows of solar
trackers. The solar trackers have rotation axes; solar receivers
are mounted onto the tracker rotation axes. Solar trackers in one
row are rotatorily mounted onto at least one foundation and share
one common rotation axis. At least two tracker rows are placed in
parallel. The single axis solar tracker drive mechanism comprises
of multiple torque arms which are perpendicularly and rigidly
connected to the said each tracker rotation axis. The rotation
center of each torque arm is the tracker rotation axis onto which
the said each torque arm is affixed.
[0012] One embodiment of the single axis solar tracker drive
mechanism further comprises of at least one rotary actuator or
drive. The rotary drive has one rotation axis which is parallel to
the said tracker rotation axes. At least one drive torque arm is
rigidly and perpendicularly connected to the said drive rotation
axis. The rotation center of the drive torque arm is coincident
with the drive rotation axis. The said at least one drive torque
arm and the tracker torque arms are hinge connected with a series
of rigid beams. The linkage beams are perpendicular to the tracker
and drive rotation axes.
[0013] In an exemplary embodiment, the rotary drive shares the
rotation axis of a tracker row, which can be a center row, a side
row, or any other row within the tracker array.
[0014] In another embodiment, the rotary drive has its rotation
axis apart from any tracker rows. The drive axis can be located
near the center of, in between any two adjacent tracker rows
within, or on one side and away from, the tracker array.
[0015] The rotary drive includes but is not limited to slew drive,
worm gear, planetary gear, or slew ring. The tracker and drive
rotation axes are horizontal, tilted, or vertical to the earth. The
tracker rotation beams vary by shapes, including but are not
limited to round, square, and so forth. Apparently to those skilled
in the art, the rotation beams may be composed of truss, tubular or
any composite of these members. The solar receivers include but are
not limited to flat panels, flat or parabolic reflectors/mirrors
for the use of solar photovoltaic, thermal or concentrator.
[0016] In another aspect of the present invention, a drive
mechanism is employed to drive at least two rows of solar trackers.
Trackers have rotation beams onto which solar panels are affixed.
Trackers in one row share one common rotation axis which are
rotationally mounted on at least one foundation and the at least
two tracker rows are placed in parallel. The drive mechanism
comprises of: at least one torque arm which is rigidly and
perpendicularly connected to the each tracker rotation axis, and
the rotation center of the torque arm is coincident with the
tracker rotation axis onto which the torque arm is affixed; at
least one rotary actuator, such as a slew drive, whose rotation
axis is parallel to the tracker rotation axes; at least one drive
torque arm which is rigidly and perpendicularly connected to the
drive rotation axis, and the rotation center of the drive torque
arm is coincident with the drive rotation axis. The at least one
drive torque arm and the tracker torque arms are hinge connected
with a series of rigid beams. The said linkage beams are
perpendicular to the tracker and drive rotation axes.
[0017] The ganged single axis tracker and its drive mechanism has
the following advantages: firstly, solar trackers can be
conveniently placed in a mirror layout about the rotary drive axis,
and the maximum force endured by the linkage member equals only to
the forces from half of the entire solar array. In another words,
the linkage member with the same size in the present invention can
drive twice as many solar panels as per the prior art. Secondly,
the drive system in embodiments of the present invention
distributes wind forces in more appropriate manners since it
produces no additional uplift and down forces on nearby foundations
and beams, nor large compression force in the drive unit which
could lead to buckling failure in the screw jack as in the prior
art. Thirdly, the drive can share the tracker axis or be located
within the tracker array such that no additional land is
required.
[0018] The above and many other objects, features, and advantages
of this invention will be set forth in part in the detailed
description to follow, taken in conjunction with the accompanying
drawings, and in part will become apparent to those skilled in the
art upon examination of the following, or may be learned by
practice of the claimed invention. The objects and advantages of
the claimed invention may be realized and attained by means of the
instrumentalities and combinations particularly pointed out in the
appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The above mentioned and other features and objects of this
invention, and the manner of attaining them, will become more
apparent and the invention itself will be better understood by
reference to the following description of an embodiment of the
invention taken in conjunction with the accompanying drawings,
wherein:
[0020] FIG. 1 illustrates a plan view of the prior art which
employs a linear actuator to drive multiple single axis tracker
rows.
[0021] FIG. 2 illustrates an east-west side view of the prior art
which employs a linear actuator to drive multiple single axis
tracker rows (or Section 2-2 in FIG. 1).
