DE102020107793A1 - Tracking device for a PV system (central tube and support structure for PV modules) - Google Patents

Abstract

A PV system with a tracking device is proposed which is very light and inexpensive to manufacture; it is and is nevertheless very resilient and has a very simple construction that gets by with little material. It is therefore relatively light and yet very robust.

Description

The power generation of PV systems can be significantly increased if the PV modules can track the position of the sun in the course of a day. This has made it possible to increase electricity generation by 30 to 40%.

A common concept of such a tracking device provides a central tube that is as torsionally stiff as possible and that is rotatably mounted on several supports. One or two rows of PV modules are arranged on an upper side of the central tube. The central tube can be rotated with the help of a (rotary) drive. The PV modules attached to the central tube take part in this rotary movement and are thus tracked to the sun.

In the PV systems available on the market, the PV modules are attached to the central tube with the help of purlins, the length of which is roughly twice the length of a PV module. These purlins protrude outward orthogonally to the longitudinal axis of the central tube and each carry a PV module on both sides of the central tube. As a result, the PV modules lie on the purlins over their entire length and are held and supported by them.

For economic reasons, efforts are made to make the central tubes very long and to provide a (rotary) drive for the central tube in the middle of the central tube. Examples of this concept are in the US 2017/0359017 A1 , the US 2018/0073773 A1 and the US 2017/0187327 A1 described. This concept has proven itself in practice.

In PV systems with central tubes, the central tube is subjected to torsion and bending due to wind loads or weight forces. It is particularly important to limit torsion, as otherwise the PV modules mounted on the central tube will be damaged.

This applies to everything for wind-induced dynamic torsion effects, such as so-called "galopping". This is understood to mean wind-induced torsional vibrations of the central tube, which increase from a certain wind speed to such an extent that the PV modules arranged on the central tube are damaged. In the worst case, “gallopping” can lead to a total loss of the PV system.

The invention is based on the object of optimizing this concept with a view to economic efficiency, availability and service life as well as installation and operating costs, taking into account the specific boundary conditions of outdoor PV systems.

This object is achieved according to the invention by a tracking system for a PV system comprising a central tube, several spaced-apart supports, a rotary drive for the central tube, the central tube being rotatably mounted on the supports, the central tube being composed of several segments, with two adjacent segments are plugged into one another directly or indirectly via a sleeve to form a form-fitting plug connection, and the plug connection is suitable for the transmission of torques and / or bending moments.

The direct plug connection according to the invention of segments of the central tube or indirectly using a sleeve makes it possible to manufacture the segments in a factory and to transport them by land or sea to the location of the PV system. Industrial production increases quality and lowers manufacturing costs. In the tracking device according to the invention, the restriction in the length of the segments, which is caused by the transport from the factory to the location of the PV system, is converted into an advantage. The form-fitting plug connection between two segments can transmit the bending and torsional moments that occur during operation. According to the invention, the connection points between two segments are placed at the locations where the bending moments and / or torques acting on the central tube are large. For example, a plug connection according to the invention is preferably provided where the central tube is rotatably mounted on the supports and / or the rotary drive introduces the torque required to pivot the central tube into the central tube. In an overlapping area of the plug connection, the material thickness is in many cases twice as great as in the other areas of the central tube; assuming that the segments and the socket have the same wall thickness. But you can also choose a larger wall thickness of the sleeve. Due to the form-fitting plug connection according to the invention with or without a sleeve, the wall thickness of the central tube is at least doubled at the connection points. As a result, higher torques and bending moments can also be transmitted there without the central tube failing.

The person skilled in the art normally strives to place the connection of components in zones in which no high mechanical stresses occur. The invention "disregards" this rule and uses the socket for local reinforcement of the central pipe in particularly polluted areas. Different In other words: the wall thickness of the central tube can be reduced in the less stressed areas.

The object mentioned at the beginning is also achieved according to the invention by a tracking system for a PV system comprising a central tube, several spaced-apart supports and a rotary drive for the central tube, the central tube being rotatably mounted on the supports, with purlins on an upper side of the central tube are attached so that they protrude on both sides of the central tube and where a length L _{13 of} the purlins is less than 0.5x the length of a PV module, so that the purlins on both sides of the central tube by only about a quarter of the Extend the length of a PV module beyond the central tube.

This reduces the material used for the purlins to less than 25%, assuming that the length of "normal" purlins is more than twice the length of a PV module. This reduces the material costs and the system weight considerably. In addition, the arrangement according to the invention is lower and offers a smaller surface area for wind and storm, thereby reducing the wind-induced excitations of the tracking device and the resulting dangers.

In the invention, the frames that are already present in PV modules rest at one end on the short purlins and are connected to them there. As a result, the frame of each PV module takes on the “load-bearing function” that the very long purlins take over with conventional tracking devices. This reduces weight, material usage and costs.

It is possible to mount one or two rows of photovoltaic modules (hereinafter PV modules) on the central pipe with the help of the purlins. In the figures, two rows of PN modules are always shown.

