Collapsible vertical-axis wind turbine

Abstract

A collapsible wind turbine includes a turbine with a vertical axis (A). The turbine is supported by a vertical pylon, pivotably mounted about a hinge, and by linking members connecting the rotation shaft of the turbine to the pylon while maintaining a separation therebetween. The wind turbine includes: —an electricity generator of which the axis of rotation is perpendicular to the longitudinal axis of the pylon, the generator being secured to the ground; and—at least one flexible link connecting and synchronising the rotation of the generator with the rotation shaft of the turbine by linear travel of the flexible link in a closed-circuit path, so as to drive the rotation shaft of the generator by the movement of the turbine. The present structure is, in particular related to land-based wind turbines in a cyclone-prone area.

Claims

1. A collapsible wind turbine, comprising: a. a turbine with a vertical axis (A) and cross flow, the turbine comprising blades moved by the wind; b. an electric generator including a rotation shaft, the rotation shaft being rotatable about a generator axis (G) and driven by the turbine; c. a holding structure for the turbine, which comprises at least one vertical pylon, with a longitudinal axis (L), and a pivot hinge (22), said pylon being connected to the ground by said hinge and being mounted pivotably about said hinge according to a folding axis (R) between a substantially vertical working position and a collapsed position; d. top and bottom linking members, which rigidly hold the turbine about an axis of rotation (A) and maintain a separation between the axis of rotation and the pylon, the axis of rotation (A) of the turbine being parallel to the longitudinal axis (L) of the pylon; and e. at least one flexible transmission link connecting and synchronizing the rotation of the rotation shaft of the generator and the rotation shaft of the turbine by linear travel of said at least one flexible link in a closed-circuit path, such that the movement of the turbine drives the generator by the rotation shaft, wherein the at least one flexible transmission link is parallel to and mounted to the pylon and thereby pivots between the substantially vertical position and the collapsed position.

2. The turbine according to claim 1, wherein the electric generator is placed at the base of the vertical pylon and joined to the ground.

3. The wind turbine according to claim 2, wherein the generator axis (G) is substantially coaxial with the folding axis (R) of the hinge.

4. The wind turbine according to claim 1, further comprising: a. a rotor wheel, rotationally joined to a rotation shaft of the turbine; b. a generator wheel, rotationally joined to the rotation shaft of the electric generator; c. a deflection device for the path of the at least one flexible link, arranged between the rotation shaft of the turbine and the rotation shaft of the generator; and the rotor wheel, the generator wheel and the deflection device being arranged to receive the at least one flexible link and couple the rotation of the generator to the rotation of the rotor, and the deflection device forming, for the at least one flexible link, a deflection which is arranged on the path of the at least one flexible link.

5. The wind turbine according to claim 4, wherein the deflection device comprises two idler wheels, coaxial with each other and rotatable about a deflection axis of rotation (F) which is perpendicular both to the axis of rotation (A) of the turbine and to the generator axis (G).

6. The wind turbine according to claim 4, wherein the diameter of the rotor wheel is at least twice as large as that of the generator wheel.

7. The wind turbine according to claim 4, further comprising a braking device comprising: a. a brake actuator; b. a brake disc rotationally linked to the rotor wheel; and c. at least one brake lining arranged between the brake actuator and the brake disc; the brake actuator being arranged and configured to act, during braking, by friction on the brake disc via the at least one brake lining.

8. The wind turbine according to claim 1, wherein the at least one flexible link is arranged on the outside, at least, of the pylon.

9. The wind turbine according to claim 1, wherein the at least one flexible transmission link is produced in the form of a timing belt, cable or chain.

10. The wind turbine according to claim 1, wherein the turbine is located at least three meters or at least one times the height of the turbine away from the ground.

11. The wind turbine according to claim 1, wherein the turbine comprises two blades extending vertically which are arranged diametrically opposite with respect to the axis of rotation (A) of the turbine, each blade comprising an upper arm and a lower arm extending to the axis of rotation respectively from a top end and a bottom end of said blade, each arm extending substantially horizontally.

12. The wind turbine according to claim 11, wherein each top and bottom linking member each include a shaft element, which are coaxial with each other, and in that the turbine comprises a top hub and a bottom hub in such a way that the upper arms of the blades are secured to the top hub and the lower arms are secured to the bottom hub, the top and bottom hubs being mounted rotatably respectively about the shaft elements of the top and bottom linking member.

