Articulating solar tracker support

Abstract

This disclosure describes an articulated support for a solar array that enables installation of the array upon uneven terrain while still enabling solar tracking using a rotating shaft. By using articulating supports as discussed herein, a single motor or actuator can rotate a tracking shaft, and thereby rotate each panel attached to the shaft, even when the solar array does not form a straight line. For example, if support piles for the array initially start on flat terrain, then climb an incline, a single rotating shaft would need to "bend" in order to follow the curvature of the terrain, yet still be able to transmit torque. Because of the forces generated by such a "bend" when using conventional supports in an uneven environment, the torque required to rotate a single shaft will be higher than that required to rotate a series of shafts using the articulated supports discussed herein.

Description

ARTICULATING SOLAR TRACKER SUPPORTBACKGROUND

[0001] Solar arrays are often installed on piles in uneven terrain. The solar panels (“panels”) in the arrays can be configured to tilt in order to track the sun and increase power the solar power generated by the panels. This solar tracking can be implemented using a shaft or series of coupled shafts that rotate and apply torque to the shaft.SUMMARY

[0002] The present disclosure involves systems, and an apparatus supporting an array of solar panels, the system including a base block that is configured to mount to a top of a pile. A rotatable shaft is coupled to the base block that includes at least one universal joint (U-joint), and is configured to couple to a solar panel. Rotating the rotatable shaft causes a coupled solar panel to rotate. At least one pillow block couples the rotatable shaft to the base block, the at least one pillow block configured to pivot about a first axis and a second axis, the second axis orthogonal to the first axis.

[0003] Implementations can optionally include one or more of the following features.

[0004] In some instances, the base block can pivot about the first axis, and the second axis is defined relative to the base block.

[0005] In some instances, the base block can mount to the top of the pile by a coupling that includes a linear actuator to raise or lower the base block relative to the pile.

[0006] In some instances, the system includes a solar panel and a support shaft configured to mate with the end of the rotatable shaft. The solar panel can be coupled to the rotatable shaft by the support shaft. In some instances, the support shaft mates with a spline connector on the end of the rotatable shaft.

[0007] In some instances, the pillow block includes a ratcheting mechanism that prevents the rotatable shaft from rotating in a first direction while permitting rotation in a second direction.

[0008] In some instances, the rotatable shaft includes an input shaft, a first U-joint, an intermediate shaft, a second U-joint, and an output shaft. The intermediate shaft can be supported by a primary pillow block.

[0009] The configuration of the disclosed system is advantageous, for example, because it reduces the precision required when driving piles that support a solar array. By using a combination of universal joints (U-joints) and adjustable blocks, multiple shafts at varying alignments can be coupled and can efficiently transmit torque. That is, piles need not be aligned in order for an array to be solar tracking using a series of coupled rotational shafts. Further the devices and / or systems discussed herein reduce the power needed to provide rotation, for example, by reducing binding or bending forces normally present in when rotating a misaligned shaft. For instance, the tracker supports discussed herein enables a series of rotating shafts to be connected in geometries other than a straight line. This is an improvement over conventional arrays using a single rotating shaft because the configuration of conventional rotating shafts require a largely straight line / alignment in order to permit rotating of the shaft without binding.

[0010] The details of these and other aspects and embodiments of the present disclosure are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the disclosure will be apparent from the description and drawings, and from the claims.DESCRIPTION OF DRAWINGS

[0011] FIG. 1 depicts an example of a tracking solar array with articulated supports.

[0012] FIG. 2 illustrates a side view of an example articulated support for use in a tracking solar array.

[0013] FIG. 3 illustrates a top view of an example articulated support for use in a tracking solar array.

[0014] FIG. 4 illustrates a side view of an example alternative articulated support for use in a tracking solar array.

[0015] FIG. 5 illustrates a top view of an example alternative articulated support for use in a tracking solar array.

