ITMO20120209A1 - WIND GENERATOR - Google Patents

Description

â € œWIND GENERATORâ €

DESCRIPTION

The present invention refers to a wind generator.

Wind generators are known to convert the kinetic energy of the wind into electrical energy.

A known type of wind generator is constituted by a support tower which supports on the top a wind turbine, rotatably connected to the tower, which turbine comprises a horizontal axis impeller, connected to an electric generator and provided with a plurality of blades (usually three, equidistant) perpendicular to the rotation axis and arranged in a radial pattern. The known wind generator works when the tower is crossed by wind having a direction parallel to the axis of the impeller, so that the lift produced by the passage of the wind between the blades produces a rotation of the impeller itself, which rotation is converted in electricity from the aforementioned electric generator.

This known generator has drawbacks.

First of all, during its operation, it produces both considerable turbulence and strong vibrations which, causing a very intense noise, make the known solution unsuitable for installation in residential areas.

Furthermore, it is known that when the wind that passes through the blades of this type of wind generator is very intense, an energy so high acts on them that it can damage the turbine; for this reason, it is necessary to limit the number of blades and it is necessary to arrange the same spaced apart from each other, with the drawback that only a small portion of the windy front is intercepted by the impeller, with which this known solution is, in the case of weak wind, very inefficient.

Another drawback of the known art is that for the orientation of the turbine it is necessary to use a gyroscope and other expensive electronic equipment.

Furthermore, the known solution is not suitable for use in the so-called â € œmini wind powerâ €, that is, the sector in which generators of modest size are used, mounted on the roofs of houses, or on boats, in gardens, etc. .

In fact, the so-called cut-in speed of this type of generators, i.e. the minimum incident wind speed necessary to drive the turbine, is quite high and, therefore, in order to make their use efficient, they will have to present large and be placed in extremely windy places.

The main task of the present invention is to devise a wind generator which has a cut-in speed lower than that of the known art.

Another purpose of the invention is to make a wind generator available for use in the so-called â € œmini-windâ € sector.

A further purpose of the invention is to devise a wind generator which, during its operation, does not produce a noise so high as to be annoying.

Yet another purpose of the invention is to make available a wind generator capable of exploiting all the windy front that affects the impeller of the proposed generator.

Furthermore, an object of the invention is to devise a wind generator that is capable of self-orienting itself in space according to the wind direction, so that it can be operated independently of the direction of the wind blowing and also in the case in which the wind changes direction.

Another object of the present invention is to devise a wind generator which allows to overcome the aforementioned drawbacks of the prior art in the context of a simple, rational, easy and effective use and low cost solution.

The above purposes are achieved by the proposed wind generator, comprising:

a wind turbine which can be rotatably associated with a support means, so as to be able to orient itself with respect to a wind direction, and comprising an impeller able to rotate on the action of the wind around an axis of horizontal rotation, said impeller comprising a plurality of blades arranged angularly spaced around said axis of rotation; and - an electric generator connected to said turbine for transforming mechanical energy of rotation of said impeller into electric energy;

said wind generator being characterized in that:

each of said blades comprises at least one active face adapted to drive the rotating impeller when affected by wind having a direction transversal to said rotation axis, and an inactive face opposite to said active face;

said turbine comprises a first and a second lateral covering wall which laterally contain the impeller, so that the latter is free to rotate, said first and second walls being crossed by said rotation axis and being arranged facing opposite sides of the impeller to define a corridor for the passage of the wind, which allows the impeller to be driven only by wind entering the corridor with a direction transversal to said axis of horizontal rotation, and which

- said turbine also comprises a spoiler element for deflecting incident wind, positioned between said first and second walls, in front of said impeller, and arranged with respect to this in such a way as to deflect wind towards the active face of at least one of said blades initially directed towards the inactive face of one or more of said blades.

Other characteristics and advantages of the present invention will become more evident from the description of a preferred, but not exclusive, embodiment of a wind generator, illustrated by way of indication, but not of limitation, in the accompanying drawings in which:

Figure 1 is a schematic axonometric view of the generator according to the invention arranged on the roof of a building;

Figure 2 is an axonometric view of a first embodiment of the generator according to the invention, in which a wall is removed to allow a view inside;

Figure 3 is a complete axonometric view of the generator according to the invention of the previous figure;

Figure 4 is a side view, in vertical section, of the generator according to the first embodiment of the invention;

figure 5 is a side view of the generator according to the first embodiment of the invention;

Figure 6 is an axonometric view of the generator according to the invention, in an alternative embodiment.

