WO2013072641A1 - Variable-geometry wind turbine - Google Patents

Abstract

A wind turbine (1) having a vertical axis, comprising a central tower (3), a wind vane (14), a supporting disk (6, 8) that is rotatably mounted on the tower (3), and blades (10), each rotatably mounted on the supporting disk (6, 8) between a driving direction (M) substantially perpendicular to the wind vane (14), and a passive direction (P) substantially parallel to the wind vane (14), said wind turbine (1) comprising: a system (20) for guiding the blades (10), configured to maintain a constant direction for each blade (10), in relation to the wind vane (14), over a predetermined angular amplitude (A), a device (21) for controlling the tilt of the blades (10) between the driving direction (M) and the passive direction (P).

Description

 Wind turbine with variable geometry

The invention relates to vertical axis wind turbines.

 Many types of wind turbines with vertical central axes are known. According to the most widespread geometry, the wind turbine comprises a rotor and a plurality of peripheral blades integral with the rotor, which provide a hold wind on a portion of their sidereal angular stroke around the central axis.

 To illustrate this geometry, reference may in particular be made to documents CA 2 616 708, JP 2008 11 578, US 5 126 584. This type of wind turbine, which has proved its worth, has the disadvantage of having a relatively low efficiency, in particular because of the wind resistance offered by the blades on a non-negligible portion of their angular travel.

 To increase the efficiency of vertical axis wind turbines, it has been proposed to pivot the blades on a vertical pivot carried by the rotor, blade rotation control means being provided to orient the blades according to their position, to to make the blades exercise a maximum engine torque on the rotor. Such a solution is particularly illustrated by the French patent application FR 2289764. More specifically, this technique consists in driving the blades in a planetary movement of synodic rotation around themselves, by means of a planetary gear ratio 2, in so to print to the blades a half-synodic revolution for each sidereal revolution.

 This solution makes it possible in theory to improve the efficiency of the wind turbine. However, the efficiency is not optimized due to a wind resistance that persists over a significant portion of the angular stroke of the blades. An object of the invention is precisely to optimize the performance of vertical axis wind turbines.

For this purpose, it is proposed a vertical axis wind turbine, comprising a central mast, a wind vane, a support plate rotatably mounted on the mast, and blades each rotated on the support plate between a driving orientation substantially perpendicular to the wind vane, and a passive orientation substantially parallel to the wind vane, this wind turbine comprising: a blade guide system, configured to maintain constant, with respect to the wind vane, the orientation of each blade over a predetermined angular amplitude,

 a device for controlling the tilting of the blades between the driving orientation and the passive orientation.

 By maintaining a constant orientation of the blades with respect to the wind vane (and thus to the direction of the wind), it is possible to optimize the yield by increasing the engine torque applied to the rotor.

 Various additional features may be provided, alone or in combination:

 the guidance system is, for each blade, in the form of a planetary gear ratio 1, comprising:

 a central wheel secured to the mast;

 o an intermediate gear rotatably mounted on the support plate and meshing with the central wheel;

 a planetary wheel rotatably mounted on the support plate and meshing with the intermediate gear, the sun gear being coupled to the blade;

the sun wheel is coupled to the blade by means of a disengageable coupling device between a coupled position in which the wheel is integral in rotation with the blade, and a disengaged position in which the blade is free to rotate by relation to the planetary wheel;

- The coupling device comprises a clutch disk integral in rotation with the sun gear and mounted in translation relative thereto between a coupled position in which the disk is integral in rotation with the blade, and a disengaged position in which blade is free in rotation relative to the disk;

 the clutch disc comprises a series of holes angularly distributed, and the blade is provided with a lug which, in the coupled position, is housed in a hole and, in the uncoupled position, is disengaged from the holes;

the device for controlling the tilting of the blade comprises:

a cam integral with a fixed support of the wind turbine, and a cam follower formed on the clutch disc, a ring gear, secured to the fixed support, and meshing with a pinion integral with the blade on a localized portion of the angular path thereof.

 the wind turbine comprises, alternatively, a cam system jointly forming the blade guide system and the tilt control system thereof, said cam system comprising: a cam path extending substantially about the circumference of the cam; wind turbine, and

 0 a cam follower provided on each blade, this cam follower being subject to follow the cam path;

 each blade includes a frame and a panel stretched over the frame; the frame comprises two uprights on which the panel is fixed;

 the panel is made in a canvas.