[0016] FIG. 6 is a cut-away illustration of an example ratcheted pillow block.DETAILED DESCRIPTION

[0017] This disclosure describes implementations of an articulated support for a solar array (“array”) that enables installation of the array upon uneven terrain while still enabling solar tracking using a rotating shaft. By using articulating supports as discussed herein, a single motor or actuator can rotate a tracking shaft, and thereby rotate each panel attached to the shaft, even when the solar array does not form a straight line. For example, if support piles for the array initially start on flat terrain, then climb an incline, a single rotating shaft would need to “bend” in order to follow the curvature of the terrain, yet still be able to transmit torque. Because of the forces generated by such a “bend” when using conventional supports in an uneven environment, the torque required to rotate a single shaft will be higher than that required to rotate a series of shafts using the articulated supports discussed herein. For example, the articulated supports discussed herein are configured to interconnect a series of shafts in a piecewise linear manner, such that the bending forces between pairs of shafts is reduced. More specifically, two different shafts can be at different angles and heights relative to the articulated supports, and still be interconnected without “bending” either of the individual shafts.

[0018] Turning to FIG. 1, an example of a tracking solar array with articulated supports is depicted. The solar array 100 includes a number of solar panels 108 mounted on a series of support piles 102 using a tracking shaft 104 that is coupled to the support piles 102 using articulated supports 106. A tracking motor 110 can apply torque to the tracking shaft 104, rotating the tracking shaft and causing solar panels 108 to rotate, increasing the array’s power output by ensuring the solar panels 108 receive more direct solar radiation. It should be noted that while FIG. 1 illustrates a string of four solar panels, more or fewer panels can be used. Additionally, certain implementations may include the tracking motor 110 in the center of the array 100, with tracking shaft 104 and solar panels 108 extending in both directions. For example, the tracking shaft 104 extending to the right of tracking motor 110 can continue and apply torque to a series of solar panels that are not illustrated.

[0019] Support piles 102 can be piles driven into the ground that provide a structural foundation for the solar array 100, and unlike in a conventional solar array, they need not provide a level or straight alignment between them. In some implementations the support piles 102 are a simple I-beam protruding from a concrete footing. In some implementations, the support piles 102are driven piles, screwed piles, steel piles, concrete piles, or include other suitable foundational elements. Mounted to the top of some or all of the support piles 102 is an articulated support 106. It should be noted that articulated supports 106 can be used any time the tracking shaft 104 needs to bend or articulate. Conventional supports such as conventional support 112 can be used when tracking shaft 104 can form a straight line. Conventional support 112 can be a simple bearing that supports a single continuous shaft (or coupled pair of shafts) while enabling rotation of the shaft.

[0020] Between support piles 102, tracking shaft 104 can include a number of solar panels 108, which can each include multiple solar cells. The solar panels 108 can be monocrystalline, polycrystalline, thin-film panels, or other devices suitable for absorbing solar radiation and converting it to electrical power. In some implementations, instead of solar panels, tracked radiators are used, which can be configured to radiate heat energy away and track perpendicular to the sun in order to minimize solar irradiance.

[0021] Articulated supports 106 can be used where the tracking shaft 104 would need to bend in order to connect between two piles 102. In general, articulated supports 106 provide at least two degrees of freedom for the tracking shaft 104 to be angled, but can provide more degrees of freedom. This multi-dimensional movement between support piles 102 is enabled by the use of a combination of bearings and universal joints (U-joints), as discussed in more detail below with respect to FIGS. 2 and 3.

[0022] In some implementations, the solar array 100 is aligned along a north-south line, and the tracking motor 110 rotates the solar panels 108 east-west. However, with articulated supports 106 other configurations are possible. For example, a solar array 100 can follow a northsouth direction for half (or another portion) of its length, then articulate and follow a northwestsoutheast line for a second half (or another portion). The articulated supports 106 enable both horizontal (e.g., bearing) changes in the solar array 100, as well as vertical (e.g., azimuthal) changes, for example, to follow terrain elevation changes.

