Abstract:
A wind apparatus which specifically comprises an essentially semi-cylindrical-shaped wind screen hood adapted to rotate about a vertical axis. The wind screen hood is external to a wind impeller and is put into rotation (to reach a position of balance) by rudders actuated by the wind so as to cover a portion of a plurality of radial thrust elements according to the direction of the wind itself.

Description:
RELATED APPLICATION 
       [0001]    The present application claims priority of Italian Patent Application No. BO2006A 000786 filed Nov. 20, 2006, which is incorporated herein in its entirety by this reference. 
       FIELD OF THE INVENTION 
       [0002]    The present invention relates to a wind generator. Specifically, the present invention finds advantageous, but not exclusive, application in the field of lighting streets, highways, etc., to which explicit reference will be made in the following description without loss in generality. 
       BACKGROUND OF THE INVENTION 
       [0003]    It is known that supplying electricity to streetlamps, road signs, emergency telephones, etc. is very expensive because it requires an extensive distribution network constituted by buried electric cables, the installation of which is expensive both in terms of employed materials and due to the specialized manpower which is required. 
         [0004]    In order to avoid the drawbacks due to the use of a centralized electric network for supplying electricity to streetlamps, during the past years streetlamps actuated, for example, by wind energy have been developed. 
         [0005]    Furthermore, in order to attempt to limit at most the visual impact that the use of wind blades implies on the territory, streetlamps using at least one vertical axis impeller have been designed, the transverse volume dimensions of which are contained within the volume of the diameter of the post itself. 
         [0006]    Not only; since obviously in normal conditions of operation, the impeller coupled to the generator produces electric energy all day long, during the daytime hours (i.e. when the streetlamp combined to the wind apparatus is not switched on) the produced energy may either be easily sent to the network and sold to an electrical energy marketing company, or used for other purposes. It is apparent that all the surplus energy which is not used for lighting by means of the streetlamp onto which the above-mentioned wind apparatus is mounted is sellable. 
         [0007]    Moreover, these streetlamps running on wind energy may present powers which easily reach 1 kW. 
         [0008]    Furthermore, because, as previously mentioned, the dimensions of the impeller blades are contained in the volume dimensions of a normal supporting post, the environmental impact of visual nature is very low, indeed, the presence of rotating elements may in this case be visually pleasant. 
         [0009]    For example, some of these solutions have been described in GB 2 246 173 (TEMPLE) and in GB 2 344 382 (SANSONE ET AL.) 
         [0010]    However, despite working in a fairly satisfactory manner, the apparatuses described in the aforesaid documents do not fully exploit the power of the wind which strikes the impeller because, as explained in greater detail below, a portion of the wind energy is lost, thus considerably decreasing the efficiency of the impeller itself and, consequently, also of the electric generator connected thereto. 
       SUMMARY OF THE INVENTION 
       [0011]    It is therefore the main object of the present invention to make a wind apparatus which is free from the above-described drawbacks and which is, at the same time, easy and cost-effective to implement. 
         [0012]    According to the present invention, a wind apparatus as claimed in the attached claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]    The present invention will now be described with reference to the accompanying drawings which illustrate two non-limitative embodiments thereof, wherein: 
           [0014]      FIG. 1  shows a global view of a first embodiment of a wind apparatus according to the present invention; 
           [0015]      FIG. 2  shows an enlarged detail of the wind apparatus of  FIG. 1 ; 
           [0016]      FIG. 3  shows a longitudinal section X-X of the first embodiment in  FIG. 1 ; and 
           [0017]      FIG. 4  is a three-dimensional illustration of some details belonging to a second embodiment of a wind apparatus object of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0018]    In  FIG. 1 , numeral  10  generically indicates, as a whole, a wind generating apparatus according to the present invention. 
         [0019]    As shown in  FIGS. 1-3 , in a first embodiment thereof, the apparatus  10  comprises a rod  11  (with longitudinal and vertical symmetry axis (A)) fixed to a base  12 . On the rod  11 , on the side opposite to the base  12 , there is provided a lamp (not shown in the accompanying figures) directly powered by the electric energy produced by a wind impeller  13  in concert with a wind generator  14  (see below). 
