IL111875A - Sun trackers - Google Patents

Description

Sun trackers Alexander BERGER C. 95620 111875/2 - 1 - The invention refers to a sun tracker, i.e. an appliance, moving solar technical application units (solar assemblies) dependent on the position of the sun.

Systems with several sun trackers (trackers) with hydraulic actuators driven by a common pressure source are known.- Each tracker must be controlled individually in these systems, on to be realized by an extensive control. Additionally, the energy consumption of such system is very high (see DE 2715334). Hydraulic trackers with counterweight are also known, with the counterweight accumulating energy while the solar assembly is sinking, -to be used for lifting. Although this counterweight does permit energy-saving drive," it does however lead to additional production costs (see DE 4240541)" The invention's task is to eliminate the above problems.

This task, to provide simple control for systems of several trackers, is basically solved by coupling actuators of two trackers directly with each other by a hydraulic direct power transmission. It is thus sufficient to move only one solar assembly in accordnce with the position of the sun, to have the other solar assembly also move accordingly, and this without additional control.

Said two trackers being able to constitute compositions of a system of severl trackers, if the solar aassembly and/or parts with variable height of one of said trackers are used as energy-accumulating counterweight for the other one,' this leads to a system of two trackers with extremely low energy consumption, resulting in considerable system advantages especially for heavy solar assemblies..

Improvements and special execution types are subject of the subclaims.

The invention is explained in more detail by the drawings. Shown are: Fig. 1 - Units of two single-axis sun trackers Fig. 2 Unit of two biaxial sun trackers Fig. 3 Systems consisting of- several units Fig. la, lb each show a tracker (la, lb), with a pole (2, 20) sliding in a guide tube (4, 22), carrying a solar assembly (1) at its top, being supported below by a single-acting cylinder (12, 27) and coupled with a counterweight acting as energy accumulator in the manner of a hydraulic balance through a hydraulic power transmission, consisting of a single-acting cylinder (12, 27), a hydraulic line (13, 14) and a second single-acting cylinder (12', 27'), with mechanical instead of hydraulic power transmission also being sensible. Serving as counterweight are the solar assembly and parts with variable height of a second sun tracker of the same construction type (Ila, lib). The trackers are coupled with each other in such way, that the pole of one tracker is lifted simultaneously while the other tracker's pole is sinking, with the direction of rotation of said solar assemblies being the same. Rotation in the same direction for trackers with vertical rotational axis is achieved in accordance with Fig. la by inverse helical guideways (16 and 16') (in the figure helical grooves (16, 16') with bolts (15, 15')), transforming a linear movement of the poles into a respective rotation. For trackers with preferably horizontal axis of rotation in accordance with Fig. lb, a rotation in the same direction is achieved by bars (21, 21'), being on the one side coupled to supporting constructions (28, 28') of the solar assemblies each through a turning knuckle and that is on different sides of the coupling points connecting the poles (20, 20') with the respective constructions (28, 28'). On the other side, the bars (21, 21') are pivotally connected with the guide tube (22, 22') or a different fixed point. In an execution variant, the -bars (21, 2Γ) are connected stationary and the guide tubes (22, 22') pivotally to the ground; or an additional pivoting bar is respectively installed between said pole (20, 20') and the construction (28, 28'), with said guide tubes (22, 22') and said bars (21, 21 ') being stationary. The rotation of both solar assemblies in one direction (e.g. during day time) is achieved by the solar assembly and parts with variable height of one tracker (la) (Fig. la) being slightly more heavy than those of said other (Ila); the rotation of both solar assemblies into the other direction (e.g. during night time) is for example achieved by a pump (26). Control in accordance with fig. lb is performed e.g. by shifting a single weight (29) connected with the tracker's (lb) construction (28) and being equipped e.g. with an electric drive; said other tracker (lib) thus inevitably rotates accordingly.

