Articulated solar tracker support

Abstract

To provide a system and apparatus for supporting an array of solar panels.SOLUTION: The present disclosure relates to a system and apparatus for supporting an array of solar panels, the system including a bearing assembly configured to support a tracking shaft while allowing the tracking shaft to rotate about an axis, and a torsion bar having a first end configured to be secured to a pile and a second end configured to be coupled to the tracking shaft, the torsion bar configured to function as a torsion spring that applies a torque to the tracking shaft in response to the tracking shaft rotating about the axis.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] Priority claims This application claims priority under 35 U.S.C. §119(e) to U.S. patent application Ser. No. 63 / 661,101, filed Jun. 18, 2024, the entire contents of which are incorporated herein by reference. [Background technology]

[0002] Ground-mounted photovoltaic solar panel arrays are often installed on mounting systems using pile foundations. The solar panels ("panels") in the array can be configured to tilt to track the sun and increase the power generated by the solar panels. This sun tracking can be accomplished using a shaft or a series of connecting shafts that rotate and apply torque to the shaft. Summary of the Invention [Means for solving the problem]

[0003] The present disclosure relates to a system and apparatus for supporting an array of solar panels, the system including a bearing assembly configured to support a tracking shaft while allowing the tracking shaft to rotate about an axis, and a torsion bar having a first end configured to be secured to a pile and a second end configured to be coupled to the tracking shaft, the torsion bar configured to function as a torsion spring applying a torque to the tracking shaft in response to the tracking shaft rotating about the axis.

[0004] Implementations may include one or more of the following features.

[0005] In some examples, the second end of the torsion bar is coupled to the tracking shaft by one or more gears, hi some examples, the one or more gears are configured to mesh with teeth of the tracking shaft.

[0006] In some examples, the torsion bar is a first torsion bar, and the system includes a second torsion bar having a first end fixed to the post and a second end coupled to the tracking shaft. In some examples, the first torsion bar and the second torsion bar are configured to be in a relaxed state when the tracking shaft is in a neutral position, the relaxed state being a state in which the torsion bar applies less than a specified amount of torque to the tracking shaft. In some examples, the neutral position is a position in which a solar panel attached to the tracking shaft is in a horizontal position.

[0007] In some examples, the first torsion bar is configured to be coupled to the tracking shaft by a first missing-tooth gear configured to engage the torsion bar with the tracking shaft when the tracking shaft rotates about its axis in a first direction from the neutral position. The second torsion bar can be configured to be coupled to the tracking shaft by a second missing-tooth gear configured to engage the torsion bar with the tracking shaft when the tracking shaft rotates about its axis in a second direction from the neutral position, the second direction being opposite to the first direction.

[0008] In some instances, the solar panel is mounted on a tracking shaft, and the solar panel and tracking shaft have centers of gravity that are not coincident with the axis.

[0009] In some examples, a helical torsion spring is coupled between the post and the tracking shaft.

[0010] The disclosed system configuration is advantageous because it reduces the size of the tracking motor required to enable tracking of solar panels and reduce the load requirements of structural materials such as torque tubes and piles, for example. Reduced-sized motors and structures generally cost less and consume less energy. Additionally, the solar array can include a rest point or neutral point in a horizontal position, which can be useful in high wind environments or cleanup operations.

[0011] The details of these and other aspects and embodiments of the present disclosure are set forth in the accompanying drawings and the following description. Other features, objects, and advantages of the present disclosure will become apparent from the description and drawings, and from the claims. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 shows an example of a tracking solar array with spring supports. [Figure 2] FIG. 1 is a side view of a solar panel mounted on a tracking shaft that causes an offset in the center of gravity. [Figure 3] FIG. 10 is a side view of a spring support with a torsion bar. [Figure 4] FIG. 1 is a side view of a spring support with a horizontal torsion bar and torsion spring. [Figure 5] FIG. 10 is a side view of a spring support with an internal torsion bar. DETAILED DESCRIPTION OF THE INVENTION

[0013] This disclosure describes an implementation of spring supports for a solar array ("array") that allows the array to rotate to an optimal solar angle while consuming less energy when tilting / rotating the plane of the solar panel array. Many arrays include a torque or tracking shaft that rotates about an axis (or a closely parallel axis) to which the solar panels are attached. As a result, the weight of the panels "hangs" off the side of the shaft, causing the center of gravity to shift off-center. Conventional systems often compensate for this by using oversized or over-geared tracking motors that can lift the panels but also require more energy and are more expensive and heavier than necessary. The disclosed solar array support system includes a spring system that uses torsion bars and / or helical springs to help offset the weight of the panels on the torque shaft. The use of spring supports can reduce the size, complexity, weight, and cost of the array's tracking motors and structural components.