With particular reference to these figures, the generator of the invention is globally indicated with 1.

As mentioned above, the generator 1 first of all comprises (see Figures 2, 3 and 6 for example) a wind turbine 2, which can be rotatably mounted on a support means.

The support means can be a pole or the like and the turbine 2 can be mounted on the top, for example by means of a suitable fifth wheel 3 or other similar mechanical means connected to a bottom wall 4 of the turbine 2; in this way the turbine 2 can be oriented with respect to a wind direction. The turbine 2 in turn comprises an impeller 5 adapted to rotate on the action of the wind around a horizontal rotation axis 6, the impeller 5 comprising a plurality of blades 10 arranged angularly spaced around said rotation axis 6 (for example equidistant) .

Like known wind generators, the invention also comprises an electric generator (not shown in the figures as it is widely known per se) connected to said turbine 2 to transform the mechanical energy of rotation of the impeller 5 into electrical energy.

The electric generator can be connected to batteries and, in the preferred case of use in mini-wind turbines (see figure 1), it can also be connected to the electricity grid, for example through special inverters, etc ..., according to widely varying aspects. known to the person skilled in the art.

On the use of the invention in mini-wind power, we will return to a later paragraph.

Each of the blades 10 of the proposed wind generator 1 comprises at least one active face 11 suitable for driving the rotor in rotation when affected by a wind which has a direction of blowing transversal to the axis of rotation; the blades 10 also comprise a respective one inactive face 11 opposite to the active one.

In order to ensure that the impeller 5 is affected by wind which blows transversely to the axis of rotation 6, the turbine 2 advantageously comprises a first and a second covering wall 7, 8 (see Figures 3, 5 and 6 for example), which laterally contain the impeller 5, so that it is free to rotate between them (the walls therefore protect the impeller 5 from direct wind on its sides).

In detail, the first and second walls are crossed by said rotation axis 6 (in the particular embodiments shown in the figures, they are perpendicular to the rotation axis 6) and are arranged facing opposite sides of the impeller 5 to define a corridor for the passage of the wind, within which corridor is mounted the impeller 5.

The corridor thus defined ensures that the impeller 5 is driven only by wind which enters the corridor itself with a direction of blowing that is transverse to the rotation axis 6, so as to drag the impeller 5 into rotation.

In practice, the wind corridor passes between the front part of the turbine 2 and the rear part of the same, to allow the wind to enter it, activate the impeller 5 for the production of energy, and then exit from the rear without being trapped. inside the turbine 2 (the preferential structure of the turbine 2 and the shape of the two side walls will be detailed below).

Before describing a further fundamental element of the invention, it is good to clarify that, given that the wind turbine 2 of the proposed generator 1 operates on the principle of aerodynamic drag and not on the basis of the creation of lift, the invention overcomes the aforementioned drawbacks of the known art, such as turbulence, vibrations and loud noises, and furthermore the impeller 5 of the invention, advantageously, must not be subject to the limit of using only three blades, which in the known art has the purpose of preventing damage to the turbine 2 (and in fact in the attached figures the number of blades is greater than three, for example fourteen, as in fig. 4). According to a fundamental aspect, the invention provides that the turbine 2 also comprises a spoiler element 9 (represented for example in Figures 2 and 4) to deflect the incident wind, positioned between said first and second walls 7, 8, in front of said impeller 5, and arranged with respect to this in such a way as to deflect towards the active face 11 of at least one of said blades 10, the wind initially directed towards the inactive face 12 of one or more of said blades 10.

In practice, thanks to this expedient, first of all it is avoided that the wind affecting the impeller 5 pushes simultaneously on blades 10 arranged in opposite positions with respect to the rotation axis 6, which would prevent, or strongly hinder, the rotation of the impeller 5 , as it would be subjected simultaneously to two moments of force having opposite directions (we will return to this aspect later in the detailed description of the structure of the impeller 5 and its blades 10). Moreover, thanks to the deviation of the wind by the spoiler element 9, all the action of the wind entering the aforementioned corridor is concentrated on the active faces of the blades 10, maximizing its efficiency.

The spoiler element 9 can have the shape of a ramp, or, as shown in the figures, it can be shaped like an arched slide, and include a concave surface comprised between an internal edge 13 closest to said impeller 5 and an opposite peripheral edge 14.