[0023] FIG. 2 illustrates a side view of an example articulated support 206 for use in a tracking solar array. The example articulated support 206 includes a single central universal joint 202, supported by a pair of pillow blocks 204. Each pillow block is mounted to a swivel base 208, which is configured to permit rotation about the swivel axis 210, which can be defined through the center of the swivel base 208. The swivel base 208 is itself pivotably mounted to the base block212. In the illustrated example, the swivel base 208 is mounted using screws and pivot slots 214 to enable the pillow block to pivot about tilt axis 216. Pivot slots 214 provide a guide or track along which the base block 212 can travel while still being retained by a screw. When the screw is tightened down, the head of the screw abuts the base block 212, securing it in place. If the screw is loosened, the base block 212 can travel along pivot slots 214 to enable position adjustment. While illustrated on the outside edge of base block 212, the swivel base 208 may instead be mounted to an internal, moving block to permit translation of the pillow blocks 204 along the top surface of the base block 212. This is shown in more detail below with respect to FIG. 3. In addition to being able to tilt about tilt axis 216, swivel base 208 can be height adjustable. In other words, each pillow block 204 can be configured to translate along its respective swivel axis 210. In some implementations, this is enabled by a threaded connection between each pillow block 204 and its respective swivel base 208. For example, rotating the threaded connection in one direction (e.g., counterclockwise) can move the distal end of the pillow block 204 away from the swivel base 208, and rotating the threaded connection in another direction (e.g., clockwise) can move the distal end of the pillow block 204 toward the swivel base 208. This moveability of the pillow blocks 204 enables shaft 218A and shaft 218B to be articulated in two degrees of freedom, providing flexibility when installing a solar array on a row of unaligned piles 226. Base block 212 is coupled to a pile 226 by coupling 220.

[0024] Coupling 220 can be configured to fit atop pile 226 and provide for vertical adjustment (e.g., height adjustment) of articulated support 206. In some implementations, coupling 220 mates with base block 212 using a threaded connection. For example, the base block 212 screws onto coupling 220, and by completing more or fewer rotations the height of the base block 212 can be adjusted in a similar manner to the pillow blocks 204 discussed above. In some implementations, coupling 220 includes one or more linear actuators, and can electrically or mechanically adjust the height of the base block 212 during operation. For example, coupling 220 may include one or more ball and screw type linear actuators that can be actuated to raise or lower base block 212 relative to the pile 226. This can be advantageous as it can provide an additional degree of tracking to solar panels connected shaft 218A or 218B. For example, where the shaft rotates the panels enabling them to track east-west, the raising and lowering of one or more articulated supports 206 can provide some amount of tracking in the north-south direction. Thisfunctionality can also provide increased flexibility and robustness. For example, the array can be “tilted” to provide more resilience to adverse weather conditions (e.g., angled in a direction to minimize wind damage, or ensure precipitation falls in a favorable direction when impacting solar panels). Base block 212 can be pivotably mounted to coupling 220. For example, FIG. 2 base block 212 has an internal threaded shaft (not shown) that mates with coupling 220, and the outer base block 212 is screwed to that internal threaded shaft by a pivot slot 214 that permits base block 212 to pivot or tilt on coupling 220.

[0025] The universal joint 202 can be a single or double jointU-joint that generally couples two shafts into an interconnected shaft 218A and 218B that results in a piecewise linear arrangement of the two shafts, which enables the path of the shafts to change direction while transmitting torque through the universal joint 202, and without putting unnecessary forces (e.g., flexion forces) on either of the individual shafts joined by the universal joint 202.

[0026] Shafts 218A and 218B can include spline connectors 224, which allow shafts 218A and 218B to be coupled with additional shafts or tubes to which solar panels are mounted. Spline connector 224 enables easier installation, as the shafts 218A and 218B do not have to be in a specific rotational position to be connected with a tube bearing solar panels. Further, spline connector 224 enables a rotational offset between the input coupling and the output coupling. That is, the solar panels connected to the right of FIG. 2 can be rotationally offset from solar panels connected to the left of FIG. 2.

[0027] FIG. 3 illustrates a top view of an example articulated support 206 for use in a tracking solar array. Illustrated in FIG. 3 are adjustment slots 222, which permit moving of the swivel bases 208 and pillow blocks 204, to allow the direction of shaft 218A to be adjusted in a horizontal direction relative to the direction of the shaft 218B. While illustrated as an arc, adjustment slots 222 can conform to any number of configurations. For example, adjustment slots could form an angular track, zig zag patten, straight lines, or other suitable shapes. While the tilting of the base block, and height adjustment of the swivel bases 208 enables shaft 218A to be redirected in the vertical direction, translating the pillow blocks 204 along the adjustment slots 222 enables horizontal changes in direction of the shaft 218. For example, the direction of the shaft 218, which can be defined by a center axis along the longest dimension of the shaft 218, can be adjusted by sliding the swivel bases 208 through voids defining the adjustment slots 222.

