DESC:The present disclosure relates to the field of solar trackers.
BACKGROUND
The background information herein below relates to the present disclosure but is not necessarily prior art.
In conventional single axis solar tracking systems, multiple solar panels are mounted on a single horizontal or inclined beam or torque tube segments with the help of clamps, purlins or top hat sections, and the solar panels along with the torque tubes in a rotating configuration are mounted on posts erected on the ground using bearings or bushings, thereby forming a support structure. One such structure is called a tracker row. To capture maximum solar energy, the tracker is angularly displaced such that an optimal angle is maintained with respect to the solar vector. Typically, to rotate the tracker row, electro mechanical actuators, slew drives or hydraulic cylinders are required. However, these mechanisms incur high costs for installation and maintenance. These mechanisms are subject to large forces and require periodic attention for lubrication or for replacement of covers and bellows. A problem faced by the support structure is that the ground on which this structure is erected is often undulating and contains multiple slopes in the span of one tracker row. This causes a non-orthogonal condition between the rotating axis of the torque tube segments and the longitudinal axis of the post erected on the ground. Driving a torque tube that is non-orthogonal with respect to the vertical post causes an out of plane displacement of the electromechanical actuator or hydraulic cylinder and requires additional ball and socket or ball end joints to enable this out of plane displacement to take place.
There is, therefore felt a need for a solar tracking displacement apparatus that obviates the above mentioned drawbacks.

OBJECTS
Some of the objects of the present disclosure, which at least one embodiment herein satisfies, are as follows:
It is an object of the present disclosure to provide a solar tracking displacement apparatus.
An object of the present disclosure is to provide a solar tracking displacement apparatus, which eliminates use of electromechanical actuator, slew drives or hydraulic cylinders to provide angular displacement of the torque tubes.
Another object of the present disclosure is to provide a solar tracking displacement apparatus, which facilitates installation of torque tubes on sloping ground such that the rotating axis of the torque tube segments comprising the torque tube need not be perpendicular to the longitudinal axis of the posts erected on the ground.
Yet another object of the present disclosure is to provide a solar tracking displacement mechanism that is highly tolerant to dust / dirt and does not require maintenance for the life of the tracker.
Still another object of the present disclosure is to provide a solar tracking displacement apparatus that is inherently stiff in torsion and not susceptible to torsional galloping and eliminates the use of oil filled dampers to damp the structure.
Other objects and advantages of the present disclosure will be more apparent from the following description, which is not intended to limit the scope of the present disclosure.
SUMMARY
The present disclosure envisages a solar tracking displacement apparatus. The solar tracking displacement apparatus comprises a plurality of vertical posts, a plurality of torque tube segments, and a plurality of displacement units. The plurality of vertical posts is arranged in a spaced apart configuration. The plurality of torque tube segments is fitted across the upper extremities of the vertical posts. The plurality of torque tube segments is being coupled to each other to form an assembled torque tube rotationally displaceable about its longitudinal axis. The plurality of displacement units is coupled to the torque tube segments in one to one relationship. Each of the displacement units is configured to angularly displace the plurality of connected torque tube segments in a controlled and synchronized manner.
In an embodiment, each of the displacement units includes a plurality of mechanically coupled gearboxes, a beam, a first wire rope, a second wire rope, a pulley, and a semi-circular member. The plurality of gearboxes is supported by a respective vertical post. The beam axis is orthogonally coupled to a torque tube segment in an offset manner. The pulley is rotatable by the gearbox. The pulley is configured to wind the first wire rope and while unwinding the second wire rope and vice versa. The semi-circular member is connected to the beam. The semi-circular member and the beam is coupled to the respective pulley via the first wire rope and the second wire rope. Each of the semi-circular members is configured to angularly displace the respective torque tube segment in a controlled and synchronized manner.
In an embodiment, the apparatus includes a motor. The motor is coupled with one of the bevel gearboxes. Each of the bevel gearboxes is connected to another bevel gearbox via a torsion rod or pipe. . Each bevel gear box is mechanically coupled to its corresponding worm gear box. The motor is configured to generate a rotary drive. The motor is further configured to drive each of the plurality of displacement units based on the generated rotary drive via the connected torsion rod or pipe.
In an embodiment, the one end of the first wire rope and the second wire rope is fitted at two ends of the beam and another end of the first wire rope and the second wire rope is fitted on of two flanges of the respective pulley.
In an embodiment, the plurality of coupled gearboxes has an output shaft. The output shaft is configured to angularly displace each of the plurality of pulleys based on the rotary drive generated by one motor.
In an embodiment, the beam is coupled to the torque tube segment via a swivel pin joint.
In an embodiment, each of the torque tube segments is coupled to a respective post via a respective connecting bracket and connecting bushing.
In an embodiment, the semi-circular member is an arcuate rope guide. In an embodiment, each of the torque tube segments has a circular cross section.
