SOLAR TRACKER WITH LINEAR ACTUATOR

Abstract

Solar tracker (1) with at least one rotation mechanism for at least one solar panel (10), comprising a first post (20) with a lower end fixed to the ground by means of a lower joint (23), and a second post (30) that connects to the first post (20) forming a cross, both posts (20, 30) being connected, at the point where they cross, by means of a joint that allows rotation and relative displacement between both posts (20, 30), the solar panel (10) being fixed to both upper ends of both posts (20, 30) by means of a joint, and with a lower end of the second post (30) fixed by means of a lower joint (33) to a linear actuator (50) that displaces said lower end of the second post (20) producing a relative movement between the two posts (20, 30) that generates the rotation of the panel (10).

Description

SOLAR TRACKER WITH LINEAR ACTUATOR TECHNICAL SECTOR The present invention relates to solar trackers with photovoltaic panels or plates, more specifically to a solar tracker with a linear actuator. BACKGROUND OF THE INVENTION To date, most photovoltaic solar plants use active solar trackers. This means they incorporate photovoltaic module panels mounted on a metal frame or structure, which, in the simplest case, is supported by a single pillar. This pillar typically houses a motor that rotates the solar panel according to the angle of the sun's rays. For large installations, the solar panels of the trackers are mounted on rotating axes supported by multiple pillars. Several panels can be arranged on these axes in different rows to complete the installation. In this type of installation, panel rotation is mostly achieved by applying the rotation directly to the solar panel by means of a linear actuator fixed to the pole and the panel itself, as can be the case of document WO16170193. And in another known example, the rotation is achieved by means of a rotation module installed on the axis itself and arranged on the pillar, acting directly on the axis of rotation, as is the case of patent document CN212163236. However, for individual installations or those with few solar panels, an alternative rotation system is expected to be necessary, which is simpler to implement and assemble. EXPLANATION OF THE INVENTION In order to achieve this objective and seek an alternative to conventional solar tracker rotation solutions, as well as to provide additional advantages that may be derived later, the present invention relates to a solar tracker with at least one rotation mechanism for at least one solar panel. This mechanism comprises a first post with a lower end fixed to the ground or supporting surface by means of a lower hinge, and a second post connected to the first post forming a cross-shaped structure. At the point where they intersect, the two posts are connected by a joint that allows rotation and relative displacement between them. The solar panel is fixed to the upper ends of both posts by means of a hinge.And the solar tracker with a lower end of the second post fixed by means of a joint to a linear actuator that displaces said lower end of the second post producing a relative movement between the two posts that generates the rotation of the panel. In this document, the expressions vertical and horizontal are understood according to their commonly used meaning, vertical being a direction parallel to the direction of fall of an object in free fall due to gravity and horizontal being a direction perpendicular to it. The fact that the rotation mechanism comprises a first and a second post helps to distribute the load caused by the solar panel, so that both posts support the weight and other forces exerted by the panel on the solar tracker. Since the first post is fixed to the ground at its lower end by means of a hinge, it can only rotate. On the other hand, since the second post is fixed at its lower end to a linear actuator by means of a hinge, it can rotate about its lower end while simultaneously moving in the direction of the linear actuator.These features, combined with the fact that the first and second posts intersect and are connected by a joint that allows rotation and displacement, or in other words, relative sliding between the two posts that generates relative rotation, allow a solar panel to be fixed to both upper ends of the posts, so that the solar panel rotates according to the movement of the linear actuator. Thanks to this configuration, a large rotation of the mechanism is achieved with a small displacement, with a simple and effective design, resulting in ease of assembly for individual installations or those with few panels. Preferably, the second post comprises a projection in an intermediate zone that slides into a longitudinal guide rail of the first post for joining the two posts at the point where they intersect. Preferably, this projection will be in the form of a hinge pin that can be fixed to the second post. Alternatively, the first post comprises a projection in an intermediate area that fits into a guide rail of the second post for joining the two posts, without altering the object of the invention. Thanks to this configuration, a connection is achieved between the two posts at their intersection, allowing for a displacement that generates relative rotation between them. Having a protrusion and a guide rail in a combined form is a simple and effective way to achieve this type of connection, enabling the advantageous relationship between movement and force offered by the present invention. Furthermore, it is very easy to manufacture and assemble. According to a feature of the invention, the linear actuator comprises a rail on which a sliding pin connected to an actuating rod of the linear actuator slides, the lower end of the second post being articulated to said sliding pin. The presence of a track, in addition to helping guide the linear actuator in a specific direction, compensates for a large part of the stress that the linear actuator might receive in directions other than its linear motion. This prevents the actuator from experiencing bending or torsional stress, thus improving its performance and reducing potential breakage or damage, extending its lifespan. Preferably, the track is located substantially horizontally, with the direction of action being parallel to the ground or support surface. The fact that the rail guiding the linear actuator is horizontal means that the force exerted by the actuator is directed horizontally, preferably parallel to the ground