13. The wind turbine according to claim 1, further comprising a hoisting device comprising a winch, at least one cable connected both to the winch and to the top of the pylon, and a hoisting arm secured to the pylon in a perpendicular position.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Other features and advantages of the invention will become apparent on reading the detailed description of embodiments and implementations which are in no way limitative, in the light of the attached figures, in which:

(2) FIG. 1 is a front view of a collapsible wind turbine according to an embodiment of the invention in which the wind turbine is secured to the ground and shown in a vertical operating state and comprises a turbine with two blades, the turbine also being viewed from the front and located approximately one times the height of the turbine away from the ground;

(3) FIG. 2 is a photo showing an example of a turbine with two blades as used in this embodiment;

(4) FIG. 3 is a view from above of the wind turbine according to FIG. 1;

(5) FIG. 4 is a view from the left, and in an inclined state with respect to the ground, of the wind turbine according to FIGS. 1 and 3;

(6) FIG. 5 is a perspective view of a bottom linking member and showing the flexible link connecting the rotor pulley to the deflection device secured to the pylon;

(7) FIG. 6 is a diagrammatic front view of a bottom linking member supporting the rotor pulley, which is connected to a braking device of said pulley;

(8) FIG. 7 is a view from above of the base of the pylon and of an electric generator secured to the ground, the pylon being viewed in cross section.

DETAILED DESCRIPTION

(9) The embodiments which will be described in the following are in no way limitative; in particular, variants of the invention will be able to be implemented which comprise only a selection of features described hereinafter in isolation from the other features described if this selection of features is sufficient to confer a technical advantage or to differentiate the invention with respect to the state of the prior art. This selection comprises at least one, preferably functional, feature without structural details, or with only a part of the structural details if this part alone is sufficient to confer a technical advantage or to differentiate the invention with respect to the state of the prior art.

(10) In particular, all the variants and all the embodiments described can be combined together if there is no objection to this combination from a technical point of view.

(11) FIGS. 1, 3 and 4 illustrate a collapsible wind turbine 10 of the vertical axis type (called VAWT for “vertical-axis wind turbine”) and with cross flow. The wind turbine is arranged and configured to collapse from a first, vertical position, called the operating position, to a second, horizontal position, called the protection position. The collapsible wind turbine is intended to be installed in isolated areas and/or areas at high risk of earthquakes and/or exposed to extreme winds, or even cyclones. In case of risk, it is thus possible to collapse the wind turbine to the ground in order to protect it, for example from projectiles propelled by the wind. It also becomes easier to dismantle it if necessary.

(12) Tie rods, cables or guy wires (not shown) are used to hold the wind turbine in position with respect to the ground and to prevent it from swaying.

(13) With reference to FIGS. 1 and 2, the wind turbine 10 comprises a turbine 30 having a vertical axis of rotation A. The turbine 30 comprises two blades 32. The turbine 30 comprises two blades 32 which extend vertically and, during operation, are subjected to the action of the wind in order to make the turbine rotate. The blades 32 extend parallel to the axis of rotation A of the turbine and are arranged diametrically opposite with respect to said axis of rotation A.

(14) Each blade 32 extends at each of its two ends, a top end and a bottom end, by a horizontal arm. At the top end, each blade 32 extends by an upper arm 33. At the bottom end, each blade 32 extends by a lower arm 31. The upper 33 and lower 31 arms are connected respectively to the blade 32 by a curved bend. The blades of each turbine describe a cylinder when they rotate. The arms are connected to shaft elements by pivot links forming the axis of rotation of the blade, see FIGS. 5 and 6 for the shaft element 45 of the bottom linking member. For example, all of the lower arms or all of the upper arms of the turbine are connected to a hub which is itself rotatable relatively about a shaft element forming the axis of rotation of the blade, the shaft element being rigidly secured to a linking member, see below. In this configuration, the central space between the blades does not comprise a rotation shaft and is completely empty.

(15) With reference to FIG. 2, the turbine 30 comprises two turbine axis hubs, a top hub 36 and a bottom hub 34. The hubs 36 and 34 are rotatable about shaft elements with a reduced height of axis A. Each upper arm 33 is secured to a top hub 36 (see FIG. 2) and each lower arm 31 is secured to a bottom hub 34 (see FIGS. 2 and 5). The bottom hub 34 is rotatable about the bottom shaft element 45, see FIG. 5.