It has proven to be advantageous if the central tube consists of a closed sheet metal profile that has been folded over several times. It is possible to assemble the central tube from two halves and to connect it to one another along the joint by cinching, riveting, gluing and / or welding. This creates a very torsionally stiff central tube. The central tube or its segments can be manufactured inexpensively from thin sheet metal, in particular sheet steel or aluminum sheet. A wall thickness of 2 mm is sufficient in many cases.

The segments of the central tube can be produced, for example, with a length of 10 meters and then transported by land to the location of the PV system.

It has proven to be advantageous if the central tube has an octagonal, axially symmetrical cross section, with a height H of the central tube greater than a width B. of the central tube is. This cross section allows the load capacity of the central tube to be adapted to the loads that actually occur. If the height of the central tube is greater than its width, the bending moments resulting from the weight of the PV modules and the torsional moments occurring during operation can be absorbed. At the same time, the stress on the material is relatively even over the circumference of the central tube. The central tube according to the invention is therefore very light and inexpensive and nevertheless very resilient and powerful.

When the sleeve is pushed into the interior of segments of the central tube (hereinafter referred to as inner sleeve), it has a cross section that enables a positive fit with the inner cross section of the segments. The clearance between the socket and the segments is small; it can even be zero.

The outer contour of the inner sleeve and the inner cross-section of the segments do not necessarily have to be geometrically similar; For example, the inner sleeve can be designed as a tube with eight ribs, with one rib being received in one corner of the segment without play or with little play. This also results in a form-fitting connection between the inner sleeve and the segment.

In a corresponding manner, the sleeve (outer sleeve), when it is pushed onto the segments of the central tube, has an inner cross-section which is designed so that it can be pushed onto the segments with little play.

In addition, it is possible to connect the segments with each other with screws or rivets in order to effectively prevent unwanted "wandering" of the socket on the central pipe.

The transmission of bending moments and torques takes place via the large-area form fit between the socket and the segments of the central tube or directly between the segments of the central tube.

The sleeve can be produced, for example, by extrusion. Of course, it is also possible to manufacture the sleeve from folded sheet metal, similar to the segments of the central tube. Length and wall thickness of the socket are in Essentially determined by the bending moments that the socket has to transmit.

In order to be able to fasten the PV modules to the "top" of the central tube and to be able to support the PV modules with the help of struts, several fastening straps are provided at regular intervals on the segments. The fastening straps are usually welded-on sheet metal straps.

As a rule, four fastening straps are arranged in one plane, the normal vector of which runs parallel to the longitudinal axis of the central tube. The two upper fastening straps are used to connect a short purlin to the central tube. A PV module is attached to this short purlin, for example by screwing or riveting the frame of the PV module to the purlin.

A strut that supports the PV module from below is attached to each of the two lower fastening straps. The struts are connected to the frame of the PV module. The distance between this connection and the support of the frame on the purlins is greater than half the length of a PV module. As a result, the weight forces of the PV module are introduced into the central tube easily and with little material expenditure.

The struts, which are attached to the underside of the central tube, are shorter than a PV module and support this PV module on its underside. As a result, the frame of the PV module, which is already present, is integrated into the PV system according to the invention as a load-bearing element. This saves construction costs and reduces the use of materials. Both improve the economy of the PV system according to the invention.

Basically, it is desirable if the angle between the frame of the PV module and the struts is as large as possible. It should be at least 10 °, but preferably more than 15 ° and ideally even more than 20 °. Then the forces that act on the frame of the PV module and the struts are minimal.

In principle, this is supported by the cross-section of the central tube according to the invention. To increase this angle without increasing the height H To change the central tube, it is possible to provide a spacer between the underside of the central tube and the bearing point of the strut.

In order to be able to introduce the torques required for tracking the PV modules into the central tube, a flange is welded to the socket or a segment of the central tube. Alternatively, the flange can also be connected to the socket or segment by cinching, riveting and / or gluing. This flange has to absorb very large forces and is therefore made of relatively thick sheet metal.

In order to improve the introduction of the load from the flange into the central tube or the socket, a reinforcement plate is provided in accordance with the invention in the interior of the central tube or the socket and, if necessary, welded in place. This causes a local reinforcement of the central pipe where the flange is welded to the central pipe or the socket. In addition, the welding of the thick-walled flange to the relatively thin-walled segment or the relatively thin-walled sleeve is facilitated. In addition, the load transfer from the flange into the segment or the socket is improved.

However, it is also possible to push two segments directly into one another and thereby implement the plug connection according to the invention without a sleeve. will. In this case, a first segment has a slightly smaller outer contour than the other segment, so that the first segment can be pushed into the other segment without play or with little play to form a plug connection. A connecting element with a flange and a lever can be arranged in the overlapping area of this plug connection.

The connecting element is preferably open on one side so that it can be pushed onto the central tube at any desired point and can be fixed there, for example by means of screws. The transmission of torque between the central tube and the connecting element takes place in a form-fitting manner via the outer contour of the central tube and the inner contour of the connecting element.

According to the invention it is provided that the drive for pivoting or rotating the central tube is a linear drive, one end of which is rotatably mounted on the flange or a lever formed on the flange. The other end of the drive is attached at least indirectly to a support of the tracking device. As a rule, you will screw a bracket to the support, which in turn takes the end of the linear drive.

