CROSS REFERENCE TO RELATED APPLICATION This application claims the benefit under 35 U.S.C. §119(e) of the following provisional application, which is incorporated herein by reference in its entirety: U.S. Ser. No. 61/207,614, entitled “SYSTEM AND METHOD OF MOVING OPTICAL ELEMENTS IN A PHOTOVOLTAIC COLLECTION SYSTEM,” filed Feb. 17, 2009.
FIELD The present disclosure generally relates to solar collection.
BACKGROUND Solar energy offers the promise of a clean source of energy. To tap that source of energy, developments have typically focused on two approaches. One approach, here called photovoltaic, converts sunlight directly into electricity using a semiconductor or Peltier device. The other, here called solar thermal, uses the sun's energy to heat a substance, typically a fluid, and then mechanically converts that heat into work, typically using a turbine.
With both photovoltaic and solar thermal approaches, it can be desirable to collect the sun's energy in a large area and concentrate the collected energy onto a smaller area for the purpose of harvesting that energy. Systems for concentrating solar energy are typically large and therefore only cost-effective when used with large power generation facilities of a scale appropriate to an electric utility. The subject matter described herein relates to relatively inexpensive techniques for concentrating solar energy which is appropriate for both utility-scale and smaller facilities.
SUMMARY In one aspect there is provided an apparatus. The apparatus may include a plurality of solar reflectors; a plurality of support rods each coupled to one of the plurality of solar reflectors; a plurality of control plates including a plurality of first openings; a tension plate providing a force to position the plurality of support rods in each of the plurality of first openings; and a driver to move at least one of the plurality of control plates, the movement of the at least one of the plurality of control plates further moving the tension plate, the plurality of support rods, and the plurality of solar reflectors.
In another aspect, there is provided an apparatus. The apparatus may include a plurality of solar reflectors; a plurality of support rods each coupled to one of the plurality of solar reflectors; a plurality of plates including a plurality of openings each including a fastener into which at least one of the plurality of support rods is inserted; and a driver to move at least one of the plurality plates, the movement of the at least one of the plurality of plates further moving the plurality of support rods and the plurality of solar reflectors.
In another aspect, there is provided a method. The method may include positioning a plurality of mirrors on a fixture to align the plurality of mirrors; and attaching the plurality of mirrors to supports such that the alignment of the mirrors is maintained.
In another aspect, there is provided a method. The method may include receiving solar energy; and generating, based on the received solar energy, at least one of an electrical energy and a heat energy by driving at least one of a plurality parallel plates and a plurality of support rods inserted into openings in the plurality of plates to position a plurality of solar reflectors coupled to the plurality of support rods.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive. Further features and/or variations may be provided in addition to those set forth herein. For example, the implementations described herein may be directed to various combinations and subcombinations of the disclosed features and/or combinations and subcombinations of several further features disclosed below in the detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS In the drawings,
FIG. 1 depicts a block diagram of a system including a plurality of plates for positioning solar collectors;
FIG. 2 depicts examples of openings in plates;
FIG. 3 depicts another block diagram of a system including a plurality of plates for positioning solar collectors;
FIG. 4A depicts another block diagram of a system including a plurality of plates and springs for positioning solar collectors;
FIG. 4B depicts a support rod positioned against a portion of an opening of a plate so as to fix the position of a pivot point on the support rod with respect to the opening;
FIG. 4C depicts examples of rod shapes;
FIG. 4D depicts examples of rods including flanges, notches, and pivot posts;
FIG. 4E depicts the system of FIG. 4A tilted to the south;
FIG. 4F depicts the system of FIG. 4A tilted to the west;
FIG. 5 depicts a self-contained system including a plurality of plates, one or more springs, and one or more motors for positioning solar collectors;
FIGS. 6A-G depict cross-sectional shapes of support rods and shapes of openings in plates;
FIG. 7 depicts an example of a support rod having a flange;
FIGS. 8A-B depicts an example of a support rod including a grommet to fix the position of a pivot point on the support rod within an opening;
FIGS. 9A-C depict a support rod fixed to the opening of a plate using a gimbal, which in this example is depicted as a gimbal (which is also referred to as a “living hinge”) implemented with flexible material rather than bushings or bearings;
FIGS. 10A-D depict a variety of positions of mirrors driven by a plurality of plates and a drive mechanism;
FIGS. 11A-D depict a process for using a jig to assemble the solar collectors; and
FIG. 12 depicts a support rod affixed to a cup containing a sellable adhesive, wherein the cup is further affixed to a mirror.
