VERTICAL AXIS WIND TURBINE

Abstract: A high aerodynamic yield turbine (10) comprises a frame (11) hinged to a fixed surface in correspondence to its vertical axis; said frame comprises transverse peripheral rings (12, 13) connected by uprights (16, 17) and supports a number of blades (28) rotating around a respective axis substantially parallel to said vertical axis.

Description: VERTICAL AXIS WIND TURBINE & & A A A TECHNICAL FIELD This invention concerns a high aerodynamic yield turbine able to absorb energy from the natural movement of a fluid. More specifically, it concerns a turbine with a structure able to adapt to the flow of a Ωuid irrespective of direction and absorb energy easily convertible into electrical energy, particularly in places difficult to reach with a normal high voltage line. BACKGROUND ART It is a well known fact that a wind or water driven turbine has a shaft, usually with a horizontal axis, mounted on special bearings and with blades or large surface area elements at one end able to offer appropriate resistance to the flow of a fluid and obtain energy from the flow tlirough variations in the quantity of motion on impact with said blades. The shaft is kinematically connected to a device which uses the energy absorbed by the turbine and converts it into rotary mechanical energy for whatever uses are most appropriate, to date, almost exclusively for the production of electricity. According to the geological configuration of the area, turbines generally comprise a tower supporting a propeller assembly designed to absorb energy from the wind. In this context, the italian electric energy provider ENEL have performed studies in regions such as Sardinia particularly exposed to the wind in order to allow alternative and above all clean energy sources to be exploited. The use of horizontal axis turbines with one or more blades is known. In both cases, these turbines may be the lift type with the wind from the front when the blades are oriented against the direction of the air flow or downwind if the blades are oriented in the same direction as the flow, or drag type such as the transverse windmill and horizontal Savonius which offer a large surface area exposed to the air flow. Also used to date are predominantly drag type vertical axis turbines either with blades or of the Savonius type; predominantly lift type turbines such as, for example, the Darrieus and Giro mill comprising a spherical or prism-shaped rotating frame supporting moulded surfaces designed to absorb wind energy and mixed vertical axis turbines such as, for example, the Magnus and eccentric Savonius with the characteristics and configurations of the previously described vertical axis turbines. One problem is that these turbines function principally by exploiting the kinetic contribution of the fluid and consequently by converting the kinetic energy of said fluid immediately into mechanical energy for "action". The contribution of the fluid is therefore determined substantially by its speed which must necessarily be high. Atmospheric situations lacking particularly strong winds therefore limit use of these turbines and often make them extremely inefficient. Another problem is that the turbines have low inertia. The movement of the fluid must therefore be continuous as otherwise they would slow down to the point of stopping. DESCRIPTION OF THE INVENTION This invention aims to provide a high aerodynamic yield turbine able to eliminate or significantly reduce the problems described above. This invention also aims to provide a turbine able to adapt to any direction of fluid flow. This invention also aims to provide a turbine able to function with even minimal fluid flow. This is achieved by means of a high aerodynamic yield turbine with the features described in the main claim. The dependent claims describe advantageous embodiments of the invention. The high aerodynamic yield turbine according to the invention comprises a frame hinged to a fixed surface in correspondence to its vertical axis and comprising peripheral transverse rings connected by uprights supporting blades rotating around a respective axis substantially parallel to said vertical axis together with channelling elements projecting from the frame itself in a non-radial direction with respect to said vertical axis. According to the invention, the hinges of the rotating blades are located on said uprights connecting the bars of the frame which is equipped with stops allowing said blades to travel through angles less than a flat angle and such as to occupy a single sector comprised between two consecutive bars. The frame has perimeter guides sliding in a respective fixed housing while the channelling elements slope in the same direction and at the same angle in such a way as to contribute