BRIEF DESCRIPTION OF ACCOMPANYING DRAWING
A solar tracking displacement apparatus of the present disclosure will now be described with the help of the accompanying drawing, in which:
Figure 1 illustrates a typical torsional moment diagram of the torque tubes, in accordance with an embodiment of the present disclosure;
Figure 2A and Figure 2B illustrates the isometric views of the torque tube segments being coupled by swaging the torque tubes segments, in accordance with an embodiment of the present disclosure;
Figure 3A through Figure 3C illustrates isometric views of the torque tube segments coupled by a pseudo universal joint, in accordance with an embodiment of the present disclosure;
Fig. 4 illustrates an isometric view of an apparatus for configuring a dent on a torque tube of circular cross section, in accordance with the present disclosure;
Fig. 5 illustrates a simple lever arm mechanism for exerting the force necessary for the creation of the dent or punching a hole in the torque tube of circular cross section, in accordance with an embodiment of the present disclosure;
Fig 6 illustrates an isometric view of the torque tube of circular cross section having a dent configured thereon;
Fig. 7 illustrates an exploded isometric view of a fitting arrangement for fitting a solar panel on a torque tube segment of circular cross section configured with a dent;
Fig. 8A through Fig. 8C illustrate an isometric views of clamps used in the fitting arrangement, in accordance with embodiments of the present disclosure;
Fig. 9 illustrates an isometric view of the plurality of solar panels being fitted to the torque tube via the fitting arrangement as seen from below the plane of the solar panels;
Figure 10 illustrates an isometric view of a solar tracking displacement apparatus, in accordance with an embodiment of the present disclosure;
Figure 11 illustrates a side view of the solar tracking displacement apparatus of Figure 10, in accordance with an embodiment of the present disclosure;
Figure 12 and Figure 13 illustrate a side view the solar tracking displacement apparatus of Figure 10, in accordance with an embodiment of the present disclosure;
Figure 14 illustrates a 3D view of a pulley and a gearbox mounted on a post, in accordance with an embodiment of the present disclosure;
Figure 15 illustrates side view of the pulley and the gearbox of Figure 14;
Figure 16 illustrates a 3D view of the pulley and the gearbox of Figure 14, in accordance with an embodiment of the present disclosure;
Figure 17 illustrates a 3D view of a semi-circular member connected to two ends of a beam, in accordance with an embodiment of the present disclosure;
Figure 18 and Figure 19 illustrate a cutaway 3D view of the wire rope end arrangement for each of a first wire rope and a second wire rope connected with the beam, in accordance with an embodiment of the present disclosure;
Figure 20 illustrates a cutaway 3D view of Figure 10, in accordance with an embodiment of the present disclosure; and
Figure 21 illustrates an isometric view of a plurality of solar tracking displacement apparatus coupled with multiple torque tube segments and multiple gearboxes linked with each other via a torsion rod, in accordance with an embodiment of the present disclosure.
LIST OF REFERENCE NUMERALS USED IN DETAILED DESCRIPTION AND DRAWING
10 – Apparatus
12 – Brackets
14 – Fastening element
16 – Space
18 – Element
20 – Plunger
22 – Lever
24 – Fixed Member
26 – Spirit level
50 – Fitting arrangement
52 – Dent
54 – Clamp
54A – Protrusions
54B – Hardened Teeth
56 – Purlin / Top Hat section
56A – U-shaped protrusions
56B – Flanges
58 – Solar Panels
60A – U-Shaped bolts
60B – Nuts
60C - Washers
101 – Apparatus
102 – A Vertical Post
102’ – A Short Supporting Post
104 – A Plurality of Connected Torque Tube Segments
104A – A Single Torque Tube Segment
106 – A Pulley
107 – A Pulley Flange
108 – A Semi-circular Member
110 – A Beam
112 – A Wire Rope
112A – A First Wire Rope
112B – A Second Wire Rope
114 – A Swivel Pin Joint
115 – Displacement Means
116 – A Wire Rope End Arrangement
117 – A Worm Gear Box
117A – A Bevel Gear Box
118 – A Motor
118A – Output Shaft of Gear Box 117
120 – Connecting Bracket
122 – Connecting Bushing
124 –Clamp for coupling Torque Tube Segments 104 with beam 110
126 – Hollow Tube
128 – Crimped Wire Rope End
130 – Taper Washer
132 – Plain Washer
134 – Wire Rope Tightening Lock Nuts
136 – Spherical Washer
138 – Wire Rope Clamp
140 – Supporting Beams
144 – Torsion Rods or Pipe for Connecting Plurality of Bevel Gearboxes 117A
146 – Plane of the Ground
200– Swaged coupling
202, 302 – First torque tube segment
204, 304 – Second torque tube segment
206 – Bolt and nut assembly
300 – Pseudo universal Joint
306 – Sleeve
308 – First pair of apertures
310 – Second pair of apertures
312 – Bolt and nut assembly
DETAILED DESCRIPTION
Embodiments, of the present disclosure, will now be described with reference to the accompanying drawing.