With regard to efficiency, it is anticipated that, as will become even clearer in the following when two different embodiments of the invention are precisely described (represented respectively in Figures 1 - 5 and 6), the active faces 11 preferably have an extension in width which is slightly less than the distance between the two aforementioned walls 7, 8, which in practice makes it possible to make available a wind generator 1 whose surface for collecting the wind is substantially coincident with the section exposed to the wind same.

This allows the proposed generator 1 to operate even in the presence of very weak winds, and therefore to have an extremely reduced cut-in speed, which allows it to overcome the aforementioned drawback of the prior art relating to the fact that the generator known must be of significant size and must necessarily be placed in very windy places.

For this reason, as will be better detailed below, the invention is particularly suitable for use in the mini-wind sector.

Furthermore, again preferably, the active faces 11 have a concave surface, so as to favor the rotation of the impeller 5 when driven by the wind which blows transversely to its rotation axis 6.

Both the aforementioned particular embodiments of the invention provide for a device which allows the self-orientation of the wind turbine 2 of the invention with respect to the wind direction, and that is its self-alignment to the wind direction.

This device, in general terms, consists in the fact that the turbine 2 is rotatable on the aforementioned support means (for example the pole) with respect to a vertical axis 15 which passes between the two walls 7, 8 (see figure 4) , which vertical axis 15 is arranged with respect to said first and second walls 7, 8 in such a way that an ideal vertical plane which passes through said vertical axis 15, and is parallel to said axis of rotation 6, defines a front half-space which includes said destroying element 9 and front parts of the two side walls 7, 8 (to therefore define a front portion of the turbine 2), and a rear half-space, which includes the rear parts of walls 7, 8 (to define the portion of the turbine 2), the rear parts having a larger surface than said front parts (as can be easily understood by looking at figures 4 and 5).

It should be noted that the proposed turbine 2 is closed, or shielded, only laterally and below, respectively by the two side walls 7, 8 and by the base floor 4 connected to the support means, and moreover a part of the impeller 5 is covered by the € ™ spoiler element 9, the rest of the turbine 2 being open to the free passage of the wind towards the inside or towards the outside.

Thanks to this aspect, the turbine 2 of the proposed generator 1 is able to orient itself automatically, in the manner of a wind vane, in an operative arrangement in which the first and second walls 7, 8 are substantially parallel to the direction of the wind and in which the axis of rotation 6 is perpendicular to the wind direction.

In practice, in the event that the turbine 2 is not immediately in this operating arrangement, that is, it is not aligned with the direction of the wind blowing, then the latter will affect one of the side walls 7, .8 and, given that their rear part has a larger surface than the front one, it will develop in the turbine 2 a moment of force that will make it rotate automatically until it is with its front portion that receives the wind directly, and therefore precisely in the arrangement aligned with the blowing direction that allows the impeller 5 to be activated and therefore the production of energy.

The first and second walls 7, 8 can be flat and mutually symmetrical with respect to a vertical plane that passes through said axis of rotation 6, as shown in the attached figures, and furthermore, according to a preferred constructive aspect, they have a profile with shape of a tapered drop in correspondence of said front half-space (i.e. of the front portion of the turbine 2) to define in the turbine 2 a prominence 16 which contains the aforementioned spoiler element 9, since it must be placed frontally, where it directly meets the wind which enters the aforementioned corridor of turbine 2, in order to carry out its essential function.

In this case, the turbine 2 of the invention describes a profile similar to that of the Nautilus mollusk, but other forms are also possible, as it is possible that the side walls 7, 8 are not vertical as shown in figure 3 or 6.

In the front or front portion of the turbine 2 which, it should be remembered, includes the destroying element 9, there is the entrance to the aforementioned corridor defined by the peripheral edges 17, 18 of said first and second side walls 7, 8 included in the front portion itself (see in this regard, figures 3 and 5).

In the construction version shown, the active face 11 of the blades 10 faces the entrance to the corridor, when the respective blade 10 is included in an upper portion of the impeller 5, while the corresponding inactive face 12 faces the € ™ inlet when the respective blade is in a lower portion than said impeller 5.

In this case, the spoiler element 9 is arranged in front of said lower portion of the impeller 5 to prevent the wind entering through the inlet from affecting the inactive faces of the blades 10, and therefore risks hindering rotation of the impeller 5.