uniformly to the movement of the turbine. These channelling elements absorb energy fiOm the moving fluid above all due to lift and thus due to a kinetic effect, guaranteeing a minimum of rotational energy to the turbine. If the flow of fluid is at right-angles to the rotating blades, these rotate around their own axis into a position of maximum opening, enabling said fluid to flow through the turbine without hindering rotation. The direction of rotation of the blades is the same as that of the turbine in such a way as to contribute additional moment to the quantity of motion so as to maintain rotational energy by increasing the inertia of the turbine itself, allowing the frame to rotate with a minimum flow of fluid. ILLUSTRATION OF DRAWINGS Other features and advantages of the invention will become evident on reading the following description of an embodiment of the invention, given as a non-binding example, with the help of the enclosed drawings in which: ; - figure 1 is a front elevation of the turbine according to the invention; figure 2 represents a cross-section from the bottom taken along the line II-II in figure 1 ; and, figure 3 illustrates a front elevation of a rotating blade. DESCRIPTION OF A FORM OF EMBODIMENT In the figures, the reference number 10 generally indicates a high aerodynamic yield turbine. In this particular case, a turbine 10 comprising a frame 11 with a bottom perimeter ring 12 and a top perimeter ring 13 each connected to a central shaft by means of bars 15. The bars 15 of the bottom ring 12 are connected to the respective bars 15 of the top ring 13 by means of intermediate uprights 16 and peripheral uprights 17, the latter being located in correspondence with said rings 12 and 13. The uprights 16 and 17 are substantially in parallel to the central shaft 14. In this way, the frame 11 has a cage-type rotor configuration, preferably cylindrical, delimited by rings 12 and 13 as well as by the peripheral uprights 17 and bars 15 strengthened by the presence of the intermediate uprights 16. At the ends of the central shaft 14, the bottom end of which may be fixed to a plinth 19 anchored to the ground 19, there are hubs 20 and 21 respectively fixed to the bars 15 of the bottom ring 12 and the bars 15 of the top ring 13. These hubs are internally hollow and each has a housing for a respective bearing in such a way as to allow the frame 11 to rotate freely around the shaft 14. The lower perimeter ring 12 has rounded projections 22 distributed uniformly around the edge and facing radially towards the outside of the frame 11. During operation, these projections 22 are designed to slide inside an external fixed hub 23 constrained to plinths 24 anchored to the ground 19. Each plinth 24 may be equipped with a respective plate 25 rising up from the ground 19 and adjacent to the hub 23 in such a way as to oppose possible centrifugal forces during rotation of the turbine 10. On the side facing the shaft 14, each peripheral upright 17 and intermediate upright 16 is equipped with hinges 26 to hinge the respective frame 27 of a rotating blade 28. This latter preferably has a frame 27 with a rectangular configuration designed to support a sail 29 in stretched fabric resistant to external agents. According to a variation shown in figure 3, the sail 29 may be reefed, for example, by releasing one end and winding it onto a respective drum 30 in correspondence to the opposite end. In the case of relatively large turbines 10, the drum 30 may be power-driven and may have guide chains sliding in a housing on the frame 27 designed to pull the sail 29 during both rolling and unrolling from the drum 30. In correspondence to each intermediate upright 16 and near the hubs 20 and 21, each bar 15 is equipped with striker plates 31 to serve as end stops during closing of each respective rotating blade 28. In addition, each peripheral upright 17 and intermediate upright 16 has an angle stop 32 to limit the angular excursion of the respective rotating blade 28 during opening of said blade. Said angle stop is generally designed to stop excursion of the blade 28 at an angle of about 45°. Each rotating blade 28 may have an appropriate means of elastic return to bring it back to the closed position after the phase of the first impact of the flow of fluid is concluded. The inclination with respect to the bar of the support ring is generally about 45°. As can be seen from figure 2, when the fluid, for example air, flows in the direction indicated by the arrow identified with the letter "A", a sector 34 comprised between consecutive bars 15 will be immediately affected by the impact of the fluid itself, while at the same time the other sectors 35 will not be influenced by the kinetic effect of the air. In sector 34, the rotating blades 28 affected by the