Electric linear drives (i.e. electromechanical screw drives), hydraulic cylinders or pneumatic cylinders, can be used as linear drives. The construction according to the invention is designed and suitable for all types of linear drives.

• Das Zentralrohr ist im Betrieb Torsionsbelastungen und Biegemomenten ausgesetzt, die über seine Länge variieren. Das Zentralrohr muss eine gewisse Steifigkeit aufweisen und ihre Konstruktion darf unter keiner der im Betrieb auftretenden Lasten (Normalbetrieb, Sturm, Schneefall) versagen.

Some aspects of the invention are summarized again below:

• During operation, the central tube is exposed to torsional loads and bending moments that vary over its length. The central pipe must have a certain rigidity and its construction must not fail under any of the loads occurring during operation (normal operation, storm, snowfall).

In order to achieve an efficient material utilization, it is desirable to load the material almost equally at all points on the central tube, so that a good material utilization is achieved. At the same time, the central tube should be simple and inexpensive to manufacture. The selected octagonal cross-section, its height H is larger than its width B. fulfills these boundary conditions in an excellent way. Because there are intermediate surfaces between the flat surfaces (top, bottom and side walls) of the central tube, local kinking problems are avoided. It is also possible to introduce local material deformations (for example in the form of beads) into the flat surfaces of the central tube in order to further reduce the risk of bulging due to local overloads.

Another problem with thin-walled tubes is the introduction of forces and / or torques into these tubes. According to the invention it is provided to weld fastening straps to the central tube. The purlins and struts according to the invention will be mounted on these fastening straps.

The tabs or fastening tabs according to the invention are preferably welded to the intermediate surfaces of the central tube and are shaped in such a way that they fill the “corners” created by the preferably octagonal tube section. The resulting rectangular cross-section of the central tube in this plane facilitates the transport of the central tubes.

If one considers the torsional load and the bending stress on the central tube, it becomes clear that under certain load conditions, both the torsional and the bending moment are locally different. In other words: the loads are a function of the location or the distance from the rotary drive. Normally, a central pipe is dimensioned in such a way that it can cope with the most unfavorable load case at any point, although this load case only occurs in a few places. The result is an oversized central tube that is very heavy and more expensive than necessary.

According to the invention, it is provided that notable segments of the central tube are positively connected by sleeves, preferably in the areas in which locally high torsional loads and / or high bending loads occur during operation. These are usually the places where the central tube is rotatably mounted on the supports.

The sleeves create overlapping areas in which the wall thicknesses of the central pipe and sleeve add up. Due to the locally greater wall thickness, the stresses [N / mm ² ] occurring in the central pipe and the socket are reduced and local overloading of the central pipe is effectively prevented.

The octagonal profile of the pipe and a large overlap between the socket and segments of the central pipe make it possible to transfer both bending and torsional moments from one segment to another. The overlapping of pipes at highly stressed points doubles the torsional strength and the moment of inertia and thus reduces stress peaks. This enables thinner elements in areas with little stress on the pipe, which reduces material consumption with constant cross-sections within an element.

In order to effectively transfer torsional loads, the pipes can either be provided with a geometric locking profile (such as the octagonal shape), which is able to transfer the torsional loads. A minimum length of the overlap is required to transfer bending loads.

• eine Verstärkungsplatte angeschweißt wird. Dies führt zu einer besseren Krafteinleitung in das Zentralrohr und vereinfacht den Schweißvorgang.

Another problem is the introduction of torques from the actuating drive into the central tube. This is done according to the invention by a flange on which a lever can be formed. A linear drive according to the invention is in turn attached to the lever. According to the invention it is provided that where the flange is welded to the socket and / or a segment of the central tube, on the inside of the socket and / or the segment

• a reinforcement plate is welded on. This leads to a better introduction of force into the central tube and simplifies the welding process.

PV tracking systems with a (long) central tube and only one rotary drive can twist under wind load. These wind-induced "harmonic" torsional vibrations ("galopping") can reach large amplitudes and destroy the tracking device and the PV modules. Therefore, they must be prevented or limited.

This is done by a twist lock according to the invention. If the torsion tube at the place where the locking device is installed (usually this is a support of the PV system) a When a defined (rotary) position is reached, the rotary lock according to the invention is activated and, as a result, further torsion of the central tube is prevented at this point. Locking device is installed on a support which is located relatively far from the drive of the central tube. There the wind-induced torsion of the central tube is relatively large. The twist lock according to the invention limits the torsion to an unktitsches amount. As a result, gallopping is prevented.

In the PV system according to the invention, a purlin with a reduced length is used, which is only long enough to connect the inner fastening tabs of the module frame / panel to the central tube. The outer mounting bracket is supported by an additional diagonal strut that is connected to the lower mounting bracket on the bottom of the central tube. The strut acts as a pressure element and reduces the bending in the purlin.

Further advantages and advantageous embodiments of the invention can be found in the following drawing and description thereof and in the claims.