 Other objects and advantages of the invention will become apparent in the light of the description of a preferred embodiment, given hereinafter with reference to the accompanying drawings in which:

 Figure 1 is an overall perspective view showing a vertical axis wind turbine with steerable blades;

FIG. 2 is a vertical sectional view of the wind turbine of FIG.

1;

 Figure 3 is a horizontal sectional view of the wind turbine of Figure 1;

 Figure 4 is a detail view in vertical section of the wind turbine of Figure 1;

 FIG. 5 illustrates the operating principle of a vertical axis wind turbine, according to an alternative embodiment.

 In Figure 1 is shown a wind turbine 1 vertical Z axis. The wind turbine 1 comprises:

a support 2 made of steel or concrete (or any other rigid material), mounted in rotation with respect to an infrastructure that may be the ground, a building, a ship, etc.,

 a central mast 3 secured to the fixed support 2, to which it is fixed for example by means of a flange 4 keyed (Figure 2),

a rotor 5 comprising: a lower support plate 6 rotatably mounted on the mast 3 at a lower end thereof, via a bearing 7 (such as a ball or roller bearing), a top support plate 8; , rotatably mounted on the mast 3 at an upper end thereof, via a bearing 9 (such as a ball or roller bearing), o a plurality of blades 10 each mounted in rotation relative to the lower tray 6 and upper plate 8, therebetween, an alternator 11 mounted on the support 2, and an input shaft 12 is rotatably coupled to the lower support plate 6.

According to a particular embodiment, the input shaft 12 is provided with a pinion 13 meshing with a toothed circumference of the lower support plate 6. Alternatively, the coupling of the alternator 11 to the lower plate 6 is achieved by means of a chain or belt drive system.

 The wind turbine 1 is also provided with a wind vane 14 secured to the mast 3 at an apex thereof. This wind vane 14 follows the orientation of the wind (arrow W) and causes in its rotation the support 2, via the mast 3.

 The rotor 5 is of variable geometry, the orientation of the blades 10 relative to the trays 6, 8 supports being variable to adapt to the direction W of the wind.

 More specifically, each blade 10 is rotatably mounted relative to the trays 6, 8 supports between a driving orientation M substantially perpendicular to the wind vane 14 (that is to say perpendicular to the direction W of the wind), and an orientation P passive substantially parallel to the wind vane 14 (and therefore to the direction W of the wind).

 Each blade 10 comprises a frame 15 and a panel 16 fixed to the frame 15. According to an embodiment illustrated in FIG. 1, the frame 15 comprises two parallel uprights 17 in the form, for example, of tubes, made of metal or of a composite material (such as a resin filled with fiberglass and / or carbon fiber).

 These uprights 17 are for example mounted between two flanges 18.

According to a preferred embodiment, the panel 16 is fixed to the uprights 17, an aperture 19 being formed between the lower edges and upper panel 16 and the flanges 18, as shown in Figure 2. This panel 16, which gives the blade 10 its hold in the wind, is preferably made of a fabric, but it can be made of any other flat material: metal plate, plastic or composite material, fine mesh mesh, etc.

 The panel 16 is preferably of an overall width greater than the distance between the uprights 17, so as to maintain a concavity favorable to the motricity of the wind turbine 1, as illustrated in FIGS. 3 and 5.

 The wind turbine 1 further comprises:

 a system 20 for guiding the blades, configured to maintain constant, with respect to the wind vane 14, the orientation of each blade 10 over a predetermined angular amplitude A or B, a device 21 for controlling the tilting of the blades 10 between the orientation Motor M and passive P orientation.