Like labels are used to refer to same or similar items in the drawings.
DETAILED DESCRIPTION FIG. 1 depicts a system 100 including a plurality of plates, such as control plates 110A-B, a drive mechanism 120 for moving the plates 110A-B, a plurality of support rods 130A-D, each of which is coupled to the plates 110A-B through openings in the plates 110A-B. The system 100 also includes a plurality of mirrors 150A-D, each of which is fixedly coupled to an end of one of the support rods 130A-D. The mirrors 150A-D collect solar energy and reflect the energy to one or more targets, such as target 160. The system 100 drives the position of the mirrors 150A-D to track the movement of the sun as it moves through the sky during the day. The position of the mirrors 150A-D tracks the position of the sun to allow the solar energy to be reflected to the target 160.
The target 160 may be implemented as a photovoltaic, a Peltier device, or any other device for converting the reflected energy to electricity. The target 160 may also be also be implemented as a thermal collector, such as one containing molten salt, water, or another medium. The medium contained in the target 160 is heated by energy reflected by mirrors 150A-D. The heated medium may then be used to generate energy, directly through a heat engine (e.g., a turbine engine, a steam engine, a Stirling engine, etc.), via a heat exchanger, and/or via a thermal storage device. The target may also comprise a Stirling engine or other heat engine, which is heated directly by energy reflected by the mirrors.
Although FIG. 1 depicts four mirrors, four support rods, one target, two plates, and a drive mechanism, other quantities of these devices may be included in system 100 as well. Indeed, in some implementations, the system 100 may include dozens if not hundreds or thousands of mirrors and corresponding support rods.
The subject matter described herein relates to the plurality of plates and, in particular, providing a compact mechanism for positioning all of the mirrors using the plurality of plates. Specifically, the control plates 110A-B may be used to synchronously move all of the support rods 130A-D, which also synchronously drives all of the mirrors 150A-D coupled to those support rods 130A-D. For example, if the drive mechanism 120 moves the control plate 110A in a northerly direction, the mirrors 150A-D synchronously move towards the north. Although this example describes moving the mirrors to have a northern orientation, the use of north, south, east, and west is only relative as the plates and the mirrors may be moved in a variety of axis systems and orientations to allow the mirrors to track the sun.
The control plates 110A-B may be implemented as any rigid or semi-rigid material that can be used to drive the support rods 130A-D. The control plates 110A-B may be substantially flat, although the control plates may be shaped in other ways as well (e.g., corrugated, lattice structure, etc). The control plates 110A-B may be implemented so that the plates 110A-B are substantially parallel to each other. The control plates 110A-B may each include openings through which the support rods 130A-D are inserted.
FIG. 2 depicts a perspective view looking down on the planar surface of plates 210 and 220, each of which may be used as control plates 110A-B. The plate 210 includes a plurality of openings through which each of the support rods 130A-D may be inserted. The openings may be spaced at regular intervals (e.g., as a grid). The plate 210 includes circular openings, although the openings may have other shapes as well including for example triangular (as depicted by plate 220), rectangular, and the like. In some implementations (which are described further below), the support rods 130A-D are coupled to the plates using fasteners, such as grommets, gimbaled bearings, a so-called “living hinge” (described further with respect to FIGS. 9A-C), and the like. In other implementations, the support rods 130A-D are coupled to openings in the plates 110 using a tension plate described further below with respect to FIG. 3.