Embodiments are provided so as to thoroughly and fully convey the scope of the present disclosure to the person skilled in the art. Numerous details are set forth, relating to specific components, and methods, to provide a complete understanding of embodiments of the present disclosure. It will be apparent to the person skilled in the art that the details provided in the embodiments should not be construed to limit the scope of the present disclosure. In some embodiments, well-known processes, well-known apparatus structures, and well-known techniques are not described in detail.
The terminology used, in the present disclosure, is only for the purpose of explaining a particular embodiment and such terminology shall not be considered to limit the scope of the present disclosure. As used in the present disclosure, the forms "a,” "an," and "the" may be intended to include the plural forms as well, unless the context clearly suggests otherwise. The terms "comprises," "comprising," “including,” and “having,” are open ended transitional phrases and therefore specify the presence of stated features, integers, steps, operations, elements, modules, units and/or components, but do not forbid the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The particular order of steps disclosed in the method and process of the present disclosure is not to be construed as necessarily requiring their performance as described or illustrated. It is also to be understood that additional or alternative steps may be employed.
When an element is referred to as being "mounted on," “engaged to,” "connected to," or "coupled to" another element, it may be directly on, engaged, connected or coupled to the other element. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed elements.
The terms first, second, third, etc., should not be construed to limit the scope of the present disclosure as the aforementioned terms may be only used to distinguish one element, component, region, layer or section from another component, region, layer or section. Terms such as first, second, third etc., when used herein do not imply a specific sequence or order unless clearly suggested by the present disclosure.
Terms such as “inner,” “outer,” "beneath," "below," "lower," "above," "upper," and the like, may be used in the present disclosure to describe relationships between different elements as depicted from the figures.
Solar trackers have been developed in the art for angularly displacing the solar panels in accordance with the motion of the earth with respect to the sun. Typically, this angular displacement is effected via electromechanical actuators, slew drives or hydraulic cylinders as actuation mechanisms, which have high installation and maintenance costs associated therewith. Periodical lubrication and maintenance of the bellow covers on the lead screws is required. Typically, non-orthogonal misalignment is introduced into the relationship between the rotating axis of the torque tube segments and the longitudinal axis of the erected posts due to non-uniformity of the ground on which the support structure is erected.
The present disclosure discloses a method for coupling the torque tubes. The method is now described in detail with reference to Figure 1 through Figure 3C.
The present disclosure allows for driving the plurality of connected torque tube segments 104 at more than one location in a row. The driving may be done by electromechanical actuators, hydraulic cylinders or by slew drives all synchronized with each other. In a preferred embodiment, the array of torque tube segments 104 is driven at three locations by use of displacement means 115. Referring to, 100 A of Figure 1 shows a typical torsion moment diagram of the solar row tracker system 100 driven at three locations in a synchronized manner. The torsion moment between any two driving locations is substantially zero as can be seen at 100-2 in the torsion moment diagram. The torsion moment is also the highest at the three locations where the row is driven as seen at 100-1.
In accordance with the present disclosure, the coupling between the two torque tube segments 104A is achieved via a swaged coupling 100B and a pseudo universal joint 100C. The locations A of pseudo universal joints 100Cand locations B of swaged couplings 100Balong the linear array of connected torque tubes segments 104, with respect to the torsional moment diagram 100 A, are illustrated in Figure 1. The location of the pseudo universal joint is decided by the magnitude of the torsional moment acting at a particular joining location. In accordance with the present disclosure, the pseudo universal joint 100 C is denoted by “A” in Figure 1. Further, Figure 1 illustrates, the location of maximum torsion 100-1 and the location of minimum torsion 100-2, with respect to the torsional moment diagram 100 A. The pseudo universal joint 100 C is provided at those joining locations where the acting torsion moment is substantially zero.
In an embodiment, in a solar tracker system 100 comprises, an array of solar panels installed with a tracker system to angularly displace the solar panels in accordance with the movement of the earth with respect to the sun to maintain an optimal angle to the solar vector so that maximum energy can be generated from the incoming solar radiation. The array of solar panels is mounted on the linear array of connected torque tubes segments 104. Further, the connected torque tube segments 104 are supported by a plurality of posts 102, wherein the posts 102 are erected on the ground to provide a foundation structure at pre-determined distance apart from each other.
Figure 2A and Figure 2B illustrate the coupling of torque tube segments 202 and 204 of type 104A by swaged coupling. In an embodiment, the torque tube segments 202, 204 of type 104A is made up of a of rigid thin-walled tube sections, wherein the ends of the torque tube sections are open. Further, the torque tubes 104A can be made of a metallic material or any suitable non-metallic material.
Further, a first torque tube segment 202 and a second torque tube 204 segment are connected in an end-to-end manner. The connection between the first torque tube segment 202 with the second torque tube segment is formed by swaging one end of the first torque tube segment 202 and inserting it into the second torque tube segment 204 after suitable apertures are configured on the surface to fasten the first torque tube 202 and the second torque tube 204.