All of the features disclosed in the drawing and the description thereof in the claims can be essential to the invention both individually and in any combination.

Figure list

• 1: Eine Isometrie einer erfindungsgemäßen PV Anlage mit Nachführsystem einer erfindungsgemäßen PV-Anlage,
• 2: eine Isometrie eines Teils der erfindungsgemäßen Nachführsystems,
• 3: eine Seitenansicht eines Teils der erfindungsgemäßen Nachführsystems,
• 4: den Querschnitt durch ein Ausführungsbeispiel eines erfindungsgemäßen Zentralrohrs,
• 5 und 6: Alternativen der erfindungsgemäßen Verbindung von Segmenten des Zentralrohrs,
• 7 und 8: ein Ausführungsbeispiel einer erfindungsgemäßen Verbindung zwischen einem Flansch und dem Zentralrohr bzw. einer Muffe,
• 9 und 10: ein weiteres Ausführungsbeispiel einer erfindungsgemäßen direkten Verbindung von zwei Segmenten ohne Muffe,
• 11 und 12: ein weiteres Ausführungsbeispiel einer erfindungsgemäßen Verbindung zwischen einem Flansch und dem Zentralrohr bzw. einer Muffe,
• 13 bis 16: Die erfindungsgemäße Lagerung des Zentralrohrs auf einem Polygon in verschiedenen Darstellungen;
• 17 bis 20: Details der erfindungsgemäßen Anordnung und Befestigung der PV-Module auf dem Zentralrohr und
• 21 und 22: zwei Ansichten des PV-Trackers.

Show it:

• 1 : An isometry of a PV system according to the invention with a tracking system of a PV system according to the invention,
• 2 : an isometry of part of the tracking system according to the invention,
• 3 : a side view of part of the tracking system according to the invention,
• 4th : the cross section through an embodiment of a central tube according to the invention,
• 5 and 6th : Alternatives of the connection according to the invention of segments of the central tube,
• 7th and 8th : an embodiment of a connection according to the invention between a flange and the central tube or a sleeve,
• 9 and 10 : Another embodiment of a direct connection according to the invention of two segments without a sleeve,
• 11 and 12th : Another embodiment of a connection according to the invention between a flange and the central tube or a sleeve,
• 13th until 16 : The storage of the central tube according to the invention on a polygon in different representations;
• 17th until 20th : Details of the inventive arrangement and fastening of the PV modules on the central tube and
• 21 and 22nd : two views of the PV tracker.

Description of exemplary embodiments:

In the 1 a PV system with a tracking system according to the invention is shown in a view from the rear.

The entire PV system with the tracking system according to the invention is denoted by the reference symbol 1 Mistake. The PV system 1 includes a variety of PV modules 3 on both sides of a central tube 5 are arranged. The central tube 5 is on supports 7th rotatably mounted. The structural details of this storage are in the 1 not visible. In the 1 but also the 2 it can be seen that each PV module 3 a frame 9 having. This frame 9 serves to stabilize so that the glasses and silicon layers of the actual PV module 3 are not exposed to any inadmissible mechanical loads. The frame 9 usually consists of four aluminum profiles that are connected to each other at the corners.

Between the "underside" of the central tube 5 and the frame 9 the PV modules 3 are striving 11 arranged. They support the PV modules 3 . In the 1 can also be seen that the frame 9 in the area of the central tube 5 on purlins 13th rest. The purlins 13th are as short metal profiles that are used as supports for the frame 9 the PV modules 3 serve in the area of the central tube. The purlins 13th are connected to the top of the central tube.

The frame 9 can with the purlins 13th be screwed. It is also possible to frame the frame over rivets or in some other way 9 the modules with the purlins 13th connect to.

The striving 11 are at one end with the central tube 5 connected at the bottom; for example by a screw or rivet connection.

The opposite end of the strut 11 is with the frame 9 of the PV module 3 also connected by screws or rivets. For the rigidity and stability of the construction according to the invention, it is important that the fastening straps of the frame 9 on the purlins 13th on the one hand and the Point at which the struts 11 the frame 9 support as large a distance A from each other as possible. There should also be an angle 15th between the struts 11 and the frame 9 choose to be as large as possible. Then the mechanical load on both the frame and the same material use 9 both of the pursuit 11 minimized.

A linear drive is arranged on the support 7. A rotary lock according to the invention is arranged on the support 7. This twist lock is explained below using the 11 until 14th explained in detail.

In the 2 the central tube 5 with the purlin 13th , a strut 11 as well as a PV module 3 with frame 9 shown. The fact that a large number of components compared to the 1 has been omitted, the clarity is improved. At the in 2 left part of the central tube 5 it can be seen that there are four fastening straps at regular intervals 19th are arranged. These four fastening straps are in one plane. A normal vector of this plane runs parallel to a longitudinal axis of the central tube 5 .

At the right end of the central tube 5 are the four fastening straps 19th can also be seen. There is a purlin on the two upper fastening straps 13th screwed on. The two in the 2 lower fastening straps serve as abutments for the struts 11 . In the left part of the 2 it can be seen that the fastening straps can be designed as bent sheet metal parts. You can with the central tube 5 be connected for example by welding, chinches or rivets.