Referring again to FIG. 1, the drive mechanism 120 may include one or more motors, one or more springs, and/or any other mechanism for moving the plurality of plates 110A-B, which thus moves the support rods 130A-D and the coupled mirrors 150A-D. In some implementations described further below, the drive mechanism 120 may include one or more motors for moving a control plate north, south, east, west, as well as intermediate positions, which results in movement of the support rods 130A-D and the corresponding positioning of mirrors 150A-D to track the sun. To track the sun, the plates 110A-B move in order to tilt the support rods 130A-D in any direction, thus moving the mirrors 150A-D through a variety of positions (e.g., so that the rods are tilted 0-360 degrees in azimuth and about 0-45 degrees or more in elevation from an orthogonal to the control plate). The rods 130A-D may be tilted in any direction, while being constrained so as not to move laterally, longitudinally, or rotationally with respect to the openings of the plates. The constraint against rotational movement is in contrast to typical two-axis concentrating solar tracking systems, which rotate in azimuth and elevation. Azimuthal movement of past systems typically results in collisions between adjacent mirrors as they track the sun if the mirrors are spaced too closely, whereas with the omnidirectional tilting movement provided by the rods and plates disclosed herein, the mirrors can be placed such that when tracking the sun when the sun's rays are orthogonal to the control plates, the mirrors can be so close as to almost touch, yet they will not collide in any position required to track the sun. As a consequence, the positioning system disclosed herein, in some implementations, enables harvesting essentially all of the sunlight incident on an available plot of land or other area hosting system 100, with reduced amounts of sunlight lost between the gaps between mirrors, providing thus high solar efficiency when compared to past approaches.
The support rods 130A-D may be implemented as any mechanism to which a mirror can be coupled. Each of the support rods 130A-D is inserted into the openings in the plurality of plates 110A-B. For example, support rod 130A may be inserted into an opening in control plate 110B and further inserted into an opening in control plate 110A, and one of the ends of support rod 130A may be fixedly attached to the mirror 150A. Although FIG. 1 depicts straight rods 130A-D, the support rods 130A-D may have a variety of shapes as described further below. Moreover, the shape of the cross section of the support rod may be circular, oval, polygonal, heart-shaped, triangular, and/or any other shape.
The mirrors 150A-D may be implemented as any device capable of reflecting the energy of the sun. Although FIG. 1 depicts mirrors 150A-D having a parabolic shape, the mirrors may have a variety of shapes including a flat shape.
In some implementations, the synchronous tilting movement provided by the plurality of plates 110A-B allows the mirrors 150A-D to follow the sun and allows the mirrors 150A-D to be closely spaced—enabling a higher amount of the solar energy to be captured by the mirrors 150A-D and reflected to the target 160.
FIG. 3 depicts another system 200. The system 200 is similar to system 100 but includes an additional plate labeled tension plate 110C. The tension plate 110C may be implemented in a similar manner as described above with respect to plates 110A-B. (e.g., having openings, rigid and/or semi-rigid material, and the like) However, tension plate 110C provides tension to the support rods 130A-B to maintain the position of the support rods 130A-D in the openings of the plates 110A-C. Thus rather than using a fastener in each of the openings of the plates 110A-C to position the support rods 130A-D in the openings of the plates 110A-C, the tension plate 110C is used to provide a force to position the support rods 130A-D within the openings of the plates 110A-C, such that the rods 130A-D are pulled against one side of the opening throughout the range of motion of the plates 110A-C, substantially eliminating any play (or other indeterminacy) of the rod's position with respect to the opening. Like a fastener, such as for example a rubber grommet, the tension plate 110C substantially maintains the position (e.g., lateral, longitudinal, and rotational) of the support rod in the opening of the plate. Moreover, the tension plate 110C may result in a more simplified manufacture of system 200 since fasteners do not have to be used in each of the openings of plates 110A-C. This simplified manufacturing may, in some implementations, result in a lower manufacturing cost of system 200.
Although FIG. 3 depicts four mirrors, four support rods, one target, three plates, and a drive mechanism, other quantities of these devices may be included in system 200 as well.
