Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F03—MACHINES OR ENGINES FOR LIQUIDS; WIND, SPRING, OR WEIGHT MOTORS; PRODUCING MECHANICAL POWER OR A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR
  • F03D—WIND MOTORS
  • F03D3/00—Wind motors with rotation axis substantially perpendicular to the air flow entering the rotor 
  • F03D3/06—Rotors
  • F03D3/062—Rotors characterised by their construction elements
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
  • F05B—INDEXING SCHEME RELATING TO WIND, SPRING, WEIGHT, INERTIA OR LIKE MOTORS, TO MACHINES OR ENGINES FOR LIQUIDS COVERED BY SUBCLASSES F03B, F03D AND F03G
  • F05B2240/00—Components
  • F05B2240/20—Rotors
  • F05B2240/21—Rotors for wind turbines
  • F05B2240/211—Rotors for wind turbines with vertical axis
  • F05B2240/213—Rotors for wind turbines with vertical axis of the Savonius type
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
  • F05B—INDEXING SCHEME RELATING TO WIND, SPRING, WEIGHT, INERTIA OR LIKE MOTORS, TO MACHINES OR ENGINES FOR LIQUIDS COVERED BY SUBCLASSES F03B, F03D AND F03G
  • F05B2240/00—Components
  • F05B2240/50—Bearings
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
  • Y02B10/00—Integration of renewable energy sources in buildings
  • Y02B10/30—Wind power
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
  • Y02E10/00—Energy generation through renewable energy sources
  • Y02E10/70—Wind energy
  • Y02E10/74—Wind turbines with rotation axis perpendicular to the wind direction