The distances between the fastening straps 19th in the longitudinal direction of the central tube 5 are based on the width of the PV modules 3 matched, this allows a purlin 13th two neighboring PV modules 3 be attached. It is also possible with a strut 11 2 neighboring PV modules 11 to support. That is in the 2 not recognizable because only one PV module 3 was shown.

the 3 shows a front view of a PV system according to the invention 1 . They are the same components as in the 2 visible. How to get out of the 3 can clearly see is the PV system with respect to the central pipe 5 symmetrically constructed, so that the weight forces of the PV modules 3 cancel each other out. Also the thrust of the struts 11 on the central tube 5 cancel each other out.

In the 3 is below the central tube 5 a warehouse 21 visible. This camp 21 forms the axis of rotation or swiveling of the central tube 5 and the components arranged thereon; especially the PV modules 3 .

In the 4th is the cross section of the central tube according to the invention 5 shown. The cross section of the central tube 5 is symmetrical with respect to one axis 23 and an axis 25. A height H of the central tube 5 is greater than a width B. of the central tube 5 . This allows the central tube 5 can absorb the bending moments resulting from the weight of the PV modules in addition to the wind-induced torques.

This is due to the magnification H opposite the width B. achieved. The width B. is ultimately largely determined by the torques to be transmitted. By appropriately coordinating the relationship H / B. it is possible to measure the material stress at different points on the central tube 5 to keep it at a high level and to equalize it. As a result, a material-saving and lightweight construction is achieved without impairing the service life and stability of the construction.

In the 4th are next to the width B. and the height H of the central tube 5 a top 27 , a subpage 29 as well as side walls 31 provided with reference numerals. Top 27 and bottom 29 have the same dimensions. The same applies to the side walls 31 . This results from the symmetry of the cross-section with respect to the axes 23 and 25.

Between the top 27 and the side walls 31 or the bottom 29 and the side walls 31 are each intermediate surfaces 33 (here at an angle of 45 °) arranged so that the cross-section of the central tube 5 composed of eight surfaces and accordingly eight corners.

In the in 4th right part is a cross section through the central tube according to the invention 5 shown in one plane in which four fastening straps 19th available. The fastening tabs 19th can be designed as multiple folded sheet metal profiles with a U-shaped cross-section when viewed from the side of the central tube (see FIG 12th ). With the fastening straps shown as an example 19th becomes the octagonal cross-sectional profile of the central tube in the plane shown 5 to a "rectangle".

The fastening tabs 19th have screw holes, which are shown by dash-dotted lines. In the area of the top 27 is made with the help of the fastening straps 19th or their screw holes in the 2 shown purlin 13th screwed on.

On the fastening straps 19th the bottom 29 become the striving 11 which the PV modules 3 to the frame 9 support, screwed on (see also the 17th and their description). Further details are given below using the 17th ff shown and explained.

To the angle 15th (please refer 3 ) between the frame 9 and the striving 11 To increase the size and thereby reduce the stress on these components, it can be advantageous on the underside 29 of the central tube an intermediate element 35 to arrange. This intermediate element 35 be a square tube. It is attached to the lower mounting tabs 19th screwed on. On its underside 36 there are screw holes for a strut 11 to fix. This can target the load on the struts 11 and the frame 9 can be reduced without the central tube 5 would have to be changed in its geometry.

Based on 5 and 6th are variants of the connection according to the invention of two segments of the central tube 5 explained with a sleeve. The segments of the central tube 5 are in the 6th and 7th marked with 5.1, 5.2 and 5.3.

The connection according to the invention between the segments 5 and 5.2 can with the help of a first embodiment of a sleeve according to the invention 37 will be realized. The socket 37 is pushed into the interior of the segments 5 and 5.2. This means that the socket 37 has an outer contour that corresponds to the inner contour of the central tube 5 is equivalent to. In the 4th is the inner contour with the reference symbol 39 designated.

The connection between segments 5 and 5.3 is made via a sleeve 43 , which is pushed over the segments 5 or 5.3 on the outside. This means that the inner contour of the socket 43 the outer contour 41 (please refer 4th ) of the central tube 5 or its segments 5, 5.3 corresponds.

The covering of the sleeves 37 respectively 43 and the segments 5, 5.2 and 5.3 is in the 5 and 6th with the reference number 45 been provided.

Between the sleeves 37 , 43 and the segments 5 to 5.3 a sliding fit or a slight clearance fit is provided for the assembly of the sleeves 37 , 43 Easy to design on site. So that the inventive transmission of bending and torque between the segments 5 and 5.2 or 5.2 and 5.3 with the help of the sleeves 37 , 43 can take place is the overlap 45 to choose sufficiently large. Starting from the main dimensions H , B. of segments 5, 5.2, 5.3 and the static and dynamic loads to which it is exposed during operation, the required overlap can be determined for each application 45 determine.