FIG. 4A depicts another system 400. System 400 is similar to system 200 in many respects as both systems include plates 110A-C. However, system 400 includes support rods 430C-D that are shaped to maintain the position of the support rods in the openings of the plates 110A-C. For example, support rod 430D is shaped to maintain the position of the support rod 430D in openings 410D, 411D, and 412D, and support rod 430C is similarly shaped to maintain the position of the support rod in openings 410C, 411 C, and 412C.
FIG. 4B depicts a perspective view of support rod 430D in openings 410D, 411 D, and 412D. The shape of support rod 430D substantially maintains the position of the support rod 430D in the openings 410D, 411 D, and 412D. In particular, the position of the support rod 430D is maintained laterally against a portion 469A-C of the openings (e.g., the north side of openings 410D and 412D and the south side of opening 411D) as the plates 110A-C and the support rod 430D (and corresponding mirror) are moved to a variety of positions. Moreover, the position of support rod 430D is substantially maintained longitudinally to prevent the support rod 430D from moving vertically within the openings 410D, 411D, and 412D (i.e., vertically with respect to the length of support rod 430D). Moreover, the position of support rod 430D is substantially maintained rotationally to prevent the support rod 430D from rotating (i.e. twisting or spinning upon its axis) within the openings 410D, 411D, and 412D. Thus, portions 469A-C serve as a pivot point about which the support rod 430D pivots but substantially maintains the longitudinal, rotational, and/or lateral position of the support rod 430D with respect to each of the openings.
Furthermore, the use of shaped support rods, such as support rod 430D, may, in some implementations, eliminate the need to use fasteners in each of the openings of plates 110A-C.
Referring again to FIG. 4A, although FIG. 4A depicts support rods 430C-D having a specific shape, other shapes may be used to maintain the position of the support rods in the openings of the plates. FIG. 4C depicts examples of other shapes. Rod 410 is shaped so that the portions 460A-C of the rod that make contact with the openings of the plates are not collinear, such that the forces applied by the control plates and tension plate prevent play within the openings. Rod 420 is similar to rod 410 but depicts notches 450A-C to prevent longitudinal play within in openings.
FIG. 4D depicts other features that may be used to restrict the play of the rod within an opening in a plate. The support rod 430D may include a flange 462 to maintain the longitudinal position of the support rod 430D within the opening 410D. The support rod 430D may include a notch 463 to maintain the longitudinal position of the support rod 430D within the opening 410D. The support rod 430D may include a pivot post 464 to maintain the longitudinal position of the support rod 430D within the opening 410D. When the pivot post 464 is used, additional tension mechanisms (e.g., a spring) may be required. These features may be integrally formed or attached to the rod in manufacture, or the features could be parts separately manufactured and affixed to the rod.
Referring again to FIG. 4A, springs 460 and 465 provide tension that pulls each of the support rods 430C-D against a portion of the openings 410C-D, 411C-D, and 412C-D regardless of the direction of movement of the plates 110A-C. In the example of FIG. 4A, the springs 460 and 465 provide tension that pulls tension plate 110C to the north, driving support rods 430C-D to substantially fixed positions at the north side of openings 410C-D and 412C-D of control plates 110A-B, and to substantially fixed positions at the opposite, south side of openings 411 C-D of tension plate 110C.
The spring 465 may be affixed to a first perpendicular member 492 at a first end of control plate 110A and affixed to second perpendicular member 494 at a distal end of tension plate 110C. The spring 460 may be affixed to a third perpendicular member 496 at a first end of control plate 110B and affixed to the perpendicular member 494 of tension plate 110C. The perpendicular members 492, 494, and 496 each extend perpendicularly from a plate to allow the springs 460 and 465 to be affixed to the plates 110A-C. In some implementations, the members 492, 494, and 496 extend at an angle that is not perpendicular to the plates 110A-C. In some implementations, the configuration of the springs 460 and 465 provides sufficient tension to maintain the position of the support rods 430C-D in the openings 410C-D, 411C-D, and 412C-D regardless of the direction of travel of the plates 110A-C.