Fig. 2 displays two biaxial trackers coupled with each other, which are a combination of said single-axis trackers described in fig. la and fig. lb. An interior pole (20) is positioned movable in an exterior pole (2), which in turn moves in the guide tube (4). A ring-shaped space (18, 18') is comprised on the perimeter of each piston (11, 11') allocated to the exterior pole, said ring-shaped spaces being connected with each other by the hydraulic line (14) and with a respective cylinder (27, 27') allocated to the interior pole (20, 20') by the hydraulic line (25, 25'). Piston seals (23) are installed above and below the ring-shaped space (18, 18'), the minimal length of which corresponds to the pole's stroke length (2). The hydraulic power transmission (12, 13, 12') between the poles (2, 2') and the hydraulic power transmission (27, 25, 18, 14, 18', 25', 27') between the poles (20, 20') are thus uncoupled from each other in every position of the poles. The bars (21, 21') are pivotaFly coupled with the constructions (28, 28') and the exterior poles (2, 2') in accordance with a same direction of rotation of the solar assemblies.

Fig. 3a and fig. 3b each show a system consisting of three units (a, b, c), with each unit comprising two trackers in accordance with fig. la or fig. lb. The poles (2, 2', 20, 20') are in this case supported by double-acting cylinders (17, 17', 37, 37'). The units (a, b, c) are coupled with each other through the top chambers of the double-acting cylinders, with the top chamber of the tracker (I) of one unit being respectively connected with only the top chamber of the tracker (II) of a different unit through a hydraulic line (19, 39). Only one tracker must therefore be controlled, e.g. as described for fig. 1; all others inevitably move correctly. The total weight of the movable parts of all trackers (I) in fig. 3a is normally higher than that of all trackers (II).

Claims (13)

111875/2 - 4 - C L A I M S:

1. Unit comprised of two solar tracking devices which move solar assemblies in relation on the position of the sun; the two solar tracking devices are via a hydraulic or pneumatic force transmission coupled directly to each other in a way such. hat, as one solar assembly is moved in a direction corresponding with the position of the sun, the other solar assembly performs a motion "in the direction corresponding with the position of the sun.

2. Unit of claim 1, wherein the actuators of both tracking devices perform relative to each other an exactly or approximately opposite linear motion.

3. Unit of claim 1, wherein the actuators of both tracking devices perform relative to each other an exactly or approximately equidirektional linear motion.

4. Unit of claim 2, wherein oppositely spiraled guides being provided for equidirectional rotation of the solar assemblies.

5. Unit of claim 3, wherein equidirektional spiraled guides being provided for equidirectional rotation of the solar assemblies.

6. Unit of one of claims 1, 2, 3, wherein the solar assemblies are rotated by means of bars und the bars of the two tracking devices each being attached in such a way that the rotation of the solar, assemblies are equidirektional .

7. Unit of on of claims 1, 2, 4, 6, wherein one tracking device there is a counterweight coordinated which, as the solar assembly and/or parts of the tracking device with a variable altitude descends, stores energy for reuse in ascending, the counterweight being realized by the solar assembly and/or parts of the tracking device with a variable altitude of another tracking device. - 5 - 111875/3

8. System of several tracking devices, includes minimum one unit of one of the above claims or a combination of units of the above claims.

9. System of claim 8, wherein the tracking devices are connected in series in such a way that rotation of the solar assemblies are equidirectional.

10. Unit or system according to one of the above claims, wherein the solar assemblies are being moved by swivel motors or by cylinders.

11. Unit of claims 7 or one of the above sub-claims of claim 7, wherein the tracking devices are coupled to one another in the fashion of mechanical balance by a mechanical force transmission device.

12. Unit or system of one of claims 1 to 11 with two axis tracker devices, wherein a void is provided between the housing and the actuator for the first axis, the minimum length of said void, to be bound by two sealings, matches the stroke of said actuator, and said void is connected hydraulically with the actuator for the second axis and with the outer hydraulic line.

13. Unit or system of claim 12, wherein the void is formed by spiraled guides. For the Applicants, REINHOLD COHN AND PARTNERS By IATSL Y