Definitions

• the present invention refers to a wind generator with vertical axis.
• the present invention refers to a wind generator with vertical axis which can be effectively used to make generators with limited size (the so-called "micro-wind” generators) .
• the main renewable resources taken under consideration are solar energy and wind energy.
• wind generators with vertical axis and small size have been developed. The latter are capable of effectively operating, even in the presence of rather weak winds, for example with speed on the order of 5 - 10 m/s.
• wind generators of "Savonius" type - from the name of the inventor, the Finnish engineer NASAd J. Savonius - are wind generators with vertical axis comprising a plurality of curved shaped blades mounted along a vertical shaft.
• the functioning of the wind generators of "Savonius” type is based on the aerodynamic resistance ("drag") : due to their curvature, the blades of a generator of "Savonius” type offer a lower aerodynamic resistance when they are moved in the direction of the wind than when they are moved in the opposite direction; the aerodynamic resistance differential can be exploited in order to rotate the vertical shaft, which can in turn be connected to known means for the transformation of the mechanical energy into electrical energy .
• each blade will have a concave portion or active portion on which the wind thrust pressure will operate in order to rotate the shaft of the generator; but each blade will also have a convex portion or passive portion which will slow said rotation movement, causing a diminution of the energy yield.
• the main object of the present invention is to overcome the abovementioned drawbacks of the prior art, by providing a wind generator with vertical axis with an improved energy yield .
• the wind generator according to the invention is a wind generator with vertical axis which includes a rotor that comprises a central rotation shaft with vertical axis and a plurality of curved radial blades, preferably mounted equidistant between a pair of support plates and connected to said central shaft; said blades have a continuous guide surface for the wind from said shaft up to the periphery of said rotor, thus to prevent the wind from radially crossing the rotor.
• first deflectors or internal deflectors are mounted between said support plates, alternating with said blades.
• Said first deflectors are shaped in a manner so as to form a narrow passage along the path that the wind follows, by following the guide surface offered by the respective blade; due to the presence of such narrow passage, it is possible to obtain an increase in the speed of the wind which acts on the concave portion of the blade, via Venturi effect.
• the invention provides for the presence of the first deflectors and the consequent narrow passage along the path of the wind; on one hand, according to the Venturi effect, such narrow passage leads to a reduction of the pressure, and on the other hand it leads to an increase of the speed.
• the wind generator according to the invention also includes a stator arranged around said rotor and comprising a plurality of second deflectors or external deflectors, suitably shaped for conveying the wind towards the blades of the rotor.
• said stator also comprises a pair of covers of frustoconical shape arranged at the respective ends of said second deflectors, which further contribute to effectively conveying the wind towards the blades of the rotor.
• each blade is made in the shape of a flat panel bent on itself around a vertical axis, in a manner such that its cross section assumes the form of an arc of circumference.
• said cross section has the shape of an arc of circumference of about 270° .
• each first interior is made in the shape of a flat panel bent on itself around a vertical axis, in a manner such that its cross section assumes the shape of an arc of circumference; the size and curvature of the first deflectors are preferably selected in a manner such that the minimum distance between an internal deflector and the corresponding blade is equal to 1/6 of the distance between said deflector and said blade at the periphery of the rotor.
• each second deflector is made in the shape of a flat panel bent on itself around a vertical axis, in a manner such that its cross section assumes a shape comprising a first arc of circumference and a second arc of circumference with opposite concavities, connected by an inflection point.
• said cross section comprises a first arc of circumference of about 90° and a second arc of circumference of about 90° with opposite concavities, connected by an inflection point.
• the wind generator according to the invention has shown to be particularly effective for making small-size generators, particularly suitable for use by private individuals, e.g. for domestic applications ("micro-wind” generators) . Nevertheless, it is possible to employ the teachings of the invention also for making larger wind generators, up to generators on the order of 50 - 100 kWp (the so-called "mini- wind” generators) .
• FIG. 1 is a front schematic view of a wind generator with vertical axis according to a first preferred embodiment of the invention
• Figures 2 and 3 are schematic views in section along the line A-A of the wind generator of Figure 1 ;
• FIG. 4 is a schematic view in section along a longitudinal plane of a wind generator with vertical axis according to a second preferred embodiment of the invention ;
• Figure 5 is a schematic view in section along the line B-B of the wind generator of Figure 4.
• FIG. 1 a first preferred embodiment of a wind generator with vertical axis according to the invention is shown, generically indicated with the reference 1.
• Said wind generator 1 includes at least one rotor 3 which comprises a rotation shaft 5 in central position, mounted at the upper and lower ends on bearings (not shown) .
• a rotation shaft 5 in central position, mounted at the upper and lower ends on bearings (not shown) .
• two support plates 7a, 7b are provided for with substantially discoid form.
• a plurality of radial blades 9a - 9d are mounted, which are extended from the central rotation shaft 5 up to the periphery of the support plates 7a, 7b.
• Said radial blades 9a - 9d - four in the preferred embodiment of Figures 1 and 2 - are preferably arranged equidistant around said central rotation shaft and are shaped as flat panels, suitably bent around a vertical axis in order to have a curved cross section, which substantially follows an arc of circumference; in particular, as will be illustrated in detail below, said blades 9a - 9d are shaped in a manner so as to offer a concave surface to the wind which hits the rotor 3 of the wind generator 1, as is visible in Figure 2.
• the blades 9a - 9d are extended from the central rotation shaft 5 up to the periphery of the support plates 7a, 7b and have a continuous guide surface for the wind from said shaft up to the periphery of said plates, defining corresponding separate and non-communicating sectors and preventing the wind from radially crossing the rotor.
• transverse reinforcement dividers 12 can be provided for.
• a plurality of first deflectors or internal deflectors 11a - lid are also provided for, mounted alternating with said blades 9a - 9d.
• Said first deflectors 11a - lid are extended from the periphery of the support plates 7a, 7b to an intermediate point between said periphery of said plates and the central rotation shaft 5 and are shaped as flat panels, bent around a vertical axis, in a manner so as to have a curved cross section which substantially follows an arc of circumference.
• each first deflector 11a - lid are selected in a manner such to determine a corresponding narrow passage 13 in the space comprised between the radial blades adjacent thereto, along the path that the wind follows, by following the guide surface offered by said blades; due to the presence of such narrow passages 13, it is possible to obtain an increase of the speed of the wind which acts on the blades 9a - 9d, via Venturi effect. Consequently, it is possible to increase the effect of the action of the wind on said blades 9a - 9d, and consequently the rotation speed of the central rotation shaft 5.