Although FIG. 4A depicts a specific configurations of springs to provide tension to limit the play of the rods within the openings of the plates, other configurations may be used as well. For example, springs 460-465 may be coupled directly to the plates rather than to members 492-496. One end of one or more springs may be attached to a container for system 400 while the other end is attached to the members 492-496 or coupled directly to the plates. Rather than use springs 460-465, a computer-controlled motor may be used in some implementations to provide a force that drives the tension plate 110C (as described above) to limit the play of the rods within the openings of the plates.
FIG. 4E depicts the system 400 after the parallel plates 110A-C move to drive the support rods 430C-D and mirrors 150C-D to an approximately 30 degree tilt to track the movement of the sun. In the example of FIG. 4E, the control plate 110A is driven to the south by the drive mechanism. The contoured shape of the support rods 430C-D fix the position of the support rods 430C-D within the openings 410C-D, 411C-D, and 412C-D, so that the support rods do not slide longitudinally within the openings, rotate within the openings, etc. As depicted in FIG. 4E, the springs 460 and 465 provide tension that pulls tension plate 110C to the north, driving the support rods 430C-D to a substantially fixed position at the north side of openings 410C-D and 412C-D of control plates 110A-B; while support rods 430C-D are substantially fixed at the opposite, south side of openings 411 C-D. If the position of the support rods were not maintained in each opening, the drive mechanism would not be able to repeatedly position the plates, support rods, and mirrors to an accurate position when tracking the sun as longitudinal and rotational changes to the support rods would cause unacceptable errors in the positioning of the support rods and mirrors. In some implementations, the springs 460 and 465 and shaped support rods 430C-D may thus be used to eliminate the need for fasteners in each of the openings 410C-D, 411 C-D, and 412C-D.
FIG. 4F depicts system 400 when the mirrors 150C-D are tilted approximately 45 degrees to the west. As noted, the springs 460-465 pull the tension plate 110C to maintain an approximately fixed point of contact between the support rods 430C-D and the edge of the openings 410C-D, 411C-D, and 412C-D regardless of the direction in which the control plates 110A-B tilt the support rods 430C-D and mirrors 150C-D. In the example of FIG. 4F, when the mirrors 150C-D are positioned by the drive mechanism and control plates 110A-B to a 45 degree tilt to the west, the springs 460-465 continue to pull the tension plate 110C so that the support rods 430C-D are in substantially fixed positions at the north side of openings 410C-D and 412C-D of control plates 110A-B, while support rods 430C-D are maintained on the opposite, south side of openings 411 C-D. For example, if the springs are arranged such that the tension plate pulls a rod into contact with approximately the northernmost edge of an opening in a control plate then the rod stays in contact with that approximately northernmost portion of the opening of that control plate regardless of the direction of movement of said control plate in the directions north, south, east or west or combinations thereof.
FIG. 5 depicts a system 500. The system 500 includes control plates 110A-B, tension plate 110C, support rods 430C-D, mirrors 150C-D, target 160, springs 460-465, a container 518, and a transparent cover 520. FIG. 5 depicts a drive mechanism having a motor 510; however two or more motors may be used as well to tilt the mirrors to any degree of tilt in any direction. Moreover, the system 500 has a virtual pivot plane 514C to fix the tilt pivot points 520A and 520B of the mirrors 150C-D. The pivot point 520A-B of each mirror remains fixed in relation to the container 518 while the mirrors tilt throughout their range of motion, even though the mechanical connection between the pivot points 520A-B and the container 518 is indirect via rods 430C-D, plates 110A-C, pivot rods 532 and 512B, and pivot mounts 514A-B.