[0022] FIG. 3 illustrates a plan view of an embodiment of the
current invention, in which the drive axis coincident with one
tracker axis near the center of the tracker array.
[0023] FIG. 4 illustrates an east-west side view of an embodiment
of the current invention, in which the drive axis coincident with
one tracker axis near the center of the tracker array (or Section
4-4 in FIG. 3).
[0024] FIG. 5 illustrates a north-south side view of an embodiment
of the current invention, in which the drive axis coincident with
one tracker axis near the center of the tracker array (or Section
5-5 in FIG. 3).
[0025] FIG. 6 illustrates a plan view of the second embodiment of
the current invention, in which the drive axis coincident with one
tracker axis located at the end of the tracker array.
[0026] FIG. 7 illustrates a plan view of the third embodiment of
the current invention, in which the drive axis is in-between and
away from two adjacent tracker rotation axes within the tracker
array.
[0027] FIG. 8 illustrates a plan view of the fourth embodiment of
the current invention, in which the drive axis is on one side of
and away from the tracker array.
[0028] Corresponding reference characters indicate corresponding
parts throughout the several views. Although the drawings represent
embodiments of the present invention, the drawings are not
necessarily to scale and certain features may be exaggerated in
order to better illustrate and explain the present invention. The
exemplification set out herein illustrates an embodiment of the
invention, in one form, and such exemplifications are not to be
construed as limiting the scope of the invention in any manner.
DESCRIPTION OF EMBODIMENTS OF THE PRESENT INVENTION
[0029] The embodiments disclosed below are not intended to be
exhaustive or limit the invention to the precise form disclosed in
the following detailed description. While the invention is subject
to various modifications and alternative forms, specific
embodiments thereof have been shown by way of example in the
drawings and will herein be described in detail. The invention
should be understood to not be limited to the particular forms
disclosed, but on the contrary, the intention is to cover all
modifications, equivalents, and alternatives falling within the
spirit and scope of the invention. Rather, the embodiment is chosen
and described so that others skilled in the art may utilize its
teachings.
[0030] With reference to the Drawings, and initially to FIGS. 1 and
2, a ganged single axis solar tracker array according to the prior
art is shown. Multiple torque tubes in a row share a north-south
axis 12, and a number of solar receivers 10 are attached onto the
tubes. At least two rows of trackers are placed in parallel and
apart from each other to form a tracker array from east to west.
Each tracker row 12 is rotationally mounted on at least one
foundation 18, which is supported on the ground 16. A torque arm 17
is rigidly and perpendicularly connected to each of the tracker
rotation axis 12. The drive system according to the prior art
comprises of a linear actuator 13 such as a hydraulic or screw jack
which is supported on a foundation 11 above the ground 16, and a
series of rigid linkage beams 14 and 15 which connect the torque
arms 17. A linear movement such as retraction or extension in the
linear actuator 13 produces a push or pull movement in the linkage
beams 14 and 15; the linkage beams push or pull the torque arms 17,
which in turn create a rotation movement of each solar tracker row
about their axis 12. The solar tracker and its drive system
according to the prior art has the following characteristics: (1)
the drive is a linear actuator; (2) the linear actuator is located
on one side of and away from the solar tracker array (in this
example, it is shown on the west; it can be on the east side as
well); the linear actuator and its foundation use additional land
on top of the land occupied by the solar array; (3) the first
linkage beam 14 has to take the wind forces transferred from all
solar receivers except the first row from the drive. When the
number of rows of the tracker array increases, the load that the
first linkage beam 14 has to bear is high; (4) the linear actuator
13 and linkage beams 14 and 15 are subject to compression forces,
which could lead to buckling damages within these parts; thus the
size of the tracker array is substantially limited; and (5) the
rotation center of the linear actuator, the rotation center of the
first torque arm 17, and the connection point of the first linkage
beam 14 and the first torque arm 17, form the three corner points
of a triangle.
[0031] An embodiment of this invention is shown in FIGS. 3 to 5,
which show a solar tracker array and its drive system, in its plan
view (FIG. 3), east-west view (FIG. 4) and north-south view (FIG.