In the 6th is the connection between the socket 37 and segment 5 of the 6th shown in a little more detail. In this illustration are a side wall 31 as well as two intermediate surfaces 33 of segment 5 visible. The socket 37 shows on its outside the inner contour 39 of the segment 5 on corresponding side walls and intermediate surfaces. These are in the 6th not provided with a reference number. Also the overlap 45 is in the 6th clearly visible.

Based on 7th is shown as an example, as by the connection according to the invention of segments of the central tube 5 with a socket 37 at the highly stressed points of the central tube 5 the local stresses and tensions in the central pipe 5 or the sleeves 37 can be reduced. the 7th illustrates that the sleeve inserted into segment 5 37 the wall thickness is increased. According to the invention it is provided that the plug connection with the sleeve 37 at the locations of the central tube 5 to provide where the highest loads on the central tube during operation 5 appear. ^{The stress [N / mm 2} ] decreases due to the local increase in wall thickness.

At the in the 7th shown sleeve 37 are several intermediate pieces 53 arranged. The intermediate pieces 53 are designed so that their outer contour matches the inner contour 41 of the central tube 5 is equivalent to. This will reveal how the left part of the 7th results, the contact area between the inner contour of the central tube 5 and the socket 37 decreased.

Nevertheless, the transmission of bending moments and torques in this embodiment is just as good as on the basis of 5 and 6th described sleeves 37 , 43 .

To an axial displacement of the segment 5 and the sleeve 37 to prevent it is a locking screw 55 provided by the segment 5 and the sleeve 37 is inserted through and then screwed. A corresponding screw connection is of course also on the other end of the sleeve 37 provided, but not shown in the figures.

Over the length of the lever 49 the actuating force to be applied by the linear drive can be specified structurally. Basically, the longer the lever 49 , the lower the actuating forces. However, this also increases the travel range.

In the 8th is another embodiment of a sleeve according to the invention 37 shown. At the socket 37 is a flange 47 welded on, which is used to control the positioning movements of a linear drive (not shown in the 8th ) into a rotary movement of the central tube 5 to implement. As from the 8th can be seen on the flange 47 a lever arm 49 with a mounting hole 51 educated. At the mounting hole 51 can be an end of a linear actuator or a locking rod of a twist lock 17th be attached.

Based on 9 and 10 is an embodiment of a positive connection according to the invention of two segments 5 and 5.4 of a central tube 5 illustrated and explained.

In the 9 and 10 is a further embodiment of a form-fitting connection according to the invention of two segments 5 and 5.4 of a central tube 5 shown. In this embodiment there is no sleeve. The main dimensions H , B. of segments 5 and 5.4 differ slightly, so that in the 9 right segment 5 with no play or with little play in the 9 left segment 5 can be inserted. The segments 5 and 5.4 have a cross section, as shown, for example, on the basis of 4th until 6th has been illustrated and explained.

Because the two segments 5 and 5.4 are pushed directly into one another, bending moments and torques can be transmitted directly via this form-fitting connection. A socket in the actual sense is not required for this. The overlap 45 is chosen according to the requirements in each individual case. As a result, the torques and bending moments occurring there can be reliably transmitted at the highly stressed points, in particular the bearing points of the central tube on the pylons.

If at this point there is a torque in the central tube 5 , should be initiated, there can be a lever 49 with the help of a shell-like fastening element 61 with the central tube 5 tied together.

In the 10 Figure 3 is a side view of the connector 61 with the lever 49 shown. In this embodiment, the connecting element 61 a U-shaped shell, the inner contour of which corresponds to the outer contour of segment 5. It can, for example, from below onto segment 5 of the central tube 5 be postponed. This creates a positive torque transmission between the lever 49 and the central tube 5 enables.

To the fastener 61 A flange is to be stiffened 47 formed of the fastening element 61 encloses and in the lever 49 transforms.

As can be seen from the 9 and 10 results are on the fastener 61 several mounting holes 63 available. With the help of these fastening holes, the fastening element can be screwed to segments 5 and 5.4.

The fastening bores are preferred 63 on the parallel legs of the shell-shaped fastening element 61 arranged opposite one another. This makes it possible for the fastening element 61 with through bolts (in the 9 and 10 not shown) with the central tube 5 to screw.

These screws are only used to secure the fastener 61 on the central tube 5 to fix. They do not transmit any torque; instead, according to the invention, this takes place via the form fit between the shell-shaped fastening element 61 and the central tube 5 or segment 5.

A major advantage of this solution can be seen in the fact that the wall thickness of the fastening element 61 and the lever 49 Limits can be selected according to the loads occurring during operation. The wall thickness can be significantly greater than the wall thickness of the central tube 5 . As a result, a material thickness corresponding to the loads occurring is achieved.

If you have the 9 considered, then the wall thickness of the central tube is where the fastening element 61 is arranged at the largest. The wall thickness is made up of the wall thickness of the segments 5, 5.1 and the fastening element 61 together.

Based on 11 and 12th is another embodiment of a positive connection according to the invention between the segments of the central tube and a sleeve 37 shown. At the socket 37 is a flange on the octagonal pipe section 47 welded on. The flange 47 is provided in this embodiment with a square or rectangular outer contour. At the corners of the flange 47 through-holes are arranged. These are not provided with a reference number.

