WO2008078354A2

WO2008078354A2 - Aerogenerator

Info

Publication number: WO2008078354A2
Application number: PCT/IT2007/000910
Authority: WO
Inventors: Franco Tozzi
Original assignee: Franco Tozzi
Priority date: 2006-12-27
Filing date: 2007-12-21
Publication date: 2008-07-03
Also published as: ITFI20060339A1; EP2109714A2; WO2008078354A3

Abstract

Aerogenerator comprising a vertical-axis rotor with a hub on which a plurality of blades is fixed, consisting of a shell (2) which delimits an opening housing the blades and the rotor hub, said shell featuring an upper wall (20), a semi-perimetral edge (21) and a lower wall (22), said upper wall (20) and said lower wall (22) featuring a side (203) having the same curved profile as that of the blades (1).

Description

Title

Aerogenerator Description

The present invention relates to an aerogenerator. It is known that aerogenerators are still not very- widespread and this is mainly due to their energetic efficiency, which is very low, to their high construction costs and, above all, to the environmental impact that they determine from a landscaping point of view.

The main aim of the present invention is to eliminate, or at least to remarkably reduce said inconveniences. According to the present invention, these results have been achieved by adopting the idea of building a device having the features described in claim 1. Further features of the present invention are the subject of the dependent claims .

An aerogenerator according to the present invention is easy ad economical to build, it is reliable and capable of functioning with the utmost efficiency even with weak intensity winds. Moreover, an aerogenerator according to the present invention has a very high energetic efficiency and its impact on the environment is very low. These and other advantages and characteristics of the invention will be best understood by anyone skilled in the art from a reading of the following description in conjunction with the attached drawings given as a practical exemplification of the invention, but not to be considered in a limitative sense, wherein:

Fig. 1 shows a schematic perspective view i^'n transparency of an aerogenerator according to the present invention; Fig. 2 and Fig. 3 show two schematic plan views of the generator of Fig. 1 with its external shell in the same position and its blades rotated a fraction of a turn;

Fig. 4 shows another perspective transparency view of an aerogenerator according to the present invention;

Fig 5 and Fig. 6 show two schematic plan views of the generator of Fig. 1 with the external shell rotated a fraction of a turn;

Fig. 7 and Fig. 8 show two alternative examples of an aerogenerator in accordance with the present invention;

Fig. 9 shows a schematic perspective view of the shell (2) alone.

Reduced to its essential structure and with reference to the figures of the enclosed drawings, an aerogenerator in accordance with the present invention comprises a vertical-axis rotor with a hub onto which a plurality of blades (1) is fixed and a shell (2) which delimits an opening for the blades and for the rotor hub. An electric generator (which known per se, so it is not shown in the enclosed drawings) is connected on the said axis (y) .

The shell (2) is mounted free to rotate on the rotor hub and is provided with an overhead sail (3) which acts as a wind direction alignment rudder.

The shell (20) features an upper wall (20) , a semi- perimetral edge (21) and a lower wall (22). The sail (3) is applied onto the upper wall (20) of the shell (2). The sail is horizontally "V"- shaped with its apex turned towards the rotor axis so as to guarantee a greater stability of the system.

When seen plan view, the upper wall (20) of the shell

(2) features a first arched side (201) having a shape which corresponds to that of the said edge (21) , a second side (202) which radially connects one end (El) of the first side with the corresponding centre (C) , and a third side (203) which has the same curved profile as that of the blades (1) and connects the other end (E2) ^'of the first side (201) with said centre (C) . Said first side (201) is a circle arch with its centre (C) on the rotor axis and an angular extension which exceeds 180 °. When assembled, the walls (20) and (22) of the shell (2) are horizontal.

The edge (21) which connects said walls (20, 22) has the same shape as that of the ends (11) of the blades (D • The blades are so mounted that they feature one side (10) which is exposed to the wind (V) . With reference to the example shown in the figures of the enclosed drawings, the side (10) of the blades (1) which is destined to be exposed to the action of the wind (V) is concave. Then, the third side (203) of the walls (20) and (22) of the shell (2) features a concave part turned towards the first side (201) and a counterposed convex part turned out- ward.