(16) Preferably, the hubs are produced from a metallic material and the blades are produced from a composite material, for example based on carbon fibres.

(17) The wind turbine 10 comprises a holding structure 40 for the turbine 30. Said structure comprises a pylon 20 extending along a longitudinal axis L. The axis L of the pylon 20 is substantially parallel to the axis of rotation A of the turbine. During operation, the pylon 20 is located in a vertical position, see FIGS. 1 and 5.

(18) The holding structure for the wind turbine 10 comprises linking members, a top linking member 43 and a bottom linking member 41, securely connected to the pylon 20 which supports the rotation shafts of the turbines and maintains a separation between them and the pylon. With reference to FIG. 1, the wind turbine 10 comprises a top linking member 43 and a bottom linking member 41 for supporting the turbine 30. The top linking member 43 extends substantially from the top of the pylon; the bottom linking member 41 extends from the pylon, in this example at approximately halfway along it. The bottom linking member is preferably located at least three metres away from the ground S. The top 43 and bottom 41 linking members thus hold the turbine at its ends by a pivot link, eliminating the need for a central drive shaft between the blades.

(19) With reference to FIGS. 1 and 4, the holding structure for the wind turbine 10 comprises a pivot hinge 22 of the pylon 20 relative to the ground S, in such a way that the pylon 20 is connected to the ground S by said hinge. The hinge 22 produces a pivot link with a horizontal axis, called the folding axis R. The folding axis R is perpendicular to the longitudinal axis L of the pylon 20, see FIG. 1. According to an embodiment, the holding structure comprises a set of feet 21, 23 secured to the ground, see FIGS. 3 and 7. With reference to FIG. 7, each foot 21, 23 comprises a bore provided to produce the female part of the pivot hinge 22. The feet 21 and 23 are arranged with respect to each other in such a way that the bores are coaxial with each other in order to receive a pivot shaft. Moreover, the holding structure comprises a pivot shaft 24, referenced only in FIG. 7. The latter is connected securely to the base of the pylon such that it extends in a direction perpendicular to the longitudinal axis L of the pylon. The pivot shaft 24 is mounted in the bores of the feet 21 and 23 in order to produce the pivot hinge 22. The pivot hinge 22 makes it possible to pivot the wind turbine between a substantially vertical operating position and a substantially horizontal collapsed position. FIG. 4 shows an inclined intermediate state between said positions.

(20) With reference to FIGS. 3 and 4, the wind turbine comprises a hoisting device 80 in order to actuate the pivoting thereof.

(21) The hoisting device comprises a winch 81 secured to the ground and a cable 83 connecting the top of the pylon and the winch 81, see FIG. 4. The hoisting device moreover comprises a hoisting arm 82 rigidly secured perpendicularly to the pylon 20. With reference to FIG. 7, the hoisting arm 82 is secured to the pivot shaft 24 of the pylon 20. With reference to FIG. 4, the hoisting arm 82 is secured to the base of the pylon, so as to create a lever arm, moving the traction point of the cable 83 away from the pylon 20, thus making it easier to lift the wind turbine. The cable 83 must lean on the distal end of the hoisting arm 82. The winch 81 is arranged at a distance from the base of the pylon and in such a way that the cable 83 leans on the hoisting arm 82, which holds it away from the hinge 22, see FIG. 4.

(22) The wind turbine comprises an electric generator 70 in order to convert the mechanical energy from rotation of the turbine into electrical energy. With reference to FIGS. 1, 3 and 7, the electric generator 70 comprises a rotation shaft 71 rotatable about the generator axis G. The shaft of the generator is driven in rotation by the rotation of the turbine. With reference to FIG. 1, the generator is located at the base of the pylon 20 and is secured to the ground S. According to a preferred embodiment, the generator axis G is substantially coaxial with the folding axis R of the hinge. This feature makes it possible not to lay down (or loosen) the mechanical transmission means between the generator and the turbine, because they are pivotable about the same axis. Advantageously, the generator can be arranged totally independently with respect to the pylon without interfering with the erecting or lowering movements thereof. Preferably, the generator is a variable speed permanent magnet generator.

(23) The wind turbine moreover comprises a flexible link 60 as mechanical transmission means between the turbine and the generator, see FIGS. 1, 3, 5 and 7. The flexible link, for example a belt or chain, is arranged and configured in order to connect and synchronize the rotation of the rotation shaft of the generator and the rotation shaft of the turbine by a linear travel in a closed-circuit path.