or supporting surface. In this way, the linear actuator only has to overcome a horizontal component exerted on the second post due to the weight supported by the solar tracker. Because of this particular configuration, the horizontal component is very small compared to the weight, thus minimizing the force required by the linear actuator motor to rotate the solar panel. Furthermore, thanks to the specific configuration of the present invention, a high ratio between the angle of rotation and the distance traveled by the linear actuator is also achieved.Thus, with this configuration, both the force exerted and the distance traveled by the actuator are optimized, thereby optimizing both factors to be taken into account to obtain the necessary energy from the actuator to achieve the desired rotational movement. Preferably, the solar tracker comprises at least one support bracket fixed to the solar panel, the first and second posts being fixed by means of a hinge at opposite ends of said support bracket. The presence of this support bracket, fixed to the solar panel, allows the ends of the poles to be attached to the support element instead of directly to the panel. By placing the support bracket between the articulated ends of the poles and the panel, the articulated ends are not attached directly to the side opposite the photovoltaic panels, a surface that is usually large and flat, which is structurally unsuitable. The support element significantly reinforces the area on which the poles act, distributing the stress more evenly over a larger surface, thus preventing potential breakage or bending. Furthermore, this support also improves adaptability to different types of panels, which, in turn, facilitates the maintenance or repair of various parts of the solar tracker, allowing for a clearer understanding of the structural components of the solar panel.This allows for changing or replacing structural parts, while keeping the panel, which is usually of greater value, or changing the panel if needed without touching the structural part. Preferably, the solar tracker comprises at least two straps attached to the solar panel for attachment to the support element. Similar to the support bracket, the presence of at least two straps between the solar panel and the support bracket helps reinforce the connection between the structural part of the device and the solar panel. These straps can be attached to stronger areas of the panel, such as its frame, so that the stresses resulting from the movement of the structure are better absorbed, reducing the risk of damage from excessive tension or pressure. Furthermore, they can provide different height and rigidity options depending on the requirements. According to another feature of the invention, the device comprises a fixing shaft and at least one solar panel, said shaft being fixed to the support bracket which comprises a fitting geometry for its fixing. By using a mounting shaft for at least one solar panel, an additional connection element is created between the structural component and the solar panels. This allows for a more robust connection between the support element and the panel, either directly or via straps attached to the panel. The shaft's geometry can be varied to achieve a better fit with the components to which it is attached. Furthermore, having a mounting shaft also allows for the attachment of more than one panel, enabling a single actuator to operate multiple panels. Preferably, the axle will be fixed to the support bracket by means of a clamp that can be fixed by mechanical joining means such as screwing, or by welding. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 shows a perspective view of a solar tracker according to the present invention. Figures 2 to 4 show an elevation view of the solar tracker in different rotation positions. Figure 5 shows a detailed view of the joint between the solar tracker posts. Figure 6 shows a detailed view of the linear actuator. Figure 7 shows a detailed view of the joint between the support bracket and the rotating solar panel. PREFERRED EMBODIMENT OF THE INVENTION In view of the aforementioned figures, and in accordance with the numbering adopted, an example of a preferred embodiment of the invention can be observed, which comprises the parts and elements indicated and described in detail below. Figure 1 shows a practical embodiment of a solar tracker (1) according to the invention, comprising a solar panel (10) with straps (60) fixed to one side opposite the surface facing the sun. These straps (60) are fixed to a shaft (70), which, in turn, is fixed to a support bracket (40). A first post (20) and a second post (30) intersecting at an intermediate point along their longitudinal dimension are also shown. The first post (20) and the second post (30) are joined by a projection, preferably a pivot pin (31), which passes through a through-hole in the second post (30), thus securing it to the post, and passes through a longitudinal guide rail (21) located in an intermediate section of the first post (20). This connection ensures that the first post (20) and the second post (30) are joined with freedom of rotation and relative displacement between them, this freedom of displacement being equal to the length of the longitudinal guide rail (21) that will define the extreme rotation positions of the solar tracker (1). On the other hand, it can be seen how the first and second posts (20) and (30) are attached to the support bracket (40) by means of respective upper joints (22) and (32) at their upper ends, while at their lower ends, the first post (20) is attached by means of a joint (23) to a clamping plate (24) fixed to the ground, and the second post (30) is slidably attached to a rail (53) by means of a sliding pin (34). This rail (53) serves as a guide for a linear actuator (50). The linear actuator (50) acts on the sliding pin (34), displacing the lower end of the second post (30) in the direction of action of the linear actuator (50) defined by the rail (53). Figure 2 shows the solar tracker (1) in its operating position, with the solar panel (10) completely horizontal, precisely at the midpoint of its rotational path. Figure 2 also reveals elements not visible in the previous figure, such as the clamp (80) securing the shaft (70) to the support bracket (40). The joint (32) between the support bracket (40) and the second post (30) is also visible. Figure 2 shows that both the pivot pin (31) and the sliding pin (34) are located at