The lower wall (22) is identical to the upper wall (20) . Due to the structure of the shell (2) described above, the wind strikes only the blades (1) which, instant by instant, are external to the shell (2) without striking the internal blades. Therefore, the action of the wind on the blades (1) is only active, as it does not affect its convex side and does not hinder their rotation.

In the figures of the enclosed drawings, arrow "RR" indicates the direction of rotation of the blades (1) under the action of the wind (V) , while arrows "RG" represent the rotation of the shell (2) when the wind changes direction.

In the embodiment shown in Fig.7, the blades (1) feature an opening (LP) along a portion which is comprised between the root and the central zone.

Moreover, each of said blades (1) features a diverging extension (12) on the side opposite to the active side

(10) . Said extension is first struck by the wind on the concave side (10) of the blade (1) which has not yet exited the shell, so as to avoid that; in the first exit phase of the blade from the shell, the wind acts like a brake.

In the embodiment shown in Fig. 8, the blades are connected by a circular-section cylindrical surface (SC) which is centered onto the rotor axis and leaves only the portion of the blades which is farther from the rotor axis exposed to the action of the wind. The whole device can be installed onto a support structure which can be fixed or telescopic. In the latter case, the generator can be positioned at the most convenient height according to the wind and it can also be interred and used during the evening and night hours so that it does not spoil the landscape. The shell (2) can also be connected to an automatic directioner which can be oriented according to the direction and intensity of the wind detected by sensors (which are known per se).In this case, if necessary, the shell can be so disposed that it intercepts the wind and prevents it from striking the blades (1) . A brake can also be foreseen, advantageously of the magnetic type, fed by the energy produced in excess by the generator itself which overcomes a predetermined number of turns and acts on the (y) axis so as to hold the rotational speed thereof within a predetermined limit. In practice, the execution details may equally vary as regards shape, disposition and size of the single elements and kind of material used, within the solution idea that has been adopted and within the limits of the protection offered by the present patent.

Claims

1) Aerogenerator comprising a vertical- axis rotor and provided with a hub on which a plurality of blades (1) is fixed, characterised in that it comprises a shell (2) which delimits an opening housing the blades and the rotor hub, said shell featuring an upper wall (20), a semi-perimetral edge (21) and a lower wall (22), said upper wall (20) and said lower wall (22) featuring a side (203) having the same curved profile as that of the blades (1) .

2) Aerogenerator according to claim 1 characterised in that said shell (2) is mounted free to rotate on the rotor hub and is provided with an overhead sail (3) for its alignment with the wind direction. 3) Aerogenerator according to claim 2 characterised in that said sail (3) is applied on the upper wall of the shell (2).

4) Aerogenerator according to claim 3 characterised in that said sail (3) is horizontally "V" shaped and its apex is turned towards the rotor axis.

5) Aerogenerator according to claim 1 characterised in that, seen in plan view, the upper wall (20) and the lower wall (22) of the shell (2) feature a first side (201) having a shape which corresponds to that of the said edge (21), a second side (202) which radially connects an end (El) of the said first side to the corresponding centre (C) , and a third side (203) having the same curved profile as the blades (1) which connects the other end (E2) of the first side (201) to said centre (C) .

6) Aerogenerator according to claim 5 characterised in that said first side (201) is a circle arch with its centre (C) on the rotor axis and an angular extension which exceeds 180°. 7) Aerogenerator according to claim 1 characterised in that the rotor blades (1) feature an opening (LP) along a portion which is comprised nearly between the root and the central zone. 8) Aerogenerator according to claim 1 characterised in that each of said blades (1) features a diverging extension (12) on the side opposite to its active side (10) .

9) Aerogenerator according to claim 1 characterised in that the blades (1) are connected to one another by a circular section cylindrical surface (SC) centered upon the rotor axis which leaves the part of the blades farther from the rotor axis exposed to the wind.