According to this constructive solution, the generator 1 proposed operates when the impeller 5, according to the point of view of Figure 4, rotates counterclockwise.

The plurality of blades 10 arranged in a radial pattern around the rotation axis 6, during the rotation of the impeller 5, are cyclically in overlying positions, like the blades indicated with 10â € ™ in figures 2, 4 and 6, and therefore are included in what instant by instant is the upper portion of the impeller 5, where its active face 11 is facing the aforementioned inlet, or they may be in underlying positions, such as the blades indicated with 10â €, that is to say in the lower portion of the impeller 5, where they offer the inactive face 12 at the entrance to the corridor for the wind and, therefore, must be shielded by the spoiler element 9.

The spoiler element 9, as we said, can be shaped like an arched slide, and in this case its concave surface is turned towards the entrance of the corridor so as to direct the incident wind towards the blades 10 unshielded, and therefore in that instant they are at a greater height than the destroying element 9 itself.

In particular, its outermost extremity 14 can be arranged in correspondence with said entrance (or alternatively at a more rearward position, as in figure 6), and its width can narrow in the direction of the opposite extremity to define a tapered spoiler element 9 which is able to carry the wind towards the blades 10 of the impeller 5, using substantially the same operating principle of the Pelton turbine, known per se, but never before applied to this technical sector and capable of giving surprising efficiency to the proposed wind generator 1.

Furthermore, according to a preferential aspect that maximizes the exploitation of the wind deflected by the spoiler element 9, well represented in Figures 3 and 4, the blades 10 have a free end and have their own active face 11 which includes a terminal edge 19 placed in correspondence with said free end (see figures 2, 3 and 4), and in this case, the spoiler element 9 is arranged with respect to the impeller 5 so that the wind deflected by it can affect one of the blades 10 (indicated with 10â € ™ â € in figure 4) directly on the peripheral portion of its active face 11.

In practice, the turbine 2 of the invention is designed so that each blade of the impeller 5, during rotation, goes to be cyclically in a position P in which the peripheral portion of its active face 11 is in proximity to and in front of the innermost end of the destroying element 9, in an arrangement in which this peripheral portion is just above this upper extremity in such a way as to receive all the air deflected by the destroying element 9 itself (yes see the blade indicated with 10â € â € ™ in figure 4).

In the following the preferred embodiment of the invention is described, represented in figures 1 - 5.

The impeller 5 comprises a central rotor element 20 (for example having a cylindrical shape), which extends longitudinally along the axis of rotation 6 between two opposite ends, in correspondence with which the rotor 20 is connected to rotate the first and second. side wall 7, 8; moreover, the impeller 5 comprises a plurality of blades 10 connected at one end to the wall (or to the side walls 7, 8 of said rotor element 20).

In this case, it is the central rotor 20 that is connected to the aforesaid electric generator, according to methods known per se to the person skilled in the art.

In detail, each blade comprises at least one wing 21 (see in particular Figures 2 and 4), which includes the active 11 and inactive 12 faces of the blade, the blade 10 also comprising at least one connecting arm 22 ( but preferably two as shown in the figures) fixed at one end to said rotor 20 and at the opposite end to said wing 21. In particular, each arm 22 has a planar and elongated shape, and the set of arms, which are practically arranged in a radial pattern around the rotor 20, define at least one internal fan capable of developing a depression following the rotation of the impeller. 5.

More in detail, each blade 10 comprises two connecting arms 22 arranged in correspondence with opposite lateral edges of the respective wing 21 to define two depression fans and, in this case, in at least one side wall 7, 8 (but preferably in both ) One or more air outlet openings are obtained (for example to form a grid 23 as shown in figures 3 and 5), arranged in front of said connection arms 22, so that the air sucked in by said depression can evacuate from the turbine 2 through said outlet openings.

The aspect just described makes it possible to eliminate the possibility that a central pressure develops in the impeller 5 which could obstruct its rotation, so that in practice the impeller 5 undergoes minimal resistance to rotation by the air.

In detail, a real depression is created within the impeller 5, with the fans pushing the air out of the turbine 2 through the outlet openings.

This brings advantages to the invention also in terms of its general aerodynamics, because essentially it favors the entry of air into the wind turbine 2 of the generator 1 proposed.

Furthermore, in the case of atmospheric precipitations, the structure just described advantageously allows the water to flow off the turbine 2 without having the possibility of settling and stagnating.