The swaging process is a cold forming process which includes the change of the cross-section of the one end of the first torque tube segment 202. One end of the first torque tube segment 202 is forced to pass through a confined die. When the end of the first torque tube segment 202 is forced through the confined die, the diameter of that end is reduced relative to the initial diameter of the first torque tube segment 202 due to plastic flow of the material at the end of the first torque tube segment 202. Suitable apertures are provided at the operative ends of first torque tube segment 202 and the second torque tube segment 204 for fastening. Thereafter, the end of the first torque tube segment 202 with the reduced diameter is inserted into the second torque tube segment 204 followed by the fastening of the first torque tube segment 202 with the second torque tube segment 204 via any conventional fastening means. In an embodiment, the fastening means include at least one bolt and nut assembly 206 (206A and 206B). The coupling can also be facilitated by the use of rivets, screws, blind bolts or any other threaded profile fasteners, or by snap fitments.
Figure 3A through Figure 3C illustrates a pseudo universal joint to couple a first torque tube segment 302 with a second torque tube 304, both of type 104A. The pseudo universal joint comprises a sleeve 306. In the sleeve 306, an end of the first torque tube segment 302 and an end of the second torque tube segment 304 are positioned in a spaced apart manner. More specifically, the sleeve 306 is mounted at the joining location between the first torque tube segment 302 and the second torque tube segment 304. The sleeve 306 is a hollow metal tube having a diameter that is greater than the diameters of the first torque tube segment 302 and the second torque tube segment 304. Further, the sleeve 306 section has open section at both the ends. The end of the first torque tube segment 302 and the end of the second torque tube 304 are inserted within the sleeve 306 through each operative end of the sleeve 306. Further, at least one pair of aperture is configured at diametrically opposite locations on the sleeve 306, wherein the axis defined by the first pair of apertures 308 is orthogonal to the axis defined by the second pair of apertures 310. At least one coupling element, such as a bolt 312 A, is made to pass through the first pair of apertures 308 and the second pair of apertures 310 for securely coupling the first torque tube segment 302 and the second torque tube segment 304 by bolt and nut assembly 312 (312 A and 312 B). In an embodiment, the diameter of the at least one pair of apertures 308, 310 configured on the sleeve 306 is shaped in a way to allow the longitudinal axis of the first torque tube segments 302 and second torque tube segment 304 to be non-aligned and intersecting during rotation. In a preferred embodiment, the at least one pair of apertures 308, 310 are in the shape of a slot with the length of the slot substantially aligned with the longitudinal axis of the first torque tube segment 302 and second torque tube segment 304. The provision of the slot provides a play to at least one bolt and facilitates the angular displacement between the first torque tube segment 302 and the second torque tube segment 304 even when the axis of the torque tube segments are non-collinear during rotation.
In an operative configuration, the swaged couplings at locations B and the pseudo universal joints at locations A are used in conjunction while connecting the numerous torque tube segments 104A in the array of the torque tube segments 104. Further, the array of solar panels is mounted on the array of connected torque tube segments 104. The locations of swaged couplings 100B and the pseudo universal joints 100C are dependent upon the torsional moment acting on the different joining locations for connecting the torque tube segments 104, as described in the previous sections of the present disclosure.
The present disclosure further envisages a fitting arrangement for fitting a solar panel on a torque tube segment of circular cross section, which provides a functionally slip-free coupling of the solar panel with the torque tube segment of circular cross section. The fitting arrangement of the present disclosure involves the configuring a deformation or a pierced hole on the body of the torque tube segment of circular cross section. The deformation is a dent or a pressed portion that has undergone plastic deformation. The fitting arrangement further comprises a clamp having a configuration that complementary with that of the deformation. The clamp is mated with the deformation, and a purlin is disposed over the clamp. The clamp, the purlin, and torque tube are held in an assembled configuration via fastening means. The solar panels are then mounted on the torque tube via the flanges of two spaced apart purlins. As such, any angular displacement of the purlin with respect to the torque tube is functionally slip-free by virtue of the locking feature provided by the mating of the clamp with the deformation.
The fitting arrangement for fitting a solar panel on a torque tube segment of circular cross section, as envisaged in the present disclosure, is hereinafter described with reference to Fig. 4 through Fig. 9.
Fig. 4 illustrates an isometric view of an apparatus for configuring a dent or a pierced hole on a torque tube of circular cross section, in accordance with the present disclosure. The apparatus 10 comprises a pair of brackets 12 that are configured to hold the torque tube segment 104A of circular cross section. The pair of brackets 12 securely holds the torque tube segment 104A of circular cross section by means of the fastening elements 14. In an assembled configuration, the brackets 12 are so constructed as to define a space 16. A punching or piercing element 18 is then disposed within the space 16 and pressed into the torque tube using any convenient motive power, thereby configuring a dent 52 or a pierced hole on the torque tube segment 104A of circular cross section.
Fig. 5 illustrates a schematic view of a lever arm mounted on the apparatus for configuring a dent or a pierced hole on a torque tube of circular cross section along with a spirit level 26. The plunger 20 presses the punching or piercing element 18 when the lever 22 is pressed downwards. The plunger 20 is restricted in its travel and hence makes a repeatable dent or pierced hole or deformation every time. The spirit level 26 enables the creation of multiple dents along the length of all the connected torque tube segments with repeatability with respect to the horizontal plane.
