A solar tracking device

Abstract

There is disclosed a tracking device formed by a plurality of struts (1) and actuator struts (1'), which are connected to a base (2) and a torque tube (4), and solar panels are mounted in pairs on the torque tube (4). The actuator strut (1') has a hinge (3), and a radial arm (5) is arranged beside the hinge. The radial arm is firmly connected to the torque tube (4), and the other end of the radial arm is hinged to a linear actuator (6) with a screw drive. The bottom end (7) of the linear actuator is also connected to the actuator strut (1') through a joint (8). Each linear actuator (6) is actuated by a gear (9), which meshes with a worm (10). The worm (10) is firmly connected to a universal joint type transmission (11-11'-11''-11''') shared by all actuators and actuated by a motor (12). The universal joint type transmission is assembled near the torque tube (4) through a support (14).

Description

TECHNICAL FIELD

[0001] The present invention relates to a solar tracking device and its actuator, of the type intended to support photovoltaic solar panels, having a rotation axis and a single row of actuating means, with a relatively large panel length and / or surface area. The present invention greatly reduces or alleviates the lack of dynamic stability of this type of tracking device under the action of the wind, as well as the possible damage caused by phenomena such as "flutter" and "galloping", which can damage the panels and even cause the collapse of the entire structure.

[0002] The object of the present invention is to provide a simple, reliable, robust, easy-to-assemble and economical solar tracking device and actuator, which minimizes or eliminates the generation of shadows on the upper and lower surfaces of the panels, a latter aspect being particularly to be considered in the case of bifacial photovoltaic panels. And, simultaneously with all of the above, since the invented system is neither suspended on the panels themselves nor on the metal structures (profiles called straps) to which they are attached, the vibrations generated on the panels are minimal. Subjecting the panels to stress and / or vibrations, however small, can cause considerable damage to the panels, even forcing their replacement, or reducing their performance or shortening their service life. BACKGROUND ART

[0003] Single-row photovoltaic solar tracking devices are known, in which the photovoltaic panels are arranged on respective straps supported by a plurality of struts transverse to the long torque axis, intended to reduce the lack of dynamic stability of their cantilevers under the action of the wind and the possible damage thereby caused.

[0004] In this sense, the invention patent WO2019183492 can be cited, which describes a solar tracking system comprising a support structure rotatable relative to a plurality of bases, wherein said support structure comprises longitudinal beams and pairs of transverse beams, said transverse beams being oriented orthogonally to the longitudinal beams, having a plurality of gearboxes, said gearboxes being rigidly connected to the pairs of transverse beams and connected to an actuating shaft extending through the support structure parallel to one of the longitudinal beams, said gearboxes being for actuating linear actuators, said linear actuators being coupled at one end to one of the bases and at the other end to the same gearbox, so that when driven by a transmission shaft they extend or retract, causing the support structure to rotate about a rotation axis.

[0005] Although this structure achieves its designed function, it gives rise to a series of complex and diverse problems, among which the following aspects should be emphasized:

[0006] · The mechanical transmission between the actuators relies on a drive shaft directly supported on the belt piece that supports the solar panel. The drive shaft is located at an eccentric point relative to the rotation axis of the tracking device, which results in stress and vibration of the drive shaft caused by its own weight and rotation respectively. All possible situations that could cause the solar panel to break will be transmitted to the drive shaft, in addition to the influence caused by the wind acting on the shaft.

[0007] · This type of tracking device has a complex structure, involving multiple protruding elements in different areas under the panel, which causes them to produce larger shadows, thereby reducing the energy generated by the reflection of sunlight on the ground / soil of the solar power plant. It is also worth noting the shadow produced on the solar panel by the same drive shaft.

[0008] · They use bevel gearboxes with high mechanical reversibility, which makes it necessary to use an electric actuating system with a brake or other elements to prevent said reversibility. In addition, due to the characteristics of this type of gear, their reduction ratio is very low, which means that the torque transmitted by the drive shaft must be very high, requiring a relatively large size and weight, and thus the material, transportation and installation costs are very high.