It should be noted that, as shown in figures 3 and 5, the aforementioned grille 23 can be made from a plurality of vertical strips, inclined and oblique with respect to the relative wall 7, 8 in such a way as to define a plurality of air passages outlet, having a rearward direction with respect to the turbine 2.

In practice, in this case, the side outlet openings of the turbine are turned towards the rear, that is, in the opposite direction to the spoiler element 9.

Preferably, each wing 21 has an arched shape, which can be parallel to said axis of rotation 6, that is to say, have generatrices parallel to the axis of rotation 6 (and therefore be shaped like a parabola or can have a shape that follows the € ™ course of a cylindrical lateral surface).

The connecting arms 22 and the respective wing 21 can be inclined, as shown in the figures, and the arms 22 can be fixed to the wing 21 at its innermost end.

As can be seen in the attached figures, in the preferred embodiment of the invention, the impeller 5 can comprise a multiplicity of blades 10 (certainly many more than the three of the prior art), each of which has a wing 21 having a width almost corresponding to the section that the turbine 2 offers to the windy front, to the full advantage of the efficiency of exploitation of wind energy.

The alternative embodiment, represented in Figure 6, in which an example of support pole 24 is also shown, has in common with the previously described embodiment the aspects relating to the central rotor 20 but, unlike that, the its blades 10 (which in the example shown are seven but can also be in different numbers) have a spoon-like conformation, fixed to one end inside the rotor 20 and tapered at the opposite free ends 19.

In figure 6, which represents the alternative embodiment, some expedients are shown which may also be present in the preferential embodiment.

In detail, the open parts of the turbine 2 can be covered by a net or a grid 25 (of which only a rear portion is represented, for reasons of legibility of the figures), to protect its internal parts, in particular the impeller. 5, to prevent the entry of foreign material or birds, etc ... and to protect the user who in this way does not risk being injured by the blades 10, when the impeller 5 is in motion.

Another expedient that can be implemented in both versions of the generator 1 described here is to arrange in correspondence with the rear part of the turbine 2, and externally to it, a sort of fin 26 arranged vertically, and for example having a shape crescent moon (as in figure 6) which assists the aforementioned alignment of the turbine 2 to the wind, allowing greater stability and therefore eliminating any possible vibrations produced during the operation of the generator 1.

As can also be seen in figure 1, the invention is particularly suitable for mini-wind turbines, as it can also be less than one meter and fifty centimeters high, and therefore can be installed on the roof of houses, on boats, on caravans, or in the garden. , so that the user can have a domestic wind generator 1, so to speak, which supplies him with electricity thanks to wind energy.

The Applicant has found that the generator 1 thus configured has a cut-in speed much lower than that of the generator of the known art and therefore allows electricity to be produced even with very weak winds, and throughout the entire Park of the year, and in essence, in the presence of wind, it almost never remains inactive ..

The various parts of the turbine 2 described above, and also the support pole, can be made of carbon fiber or bamboo fiber or other light materials, in order to maximize the efficiency in the use of the generator 1 proposed in the mini-wind sector.

In practice it has been found that the described invention achieves the proposed aims by making available a wind generator 1 which completely overcomes the drawbacks of the known art.

Claims (15)