 More specifically, the blade guide system 20 is configured to keep the driving direction M of the blades 10 constant with respect to the wind vane 14 over a predetermined first angular amplitude A, but also to maintain the passive P orientation of the blades 10 constant. relative to the wind vane 14 on a second predetermined angular amplitude B.

 According to an exemplary embodiment, the guiding system 20 and the control device are distinct. In this embodiment, illustrated in Figures 2, 3 and 4, the guide system 20 is, for each blade, in the form of a planetary gear comprising:

 a toothed central gear 22 integral with the mast 3;

 an intermediate gear 23 mounted in rotation on the support plate

6 and / or 7 and meshing with the central wheel 22;

 a toothed planet gear 24 coupled to the blade 10, rotatably mounted on the support plate 6 and / or 7 and meshing with the intermediate pinion 23.

A planetary gear is provided at each support plate 6, 7, so that two planetary gear trains 20 are provided for each blade 10, as illustrated in FIG. 2 where it can be seen that the rotor 5 has a symmetry relative to a median horizontal plane. Each planetary gear is of ratio 1, that is to say that the central wheel 22, the intermediate gear 23 and the planetary wheel 24 have the same diameter (and therefore the same number of teeth).

 According to a particular embodiment, the sun wheel 24 is coupled to the blade 10 by means of a disengageable coupling device 25 between a coupled position in which the wheel 24 is integral in rotation with the blade 10, and a uncoupled position in which the blade 10 is free in rotation relative to the sun wheel 24.

 As illustrated in FIGS. 2 and 4, the coupling device 25 comprises a clutch disc 26 integral in rotation with the sun wheel 24, this disc 26 being pierced with a fluted central hole 27 mounted on an end portion splined an axis 28 of the wheel 24 planetary.

 The clutch disk 26 is mounted in translation relative to the sun wheel 24 (thanks to the splines) between a coupled position (solid line in FIG. 4) in which the disk 26 is integral in rotation with the blade 10, and an uncoupled position (in dashed lines in FIG. 4) in which the blade 10 is free to rotate relative to the disk 26.

 More specifically, as illustrated in FIG. 4, the clutch disc 26 comprises a series of holes 29 (four in this case) angularly distributed around the central hole 27 of the disc 26, whereas the flange 18 of the blade 10 is provided with a projecting lug 30 which, in the coupled position, is housed in one of the holes 29 and, in the uncoupled position, is clear of the holes 29.

 In this exemplary embodiment, the device for controlling the tilting of the blade (of a quarter of a turn) comprises:

 a cam 31 secured to the support 2 of the wind turbine 1, and a cam follower 32 formed on the clutch disc 26,

 a ring gear 33, secured to the support 2, and meshing with a pinion 34 (integral with the blade 10) on a localized portion of the angular path thereof.

According to an embodiment illustrated in Figure 4, the cam 31 extends over a localized angular portion of the support 2, and is for example in the form of a pair of substantially parallel rails, which cooperate locally with a groove dug in one peripheral edge of the clutch disk 26 and which forms the cam follower 32. The rails 31 form a vertical guide ramp which drives the disk 26 in a vertical translation movement from its position coupled to its uncoupled position.

 As can be seen in FIG. 2, the wind turbine comprises two devices 10 for controlling the tilting of the blade 10, diametrically opposed, one of which makes it possible to release the blade 10 so as to tilt it from its driving orientation M to its orientation P passive, the other to impart to it the opposite movement, from its passive orientation P to its motor orientation M.

 The wind turbine 10 operates in the following manner, as the wind rises and blows in a direction shown in Figure 3 by the arrow W. It is assumed that the rotor 5 is configured to turn clockwise, when seen from above.

 The wind vane 14 drives the mast 3 and the support 2 to a position in which it extends parallel to the direction W of the wind.

