Wind converter

Technical Field of the Invention

The present invention relates to a device for converting wind energy comprising a plurality of wing elements arranged to a vertical shaft.

The present invention further relates to use this device for households, boats, commercial activities or any combinations thereof.

Background of the Invention In the field of energy converters to convert renewable energy sources into usable energy i.e. electricity generation, wind converters are widely known and exist in a variety of different designs. Some designs apply vertical shafts, some horizontal shafts. Also the numbers of wings vary, but the predominant types comprise two or three wings .

Common for the energy converters of the current art is that their designs are optimised for energy output. This usually entails a sophisticated wing design, complex gearing and advance control systems, all designed to make for as high a conversion rate between the kinetic energy of the wind and the accumulated energy in the form of electricity as possible.

To ensure a high electricity output, the wind converters should be able to operate at strong wind levels, as this naturally provides the most wind energy to convert into electricity. Hence, the wind converters should also be able to withstand extreme forces, such as strong gusts of wind. In the current art compromises between ensuring energy output as well as stability are sought in various ways. The most common for wind converters are brakes or means for lessening the force

exerted by the wind by turning the wings. These means tend to be quite complicated and thus impact the cost of producing and maintaining the wind converter considerably. The costs of production and maintenance are especially influential for wind converters intended for small-scale use, such as households or remote areas, as the costs here easily outweigh the benefits in terms of the electricity generated.

There is a need for providing a wind converter which can withstand strong winds, while being simple and inexpensive and at the same time have a high electricity output.

Some alternative wind converters operate in small- scale application areas such as for example single households, boats or commercial activities. In these situations the demand for a high electricity output may take a secondary priority to the appearance of the wind converter. Since the wind converter usually must be placed at a high and thus visible point, it is important to the user that the appearance of the wind converter does harmonize with his house or his boat.

Given the widespread debate in the public and in the media over how current wind converters are -damaging to the landscape, there is a need for a wind converter that has a high aesthetic value while at the same time providing the electricity output required by its application area.

Summary of the Invention

An object of the present invention is to wholly or partly overcome the above disadvantages and drawbacks of the prior art. More specifically, it is an object to provide a device for converting wind energy comprising a plurality of wing elements arranged to a vertical shaft

(3) , said wing elements comprising a surface area, wherein the surface area of said wings is adjustable. An adjustable surface area enables adjustment of the force applied to the wind converter by the wind. Hence, a device according to the invention provides a simple but effective protection against strong winds. According to various embodiments, the device comprises of at least two wing elements, preferably four to seven wing elements, and most preferably six wing elements. As an advantage, a certain number of wing elements provide optimal performance, for instance with regard to stability. Examples of other factors that have influence on the optimal number of wing elements are the aerodynamic profile of the wing elements, dimensions, material. Preferably, the wing elements comprised by said device comprise horizontal cross-sections having essentially triangular-like shapes. The triangular shape enables the wing elements to have a wind positive side and a wind negative side, which enable said device to rotate in the wind. Furthermore, the triangular shape provides a nice appearance, which harmonizes with that of most houses and boats or the like.

Advantageously, any of the wing elements comprised by said device comprise an inflatable element. By inflating this inflation element the surface area of the wing element increases, and the force applied to the wing element by the wind increases. Likewise, by deflating the inflation element the surface area of the wing element decreases, and the force applied to the wing element by the wind decreases. Thus, the inflation element provides a simple way to avoid the device being overloaded from a strong wind.

Preferably, said inflatable element, comprised by said device, is enclosed in a perforated shell. The shell

keeps the inflatable element within the wing element, and the perforations allow the wind to reach the surface of the inflatable element.

According to the invention, said inflatable element comprised by said device may be held in place by an element protruding from said vertical shaft. This has the advantage that it can replace the perforated shell and thus reduce the weight and complexity of said device.

Preferably, said device further comprises an inflation means for adjusting the surface area of said wing elements by inflation or deflation of said wing elements .

Advantageously, said device further comprises a control means for controlling said inflation means. This enables adjustment of the degree of inflation of the inflatable element according to for example the current wind speed.

According to the invention, said device may further comprise an energy conversion means for converting kinetic energy to electricity.

Preferably, the control means 12 comprised by said device further controls said second means.

Advantageously, the vertical shaft comprised by said device comprises a hub element to which said wing elements are attached. This makes for a simple mounting of the wing elements 2.

According to the invention, the hub element 13 of said device comprises any of said inflation means, said energy conversion means and said control means or any combination thereof. This enables a compact and stable construction of the device.

Advantageously, said device is used for households, boats, commercial activities or any combinations thereof.

Brief Description of the Drawings

The invention and its many advantages will be described in more detail below with reference to the accompanying schematic drawings, which for the purpose of illustration show some non-limiting embodiments and in which

Fig. 1 shows a schematic view of a wind converter as seen from the side;

Fig. 2 shows in section a) a schematic view of a wind converter as seen from above, and in section b) a detailed view of a wing element as seen from above;

Fig. 3 shows embodiments of a wing element comprising an inflatable element, wherein the inflatable element is in section a) fully inflated, section b) partially inflated, and in section c) deflated;

Fig. 4 shows embodiments of a wing element comprising in section a) a perforated shell with an inflatable element within, and in section b) an inflatable element held in place by an element; and Fig. 5 shows another preferred embodiment of a wind converter .

All the figures are highly schematic, not necessarily to scale, and they show only parts which are necessary in order to elucidate the invention, other parts being omitted or merely suggested.