CLAIMS 1) Wind generator (1) comprising: - a wind turbine (2) able to be rotatably associated with a support means, so as to be able to orient itself with respect to a wind direction, and comprising an impeller (5) able to rotate around a horizontal rotation axis (6 ) upon action of the wind, said impeller (5) in turn comprising a plurality of blades (10) arranged angularly spaced around said axis of rotation (6); and - an electric generator connected to said turbine (2) to transform mechanical energy of rotation of said impeller (5) into electrical energy; said wind generator (1) being characterized in that: - each of said blades (10) comprises at least one active face (11) able to drive the impeller (5) in rotation when affected by wind having a direction transversal to said rotation axis (6), and an inactive face (1 1) opposite to said active face (12); - said turbine (2) comprises a first and a second lateral covering wall (7, 8) which laterally contain the impeller (5), so that it is free to rotate between them, said first and second wall (7, 8) being crossed by said rotation axis (6) and being arranged facing opposite sides of the impeller (5) to define a corridor for the passage of the wind, which allows the impeller (5) to be operated only by wind entering the corridor with a direction transverse to said axis of horizontal rotation (6); is that - said turbine (2) also comprises a spoiler element (9) to deflect incident wind, positioned between said first and second walls (7, 8), in front of said impeller (5), and arranged with respect to it in such a way to be deflected towards the active face (11) of at least one of said blades (10), wind initially directed towards the inactive face (12) of one or more of said blades (10). 2) Generator according to claim 1, characterized in that it comprises a support means (24), and in that said turbine (2) is rotatable on said support means (24) with respect to a vertical axis (15) which passes between said first and second walls (7, 8), said vertical axis (15) being arranged with respect to said first and second walls (7, 8) in such a way that an ideal vertical plane passes through said vertical axis (15) , and is parallel to said axis of rotation (6), defines a front half-space, which includes said spoiler element (9) and front parts of said first and second walls (7, 8), and a rear half-space, which includes parts rear of said first and second walls (7, 8) having a larger surface than said front parts, so that, following the action of the wind, the turbine (2) automatically orients itself like a weather vane, in a operative arrangement in which said first and second walls (7, 8) are substantially lmente parallel to the wind direction and in which said rotation axis (6) is perpendicular to the wind direction. 3) Generator according to one or more of the preceding claims, characterized in that said first and second walls (7, 8) are flat and mutually symmetrical with respect to a vertical plane passing through said rotation axis (6). 4) Generator according to one or more of the preceding claims, characterized by the fact that the turbine (2) comprises a front portion which includes the diverter element (9), and in which peripheral edges (17, 18) of said first and second side wall included in the front portion define an entrance to said corridor, and by the fact that said active face (11) of the blades (10) is turned towards said inlet when the respective blade is included in an upper portion of the impeller (5) , while said inactive face (12) is turned towards said inlet when the respective blade (10) is in a lower portion of said impeller (5), said diverter element (9) being arranged in front of said lower portion to prevent wind passing through said input interests inactive faces. 5) Generator according to one or more of the preceding claims, characterized in that each of said blades (10) has a free end and a respective active face which comprises a peripheral portion that ends in a terminal edge (19) placed in correspondence with said free end, in which said spoiler element (9) is arranged with respect to said impeller (5) so that the wind deflected by it can affect a blade (10) directly on the respective peripheral portion. 6) Generator according to claim 4 or claim 5, characterized by the fact that said spoiler element (9) is shaped like an arched slide, and comprises a concave surface facing towards said inlet between a closer edge (13 ) to the latter and an opposite edge (14) closer to said impeller (5). 7) Generator according to one or more of the preceding claims, characterized by the fact that said active face (11) has a concave surface to favor the rotation of the impeller (5) on the action of the wind. 8) Generator according to one or more of the preceding claims, characterized by the fact that said impeller (5) comprises a central rotor element (20), which extends longitudinally along said axis of rotation (6) between two opposite ends, at which said rotor element (20) is rotatably connected to said first and second walls (7, 8), said impeller (5) also comprising a plurality of blades (10) connected to the wall or side walls of said rotor element (20 ). 9) Generator according to claim 8, characterized in that each of said blades (10) has a spoon-like conformation and is tapered at its own free end (19). 10) Generator according to claim 8, characterized in that each of said blades (10) comprises at least one wing (21) which includes said active and inactive faces (11, 12), and at least one connecting arm (22) fixed at one end to said rotor (20) and at the opposite end to said wing (21). 11) Generator according to claim 10, characterized by the fact that said arm (21) has a planar and elongated shape, the set of blade arms arranged in a radial pattern around said rotor (20) defining an internal fan able to develop a depression following the rotation of the impeller (5). 12) Generator according to claim 11, characterized in that each blade (10) comprises two connecting arms (22) arranged in correspondence with opposite lateral edges of the respective wing (21) to define two vacuum fans. 13) Generator according to claims 10 or 11, characterized by the fact that in at least one of said first and second walls (7, 8) there is obtained one or more air outlet openings, arranged in front of said connection arms (22), so that the air sucked in by said depression can evacuate from the turbine (2) through said outlet openings. 14) Generator according to one or more of claims 10 to 13, characterized in that said wing (21) has an arched shape parallel to said rotation axis (6). 15) Generator according to one or more of claims from 2 to 14, in which said first and second walls (7, 8) have a drop-shaped profile, tapered in a part thereof included in said front half-space, to define in said turbine a front prominence (16) which contains said spoiler element (9).