5), respectively. The solar tracker array comprises of multiple
rows of solar trackers placed in parallel and aligned in
north-south orientation, and its drive mechanism which rocks the
solar trackers to follow the sun's east-west movement. Trackers in
one row share the same rotation axis 112 onto which solar receivers
110 are mounted. Each tracker row is rotationally mounted on at
least one foundation 118, which is supported on the ground 116. In
each tracker row, a torque arm 117 is rigidly and perpendicularly
connected to its rotation axis 112. The rotation center of the
torque arm 117 is coincident with the tracker rotation axis 112
onto which the torque arm is affixed. The drive system of the
tracker array comprises of a rotary actuator or drive such as a
slew drive 111. The drive is mounted on a drive foundation 119
which is affixed to the ground 116. In general, a motor (as well as
a controller) 120 is mechanically connected with the drive. The
rotary drive has a rotation axis or drive axis and a drive torque
arm 113 is rigidly and perpendicularly connected to the drive axis.
The rotation center of the drive torque arm 113 is coincident with
the drive rotation axis. The rotary drive is placed near the center
of the solar tracker array, and it rotation axis is coincident with
one tracker rotation axis. The drive torque arm is hinge connected
with other torque arms 117 thru a series of rigid beams 114 and
115. The rigid linkage beams 114 and 115 are perpendicular to the
tracker axes. The two connection points between any two adjacent
torque arms 113 or 117 and the linkage beam 114 or 115, and the
rotation centers of the two torque arms 113 or 117, form the four
corner points of a quadrilateral. A rotary movement within the
drive 111 rocks the center tracker row and the drive torque arm 113
rotates about the rotation axis 112. The rotary movement of the
drive torque arm converts to a linear push-pull movement within the
linkage beams 114 and 115. The linkage beams push or pull the
torque arms 117 to rock the each tracker row to rotate about the
each tracker rotation axis 112. Generally, the rigid linkage
members are articulated to one another and to the torque arms of
the respective rows of solar trackers, thus allowing the solar
trackers to be employed on uneven terrain.
[0032] The solar tracker array and its drive system according to
this invention as shown in FIGS. 3 to 5 has the following
characteristics: (1) the drive is rotary actuator, such as a slew
drive; (2) the drive axis shares one tracker rotation axis near the
center of the tracker array; no additional land is needed for the
drive and its foundation; (3) the largest force the first linkage
beam 114 has to take is equal to the forces on the east or west
half of the tracker array instead of that from the entire tracker
array; (4) the drive and the drive torque arm do not bear large
compression forces; and (5) The rotation center of the drive or the
drive torque arm, the two connection points of the first linkage
member 114 between the drive torque arm and the first tracker
torque arm, and the rotation center of the first tracker torque
arm, form the four corner points of a quadrilateral.
[0033] In the first example, the rotary is a slew drive. In this
and other applications, the rotary actuator or drive can also be
slewing ring, planetary or worm gear. The optimal drive can be
determined based on economy and site conditions. The use of various
rotary drive types should be covered by the present invention.
[0034] In the first embodiment, the drive axis shares the rotation
axis of the center tracker. Apparently, the drive axis can
conveniently be coincident with any other tracker rotation axis
within the tracker array. In accordance with such an aspect of the
present invention, the second embodiment of this invention is shown
in FIG. 6. The difference between the second and first embodiment
lies in that the drive axis in the second embodiment shares the end
tracker rotation axis.
[0035] The third embodiment of this invention is shown in FIG. 7.
In this example, the drive axis is located near the center of the
tracker array while it is apart from any tracker rotation axis.
[0036] In the fourth embodiment of this invention as shown in FIG.
8, the drive axis is located on one side of and apart from the
tracker array.
[0037] In any particular applications of the present invention,
solar receivers can all have the same or various initial tracker
angles; the tracker rotation beam can be of round or square cross
section, a truss or any other composite structure.
[0038] In all embodiments as shown the tracker axes are flat. It is
not difficult to persons skilled in the art that the tracker axes
can be aligned tilted to the ground or vertical.
[0039] The term "ground" as used in reference to the foundation is
not limited to earth or soils, but can be a rooftop or any other
supporting structures.
[0040] While this invention has been described as having an
exemplary design, the present invention may be further modified
within the spirit and scope of this disclosure. This application is
therefore intended to cover any variations, uses, or adaptations of
the invention using its general principles. Further, this
application is intended to cover such departures from the present
disclosure as come within known or customary practice in the art to
which this invention pertains.
* * * * *