[0014] 1, an example of a spring-supported tracker solar array 100 is shown. In the illustrated example, a single tracker motor assembly 110 provides torque to a tracker shaft 104, which is supported by a series of support pegs 102 with spring supports 106. Solar panels 108 are mounted on the tracker shaft 104.

[0015] Each solar panel 108 may be formed from multiple solar modules, which themselves are composed of multiple solar cells. The cells use photovoltaic technology to convert solar radiation into electrical charge, which is used to generate current and / or voltage. To maximize generated power using only one axis of free motion, the solar panels 108 should be oriented at an angle that coincides with the azimuth angle of the sun at each instant, thereby maximizing captured solar irradiation. This is achieved by mounting the solar panels 108 on a rotating tracking shaft 104. The tracking shaft 104 may be formed from multiple segments and acts as a torque tube to hold and rotate the solar panels 108 for improved alignment with the sun throughout the day.

[0016] The tracking shaft is supported by one or more bearings on support pegs 102, spring supports 106 that help counteract the torque on the tracking shaft generated by the weight of the solar panels 108. Tracking motors 110 provide torque to rotate the array 100 as needed to maximize power output or for other purposes such as alignment for cleaning or positioning to minimize weather effects (e.g., hail damage, wind, etc.).

[0017] While the illustrated example includes a spring support 106 for each support peg 102 shown, other configurations are possible. For example, some supports may include only bearings, and there may be only a few spring supports 106 throughout the array. In another example, the support pegs 102 that hold the tracking motors 110 may be spring-loaded, while the remaining supports are springless.

[0018] 2 shows a side view of solar panels 208 mounted on a tracking shaft 204, which causes a center of gravity offset. The tracking shaft 204 rotates about its centerline along a rotation axis 214. However, the panels 208 are mounted on the side or end of the tracking shaft 204. Additionally, in many implementations, the panels 208, or groups of panels 208, are significantly heavier than the tracking shaft 204. This results in an off-axis center of gravity 216 that creates a moment 212 about the rotation axis 214 in the tracking shaft 204.

[0019] This moment 212 is caused by an off-axis center of gravity 216 that is a result of the combination of the panel 208 and the tracking shaft 204. Its effect is to "pull" the panel 208 downward toward a vertical position in its direction of rotation. For example, in the implementation shown, the panel 208 and tracking shaft 204 are rotated approximately 45 degrees to the right (clockwise). In an implementation in which the panel 208 and tracking shaft 204 are rotated to the left (counterclockwise), the moment 212 is reversed. This creates an unstable system in which, without external stabilization, the panel 208 tends to "tip" toward a vertical position.

[0020] To counteract this moment 212, conventional systems may use oversized tracking motors or ratchet or gear mechanisms to limit movement and counteract the moment 212. This disclosure focuses on the use of a spring mechanism to store energy as the panel 208 descends and return it to the system as it ascends. This reduces the overall torque that needs to be supplied by the tracking motors and can result in an inherently stable system in the upright / horizontal position of the solar panel 208.

[0021] FIG. 3 shows a side view of the torsion bar spring support. The tracking shaft 304 is mounted within a bearing assembly 322 and can rotate about its axis. A pair of torsion bars 320A and 320B are fixed at one end to the peg 302 and coupled to the tracking shaft 304 by a pair of coupling gears 336. In the illustrated example, the coupling gears 336 are bevel gears, but any suitable gear mechanism is contemplated. Additionally, gears are not required. In some implementations, the torsion bars 320A and 320B can be coupled to the tracking shaft 304 using pivot links or fixed lever arms, among others.

[0022] As tracking shaft 304 rotates, torsion bars 320A and 320B twist, creating shear stress within the torsion bars and causing the bars to exert opposing forces. Torsion bars can be an inexpensive and reliable way to achieve a weather-resistant, heavy-duty spring.