 The rotor 5 comprises at least one blade 10 occupying its driving orientation M, in which the blade 10 extends perpendicular to the wind vane 14, and therefore perpendicular to the direction W of the wind. In this orientation, the driving torque exerted by the blade 10 on the rotor 5 is maximum. This configuration is adopted by the blade 10 on the angular amplitude A, which is for example between 30 ° and 180 °, and preferably between 45 ° and 160 °. According to a particular embodiment, illustrated in FIG. 3, this angular amplitude is about 120 °.

When the blade 10 reaches the tilting control device 21, the latter imparts a rotational movement of a quarter turn synod to place it in its passive orientation P. The rotational movement is performed more or less quickly depending on the configuration of the control device 21. According to a particular embodiment, the angular amplitude of the tilting movement is between 30 ° and 90 °, and preferably between 30 ° and 45 °. Specifically, the cam 31 places the disc 26 in its uncoupled position, the lug 30 out of its hole 29, while the pinion 34 meshingly engages with the ring 33. The disc 26 is held in its uncoupled position on amplitude angular of the ring 33, it can freely print the pinion 33 (and therefore the blade 10) a movement of a quarter turn synodic. As soon as the pinion 34 leaves the ring gear 33, the cam 31 releases the disc 26 which resumes its coupled position, the pin 30 being housed in the next hole 29, offset by a quarter turn relative to the hole 29 in which he was previously.

 The blade 10 then adopts its passive orientation P (in which its taking wind is minimal since it is parallel to it), on the angular amplitude B which is for example between 10 ° and 120 °, and preferably between 10 ° and 90 °, and preferably between 10 ° and 45 °.

 The fact that the angular amplitude B is smaller than the angular amplitude A comes from the fact that it is preferable to maintain as long as possible the inclined blade with respect to the wind vane 14 in order to maximize the angular amplitude along which the blade 10 offers a catch to the driving wind.

 Alternatively, as illustrated in FIG. 5, the wind turbine comprises a cam system 35 which jointly forms the blade guide system 20 and the tilt control system 21.

 This cam system comprises:

a cam path 36 which extends over substantially the circumference of the wind turbine 10, and

 a cam follower 37 provided on each blade 10, this cam follower 37 being constrained to follow the cam path 36.

 According to a preferred embodiment, illustrated in FIG. 5, the system 35 comprises two cam followers 37, each blade 10 performing a synodic half-revolution at each orbital revolution, so that each cam follower 37 cooperates alternatively with the path 36 cam.

 The blade 10 can be made in the same manner as described above, each cam follower 37 being for example in the form of a roller mounted on a finger projecting from the flange 18.

It can be seen in FIG. 5 that the cam path 36 has an upstream end 38, through which a first cam follower 37 engages in order to tilt the blade 10 from its passive orientation P to its driving orientation M ( left of Figure 5), and extends to a downstream end 39, located substantially on a same radius as the upstream end 38, where the first cam follower 37 leaves the cam path 36 while the second follower 37 enters the cam path 36 by the upstream end 38.

 FIG. 5 shows the angular amplitudes A and B mentioned in the previous embodiment. These amplitudes can take the values indicated above. Between the angular sectors of amplitude A and B are carried out:

 downstream of the sector A (in the rotational direction of the rotor), the tilting of a quarter turn of each blade from its driving orientation to its passive orientation,

 downstream of sector B, the tilting of each blade from its passive orientation to its driving orientation.

 According to a particular embodiment, illustrated in FIGS. 1 and 2 (and applicable to the variant of FIG. 5), the wind turbine 1 comprises a deflector 40, integral with the support 2, which comprises an amount 41 fixed to the support 2 and on which is fixed a deflector panel 42, whose function is to guide the wind towards the blade 10 occupying its driving direction M.

 FIGS. 1 and 2 also show that the wind turbine 1 can be equipped with a roof 43 (preferably conical for draining precipitation) mounted on the mast 3 via a liner 44, and fixed on this one for example by bolting. Roof 43 flips over the blade guide system 101 provided in the upper part of wind turbine 1.