The motor 510 drives a first end of a lateral rod 512A. The opposite end of lateral rod 512A is coupled to a pivot rod 512B. A spring 516 provides tension to couple the pivot rod 512B to the pivot mount 514A. The system 500 includes a similar pivot mount 514B and pivot rod 532 at the opposite end of the container 518. In the configuration of FIG. 5, the pivot rod 512B pivots about a pivot point defined by the pivot mount 514A. As a consequence, when the motor 510 moves for example to the north, the lateral rod 512A and pivot rod 510B also move, which causes the plates 110A-C and the support rods 430C-D to move. However, this movement by the rods and plates results in the mirrors 150C-D being tilted about the pivot points 520A-B rather than moved laterally north and south within the container 518. In short, the lateral position of the mirrors 150C-D remains fixed at the pivot points 520A-B, so that movement by the plates and rods causes the mirrors 150C-D to tilt about the substantially fixed pivot points 520A-B, which maintains alignment between the mirrors 150C-D and the target 160.
Furthermore, system 500 depicts that the plates 110A-C essentially float relative to the pivot mounts 514A-B, although in some implementations one of the plates may be fixed relative to the container 518. Although system 500 is described using a north-south moving motor 510, system 500 may move in any other direction as well. In some implementations, system 500 includes a second motor, which is similar to motor 510. The second motor is coupled to a second lateral rod, which is also coupled to pivot rod 512B. But the second lateral rod is orthogonal (e.g., in an east-west orientation) to lateral rod 512A. When the second motor moves the second lateral rod east or west, the mirrors tilt respectively west or east. The combined motion of the two motors serves to tilt the rods in any direction with respect to north (e.g., north, northeast, south-southwest, 137 degrees east of north, etc.), and at any angle with respect to the plane of the control and tension plates, such as 10 degrees from normal or 45 degrees from normal.
The system 500 may include other components, such as additional mirrors, rods, targets, a steam generator, a heat exchanger, and the like, to provide a self-contained solar collection unit that outputs steam or other heated fluid. The system 500 may include targets that are implemented as photovoltaic cells or Peltier cells, in which case the system 500 outputs electricity. The system 500 may include a heat engine such as a steam engine or Stirling, in which case the system outputs mechanical energy. The system 500 may further incorporate an electrical generator, in which case the system 500 outputs electricity. Moreover, although FIG. 5 depicts a specific configuration of springs, motors, support rods, and the like, other configurations may be used as well.
As noted, the use of plates 110A-C allows the system 500 to include closely spaced mirrors 150C-D improving collection efficiency by avoiding loss of incident solar energy when light passes through gaps between the mirrors. In some implementations, the system 500 also includes two drive motors, reducing cost, weight, and size to allow inexpensive and compact implementations.
As noted above, the pivot point of the support rods within the openings of the plates is fixed with respect to the opening to prevent play within the opening. For example, the support rod should not move longitudinally within a plate opening, nor should the support rod rotate within the opening. FIG. 6A depicts a top view of support rod 430D (which has a circular cross section) in an opening 410D of control plate 110A. As can be seen in FIG. 6A, the circular cross section of support rod 430F does not alone prevent rotation of the support rod 130 within opening 410D. However, if rod 430D passes through two control plates and one or more tension plates (as described with respect to FIG. 5) and the rod 430D is bent such that a plurality of contact points of the rod 430D are not collinear, then the opposing tension between the tension plate and control plates forces the rod 430D into a fixed rotational position where the plane of the non-collinear contact points is aligned in the direction of the tension.
FIG. 6B depicts support rod 430D having a polygonal cross section, which in this example is triangular, although other shapes may be used as well. The opening 410D in the control plate 110A also has a polygonal shape. FIG. 6B shows that the polygonal shape of the support rod 430D and opening 410D reduces rotation of the support rod 430D within the opening 410D. FIGS. 6B and 6D depict that support rod 430D is maintained at a substantially fixed position in the openings 410D and 412D of control plates 110A-B (e.g., the north side of the openings as described above). FIG. 6C depicts that the support rod 430D is maintained at a substantially fixed positioning in the opening 411D of tension plate 110C (e.g., the opposite, south side of opening 411D as described above).