In another embodiment, the plunger 20 may be replaced with a screw jack mechanism wherein a high efficiency lead screw or ball screw exerts the force creating the dent or pierced hole.
Fig. 6 illustrates an isometric view of the torque tube segment 104A of circular cross section having the dent 52 configured thereon. In another embodiment, the torque tube can have any other cross-section apart from the circular section, e.g., elliptical cross section, oval cross section, geometric configuration, and non-geometric configuration.
Fig. 7 illustrates an exploded isometric view of a fitting arrangement 50 for fitting a solar panel on a torque tube segment. The fitting arrangement 50 comprises a clamp 54. The clamp 54 has protrusion 54A. The clamp 54 is configured to be disposed on the torque tube of circular cross section 62 such that the protrusion 54A mates with the dent 52.
The fitting arrangement 50 further comprises at least one purlin 56 having a top-hat configuration defined by a U-shaped portion 56A having flanges 56B extending from U-shaped portion 56A. The purlin 56, the clamp 54, and the torque tube segment 104A of circular cross section are held in an assembled configuration via a fastening means. In an embodiment, the fastening means include a U-shaped bolt 60A and nuts 60B with appropriate washers 60C.
In the assembled configuration, the dent 52 and the protrusion 54A are mating with each other, while the fastening means allows the secure assembly of the purlin 56, the clamp 54, and the torque tube segment 104A of circular cross section. Therefore, any angular displacement that is given to the torque tube segment 104A of circular cross section, via a tracking mechanism, translates to the angular displacement of the purlin 56 and the solar panel 58 mounted on the flanges 56B of the purlin 56. This transmission of the angular displacement is functionally slip-free by the virtue of the mating of the protrusion 54A with the dent or pierced hole 52.
Fig 8A through Fig. 8C illustrates the various types of clamps that can be used in this application. Fig 8A shows the clamp 54 provided with hardened teeth 54B. Fig 8B shows the clamp 54 with a protrusion 54A that is complementary to the dent 52 in the torque tube segment 104A of circular cross section. Fig 8C shows a stiffening member between the two flanges of clamp 54 that adds to the buckling strength of the flanges of the clamp 54.
Fig. 9 illustrates an isometric view of the solar panels from a viewpoint below the solar panels, being fitted to the torque tube segment 104A of circular cross section via the fitting arrangement 50, as disclosed in the present disclosure. The plurality of solar panels 58 are mounted on the purlins 56, which are coupled to the torque tube segment 104A of circular cross section via the clamp 54 and the U-shaped screw 60A.
As explained previously, the fitting arrangement 50, as disclosed in the present disclosure, facilitates a functionally slip-free coupling of the solar panels 58 with the torque tube segment 104A of circular cross section. The engagement of the protrusion 54A with the dent 52 ensures the functionally slip-free coupling of the solar panels 58 with the torque tube segment 104A of circular cross section.
The present disclosure further envisages a solar tracking displacement apparatus that alleviates the above mentioned drawbacks. The solar tracking displacement apparatus (hereinafter referred as “apparatus 101”), of the present disclosure, is now described with reference to Figure 10 to Figure 21.
Referring to Figure 10 to Figure 13, the apparatus 101 comprises a plurality of vertical posts 102, a plurality of torque tube segments 104A, and a plurality of displacement units 115. The plurality of vertical posts 102 is arranged in a spaced apart configuration. The plurality of torque tube segments 104A is fitted across the upper extremities of the vertical posts 102. The plurality of torque tube segments 104A is being coupled to each other to form an assembled angularly displaceable torque tube segment 104 rotationally about its longitudinal axis. The plurality of displacement units 115 is coupled with the torque tube segments 104A in one to one relationship. Each of the plurality of displacement units 115 is configured to angularly displace the plurality of connected torque tube segments 104 in a controlled and synchronized manner.
In an embodiment, each of the displacement units 115 includes a worm gearbox 117 mechanically coupled to a bevel gearbox 117A, a beam 110, a first wire rope 112A, a second wire rope 112B, a pulley 106, and a semi-circular member 108. The worm gearbox 117 and the bevel gearbox 117A are connected with each other and are supported by a vertical post 102. The beam 110 is orthogonally coupled to a torque tube segment 104A. The pulley 106 is rotatable by the worm gearbox 117. The pulley 106 is configured to wind and unwind the first wire rope 112A and the second wire rope 112B. The semi-circular member 108 is connected to the beam 110. The semi-circular member 108 is coupled to the pulley 106 via the first wire rope 112A and the second wire rope 112B. The semi-circular member 108 is configured to angularly displace the torque tube segment 104A in a controlled manner.
In an embodiment, the semi-circular member 108 has a plurality of supporting beams 140. One end of each of the beams 140 is connected at the beam 110 and another end of each of the beams 140 is connected at arcuate portion of the semi-circular member 108.