the midpoint of their respective guide rails (21) and guide rail (51) of the track (53), indicating that the solar tracker (1) is at its midpoint, allowing the solar panel to rotate in either direction depending on the movement of the linear actuator (50). Figure 3 shows the solar tracker (1) in its maximum rotation position after the linear actuator (50) has extended. Compared to the previous figure, where the solar tracker (1) is at its midpoint, the linear actuator (50) has extended, pushing the sliding pin (34). This action moves the lower end of the second post (30) linearly, bringing it closer to the lower end of the first post (20), while allowing it some rotation. This causes the articulation pin (31) to act on the first post (20), traveling along the guide rail (21) and exerting a force perpendicular to it, thus rotating it about its articulation (23) and away from the actuator (50).This combination of movements causes the upper ends of both posts (20, 30) to move, while remaining at a constant separation distance determined by the support bracket (40). Each post rotates relative to this support bracket (40) and pushes it in different directions. The support bracket (40) is forced to rotate, which, in turn, causes the solar panel (10) to rotate. Furthermore, due to the configuration of the solar tracker (1), the integrated assembly formed by the support bracket (40), the shaft (70), the straps (60), and the solar panel (10) not only rotates but also moves, following an arc-like path. In Figure 3, it can be seen how the articulation pin (31) is located at an end point of the guide rail (21). At this point, the guide rail (21) acts as a displacement stop for the articulation pin (31). This marks the end of rotation in this direction, which may coincide with the extension stop of the actuator (50) or the guide stop (51) of the rail (53), but this is not a necessary condition for its operation. In Figure 4, the solar tracker (1) can be seen in a position of maximum rotation after the linear actuator (50) has retracted. Compared to Figure 2, where the solar tracker (1) is at its midpoint, the linear actuator (50) has retracted, pulling the sliding pin (34). This action moves the lower end of the second post (30) linearly away from the lower end of the first post (20), while allowing some rotation. This causes the hinge pin (31) to act on the first post (20), traveling along the guide rail (21) and exerting a force perpendicular to it, thus rotating it about its lower hinge (23) and bringing it closer to the actuator (50).This combination of movements causes the upper ends of both posts (20, 30) to move, always maintaining a constant distance from the support bracket (40). Each post rotates relative to the support bracket (40) and pushes it in different directions, forcing it to rotate. This rotation, in turn, causes the solar panel (10) to rotate. Similarly, as in the previous figure, the assembly formed by the support bracket (40), the shaft (70), the straps (60), and the solar panel (10) not only rotates but also moves, following an arc-like path and ultimately positioning itself above the actuator (50).In this figure 4, it can also be seen how the articulation pin (31) is located at an end point of the guide rail (21) opposite to that of the previous figure, which, in the same way as detailed above, also marks the limit of rotation in the opposite direction. Figure 5 shows in greater detail the connection between the first and second posts (20) and (30), using the pivot pin (31) and the longitudinal guide rail (21). The pivot pin (31) passes through both posts and can move along the longitudinal guide rail (21). This pivot pin (31) cannot move axially because it has a head (311) with a wider diameter at one end and a stop (312) at the opposite end, which was installed after the pivot pin (31) was attached. The stop (312) can be made of elements such as rings, threaded inserts, washers, caps, or other similar components. Figure 6 shows the linear actuator (50) in detail, comprising a rod (52) capable of entering and exiting a sleeve (54). The rod (52) is articulated, by means of the sliding pin (34), to the lower end of the second post (30), which comprises a fork (33) through which said sliding pin (34) passes. The sleeve (54) has a cross-section conjugate to the rail (53), and is fixed within it, such that the rod (52) is surrounded by the rail (53) as it moves in and out of the sleeve (54) during the operation of the actuator (50). The sliding pin (34) is located within the guide (51), thus passing through the rail (53) and protruding on each side. This way better guidance of the end of the stem (52) is achieved, and consequently of the lower end of the second post (30).This greatly reduces bending or twisting stresses that the stem (52) may suffer, improving the efficiency and durability of the actuator (50). Figure 7 shows in greater detail the integrated assembly consisting of the solar panel (10), the straps (60), the shaft (70), and the support bracket (40). In this figure, both straps (60) can be seen on opposite sides of a frame (11) of the solar panel (10). These straps (60) are fixed to the frame (11) and, in turn, to the shaft (70). In this representation, only one solar panel is shown, but the shaft (70) could be longer so that more solar panels could be attached along it. Furthermore, the shaft (70) is rigidly connected to the support bracket (40). Due to the high torsional stresses to which the shaft is subjected, the connection between the shaft (70) and the support bracket (40) includes ribs (81) in the clamp (80) on each side of the shaft (70) to strengthen this connection.On the other hand, the joints can also be observed through the joints (22) and (32) between the support support (40) and the respective first post (20) and second post (30). It should be mentioned that the examples of bolts (31) and (34) shown in figures 5 and 6 and other joints in general are merely one of many possible embodiments represented, but the use of all types of bolts and simple joints is well known and it is obvious to an expert in the field the use of any type of bolt and / or joint that allows rotation and / or displacement in a direction perpendicular to its longitudinal axis but does not allow displacement in an axial direction. The figures correspond to a non-limiting example of practical implementation, and variations in the configuration of the complement may occur as long as the essence of the complement is not altered.