         [0020]    The wind impeller  13 , in turn, comprises a hub  15  coaxial with the axis (A) of the rod  11 . Furthermore, the rod  11  is inside the hub  15  and a pair of bearings  16 ,  17  onto which the weight of the entire impeller  13  is relieved, are keyed thereon. The bearings  16 ,  17  allow the relative rotation of the impeller  13  itself with respect to the rod  11 . 
         [0021]    A plurality of essentially tile-shaped blades  18  is integral with the hub  15 . Each tile presents a corresponding concave surface  18   a  and a corresponding convex surface  18   b.    
         [0022]    In embodiment shown in  FIGS. 1-3 , the wind impeller  13  is completed by a plurality of horizontal reinforcement plates  19 , possibly integrally obtained with the hub  15 . Such horizontal plates  19  divide the blades  18  into vertical sections. 
         [0023]    Furthermore, the lower portion of the hub  15  is provided with a flange  20  (essentially perpendicular to axis (A)), which, in use, rests on a thrust bearing assembly  21  by means of which the weight of the entire impeller  13  is relieved onto the base  12  ( FIG. 3 ). 
         [0024]    In a known manner, the generator  14  is electrically connected to a battery (not shown) and/or to an electric line (not shown). 
         [0025]    A rotor  14   a  of the wind generator  14  is made integral with the lower end  15   a  of the hub  15 , in a known manner, while a stator  14   b  of the same wind generator  14  is accommodated in a cavity CAV provided in the base  12 . 
         [0026]    In order to facilitate the assembly/disassembly of the wind generator  14  in/from the cavity CAV, the base  12  may be made in two portions  12   a ,  12   b , reciprocally coupled in use by means of known systems and thus not shown. 
         [0027]    As shown in  FIG. 3 , the rod  11 , the lower portion of the hub  15  and the thrust bearing assembly  21  are inserted through a through hole FF made in the base  12  so as to allow the lower end  15   a  of the hub  15  to extend into the cavity CAV. 
         [0028]    Obviously, if the base  12  consists of two portions  12   a ,  12   b , also the through hole FF may be made in two halves. 
         [0029]    Furthermore, since the lower portion of the hub  15  and the flange  20  are nearly always rotating about the axis (A) (it is presumed that such apparatuses are installed in places which are mostly windy), in order to avoid dangers for bystanders, the lower part of the apparatus  10  is protected by a protective hedge  22  ( FIGS. 1 ,  3 ), which, for example, may consists of two semi-cylindrical half shells (not expressly indicated in the accompanying figures) reciprocally coupled in a known manner. 
         [0030]    Now, we will assume that the wind blows according to a direction shown by an arrow (W) ( FIG. 1 ). 
         [0031]    In case the wind impeller  13  was in no way shielded, the wind (which blows according to (W)) would strike a first portion of the blades  18  (more in detail, the blades  18  which are approximately situated on the right-hand part of the apparatus  10  shown in  FIG. 2 ) on their concave surfaces  18   a  causing a rotation of the impeller about the axis (A) according to an arrow (R) ( FIG. 2 ); however, the wind would act also on the convex surfaces  18   b  of a second portion of blades  18  (more in detail, the blades  18  which are approximately situated on the left-hand side of the apparatus  10  shown in  FIG. 2 ). 
         [0032]    The action on the second portion of blades  18  would be counter-productive for the purpose of electric energy production because it would counter-react the action of the wind on the first portion of blades  18  and, thus, would “slow down” the rotation of the wind impeller  13  about the axis (A) according to the arrow (R) causing a considerable waste of energy as a consequence. 
         [0033]    Therefore, it has been inventively thought to shield the aforesaid second portion of blades  18  with an essentially semi-cylindrical-shaped wind screen hood  23 . Such wind screen hood  23  rests on the rod  11  by means of a thrust bearing  24  and, thus, is also adapted to rotate about the axis (A). 