flow substantially at right- angles to the respective sails 29 tend to open, rotating in the direction indicated by the arrows identified with the letter "B", while the blades 28 of the other bar 15 remain in the closed position thanks to the opposing action of the striker plates 31. In this way, the bar 15 with the blades 28 closed offers resistance to the fluid, inducing the turbine 10 to rotate in the direction indicated by the arrow identified with the letter "C", while at the same time the blades on the successive bar 15 are open and do not hinder the rotary movement of the turbine 10 itself. ' The frame 1 1 is made of light metal with good mechanical resistance and a high degree of resistance to atmospheric agents, for example, it may be in aluminium. Each rotating blade 28 may typically have the respective sail 29 in a material used to construct sails for boats. The high aerodynamic yield turbine according to the invention can be used with any type of fluid, for example air or water. The invention is described above with reference to a preferred embodiment. However, the invention is obviously open to numerous technically equivalent variations. By way of example, according to a possible embodiment, the turbine may operate with a number of generators. According to another embodiment, the perimeter ring may function directly from a power takeoff point by means of a coupling with a ring gear or belt. Again, with the aim of strengthening the structure, further smaller diameter rings concentric to the perimeter ring may be inserted in the support base. According to a further embodiment, the turbine is not equipped with air channelling elements. Finally, the hinges on the rotating blades may be central with respect to the blades themselves and not arranged on one side as in the figures shown. According to a final preferred embodiment, the turbine may be equipped with a number of superimposed units connected to a single central shaft.

Claims: CLAIMS 1. A high aerodynamic yield turbine (10) comprising a frame (11) hinged to a fixed surface in correspondence to its vertical axis, characterised in that said frame comprises transverse peripheral rings (12, 13) connected by uprights (16, 17) and supports a number of blades (28) rotating around a respective axis substantially parallel to said vertical axis. 2. A turbine (10) according to claim 1 characterised in that said frame (1 1) has bars (15) in correspondence with said rings (12, 13) to which said uprights (16, 17) equipped with hinges (26) for said rotating blades (28) are fixed. 3. A turbine (10) according to anyone of the preceding claims characterised in that said frame (11) is equipped with end stops (31, 32) designed to allow said rotating blades (28) to move through angles less than a flat angle and such as to occupy a single sector (35) between consecutive bars (15). 4. A turbine (10) according to anyone of the preceding claims characterised in that each of said rotating blades (28) has an elastic return device designed to bring it back from an open position resulting from the flow of a fluid into a closed position. 5. A turbine (10) according to anyone of the preceding claims characterised in that said frame (11) has perimeter guides (22) sliding in a respective fixed housing (23). 6. A turbine (10) according to claim 5 characterised in that said perimeter guides (22) comprise rounded projections with a spherical configuration. 7. A turbine (10) according to claim 5 or 6 characterised in that said fixed housing has plates (25) designed to oppose possible centrifugal forces. 8. A turbine (10) according to anyone of the preceding claims characterised in that each rotating blade (28) comprises a frame (27) designed to support a sail (29). 9. A turbine (10) according to claim 10 characterised in that said sail (29) can be reefed. 10. A turbine (10) according to claim 10 or 1 1 characterised in that said frame (27) has a drum (30) on which said sail (29) can be wound. 1 1 . A turbine (10) according to claim 12 characterised in that said drum is power-driven. 12. A turbine (10) according to claim 12 or 13 characterised in that said drum (30) has a guide chain running in a housing on said frame (27) designed to pull said sail (29) both during winding and unwinding of the sail from or onto said drum (30). 13. A turbine (10) according to anyone of the preceding claims characterised in that said frame (11) is made from aluminium. 14. A turbine (10) according to anyone of the preceding claims characterised in that it comprises a number of superimposed units mounted on the same shaft coinciding with said vertical axis.

Inventors: ZAMBON GIANCARLO, ZAMBON, GIANCARLO
Applicants: ZAMBON GIANCARLO, ZAMBON, GIANCARLO
Application year: 2001
Main classification: F03D3
IPC codes: F03D3, F03D11