[0009] · The assembly of the tracking device is complex because its actuating system is connected to the belt piece that supports the panel, which means that the tracking device can only be installed after the belt is in place. Summary of the Invention

[0010] The solar tracking device recommended in this article solves the above problems in a completely satisfactory manner in each of the above aspects.

[0011] For this purpose, a tracking device is designed in which the actuating device of the tracking device is not directly connected to the device for supporting and attaching the photovoltaic solar panel, which eliminates the transmission of stress and / or vibration to the panel, greatly facilitating the assembly of the tracking device and a series of additional advantages that will be described in this specification.

[0012] More specifically, the tracking device of the present invention is formed by a plurality of vertical struts, which are connected to the relevant corresponding bases or support bases. The struts are arranged in parallel, and a torque tube is placed on the struts through bearings or bushings. The device for supporting and attaching the photovoltaic solar panel will be assembled on the torque tube. Among them, the device for supporting and attaching the panel will be a conventional device, such as a belt piece, a rectangular frame, a Ω-shaped or U-shaped profile piece, or any other device adapted to the characteristics of the panel to be installed in the solar tracking device.

[0013] To control the tilt of the assembly, it has been proposed that for a plurality of struts which we will call actuator struts to distinguish them from the remaining struts, corresponding to the hinges (bearings or bushings) provided at the upper ends of each actuator strut, radial arms are arranged which are firmly connected to the torque tube.

[0014] The other end of each radial arm is hinged to a linear actuator having a screw drive, and the bottom end of the linear actuator is also hinged and connected to the actuator strut.

[0015] Thus, actuation of the linear actuator will cause angular movement of the radial arm, and since the radial arm is firmly connected to the torque tube, it will cause angular movement of the torque tube and thus the angular movement of the associated panel assembly.

[0016] For this purpose, it has been provided that each linear actuator will be actuated by a gear - worm assembly, where the worm will be associated with a transmission formed by a universal - joint type joint and a transmission shaft (which is telescopic in the diagonal part closest to the actuator), such that the transmission will be driven by one or more electric motors, so that in the case of more than one motor, they will be electronically synchronized.

[0017] One or more electric motors can rotate in one direction or the other, depending on the angular movement to be imparted to the structure carrying the solar panels. It has been provided that the structure is arranged such that it can be oriented from east to west and return to its initial position at the end of the day by reversing the rotation of the motors, thus being able to provide an orientation range of typically ±55 - 60 degrees, and these values can be exceeded if required by the design of the tracking device.

[0018] In this way, the described transmission is able to simultaneously actuate a plurality of linear actuators, and its particularity lies in that although the application points of the linear actuators are separated from the torque tube, the transmission system between the actuators actually runs along its entire length, with the part between the actuator struts being assembled close to and parallel to the torque tube, thus eliminating the generation of shadows, defining an inclined part near the area for implementing the linear actuators, where the transmission shaft will be telescopic to absorb the distance difference between the part carrying the worm and the part extending close to and parallel to the torque tube, depending on the different extended and retracted positions of the actuators.

[0019] Starting from this structure, the following advantages can be obtained:

[0020] · The mechanical transmission between the linear actuators is achieved through a transmission shaft which is supported at multiple points along the torque tube of the tracking device and is not directly connected to the solar panel at any point, thus avoiding the transmission of stress and vibration to it.

[0021] · Since the drive shaft is assembled in the part between the actuator struts near the torque tube of the tracking device, the shadow generated under the bifacial solar panel is greatly reduced (if not completely eliminated). It usually does not cover the area of the torque tube where the drive shaft is located in the present invention, precisely avoiding the shadow of the above-mentioned torque tube.