         [0034]    Furthermore, on a vertical edge (B) of the wind screen hood  23  there are provided two rudders  25 ,  26  ( FIG. 1 ) which allow the orientation of the wind screen hood  23  itself according to the direction of the wind given by the arrow (W) so as to reach a position of balance. Indeed, since the action of the wind will also occur on them, such rudders  25 ,  26  (in stationary wind conditions) will align with the direction of the wind itself, direction given by the arrow (W), as explained. 
         [0035]    Therefore, the system will be configured as shown in  FIGS. 1 ,  2  in a condition of balance until the wind blows in the direction identified by the arrow (W). It is apparent that if the wind changes direction, the system will reposition itself in a new condition of balance. 
         [0036]    For the optimal operation of the impeller  13 , the left-hand portion of the blades  18  shown in  FIGS. 1 ,  2  must be covered by the wind screen hood  23  so that no significant wind action occurs directly on such blades  18 . 
         [0037]    Furthermore, since such second portion of blades  18  does not “hit” into the wind with its own convex surfaces  18   b  (because they are “covered” by the wind screen hood  23 ), there will be no significant negative effect which would tend to slow down the wind impeller  13  in its rotation about the axis (A) according to the arrow (R). 
         [0038]    In this manner, there is no loss of a part of energy as occurs instead in traditional wind apparatuses. 
         [0039]    As previously mentioned, if the direction of the wind changes, the wind screen hood  23  will be oriented as a consequence according to the new direction. 
         [0040]    In other words, the wind screen hood  23 , combined with the corresponding rudders  25 ,  26 , forms a sort of “weather vane” or “wind sock” adapted to align in the same direction as the wind (direction indicated by the arrow (W)). 
         [0041]      FIG. 4  shows a second embodiment of the invention in which the traditional blades  18  of the impeller  13 , which were previously illustrated with reference to  FIGS. 1-3 , are replaced by a plurality of propeller segments  180  of an impeller  13 *. 
         [0042]    For example, the propeller segment  180 * shown in  FIG. 4  contemplates a first surface  180 *a and a second surface  180 *b. 
         [0043]    For the previously explained reasons, the second surface  180 *b must be shielded by the wind screen hood  23 * with which two rudders  25 * and  26 * are integral. As the wind direction given by the arrow (W) changes, the position of the wind screen hood  23 * will also change with the implications which have been described with reference to the first embodiment shown referring to  FIGS. 1-3 . 
         [0044]    Obviously, a generator (not shown) of the previously seen type is associated to the impeller  13 *. 
         [0045]    In a further embodiment (not shown), at least one portion of the wind screen hood is scroll-shaped to create an air inlet funnel, in which the air itself is compressed. 
         [0046]    The main advantage of the apparatus according to the present invention is in that, by adopting a simple, essentially semi-cylindrical hood moved by the wind force itself by means of at least one rudder, either only the concave surface of the blades (first embodiment), or a particular surface of the propeller segments (second embodiment) are directly struck by the wind, while the surfaces which would “brake” the impeller when struck by the wind are shielded. 
       REFERENCE NUMBERS 
       [0000]    
       
         
           
               10 —wind apparatus 
               11 —rod 
               12 —base 
               12   a —portion (of the base  12 ) 
               12   b —portion (of the base  12 ) 
               13 —wind impeller 
               13 —wind impeller 
               14 —wind generator 
               14   a —rotor (of the wind generator  14 ) 
               14   b —stator (of the wind generator  14 ) 
               15 —hub (of the wind impeller  13 ) 
               15   a —lower end (of the hub  15 ) 
               16 —bearing 
               17 —bearing 
               18 —blade (of the wind impeller  13 ) 
               18   a —concave surface (of the blade  18 ) 
               18   b —convex surface (of the blade  18 ) 
               19 —plate 
               20 —flange 
               21 —thrust bearing assembly 
               22 —protective hedge 
               23 —wind screen hood 
               24 —thrust bearing 
               25 —rudder 
               25 *—rudder 
               26 —rudder 
               26 *—rudder 
               180 —propeller segment 
               180 *—propeller segment 
               180 *a—first surface (of a propeller segment) 
               180 *b—second surface (of a propeller segment) 
             (A)—vertical axis (of rod  11 , impeller  13  and wind screen hood  23 ) 
             (B)—edge 
             (CAV)—cavity 
             (FF)—through hole