In an embodiment, one end of the first wire rope 112A and the second wire rope 112B is fitted at two ends of the respective beam 110 and another end of each of the first wire ropes 112A and each of the second wire ropes 112B is fitted on one of the two pulley flanges 107 of a respective pulley 106.
The displacement means 115 includes wire rope end arrangements 116 as shown in Figure 14 to Figure 19. The wire rope arrangement 116 comprises a crimped wire rope end 128. The crimped wire rope end 128 helps to anchor one end of each of the first wire rope 112A and the second wire rope 112B to the operative ends of the beam 110. One end of each of the first wire rope 112A and the second wire rope 112B is inserted into a crimped wire rope end 128 and is permanently fixed by means of a hydraulic crimping operation. The crimped wire rope end 128 is threaded. The threaded end is inserted into the beam 110 at one of its operative ends. The crimped wire rope end 128 is connected to one end of each of the first wire rope 112A and the second wire rope 112B and is further inserted into a taper washer 130 having a spherical seat. In an embodiment, a spherical washer 136 mates with the spherical seat of the taper washer 130, the hollow tube 126, and a plain washer 132. One end of each of the First wire rope 112A and the second wire rope 112B is finally fitted at two ends of the respective beam 110 by means of wire rope tightening lock nuts 134.
The wire rope end arrangement 116 is provided at one operative end of each of the first wire rope 112A and the second wire rope 112B and is configured to be fitted with two operative ends of the beam 110. More specifically, the wire rope end arrangement 116 provided at one operative end of each of the first wire rope 112A and the second wire rope 112B is inserted into the two ends of the respective beam 110 in such a manner that a self-aligning secure fitment is configured between the beam 110 and each of the first wire rope 112A and the second wire rope 112B. In an embodiment, the spherical seat on the taper washer 130 and the spherical washer 136 together provide for the self-aligned seating of the wire rope end arrangement 116 with the respective beam 110.
The other operative end of each of the first wire rope 112A and the second wire rope 112B is inserted through a hole in one of the two pulley flanges 107 of the pulley 106 and is fitted with a wire rope clamp 138. The wire rope clamp 138 is bolted to each of two flanges 107 of the pulley 106.
In an embodiment, the apparatus 101 includes a motor 118, as shown in Figure 10 to Figure 20. The motor 118 is coupled to the one of the worm gearboxes 117 and bevel gearboxes 117A. The other gearboxes 117A that are mechanically coupled with the other worm gear boxes 117 on the other posts 102 are coupled via a torsion rod or pipe 144 as depicted in Figure 21. The motor is configured to generate a rotary drive and is further configured to drive each of the displacement units 115 based on the generated rotary drive via the torsion rod or pipe 144.
In an embodiment, the gearbox 117 is having an output shaft 118A. The output shaft 118A is configured to angularly displace the pulley 106 based on the rotary drive generated by the motor 118 through the worm gear box 117 and is transmitted to the other worm gear boxes 117 through the torsion rods 144 and bevel gear boxes 117A.
The apparatus 101 further comprises a swivel pin joint 114, a clamp 124, a connecting bracket 120, and a connecting bushing 122 as depicted in Figure 10 to Figure 14. The swivel pin joint 114 is mounted between a clamp 124 for the torque tube segment 104A and the beam 110. The connecting bracket 120 is mounted on each of the posts 102. The connecting bracket 120 is connected to the post 102 and is configured to securely connect the connecting bushing 122 with the post 102 such that the rotating axis of the torque tube segment 104A is held in the connecting bushing 122. The connection of the connecting bracket 120 with the post 102 allows the connecting bushing 122 to hold the torque tube segments 104 such that the rotating axis of the torque tube segments 104 need not be perpendicular to the longitudinal axis of the post 102 erected on the plane of ground 146. More specifically, a tilt of up to ±7º is provided to the inclination of the rotating axis of each of the torque tube segments 104A with respect to the axis perpendicular to the longitudinal axis of each of the posts 102 to accommodate installation of the tracker on sloped land. The swivel pin joint 114 between the beam 110 and the clamp 124 for the torque tube segments 104A accommodates the tilt of the torque tube segments 104A such that the semi-circular member 108 stays between the two pulley flanges 107 of the pulley 106 by virtue of the tension in the first wire rope 112A and the second wire rope 112B and the location of the semi-circular member 108 between the two pulley flanges 107 of pulley 106.