• the wind generator 1 also preferably includes a stator 14 arranged around the rotor 3.
• Said stator 14 comprises a framework 15 on which second deflectors or external deflectors 17a - 17d are radially mounted .
• Said second deflectors 17a - 17d are preferably provided for in a number equal to the number of blades 9a - 9d of the rotor 3 - four in the embodiment of Figures 1 and 2 - and are preferably arranged equidistant around the rotor 3.
• Said second deflectors 17a - 17d are in the shape of flat panels, which are subjected to subsequent bending operations in a manner such that their cross section comprises two curved contiguous portions 17', 17''; each of such portions substantially follows an arc of circumference, said portions 17' , 17' ' having opposite concavities and being connected by an inflection point 11'''.
• Said second external, static deflectors 17a - 17d have the function of cooperating with the blades 9a - 9d and with the first, rotatable deflectors 11a - lid, in order to more effectively convey the wind which hits the wind generator 1 towards the path defined by said blades and by said first deflectors .
• the stator 14 of the wind generator 1 can also comprise a pedestal 19 which allows placing and maintaining the rotor 3 with the blades 9a - 9d and the first deflectors 11a - lid, as well as the second deflectors 17a - 17d, at a height from the ground that is suitable for optimally exploiting the wind present.
• the rotatable components of the generator 1, and particularly the support places 7a, 7b, the radial blades 9a - 9d and the first deflectors 11a - lid are made of a light material, preferably aluminum or an alloy thereof .
• the stationary components of the generator 1, including the second deflectors 17a - 17d, are preferably made of steel or a similar material.
• FIG 3 is a reproduction of Figure 2 in which the path of the wind which hits the wind generator 1 according to the invention is schematically reported.
• the kinetic energy of the rotation shaft 5 will then be transformed into electrical energy by means of suitable means provided for in the wind generator 1 (not illustrated) .
• the blades 9a - 9d of the rotor 3 of the wind generator 1 offer a continuous guide surface for the wind flow and prevent the radial crossing of the rotor itself, such that the flow of wind which enters into the space comprised between two contiguous blades 9a and 9b or 9a and 9d will remain confined in said space and will be guided from the surface of said blades up to the output of the rotor .
• the structure of the wind generator according to said second embodiment is substantially similar to that of the first embodiment described above and therefore the same numeric references used for said first embodiment will be used here for indicating identical or equivalent components.
• the wind generator 1 includes at least one rotor 3 which comprises a central rotation shaft 5, mounted at the upper and lower ends on bearings 6a, 6b, and a pair of support plates 7a, 7b integral with said rotation shaft 5, of substantially discoid shape, which are respectively provided close to the upper end and the lower end of said rotation shaft; between such plates, a plurality of radial blades 9a - 9d are mounted, which are extended from the central rotation shaft 5 up to the periphery of the support plates 7a, 7b.
• Said radial blades 9a - 9d - four in the preferred embodiment of Figures 1 and 2 - are preferably arranged equidistant around said central rotation shaft and are shaped as flat panels, suitably bent around a vertical axis in a manner so as to have a curved cross section, which substantially follows an arc of circumference.
• said blades 9a - 9d are bent in a manner such that their cross section follows an arc of circumference of about 270°.
• the blades 9a - 9d offer a concave surface that is optimized for the wind flow that hits the rotor 3 of the wind generator.
• the blades 9a - 9d are extended from the central rotation shaft 5 up to the periphery of the support plates 7a, 7b and have a continuous guide surface for the wind from said shaft up to the periphery of said plates.
• a plurality of first deflectors or internal deflectors 11a - lid are also provided for, mounted alternating with said blades 9a - 9d.
• Said first deflectors 11a - lid are extended from the periphery of the support plates 7a, 7b to an intermediate point between said periphery of said plates and the central rotation shaft 5, and have the shape of flat panels, bent around a vertical axis in a manner so as to have a curved cross section, which substantially follows an arc of circumference .
• the size, the shape and the position of the first deflectors 11a - lid are selected in a manner such to determine corresponding narrow passages along the path that the wind follows, by following the guide surface offered by the respective blade; in particular, in order to optimize the Venturi effect, they are advantageously selected in a manner such that the minimum distance d between one internal deflector and the corresponding blade is equal to about 1/6 of the distance D between said deflector and said blade at the periphery of the rotor.
• the wind generator 1 also preferably includes a stator 14 arranged around the rotor 3.
• Said stator 14 comprises an upper cover 21a and a lower cover 21b, between which second deflectors or external deflectors 17a - 17d are radially mounted.
• Said covers 21a, 21b preferably have frustoconical shape, possibly flared, which narrows in the direction towards the rotor 3 of the wind generator 1, and their smaller base substantially has the same diameter as the respective support plate 7a, 7b of the rotor 3.
• Such shape advantageously contributes to conveying the wind towards said rotor 3.
• the second deflectors 17a - 17d are preferably provided for in a number equal to the number of the blades 9a - 9d of the rotor 3 and are preferably arranged equidistant around the rotor 3.
• Said second deflectors 17a - 17d are shaped as flat panels, which are subjected to subsequent bending operations in a manner such that their cross section comprises two curved contiguous portions; each of such portions substantially follows an arc of circumference, said portions having opposite concavities and being connected by an inflection point.
• each portion of said second deflectors 17a - 17d preferably follows an arc of circumference with angle equal to about 90°.
• the pedestal 19 of the stator 14 is also illustrated; such pedestal allows placing and maintaining the rotor 3 with the blades 9a - 9d and the first deflectors 11a - lid, as well as the second deflectors 17a - 17d, at a height from the ground suitable for optimally exploiting the wind present.
• the present invention attains the pre-established objects, since it allows obtaining a wind generator with vertical axis with an improved energy yield.
• first deflectors could be different from the number of blades and more than one first deflector could be provided for between each pair of contiguous blades.
• the number of second deflectors could be different from the number of the blades and suitably selected on the basis of user requirements.

Landscapes

• Engineering & Computer Science (AREA)
• Life Sciences & Earth Sciences (AREA)
• Sustainable Development (AREA)
• Sustainable Energy (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Wind Motors (AREA)
• Motor Or Generator Cooling System (AREA)
• Treating Waste Gases (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (1)

Family

ID=42983472

Family Applications (1)

Country Status (3)

Cited By (6)

Citations (3)

Family Cites Families (4)

• 2010
  • 2010-02-09 IT IT000015A patent/ITGE20100015A1/it unknown
• 2011
  • 2011-02-09 EP EP11710315A patent/EP2534375A1/en not_active Withdrawn
  • 2011-02-09 WO PCT/IB2011/050545 patent/WO2011098957A1/en active Application Filing

Patent Citations (3)

Also Published As

Similar Documents

Legal Events