There is a lever on two of these fastening or through holes 49 screwed on. At this lever 49 is a mounting hole 51 formed, which in turn cooperates with a linear actuator, not shown, to rotate the central tube 5 to be able to perform. The flange 47 the socket 37 can also be used for this to a segment 5 of the central tube 5 with the flange 47 to screw.

A correspondingly designed segment 5 is in the 12th shown. In this exemplary embodiment, there is a frame at one end of the segment 5 65 attached with a square outer contour. In the corners of the frame 65 are triangular plates 67 arranged. The plates 67 are both with the frame 65 as well as with the intermediate surfaces 33 of the central tube 5 welded.

The plates 67 have through holes 63 whose drilling pattern corresponds to the corresponding holes in the flange 47 is equivalent to. This makes it possible to have two segments 5 with one socket 37 according to 11 to connect positively to each other and the end of the segments 5 with the flange 47 the socket 37 to screw.

In the 13th is a support 7th shown. On the support 7th is a console 69 attached. The console 69 serves as an abutment for a linear actuator (not shown) between the console 69 and the lever 49 of the central tube is arranged. By changing the length of the linear actuator, the central tube 5 turned.

The console 69 can be designed as a double-folded sheet metal blank. It includes mounting holes 71 in which the linear actuator can be accommodated.

At the top of the support 7th is a bearing block 73 educated. The bearing block 73 is in two parts in this embodiment. It consists of two folded pieces of sheet metal that attach to the support 7th be screwed.

To the ones in the 13th upper ends of the bearing block 53 are mounting holes 75 formed, which receive a bolt that serves as a bearing axis. The two mounting holes 75 of the trestle 73 to a certain extent form a warehouse alley (in the 13th not shown). This bolt is in the 13th not shown. However, he is in the 14th , 15th and 16 shown and with the reference number 77 Mistake.

In the 14th is in an isometric view and partially sectioned, a pivot bearing of the central tube 5 or a segment 5 on the bearing block 73 shown. The two-part design of the bearing block can be derived from this isometry 73 recognize well. Also is the bearing pin 77 clearly visible.

The bearing pin 77 is in this embodiment via a locking plate 79 secured in the axial direction so that it does not accidentally come out of the mounting holes 71 can wander out.

On the bearing pin 77 is the central pipe 5 rotatably mounted. This can be done, for example, with the aid of a sleeve 73 like them in the 7th , 8th , 9 or 10 shown and explained. This is done in the flange 47 one with the bearing pin 77 cooperating mounting hole introduced.

As a result, a very efficient storage is realized in a cost-effective manner. This bearing allows axial displacements, for example due to thermally induced expansions of the central tube 5 .

In the 15th a section through the bearing is shown. In the 16 Figure 3 is a side view of a post 7th , a bearing block 73 as well as a socket 37 and a central tube or tube segment according to FIG 12th shown. These figures show the interaction between the bearing block and the bearing pin flange 47 and levers 49 clearly visible.

Based on 17th , 18th and 19th is the inventive arrangements of the fastenings of the PV modules 3 explained in more detail.

the 17th shows that on the fastening tabs 19th at the top of the central tube 5 short purlins 13th are arranged. The fastening tabs 19th are in the 17th not provided with reference symbols for the sake of clarity. On the fastening straps on the underside of the central tube 5 are striving 11 attached to the PV module 3 support from below.

In the 18th are the connections of the PV module 3 with the purlins 13th and the connection of the strut 11 with the frame of the PV module 3 enlarged and shown in detail. Because the arrangement of the PV modules 3 with respect to the central tube 5 is symmetrical is in the 18th only one half of the arrangement is shown. In particular, there is only half the central tube 5 shown with a side wall 31 and two intermediate or connecting surfaces 33 .

At the intermediate or connecting surfaces 33 are the fastening tabs 19th arranged. The fastening tabs 19th show, for example, from the 12th results in holes over which a purlin 13th can be screwed to the central tube. The purlins according to the invention 13th are relatively short. They only protrude about 30 to 50 cm laterally over the central tube 5 out. The purlins 13th are a support for the frame 9 of the PV module 3 . This frame 9 comes with one or more fastening screws 81 with the purlin 13th tied together. Care must be taken that the frame 9 even and flat on the purlin 13th so that there is no bending moment in the frame 9 and thus also in the PV module 3 is initiated.

The contact surfaces on the lower connecting straps 19th are therefore preferably placed at a slight angle so that they are in the direction of the longitudinal axis of the struts 11 get lost. This prevents bending stress from occurring there.

In 19th is the outer end of the strut 11 shown. The strut 11 can be designed as a thin-walled tube with a tab at its ends 83 having. The tab 83 can for example be made of sheet metal and with the strut 11 for example, be connected by welding. The tab 83 but can also be done by reshaping the strut 11 are made at the ends. The tab 83 has at least one through hole. The strut is via the through hole 11 with a fastening screw 85 with the frame 9 of the PV module screwed.