 Thanks to the conservation, over a relatively large angular amplitude, of the driving orientation of the blades 10, the wind turbine 1 has an optimized efficiency compared to known wind turbines, while in its passive orientation P each blade 10 offers a minimum resistance to wind. As we have seen, it is possible to further optimize the efficiency by orienting the blades 10 in the intermediate angular areas between the amplitude sectors A and B so as to make them motor, which maximizes the engine torque applied to the rotor.

 It is possible to couple two wind turbines 1 as described above, for example symmetrical with respect to a central plane and rotating in the opposite direction. The deflectors 40 can channel the wind to the central plane, so as to jointly drive the rotors.

Claims

1. Wind turbine (1) with a vertical axis, comprising a central mast (3), a wind vane (14), a support plate (6, 8) rotatably mounted on the mast (3), and blades (10) each mounted in rotation on the support plate (6, 8) between a driving orientation (M) substantially perpendicular to the wind vane (14), and a passive orientation (P) substantially parallel to the wind vane (14), the wind turbine (1) being characterized in that it comprises:  a blade guide system (10) configured to maintain constant, relative to the wind vane (14), the orientation of each blade (10) on a predetermined angular amplitude (A), a device (21) for controlling the tilting of the blades (10) between the driving (M) orientation and the passive (P) orientation.  2. Wind turbine (1) according to claim 1, characterized in that the guide system (20) is, for each blade (10), in the form of a planetary gear (20) ratio 1, comprising:  a wheel (22) central integral with the mast (3);  an intermediate gear (23) rotatably mounted on the support plate (6, 8) and meshing with the central wheel (22);  a planet wheel (24) rotatably mounted on the support plate (6, 8) and meshing with the intermediate pinion (23), the planet wheel (24) being coupled to the blade (10).  3. Wind turbine (1) according to claim 2, characterized in that the planet wheel (24) is coupled to the blade (10) via a coupling device (25) disengageable between a coupled position in which the wheel (24) is integral in rotation with the blade (10), and a disengaged position in which the blade (10) is free to rotate with respect to the planet wheel (24). 4. Wind turbine (1) according to claim 3, characterized in that the coupling device (25) comprises a clutch disc (26) integral in rotation with the planet wheel (24) and mounted in translation relative to that between a coupled position in which the disk (26) is integral in rotation with the blade (10), and a disengaged position in which the blade (10) is free to rotate relative to the disk (26). 5. Wind turbine (1) according to claim 4, characterized in that the clutch disc (26) comprises a series of holes (29) distributed angularly, and in that the blade (10) is provided with a lug ( 30) which, in the coupled position, is housed in a hole (29) and, in the uncoupled position, is disengaged from the holes (29).  6. Wind turbine (1) according to claim 4 or claim 5, characterized in that the device (21) for controlling the tilting of the blade (10) comprises:  a cam (31) integral with a fixed support (2) of the wind turbine (1), and a cam follower (32) formed on the clutch disc (26), a toothed crown (33) integral with the support (2) fixed, and meshing with a pinion (34) secured to the blade (10) on a localized portion of the angular path thereof.  7. Wind turbine (1) according to claim 1, characterized in that it comprises a system (35) cam jointly forming the system (20) for guiding the blades (10) and the system (21) for controlling their tilting said cam system (35) comprising: a cam path (36) extending substantially around the circumference of the wind turbine (1), and a cam follower (37) provided on each blade (10), this follower (37) being subject to follow the cam path (36).  8. Wind turbine (1) according to one of the preceding claims, characterized in that each blade (10) comprises a frame (15) and a panel (16) stretched on the frame (15).  9. Wind turbine (1) according to claim 8, characterized in that the frame (15) comprises two uprights (17) on which is fixed the panel (16).  10. Wind turbine (1) according to claim 9, characterized in that the panel (16) is made of a fabric.