[0028] FIG. 4 illustrates a side view of an example alternative articulated support 406 for use in a tracking solar array. Articulated support 406 is an alternative to articulated support 206, and includes two universal joints 402 with a central pillow block 404. Shaft 418 is formed of an intermediate shaft with a universal joint 402 on either end coupled to transfer shafts, each having a spline connector 424.

[0029] Base block 412 illustrates an alternative height adjustment mechanism, in which it is mounted to pile 426 using set screws 428 in adjustment slots 422. Generally, the adjustment slots 422 are voids created in the base block, and extend in a primarily vertical direction relative to the installed pile 426, thereby enabling movement of the set screws 428 in a vertical direction relative to the base block 412 to adjust the height of the height of the base block 412 on the pile 426. Of course, other appropriate height setting hardware, such as rigid pins, clamps, or other hardware capable of setting the height of the base block 412 on the pile 426 can be used. In some implementations, base block 412 includes an internal mount which is rigidly affixed to pile 426, and an outer shell which is adjustably positioned on the internal mount. A swivel base 408, which can be similar to or different from swivel base 208 as described above with respect to FIG. 2, can be mounted to base block, and configured to both swivel (e.g., via a bearing) and tilt, using pivot slots 414 and set screws 430. The swivel base 408 is coupled with pillow block 404, which supports the shaft 418, preventing radial translation while permitting rotation.

[0030] Articulated support 406 can be configured to enable a same (or different) axis offset of its input and output shafts. That is, in some implementations the input to articulated support 406 and the output travel in the same direction, but are off axis (e.g., the output can be 3 inches higher than the input, such that the paths of the input and output are parallel, or substantially parallel).

[0031] It should be noted that features of the articulated support 206 in FIG. 2 and articulated support 406 in FIG. 4 can be interchangeable. For example, coupling 220 of FIG. 2 can be used to mount base block 412 to pile 426. Or in another example, two universal joints 402 as in FIG. 4 could be used with the pair of pillow blocks 204 and base block 212 of FIG. 2.

[0032] FIG. 5 illustrates a top view of an example alternative articulated support for use in a tracking solar array. Additional adjustment slots 422 are visible in FIG 5, which are configured to enable horizontal adjustment of base block 412. While illustrated as a straight line, adjustmentslots 422 can conform to any number of configurations. For example, adjustment slots could form an angular track, zig zag patten, arc, or other suitable shapes for adjusting the position of the base block 412 relative to pile 426. In some implementations, swivel base 408 can be positionally adjusted as well, similar to swivel base 208 in FIG. 3.

[0033] FIG. 6 is a cut-away illustration of an example ratcheted pillow block. The example pillow block 600 includes an integrated ratchet 602 and pawl 604. Ratchet 602 and pawl 604 form a mechanical device configured to enable a shaft supported by the pillow block 600 to rotate in one permissive direction 610. Ratchet 602 is a toothed wheel or gear. In some implementations the ratchet 602 includes angled teeth. Pawl 604 is a spring-loaded lever that fits into the gaps between the teeth. Pawl 604 can be spring-loaded using spring 606. When ratchet 602 is rotated in the permissive direction 610, pawl 604 rides up over the teeth and allows the shaft to turn. When ratchet 610 is rotated in the reverse direction, pawl 604 engages with the teeth and prevents the shaft from turning.

[0034] A solenoid 608 can be provided which can selectively engage or disengage the pawl 604. This can allow free movement or resetting of the shaft. In some implementations, a second ratcheting mechanism (not shown) is provided within the pillow block 600 that operates in the opposite direction. In some implementations, a single ratchet 602 is used, with two pawls 604, or a linked, two-finger pawl 604 which allows the permissive direction 610 to be switched (e.g., from a clockwise direction to a counter-clockwise direction and back).

[0035] Although this disclosure has been described in terms of certain embodiments and generally associated methods, alterations and permutations of these embodiments and methods will be apparent to those skilled in the art. Accordingly, the above description of example embodiments does not define or constrain this disclosure. Other changes, substitutions, and alterations are also possible without departing from the spirit and scope of this disclosure.

[0036] The foregoing description is provided in the context of one or more particular implementations. Various modifications, alterations, and permutations of the disclosed implementations can be made without departing from scope of the disclosure. Thus, the present disclosure is not intended to be limited only to the described or illustrated implementations but is to be accorded the widest scope consistent with the principles and features disclosed herein.