Detailed Description of Preferred Embodiments

Fig. 1 shows a preferred embodiment of a wind converter 1 seen from the side. The wind converter shown comprises six wing elements 2 (four of which are shown), which are attached to vertical shaft 3. The wind converter can also comprise any other amount of wing elements. Fig. 1 furthermore shows a sphere-like shaped hub element 13, to which the wing elements 2 are

attached. The hub element 13 can also be shaped in other ways, such as oval, box-like, egg-like or the like. The hub element 13 can comprise various means of the invention, which becomes evident from the description of Fig. 5 in the below. The wing elements comprise a straight inner edge 4 connected to the vertical shaft 3, and an arched outer edge 14 furthest away from the vertical shaft 3. For reasons of simplicity, the wing elements in figure 1 are not shown in detail, and further components will be indicated and explained in the remaining figures. The illustrated over-all shape of the wind converter resembles a sphere, although other alternatives are possible and desirable for various reasons such as stability, appearance, efficiency. Figure 2 illustrates a wind converter as seen from above. For simplicity, the wind converter shown in figure 2 comprises only four wing elements 2, and although any number of wing elements are possible, an embodiment having six wing elements may be preferred for aesthetic and functional reasons. Section b) of figure 2 shows a detailed view of a single wing element 2 from section a) . The wing elements 2 in section a) of figure 2 are attached to a vertical shaft 3, and to a hub element 13. The wing elements 2, the shaft 3, and the hub 13 shown in figure 2 correspond to those shown in figure 1.

Section b) of figure 2 shows a schematic view of a horizontal cross section of a single wing element 2, in which the three surfaces 5, 6, 16 of the wing element 2 according to a preferred embodiment form a triangular shape. The triangular shape enables the wing element 2 to have a wind positive side, turned towards the wind indicated by arrow 17, comprising the surface 5 and a wind negative side comprising the surface 6 and the surface 16, enabling the wind converter to rotate in the

wind. According to a preferred embodiment, surface 6 is larger than surface 16. Also indicated are edges 4, 14 and 18.

Figure 3 shows a preferred embodiment of a wing element 2 with an inflatable element 7 inside. The wing element 2 is shown attached along a straight edge 4 to a vertical shaft 3, and comprising arched edges 14 and 18, edge 14 being longer than edge 18. The wing element 2 is seen from the wind negative side, such that surfaces 6 and 16 are shown.

The form of a wing element 2 is further visualized in figure 3. The first, and largest surface 5 is spanned by the straight edge 4 and the arched edge 14. A second surface 6 of the wing element is spanned by the straight edge 4 and the arched edge 18. A third surface 16 is spanned by the two arched edges 14 and 18. Hence, the three surfaces 5, 6, and 16 span a volume. In a preferred embodiment, the third surface 6 is smaller than the second surface 16, while the second surface 16 is smaller than the first surface 5. The wing elements can also comprise more than 3 edges and more than 3 surfaces, and the relation between edge lengths and surface areas can be varied in several other ways in other embodiments of the present invention. Figure 3 shows in section a) a completely inflated element 7, in section b) a partially inflated element 7, and in section c) an empty inflatable element 7. Preferably, the inflatable element 7 is made from a strong yet elastic fabric, such as sail material, which is sowed to fit the interior of the wing element 2. The inflatable element can also be made from other air-tight materials, such as rubber or other textiles, and it can also not be sowed together, but have a simpler balloon- like shape.

Figure 4 shows preferred embodiments of a wing element 2 according to the invention. Section a) of figure 4 shows a wing element 2 with a perforated shell 8 with an inflatable element 7 within. The perforated shell 8 is in a preferred embodiment made from perforated sheet metal, although it can also be made from perforated plastic material or the like. In a preferred embodiment, the perforations comprised by the perforated shell 8 are of a size that allow wind passage adequate for the inflatable element to serve its purpose of varying the surface area of the wing element 2. The perforated shell can also be replaced by a framework of beams (not shown) encapsulating the inflatable element. As schematically shown in section b) of figure 4, the perforated shell 8 with the inflatable element 7 within can also be replaced by an inflatable element 7 being held in place by an element 9 protruding from a vertical shaft 3. The protruding element 9 is attached to the inflatable element 7 at connection points 20 and 21, and further attached to the vertical shaft 3 at point 19, preferably by hinge means allowing rotation in one direction, such that the inflatable element 7 may collapse in a deflated state along the vertical shaft 3, ensuring minimal exposure to wind pressure. A connection to compression means (not shown) for inflating the inflatable element is indicated at connection point 22.

Figure 5 shows a schematic view of a wind converter 1 as shown in figure 1 further comprising inflation means 10, energy conversion means 11 and control means 12. In a preferred embodiment, the inflation means 10 and the energy conversion means 11 are arranged within the hub element 13, whereas the control means 12 are arranged outside the hub element 13. In other embodiments, the inflation means 10, the energy conversion means 11 and

the control means 12 are arranged within or outside the hub element 13 in any combination that serves a specific need. In a preferred embodiment, the inflation means 10 comprise a compressor having a nozzle situated within the hub element 13. The compressor may be replaced by any means for inflating and deflating the inflatable element 7. In a preferred embodiment, the energy conversion means 11 is electromagnetic and comprises a stator and a rotor, the rotor being arranged in any of the wing elements and the stator being arranged within the hub element 13. Any other type of energy conversion means can also be applied. In a preferred embodiment, the control means 12 controls the inflation and deflation of the inflation elements 7 according to the current wind strength. Preferably, the vertical shaft 3 may house any electrical wiring 20 or pneumatic piping (not shown) necessary for the function of the wind converter.

Although the invention above has been described in connection with preferred embodiments of the invention, it will be evident for a person skilled in the art that several modifications are conceivable without departing from the invention as defined by the following claims.