Claims

1. A solar tracker (1) with at least one rotation mechanism for at least one solar panel (10), comprising a first post (20) with a lower end fixed to the ground by means of a lower hinge (23), and a second post (30) connected to the first post (20) forming a cross, both posts (20, 30) being connected at the point where they intersect by means of a joint that allows rotation and relative displacement between both posts (20, 30), the solar panel (10) being fixed to the upper ends of both posts (20, 30) by means of a hinge, and with a lower end of the second post (30) fixed by means of a lower hinge (33) to a linear actuator (50) that displaces said lower end of the second post (20), producing a relative movement between the two posts (20, 30) that generates the rotation of the panel (10). 2.- Solar tracker (1) according to the preceding claim, wherein the linear actuator (50) is fixed to the ground such that its direction of action is parallel to said ground.

3. Solar tracker (1) according to the preceding claim, wherein the second post (30) comprises a projection in an intermediate zone that slides into a longitudinal guide rail (21) of the first post (20) for the articulated connection between both posts (20, 30) at the point where they intersect.

4. Solar tracker (1) according to any of the preceding claims, wherein the linear actuator (50) comprises a rail (53) on which a sliding pin (34) slides, connected to an actuating rod of the linear actuator (50), the lower end of the second post being articulated to said sliding pin (34). 5.- A solar tracker (1) according to any of the preceding claims, comprising at least one support bracket (40) fixed to the solar panel (10), the first post (20) and the second post (30) being fixed by means of a hinge at opposite ends of said support bracket (40).

6. A solar tracker (1) according to the preceding claim, comprising at least two straps (60) fixed to the solar panel (10) for fixing it to the support bracket (40).

7. A solar tracker (1) according to the preceding claim, comprising a shaft (70) for fixing at least one solar panel (10), said shaft (70) being fixed to the support bracket (40).

8. A solar tracker (1) according to the preceding claim, comprising at least one fixing clamp (80) for fixing the shaft (70) to the support bracket (40).

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