[0022] · The support of the drive shaft is connected to an element that is more rigid than the belt used for installing the solar panel. This enables a smaller size of the shaft because it is more firmly supported and thus less likely to bend / vibrate due to the action of the wind. Based on this, it is further protected by the shielding of the same torque tube of the tracking device.

[0023] · Using a worm-gear type transmission with a high reduction ratio makes them mechanically almost irreversible. This enables the use of a screw with higher reversibility / efficiency in the linear actuator and also allows the use of a motor without a brake to achieve simplicity and cost. At the same time, this high degree of simplification enables the reduction of the torque required for transmission between the actuators through the drive shaft, thus enabling the reduction of the cost of the drive shaft between the actuator gearboxes.

[0024] · The described solution allows for the complete installation of the actuation system of the solar tracking device without installing the devices for supporting and attaching the panels. This is an advantage when installing the tracking device because the transmission system is positioned without being interfered with by the belt, as it does not interfere with the subsequent assembly of the panels. In addition, the actuation can be operated from the early stage of the entire assembly, so that a motor can be used to orient the torque tube to facilitate the rest of the assembly process. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] As a supplement to the description to be provided herein and to help make the features of the present invention more easily understood, according to the preferred practical exemplary embodiments of the present invention, the description is accompanied by a set of drawings that form an integral part thereof, in which, by way of illustration and not limitation, are shown as follows:

[0026] Figure 1 A partial perspective view of a solar tracking device manufactured according to the present invention is shown, without a solar panel and without the devices for supporting and attaching the panel to the torque tube of the tracking device.

[0027] Figure 2 A detailed perspective view of the tracking device at the level of the adjusting device according to the preferred practical embodiment of the present invention is shown, and the adjusting device is used to adjust the inclination of the tracking device.

[0028] Figure 3 A detailed perspective view and a cross-sectional view of the mechanism at the worm-gear assembly are shown, and the assembly controls the actuation of the actuator through a corresponding motor.

[0029] Finally, Figure 4 a detailed perspective view and a partial cross-sectional view of a gearbox are shown, the gearbox being associated with an electric motor acting on the worm of the previous figure.

[0030] Figure 5 A detailed perspective view at the level of an adjustment device of a tracking device according to a second variant embodiment of the invention is shown, the adjustment device being for adjusting the inclination of the tracking device. DETAILED DESCRIPTION

[0031] From the drawings shown above, it can be seen how the solar tracking device of the invention is formed by a plurality of vertical struts (1) and actuator struts (1'), which are connected to the associated respective bases (2) or support bases, these struts being arranged in parallel, and the torque tube (4) is rested on the struts by means of hinges (3), such as bearings or bushings, and the device for supporting and attaching the photovoltaic solar panels will be assembled on the torque tube (4).

[0032] Each strut (1) and actuator strut (1') should be provided with a single hinge (3) or a group of hinges, depending specifically on the exposure to the wind.

[0033] Lateral to the single hinge (3) of each actuator strut (1') or between each group of hinges (3), a radial arm (5) is arranged to be firmly connected to the torque tube (4), and the radial arm (5) is hinged at the other end to a linear actuator (6) with a linear screw drive, and the bottom end (7) of the linear actuator (6) is connected to the actuator strut (1') by a connecting piece (8).

[0034] In this way, the actuation of the actuator will cause an angular movement of the radial arm (5), and thus an angular movement of the entire solar panel group.

[0035] According to Figures 2 to 4 , the screw of each linear actuator (6) is actuated by a gear (9), which meshes with a worm (10), and the worm (10) is firmly connected to a universal joint type transmission (11 - 11' - 11” - 11”') common to all linear actuators, which is actuated by at least one electric motor (12) through a gearbox (16).

[0036] As Figure 2 shown, the structure of the universal joint type transmission means that, since the application point of the linear actuator is at a certain distance from the torque tube (4), the transmission depending on its hinge (13) can operate in such a way that it is assembled in the part between the actuator struts (1') to be close to and parallel to the torque tube (4), and this part is connected to the torque tube by a corresponding support (14).