In an operative configuration, the motor 118 is configured to provide a rotary drive to the gearbox 117 to rotate the pulley 106 via the output shaft 118A. The first wire rope 112A and the second wire rope 112B wound on the pulley 106 and the semi-circular member 108 such that one end of the first wire rope 112A and the second wire rope 112B is fitted in the crimped wire rope end 128 and is fitted at two operative ends of the beam 110. The another end of the first wire rope 112A and the second wire rope 112B is fitted on one of the two pulley flanges 107 of the pulley 106 by means of the wire rope clamp 138. The gear box 117 is configured to provide a rotary drive to the pulley 106 via the output shaft 118A and facilitates the winding and unwinding of the first wire rope 112A and the second wire rope 112B on the pulley 106. The winding and unwinding of the first wire rope 112A and the second wire rope 112B facilitates angular displacement of the semi-circular member 108 about the longitudinal axis of torque tube segment 104A. The winding and unwinding of the first wire rope 112A and the second wire rope 112B in tandem is such that when the first wire rope 112A is reeled in and wound on the pulley 106, the second wire rope 112B is paid out or is being unwound on the pulley 106. The semi-circular member 108 is angularly displaced by rotation of the pulley 106 such that one operative end of the beam 110 experiences a force due to the tension transferred through the one of the wire ropes 112A or 112B. The angular displacement of the semi-circular member 108 tends to rotationally displace the torque tube segment 104A about its longitudinal axis. Thus the apparatus 101 of the present disclosure displaces the torque tube segments 104A in controlled manner.
The apparatus 101 is mounted on one or more posts 102 in one row of the tracker as shown in Figure 21. In an embodiment, a plurality of bevel gearboxes 117A which are a connected to the plurality of corresponding worm gear boxes 117 are linked together mechanically using torsion rod or pipe 144 fixed substantially above the ground plane 146 and suitable combination of gears in the gearboxes 117 and 117A such that only one of the gearbox 117 requires the motor 118. Such an arrangement is lower in cost as fewer motors and electronic driving boards are used to drive one tracker at multiple locations. Additionally, each of the gearboxes 117 and 117A is configured using a suitable combination of worm and bevel gears. This combination of gears provides for functional self-locking of each of the output shaft 118A. The suitable combination of worm gearboxes 117 and bevel gearboxes 117A also provides for a parallel configuration between the torsion rod or pipe 144 and the output shafts 118A of the plurality of worm gearboxes 117.
In an embodiment, the output shaft 118A of the gearbox 118 experiences a lateral bending force when one of the first wire rope 112A and the second wire rope 112B experiences tension. This lateral bending force is transferred as a twisting moment on the post 102. A suitable arrangement to eliminate this transfer of twisting moment to the post 102 is configured in the form of a second short supporting post 102’ at the far end of the output shaft 118A of the worm gearbox 117. This second short supporting post 102’ is embedded into the ground and is configured of unsymmetrical cold formed sections like C Lip sections, which are otherwise susceptible to torsional twisting but cheaper than heavier hot rolled steel sections.
In another embodiment the post 102 is configured as a back to back bolted post comprising of one long length and one short length cold formed sections like the C Lip section. The bolted configuration is configured in the region of the post 102 which is embedded in the ground and can be connected to the supporting post 102’. This configuration is substantially stronger in twisting about its longitudinal axis and avoids the cost of a different type of foundation The connection between the short supporting 102’ and the vertical post 102 is shown in figure 10. This arrangement transfers the lateral load on the output shaft 118A directly to the foundation.
A typical array of solar panels is approximately 65.45m long. In an embodiment, the apparatus 101 comprises 8 torque tube segments 104A having a length of 7.7m and one torque tube segment 104A having half the length of the longer torque tube segments 104A. In accordance with the present embodiment, the 9 torque tube segments 104A are supported on 9 posts 102 which are erected on the ground in a spaced apart manner. The solar panels are mounted on these torque tube segments 104A, and assembly of all the torque tube segments 104A is rotated as a single connected torque tube segment 104 in a controlled and synchronized manner.
The apparatus 101 of the present disclosure, further discloses an advantage that the torsion capacity of the torque tube segments 104A is utilized in an optimal manner. When driven at multiple locations that are suitably spaced apart, the torsion capacity of the torque tube segments 104A is not exceeded during the operation as the torsion is transferred in the form of tension to each of the first wire rope 112A and the second wire rope 112B to the pulley 106 which is configured on the output shaft 118A of the worm gearbox 117 configured with self-locking gear combination. The support of the second short post to the far end of the output shafts 118A and the load path enumerated above converts the torsion experienced by the torque tube segments 104A to bending of the output shaft 118A. The bending of the output shaft 118A is further transferred to the foundation in the manner enumerated previously. This configuration has the further advantage of the ability to design a majority or all of the torque tube segments 104A of the same circular cross section. Additionally as the maximum amount of torsion induced in the connected torque tube segments 104 is limited due to it being locked in torsion by displacement means 115 at multiple locations, the cross section of the torque tube segments 104A can be lower. This leads to economy of scale and ease of sourcing and a more economical structure.
The apparatus 101 of the present disclosure, further discloses an advantage that the torque tube segment 104A is locked in torsion at multiple locations along its length. This is because any torsion experienced in operation is transferred to the self-locking worm gear box 117 mounted on post 102 through the displacement means 115. The worm gear box 117 is configured to rotate only with the motor rotates its input shaft. This makes the torque tube segment 104A of the apparatus 101 stiff in torsion and eliminates the possibility of the apparatus 101 suffering damage due to torsional galloping. This is also accomplished without the use of oil filled dampers, thereby making the apparatus 101 economical to construct and safe to operate.