So that no bending moments in the bracket 83 and the striving 11 are initiated on the fastening screw 85 Spacer sleeves arranged that an inclined position of the tab 83 allow so that even after tightening the fastening screw 85 the strut 11 is not subjected to bending stress.

In 20th is a section through two neighboring PV modules 3 at the height of the fastening screws 85 shown. It also follows that the tab 83 a strut 11 is made so wide that it can be used to support two adjacent PV modules 3 suitable is. Therefore, in the 20th two through holes and two fastening screws 85 shown.

List of reference symbols

1

PV system

3

PV module

5

Central tube

7th

support

9

Frame of a PV module

11

strut

13th

Purlin

15th

angle

17th

Twist lock

19th

Fastening tab

21

camp

23, 35

axis

H

Height of the central tube

B.

Width of the central tube

27

Top

29

bottom

31

side walls

33

Intermediate or connecting surface

35

Intermediate piece

37

sleeve

39

Inner contour of the central tube

41

Outer contour of the central tube

43

sleeve

45

Overlap

47

flange

49

lever

51

Mounting hole

53

Intermediate piece

55

screw

57

Weld

59

Counter plate

61

Connecting element

63

Through hole

65

frame

67

plate

69

console

71

Mounting hole

73

Bearing block

75

Mounting hole

77

Bearing pin

79

Lock plate

81

Fastening screw

83

Tab

85

Fastening screw

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• US 2017/0359017 A1 [0004]
• US 2018/0073773 A1 [0004]
• US 2017/0187327 A1 [0004]

Claims (16)

Tracking system for a PV system comprising a central tube (5), several spaced-apart supports (7) and a rotary drive for the central tube (5), the central tube (5) being rotatably mounted on the supports (7), the Central tube (5) is composed of several segments (5.1, 5.2, 5.3, 5.4), with two adjacent segments (5.1, 5.2, 5.3, 5.4) directly or indirectly via a sleeve (37, 43) to form a form-fitting plug connection are plugged into one another, and wherein the plug connection is suitable for the transmission of torques and bending moments. Tracking system for a PV system comprising a central tube (5), several spaced apart supports (7) and a rotary drive for the central tube (5), the central tube (5) being rotatably mounted on the supports (7), with Purlins (13) are attached to the central tube (5) in such a way that they protrude beyond the central tube (5) on both sides, a length (L ₁₃ ) of the purlins (13) being less than 0.5x a length (L ₃ ) of a PV module (3). Tracking system according to Claim 1 or 2 , characterized in that the central tube (5) or the segments (5.1, 5.2, 5.3, 5.4) and the sleeves (37, 43) have a symmetrical cross section with one or more lines of symmetry, a height (H) of the central tube (5 ) or the sleeve (37, 43) is greater than a width (B) of the central tube (5) or the sleeve (37, 43). Tracking system according to one of the preceding claims, characterized in that the central tube (5) or the segments (5.1, 5.2, 5.3, 5.4) and the sleeves (37, 43) have an octagonal cross-section. Tracking system according to one of the preceding claims, characterized in that several fastening tabs (19) are arranged on the central tube (5) or its segments (5.1, 5.2, 5.3), that the fastening tabs (19) are arranged in one plane, and that a The normal vector of this plane runs parallel to a longitudinal axis of the central tube (5). Tracking system according to Claim 5 , characterized in that the purlins (13) are attached to the fastening straps (19) on an upper side (27) of the central tube (5). Tracking system according to Claim 5 or 6th , characterized in that support struts (11) are fastened to the fastening straps (19) on an underside (29) of the central tube (5). Tracking system according to one of the preceding claims, characterized in that two rows of PV modules (3) are arranged on the central tube (5), a frame (9) of the PV modules (3) having its underside at a first end ( ) rests on two purlins (13) and is detachably connected to the purlins (13). Tracking system according to Claim 7 and 8th , characterized in that the frame (9) of a PV module (3) is supported by two struts (11) in an area spaced apart from the first end and is detachably connected to them. Tracking system according to one of the preceding claims, characterized in that a flange (47) is welded to at least one sleeve (37, 43). Tracking system according to Claim 9 , characterized in that the sleeve (37) has at least one reinforcement plate or counter plate (59) in the area of the weld seam (57) between the sleeve (37, 43) and the flange (47). Tracking system according to one of the preceding Claims 1 and 3 to 11, characterized in that a flange (47) is welded to at least one sleeve (37, 43). Tracking system according to one of the Claims 1 and 3 to 9, characterized in that two adjacent segments (5.1, 5.4) are plugged directly into one another, and that in an overlapping area (45) of the segments (5.1, 5.4) a connecting element (61) with a flange (47) and / or a lever (49) is arranged. Tracking system according to Claim 13 , characterized in that the connecting element (61) has an open cross-section on one side, and that the connecting element (61) is pushed onto the central tube (14). Tracking system according to one of the preceding claims, characterized in that a flange (47) is welded to at least one sleeve (37, 43). Tracking system according to one of the preceding claims, characterized in that the drive is a linear drive, that a bracket (69) is present on at least one support (7), and that the linear drive is between the bracket (69) and one on the flange (47 ) formed or on the flange (47) attached lever (49) is arranged.

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