[0023] Torsion bars 320A and 320B interface with tracking shaft 304 by integral missing-tooth gears 324A and 324B, respectively. While missing-tooth gear 324 is shown as integral with tracking shaft 304, it can be a component of bearing assembly 322 or can be separately secured to the tracking shaft, for example, using a key / keyway mounting system. Missing-tooth gears 324A and 324B can engage a single torsion bar for tracking in one direction (e.g., east) and another torsion bar for tracking in the other direction (e.g., west).

[0024] For example, when tracking shaft 304 is in the neutral or 12 o'clock position and the solar panel is in a horizontal configuration, both torsion bars 320A and 320B are relaxed or relatively untwisted, requiring little or no torque to be applied to tracking shaft 304. For example, torsion bars 320A and 320B may apply a torque of less than 50 N-m. When tracking shaft 304 is rotated in a first direction, easterly, torsion bar 320A may twist when engaged with missing-tooth gear 324A via coupling gear 326. As tracking shaft 304 rotates in the first direction, missing-tooth gear 324B disengages, preventing twisting and allowing torsion bar 320B to relax. The opposite occurs when tracking shaft 304 is rotated in a second direction, easterly. Missing-tooth gear 324B engages, causing torsion bar 320B to twist, while torsion bar 320A relaxes as missing-tooth gear 324A disengages. The use of separate torsion bars 320A and 320B and missing-tooth gears 324A and 324B means that each torsion bar only needs to be able to twist through half of the total range of motion of tracking shaft 304. This allows for the use of shorter torsion bars.

[0025] In some implementations, missing-tooth gear 324 is not used; instead, torsion bars 320A and 320B remain engaged throughout their entire range of motion. In these implementations, torsion bar 320 must twist in two directions, with the alignment or no-twist point being in the horizontal position.

[0026] 4 shows a side view of a spring support with a horizontal torsion bar and torsion spring. Tracking shaft 204 is supported by tracking motor assembly 430, which may include bearings similar to bearing assembly 322, in addition to motor components that apply torque to rotate tracking shaft 204. Torsion bars 420A and 420B are fixed at one end to peg 402 or tracking motor assembly 430 and engage gears 434A and 434B, respectively. In addition, a helical torsion spring 432 is included in each torsion bar 420A and 420B to provide additional spring moment to counteract the weight of the panels on tracking shaft 204.

[0027] The tracking motor assembly 430 can be an electric motor capable of providing reliable positioning of the tracking shaft 204. For example, the tracking motor 430 can be a brushless DC motor, a stepper motor, a servo motor, a brushed motor with encoder or potentiometer position measurement, or other suitable motor. In some implementations, the tracking motor assembly 430 includes bearings, supports, and other necessary mechanical components, as well as circuitry and electronics for operation of the tracking motor assembly 430.

[0028] A helical torsion spring 432 may be implemented to provide supplemental torque. Although shown surrounding torsion bars 420A and 420B, helical torsion spring 432 can be separate from torsion bar 420A. For example, helical torsion spring 432 may be implemented within tracking shaft 204, tracking motor assembly 430, or elsewhere. In some implementations, helical torsion spring 432 may be used in place of or independent of the torsion bars.

[0029] Other springs are also possible, such as spiral or "clock" springs, sets of coil springs, or other devices that can be used independently or to augment the torque provided by torsion bars 420A and 420B and / or helical torsion spring 432.

[0030] The torsion bars 420A and 420B are shown in a horizontal configuration. This positioning allows the torsion bars 420A and 420B to be geared more directly to the tracking shaft 204 without the need for an intermediate coupling gear as described above in FIG. 3 . Horizontal torsion bars can be longer than vertical torsion bars, which can be advantageous in that they allow for greater deflection or “twist” and therefore greater spring displacement. In some implementations, the torsion bars 420A and 420B can be installed at a 45-degree angle relative to the tracking shaft 204, for example, or at other desired angles. The fixed ends of the torsion bars 420A and 420B can be secured to the tracking motor assembly 430 (or bearing assembly 322), the piling 402, or another structure, such as an anchor or foundation embedded in the ground.