[0037] Furthermore, asFigure 2 As shown, in order to accommodate the different positions that a linear actuator can assume due to its own actuation, the inclined part (11') of the transmission will be telescopic, defining a hollow tubular part, which in this case has a square cross-section, but can also have any other cross-section, corresponding to the same reference numeral (11') and a movable part (11''') located within this part, and which can include limiting means for restricting its telescopic path.

[0038] A gimbal-type transmission allows multiple linear actuators to be actuated simultaneously by a single electric motor.

[0039] The electric motor (12) will preferably be arranged corresponding to one of the central linear actuators (6) such that its gearbox (16) is connected in series with the gimbal-type transmission (11 - 11' - 11'' - 11'''), the shaft (11) defining a double-output shaft, which passes through the gearbox (16) through a hole (18) and is actuated by the drive shaft (15) of the electric motor (12) through a reduction drive based on bevel gears (17), without excluding any other conventional transmission systems.

[0040] This arrangement reduces the torque transmitted between the linear actuators through the transmission shaft. Optionally, the electric motor can also be mounted corresponding to one of the linear actuators of the end actuator strut (1'). In this particular embodiment, as Figure 5 shown, by arranging the electric motor parallel to the torque tube, the gearbox (16) can be omitted.

[0041] Optionally, another particular embodiment is also foreseen, in which the electric motor (12) has a double-output shaft, in which case the double-output shaft is arranged corresponding to one of the central linear actuators (6) and parallel to the torque tube (4), and in which the said double-output shaft of the electric motor (12) corresponds to the shaft (11) of the gimbal-type transmission (11 - 11' - 11'' - 11'''). This particular embodiment makes it possible to omit the gearbox (16) of the preferred embodiment while maintaining the same torque requirements transmitted by the transmission shaft, although increasing the cost of the electric motor to be installed.

[0042] However, if the device is very large and very heavy, the participation of more than one asynchronous electric motor is not excluded, and the said electric motors are appropriately synchronized at their start-up by mechanical means (such as those proposed in the present invention) and / or electronic means.

Claims

1. A solar tracking device is formed by a plurality of struts (1) and actuator struts (1') connected to a corresponding associated base (2) or support base, the struts being arranged in parallel, a torque tube (4) being supported on the struts by at least one hinge (3) of each strut, and devices for supporting and attaching solar panels being assembled on the torque tube, characterized in that, Corresponding to each actuator strut (1'), a radial arm (5) is arranged beside its hinge (3), the radial arm being firmly connected to the torque tube (4), the radial arm being hinged at the other end to a linear actuator (6) with a screw drive, the bottom end (7) of the linear actuator (6) also being connected to the actuator strut (1') via a joint (8), each linear actuator (6) being actuated by a gear (9) which meshes with a worm (10), the worm (10) being firmly connected to a universal joint type transmission (11 - 11' - 11'' - 11''') shared by all the actuators, the universal joint type transmission being actuated by a motor (12), the part (11'') of the universal joint type transmission defined between the linear actuators (6) being assembled close to the torque tube (4) via a support (14).

2. The solar tracking device according to claim 1, characterized in that, The part (11') of the universal joint type transmission which is arranged in an inclined manner between the torque tube (4) and the worm (10) for actuating each actuator has a telescopic structure.

3. The solar tracking device according to claim 1, characterized in that, The motor (12) is arranged on the central linear actuator of the assembly and is in series with the universal joint type transmission (11 - 11' - 11'' - 11''') via a gearbox (16).

4. The solar tracking device according to claim 1, wherein, The motor (12) has a double output shaft which is arranged parallel to the torque tube (4) and corresponds to one of the central linear actuators (6), the double output shaft of the motor (12) corresponding to the shaft (11) of the universal joint type transmission (11 - 11' - 11'' - 11''').

5. The solar tracking device according to claim 1, wherein The motor (12) is arranged on one of the linear actuators at the end of the assembly.

Images