FIG. 6E-G shows circular openings with a support rod 430D having another shape (e.g., a blade-like shape). FIGS. 6E and 6G depict that support rod 430D is maintained at a substantially fixed position in the openings 410D and 412D of control plates 110A-B (e.g., the north side of the openings as described above). FIG. 6F depicts that the support rod 430D is maintained at a substantially fixed positioning in the opening 411 D of tension plate 110C (e.g., the opposite, south side of opening 411D as described above).
To prevent longitudinal movement of a support rod within an opening of a plate, the support rod may also include a notch or a flange, as noted above. FIG. 7 depicts another example of flanges 710A-B. The flanges 710A-B fixedly position the support rod 430D within opening 410D, although the flange 710A-B may be used with any of the openings and/or plates to prevent longitudinal movement of a support rod within the plate opening.
In some implementations, the position of the support rod within an opening is maintained with the use of a fastener. FIG. 8A depicts an example of a triangular grommet 810 which fixedly positions the support rod 430D within opening 410D of control plate 110A. In the example of FIG. 8A, the triangular grommet substantially limits longitudinal, rotational, and lateral play within an opening of a plate but allows the rod to tilt within the opening to allow mirror positioning. FIG. 8A also depicts a side view of triangular grommet 810 within opening 410D of control plate 110A. In this example, the support rod 430D includes a shoulder 812 on which the triangular grommet 810 sits to prevent the triangular grommet 810 from moving longitudinally along the support rod 430D. The diameter of the support rod 430D may also be narrowed 830 to fix the position of the grommet 810 and the support rod 430D. In some implementations, the triangular grommet 810 is made out of a flexible material, such as rubber, plastic, etc, to allow limited tilting movement of the support rod 430D within the opening 410D.
FIG. 8B depicts another example of a triangular grommet and flanges 814A-B rather than shoulder 812. The flanges 814A-B prevent the support rod 430D from moving longitudinally with respect to opening 410D. Although FIGS. 8A-B depict triangular grommets being used with support rod 430D and opening 410D, the triangular grommets may be used with any other opening and/or support rod. Moreover, although the grommets are depicted as triangular, other shapes may be used as well.
FIG. 9A depicts another example of a fastener 910 that can be used to position a support rod within openings of the control plates. The fastener 910 provides a gimbal mechanism which is referred to herein as a “living hinge.” The plate 110A includes a first opening 912 sized to allow a rod, such as rod 130A, to be inserted therein. The first opening 912 may be implemented for use with any of the openings described herein with respect to the control plates and/or tension plate. The plate 110A also includes a first set of semi-circular gaps 914 separated by bridges 922C-D and a second set of semi-circular gaps 916 separated by bridges 922A-B.
FIG. 9B depicts a side-view of rod 130A after insertion into opening 912. The rod 130A is positioned within opening 912 of plate 110A to prevent play within opening 912 (e.g., the rod 130A may be fixed in opening 912 with an adhesive, press fit, snap fit, weld, or other mechanism). The semi-circular gaps 914 and 916 enable the rod 130A to pivot about plate 110A like a gimbal or a hinge that tilts in any combination of north/south and east/west while captivated within opening 912, such that the an action of the living hinge is similar to the action of a gimbal.
FIG. 9C depicts rod 130A as it pivots about plate 110A. The living hinge 910 depicted in FIGS. 9A-C may be manufactured using a punch out, etch out, mold, or cutout, to form the opening 912 and semi-circular gaps 914 and 916. The semi-circular gaps essentially form a gimbal ring 962 that flexes to allow the rod 130A to pivot while captivated within opening 912. An alternative implementation for the living hinge case may be used given a plate made of a moldable, flexible material. In this case, the plate and portion of the rod or rods that penetrates the plate may be molded as a single part, such that the living hinge is permanently coupled to the plate. In this example, the portions of the rods that are associated with various plates can be attached end-to-end to form a single rod.