Claims

CLAIMS1. A support structure comprising: a base block configured to mount to a top of a pile; a rotatable shaft coupled to the base block, wherein: the rotatable shaft comprises at least one universal joint (U-joint); the rotatable shaft is configured to couple to a solar panel, wherein rotating the rotatable shaft causes a coupled solar panel to rotate; and at least one pillow block configured to receive the rotatable shaft, coupling the rotatable shaft to the base block, the at least one pillow block configured to pivot about a first axis and a second axis, wherein the second axis is orthogonal to the first axis.

2. The support structure of claim 1, wherein the base block is configured to pivot about the first axis, and wherein the second axis is defined relative to the base block.

3. The support structure of claim 1, wherein the base block is configured to mount to the top of the pile by a coupling, and wherein the coupling comprises a linear actuator configured to raise or lower the base block relative to the pile.

4. The support structure of claim 1, further comprising: the solar panel; and a support shaft configured to mate with an end of the rotatable shaft, wherein the solar panel is coupled to the rotatable shaft by the support shaft.

5. The support structure of claim 4, wherein the support shaft mates with a spline connector on the end of the rotatable shaft.

6. The support structure of claim 1, wherein the at least one pillow block comprises a ratcheting mechanism configured, when engaged, to prevent the rotatable shaft from rotating in a first direction, while permitting rotation in a second direction.

7. The support structure of claim 1, wherein the rotatable shaft comprises an input shaft, a first U-joint, an intermediate shaft, a second U-joint, and an output shaft, and wherein the intermediate shaft is supported by a primary pillow block.

8. The support structure of claim 1, wherein the rotatable shaft comprises and input shaft, a U-joint, and an output shaft, and wherein the output shaft and the input shaft are each supported by a pillow block.

9. A support structure comprising: a base block configured to mount to a top of a pile and pivot about a first axis; a rotatable shaft coupled to the base block by two pillow blocks, the rotatable shaft comprising at least one universal joint (U-joint) positioned between the two pillow blocks, wherein: the two pillow blocks are each configured to pivot about the first axis and a second axis, wherein the second axis is orthogonal to the first axis; and the rotatable shaft is configured to couple to a solar panel, wherein rotating the rotatable shaft causes the solar panel to rotate.

10. The support structure of claim 9, wherein the second axis is defined relative to the base block.

11. The support structure of claim 9, wherein the base block is configured to mount to the top of the pile by a coupling, and wherein the coupling comprises a linear actuator configured to raise or lower the base block relative to the pile.

12. The support structure of claim 9, further comprising: the solar panel; and a support shaft configured to mate with an end of the rotatable shaft, wherein the solar panel is coupled to the rotatable shaft by the support shaft.

13. The support structure of claim 12, wherein the support shaft mates with a spline connector on the end of the rotatable shaft.

14. The support structure of claim 9, wherein at least one of the two pillow blocks comprise a ratcheting mechanism configured, when engaged, to prevent the rotatable shaft from rotating in a first direction, while permitting rotation in a second direction.

15. The support structure of claim 9, wherein the rotatable shaft comprises and input shaft, a U-joint, and an output shaft, and wherein the output shaft and the input shaft are each supported by a pillow block.

16. A support structure comprising: a base block configured to mount to a top of a pile at an adjustable height, the base block configured to pivot about a first axis; an intermediate shaft coupled to the base block by a pillow block, the intermediate shaft having a first end and a second end, the pillow block configured to pivot about the first axis and a second axis, wherein the second axis is orthogonal to the first axis; an input shaft coupled to the first end of the intermediate shaft by a first U-joint; and an output shaft coupled to the second end of the intermediate shaft by a second U-joint, wherein the output shaft is configured to couple to a solar panel, wherein rotating the output shaft causes the solar panel to rotate.

17. The support structure of claim 16, wherein the base block is configured to mount to the top of the pile by a coupling, and wherein the coupling comprises a linear actuator configured to raise or lower the base block relative to the pile.

18. The support structure of claim 16, further comprising: the solar panel; and a support shaft configured to mate with an end of the output shaft, wherein the solar panel is coupled to the output shaft by the support shaft.

19. The support structure of claim 18, wherein the support shaft mates with a spline connector on the end of the output shaft.

20. The support structure of claim 16, wherein the pillow block comprises a ratcheting mechanism configured, when engaged, to prevent the output shaft from rotating in a first direction, while permitting rotation in a second direction.

Images