[0031] Gears 434A and 434B may or may not have missing teeth. If they do, they can operate similarly to gears 324A and 324B in FIG. 3. As shown, gears 434A and 434B do not have missing teeth, and torsion bars 420A and 420B twist each time tracking shaft 204 rotates from a neutral position. This configuration can be advantageous in that both torsion bars 420A and 420B operate in unison, so each individual bar must apply less torque to tracking shaft 204 to compensate for the weight of the solar panel.

[0032] 5 shows a side view of a spring support with internal torsion bars. Torsion bars 520A and 520B are located inside the tracking shaft 204 and may be fixed or geared at their outer ends and fixed to stationary components of the tracking motor assembly 420 at their inner ends.

[0033] The internal torsion bars 520A and 520B can be advantageous in that they do not take up additional volume or space outside of the standard footprint of a tracking solar system, and can be protected from environmental / weather conditions, resulting in reduced need for corrosion and wear mitigation.

[0034] While the present disclosure has been described in terms of particular embodiments and generally associated methods, modifications and variations of these embodiments and methods will be apparent to those skilled in the art. Accordingly, the above description of exemplary embodiments does not define or constrain the present disclosure. Other changes, substitutions, and alterations are also possible without departing from the spirit and scope of the present disclosure.

[0035] The above description is provided in the context of one or more specific implementations. Various modifications, alterations, and variations of the disclosed implementations can be made without departing from the scope of the present disclosure. Thus, the present disclosure is not intended to be limited to only the implementations described or illustrated, but is to be accorded the widest scope consistent with the principles and features disclosed herein. [Explanation of symbols]

[0036] 100 Array 102 Support pile 104 Tracking Shaft 106 Spring support 108 solar panels 110 Tracking motor assembly 204 Tracking Shaft 208 solar panels 212 Moments 214 Rotational Axis 216 Off-axis center of gravity 302 Pile 304 Tracking Shaft 320A Torsion Bar 320B torsion bar 322 Bearing Assembly 324A Missing Tooth Gear 324B Missing Tooth Gear 326 Coupling Gear 336 Coupling Gear 402 Pile 420A Torsion Bar 420B torsion bar 430 Tracking motor assembly 432 Spiral Torsion Spring 434A Gear 434B Gear 520A Torsion Bar 520B torsion bar

Claims

1. a bearing assembly configured to support the tracking shaft while allowing the tracking shaft to rotate about an axis; a torsion bar having a first end configured to be secured to a peg and a second end configured to be coupled to the tracking shaft, the torsion bar configured to function as a torsion spring that applies a torque to the tracking shaft in response to the tracking shaft rotating about the axis; A solar cell array system comprising:

2. 10. The solar array system of claim 1, wherein the second end of the torsion bar is configured to be coupled to the tracking shaft by one or more gears.

3. 3. The solar array system of claim 2, wherein the one or more gears are configured to mesh with teeth of the tracking shaft.

4. 10. The solar array system of claim 1, wherein the torsion bar is a first torsion bar, and the solar array system further comprises a second torsion bar having a first end configured to be secured to the pile and a second end configured to be coupled to the tracking shaft.

5. 5. The solar cell array system of claim 4, wherein the first torsion bar and the second torsion bar are configured to be in a relaxed state when the tracking shaft is in a neutral position, the relaxed state being a state in which the torsion bar applies a torque to the tracking shaft that is less than a specified amount.

6. 6. The solar cell array system according to claim 5, wherein the neutral position is a position where the solar cell panels attached to the tracking shaft are in a horizontal position.

7. the first torsion bar is configured to be coupled to the tracking shaft by a first missing-tooth gear, the first missing-tooth gear configured to engage the torsion bar with the tracking shaft when the tracking shaft rotates about the axis in a first direction from the neutral position; the second torsion bar is configured to be coupled to the tracking shaft by a second missing-tooth gear, the second missing-tooth gear configured to engage the torsion bar with the tracking shaft when the tracking shaft rotates about the axis from the neutral position in a second direction, the second direction being opposite to the first direction; The solar cell array system according to claim 5.

8. 10. The solar array system of claim 1, comprising a solar panel mounted on the tracking shaft, the solar panel and the tracking shaft having a center of gravity that is not coincident with the axis.

9. 10. The solar array system of claim 1, comprising a helical torsion spring coupled between the pile and the tracking shaft.

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