(24) With reference to FIG. 5, the wind turbine comprises a rotor pulley 64 arranged coaxially with the bottom hub 34 of the turbine. With reference to FIG. 7, the wind turbine comprises a generator pulley 62 arranged coaxially with the rotation shaft 71 of the generator. With reference to FIG. 5, the wind turbine comprises idler wheels 68 arranged coaxially with each other and mounted freely rotatable with respect to the holding structure. The rotor pulley 64, the generator pulley 62 and the idler wheels 68 are arranged to receive, on their circumferential surface, the flexible link and to cooperate therewith by adherence. The idler wheels 68 make it possible to produce a deflection device of the path between the bottom hub of the rotor and the pulley 62 of the generator such that the path of the flexible link runs along the bottom linking member (see FIG. 5) and the part of the pylon between the bottom linking member and the base of the pylon (see FIGS. 1 and 4).

(25) The idler wheels 68 are arranged vertically and mounted pivotably linked about the horizontal axis, called pivot axis F, with respect to the bottom linking member and the pylon. The pivot axis F is perpendicular both to the axis of rotation A of the turbine and to the generator axis G. The fixed part of the pivot link is secured to the pylon 20 and/or to the linking member 41. Preferably, the fixed part of the pivot link is secured to the pylon. The idler wheels 68 are arranged relative to the pylon at a height such that the axis F of rotation of the idler wheels is arranged at the same height as the bottom linking member. Moreover, the idler wheels 68 are arranged such that the geometric plane, containing the rotor pulley, draws a tangent to the circumference of the idler wheels. This feature makes it possible for the at least one flexible link to extend substantially horizontally between the rotor pulley and the idler wheels, and makes it possible to shift the flexible link outside the rotor pulley or idler wheels. Similarly, the plane of the generator pulley 62 draws a tangent to the idler wheels 68. Preferably, the axial spacing of the idler wheels is less than or equal to the diameter of the rotor pulley 64.

(26) Owing to the arrangement of the vertical-axis turbine on the wind turbine, the securing of the generator to the ground and the use of a flexible link, the mass of the wind turbine, in particular at the top thereof, is reduced, which has the result of reducing the mechanical stresses in the pylon and therefore of reducing the quantity of material needed to produce said pylon, because of the reduction of the weight compared with the wind turbines of the prior art. Thus, it becomes easier to collapse and/or erect the wind turbine and/or more quickly collapse the wind turbine, for example over a period shorter than 45 minutes. For example, the time it takes to wind up the flexible link can be of the order of 5 minutes during the procedure of erecting or collapsing the wind turbine. Moreover, the strains on the hoisting device are reduced. It becomes possible to use a hoisting winch called standard or of reduced pulling power, which is therefore less expensive.

(27) The wind turbine has the advantage of largely dispensing with expensive and delicate components, namely: the variable-pitch system (in fact, the present wind turbine has a fixed pitch and therefore operates at variable speed in line with a variable-speed permanent magnet generator), the system for orienting the nacelle into the wind (in fact, a wind turbine of the single-rotor vertical-axis type can operate whatever the direction of the wind), the multiplier (in fact, the transmission by cable will make it possible to ensure this function for driving a variable-speed permanent magnet generator), the swivel connector which ensures, on wind turbines of the horizontal-axis type, the electrical connection between the nacelle (mobile) and the mast (fixed).

(28) With reference to FIG. 6, the wind turbine comprises a braking device 90 of the turbine. In the case of emergency, the braking device makes it possible to slow down, until completely stopped, the rotation of the rotor pulley so as to collapse the wind turbine more quickly.

(29) The braking device comprises: a braking actuator 91, connected (not shown) to the bottom linking member 41, a brake disc 92 rotationally linked to the rotor pulley 64, and two brake linings 93 arranged respectively between the brake actuator 91 and the brake disc 92.

(30) With reference to FIG. 6, the rotation shaft element 45 of the turbine crosses the thickness of the bottom linking member 41 and emerges from a lower side, facing the ground, opposite the upper side on which the rotor pulley 64 is arranged. The brake disc 92 is secured to the rotation shaft element 45 under the bottom linking member 41.

(31) The brake actuator 91 is arranged and configured to act, during braking, by adherence on the brake disc 92 via the brake linings 93.