FIGS. 10A-D depicts a system 1000 including dozens of mirrors in various positions as the mirrors track the sun and reflect the energy to one or more targets. When a drive mechanism 120 of system 1000 drives plates 110A-B and support rods 1010, a plurality of mirrors 1050 are positioned, so that these mirrors track the sun and reflect the solar energy to one or more targets. The drive mechanism 120 may directly couple to only control plate 110B and synchronously move the mirrors 1050. FIGS. 10A-D also depict that the mirrors may be closely spaced due to the synchronous positioning provided by system 1000. Although FIGS. 10A-D depicts the use of fasteners, such as fastener 1060, the system 1000 may be implemented using the tension plate described herein as well.
To facilitate manufacture of the systems described herein, which may include dozens if not hundreds of mirrors, a specialized jig may be used as depicted at FIGS. 11A-D. Referring to FIG. 11A, all of the mirrors 1110A-H of a system, such as for example systems 100, 200, 400, 500, and 1000, may be placed into a jig 1105. The placement may include the relative placement of each mirror 1110A-H to allow efficient reflection to one or more targets. In some implementations, an adhesive 1120A-H is applied to each mirror 1110A-H.
FIG. 12 depicts an example of mirror 1110A with settable adhesive applied in a cup 1200 mechanism into which the support rod 130A is inserted. Although FIG. 12 depicts cup 1200, in some implementations the adhesive is applied without cup 1200.
Referring to FIG. 11 B, the support rods 130A-E and plates 110A-C are assembled, so that the support rods are positioned within the opening of the plates as described herein. Any springs, pivot rods, and drive mechanisms may also be added to the support rod and plate assembly. This support rod and plate assembly 1130 is then placed onto the mirrors 1110A-H, which have been accurately positioned relative to each other on the jig 1105.
FIG. 11C depicts the mating of the support rod and plate assembly 1130 with the mirrors 1110A-H on the jig 1105. Once the adhesive hardens, the mirrors 1110A-H are released from the jig 1105 as depicted at FIG. 11D. Because the mirrors 1110A-H were accurately placed within the jig 1105, the relative errors among the support rod and plate assembly 1130 are no longer a concern as each of the mirrors 1110A-H is positioned accurately relative to other mirrors. This accuracy is maintained once the adhesive has set (e.g., hardened/dried) and is typically not affected by minor variations in shaft positioning.
In some implementations of the above-described jig, a single textured sheet comprising multiple mirrors may be applied to the jig rather than individually applying multiple mirrors. When the single textured sheet is used, the jig positions the sheet and then a cutting mechanism cuts the single sheet into individual mirrors to create individual mirrors. In any case, the use of the above-described jig corrects for the relative errors in the positioning of the mirrors by essentially absorbing and compensating for variations in the orientations of the plates and rods. In the case of the textured sheet of mirrors, connections in the sheet between mirrors may augment or replace the function of the jig to accurately position the mirrors relative to each other before mating the mirrors to the support rods.
While the above described systems accurately position the mirrors with respect to each other (using a jig or other mechanism) and then use a settable adhesive to attach the mirrors to the rods in such a way that accumulated errors in the relative positions of the rods are compensated for to accurately maintain the position of each mirror with respect to the other mirrors, any method of mating the mirrors fixedly to the support rods may be used, for example though lock nuts, set screws, or a thermosetting connection.
While the above describes mating mirrors to support rods in a mechanism where the rods move with respect to plates, the mechanisms of FIGS. 11A-D is also applicable to the mating of multiple mirrors to an approximately rigid support structure wherein after mating, the mirrors move as a group to track the sun. In some implementations, there may be a benefit to be gained by first positioning the mirrors accurately with respect to each other, then attaching the mirrors to a support structure so that the relative position of the mirrors is maintained after the mirrors are separated from each other and/or from the jig. Thus, the need to adjust or calibrate the mirror positions after they are mated to their supports is reduced or eliminated.
Although the examples described herein include a given quantities of mirrors, support rods, targets, plates, and a drive mechanisms, these are merely examples as other quantities of these devices may be included in a corresponding system implementation.
The foregoing description is intended to illustrate but not to limit the scope of the invention, which is defined by the scope of the appended claims. Other embodiments are within the scope of the following claims.