TECHNICAL ADVANCES AND ECONOMICAL SIGNIFICANCE
The present disclosure described herein above has several technical advantages including, but not limited to, the realization of an apparatus that:
• is cost effective;
• eliminates the use of expensive electromechanical actuators, slew drives or hydraulic cylinders;
• provides for a distribution of torsional moments at multiple locations in the tracker row;
• provides for a maintenance free mechanism for driving the solar tracker;
• provides mounting arrangement of solar trackers on sloped land;
• facilitates installation of torque tubes on sloping ground such that the rotating axis of the torque tube segments comprising the torque tube need not be perpendicular to the longitudinal axis of the posts erected on the ground;
• eliminates the use of oil filled dampers required to keep the mechanism safe from damage due to torsional galloping; and
• provides for an economical and cost effective module mounting structure.
The foregoing description of the specific embodiments so fully reveals the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.
Throughout this specification the word “comprise”, or variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.
The use of the expression “at least” or “at least one” suggests the use of one or more elements or ingredients or quantities, as the use may be in the embodiment of the disclosure to achieve one or more of the desired objects or results.
Any discussion of documents, acts, materials, devices, articles or the like that has been included in this specification is solely for the purpose of providing a context for the disclosure. It is not to be taken as an admission that any or all of these matters form a part of the prior art base or were common general knowledge in the field relevant to the disclosure as it existed anywhere before the priority date of this application.
While considerable emphasis has been placed herein on the components and component parts of the preferred embodiments, it will be appreciated that many embodiments can be made and that many changes can be made in the preferred embodiments without departing from the principles of the disclosure. These and other changes in the preferred embodiment as well as other embodiments of the disclosure will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the disclosure and not as a limitation.
,CLAIMS:WE CLAIM:
1. A solar tracking displacement apparatus (101) comprising:
a. a plurality of vertical posts (102) arranged in a spaced apart configuration;
b. a plurality of torque tube segments (104A) fitted across the upper extremities of said vertical posts (102), said torque tube segments (104A) being coupled to each other to form an assembled torque tube (104) displaceable rotationally about its longitudinal axis; and
c. displacement means (115) coupled to said torque tube segments (104A), said displacement means (115) configured to rotationally displace said plurality of connected torque tube segments (104) in a controlled and synchronized manner.
2. The apparatus (101) as claimed in claim 1, wherein said displacement means (115) includes:
a. a plurality of mechanically coupled gearboxes (117 and 117A), wherein each of said plurality of mechanically coupled gearboxes (117 and 117A) is supported by a respective vertical post (102);
b. a plurality of beams (110), wherein each of said plurality of beams (110) is orthogonally coupled to a respective torque tube segment (104A);
c. a plurality of first wire ropes (112A);
d. a plurality of second wire ropes (112B);
e. a plurality of pulleys (106), wherein each of said plurality of pulleys (106) is rotatable by a respective worm gearbox (117), each of said pulleys (106) is configured to wind the first wire rope (112A) while unwinding the respective second wire rope (112B) and vice versa; and
f. a plurality of semi-circular members (108), wherein each of said plurality of semi-circular members (108) is connected to a respective beam (110), wherein each of said semi-circular member (108) is coupled to a respective pulley via a respective first wire rope (112A) and respective second wire rope (112B), each of said semi-circular members (108) is configured to rotationally displace a respective torque tube segment (104A) about its longitudinal axis in a controlled manner and hence the plurality of connected torque tube segments (104) in a controlled and synchronized manner.
3. The apparatus (101) as claimed in claim 2, wherein said apparatus includes a motor (118), said motor (118) is coupled with one of said plurality of worm gearboxes (117) mechanically coupled to corresponding bevel gear boxes (117A). The plurality of bevel gear boxes (117A) are coupled via a torsion rod or pipe (144), said motor (118) is configured to generate a drive, said motor (118) further configured to drive each of said plurality of bevel gearboxes (117A) based on said generated drive via said torsion rod or pipe (144).
4. The apparatus (101) as claimed in claim 2, wherein one end of each of said first wire ropes (112A) and each of said second wire ropes (112B) is fitted at two ends of a respective beam (110) and another end of each of said first wire ropes (112A) and each of said second wire ropes (112B) is fitted on one of the two pulley flanges (107) of a respective pulley (106).
5. The apparatus (101) as claimed in claim 3, wherein each of said plurality of gearboxes (117) has an output shaft (118A), said output shaft (118A) configured to angularly displace each of said plurality of pulleys (106) based on said drive generated by said one motor (118).
6. The apparatus (101) as claimed in claim 2, wherein each of said plurality of beams (110) is coupled to a respective torque tube segment (104A) via a respective swivel pin joint (114).
7. The apparatus (101) as claimed in claim 1, wherein each of said torque tube segments (104A) is coupled to a respective post (102) via a respective connecting bracket (120).
8. The apparatus (101) as claimed in claim 2, wherein each of said semi-circular members (108) is an arcuate rope guide.
9. The apparatus (101) as claimed in claim 1, wherein each of said torque tube segments (104A) has a circular cross section.