JP2020029853A - Lift-type vertical axis wind turbine - Google Patents

Abstract

To suppress blade parts of a windmill from rotating excessively to reduce influence of friction and suppress enlargement of an overrotation suppression mechanism, without the axial movement of an arm.SOLUTION: A lift-type vertical axis wind turbine 1 includes a rotation hub 3 and wind turbine blade parts 4. The wind turbine blade part 4 has an arm 41 and a blade 42. The arm 41 is provided so as to twist around a rotational axis Y of the arm 41. The lift-type vertical axis wind turbine 1 further includes a tuning mechanism 6 that tunes the rotations of the arms 41 about the rotation axis Y with each other, and an energization member SP that energizes the arm 41 in a direction in which a wind receiving area of the blade 42 increases.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a lift type vertical axis wind turbine used for a wind power generator. More specifically, the present invention relates to a lifting type vertical axis wind turbine configured to prevent damage to wings and failure of a generator due to excessive rotation even when a strong wind due to a gust or the like blows.

  The small wind turbine is useful as a power source in a place where there is no system power supply or as an emergency power source when the system power supply is cut off in the event of a disaster. However, safety considerations are important because high-speed rotation easily occurs in strong winds.

  As a safety measure at the time of such a strong wind, for example, Patent Document 1 discloses a windmill having a mechanism for preventing over rotation of a blade portion of the windmill. In the wind turbine disclosed in Patent Document 1, a blade shaft (hereinafter, referred to as an arm) can move in a radial direction due to centrifugal force caused by rotation of the blade, and can rotate with the axis in the radial direction as an axis. It is configured to change the wind area. Thereby, at the time of strong wind, the centrifugal force applied to the blade causes the blade to move radially outward to reduce the wind receiving area, thereby reducing the number of rotations of the blade.

JP 2016-17463 A

  However, the windmill disclosed in Patent Literature 1 is a mechanism in which the arm simultaneously performs a parallel radial outward movement and a rotational movement about the rotation axis of the arm, and requires a non-linear guide groove. easy. Further, the structure is complicated, and a space for securing the stroke of the arm in the axial direction is required at the center of the rotor and the outer side in the radial direction.

  Accordingly, the present invention has been made in view of such a problem, and in a lift-type vertical axis wind turbine, it is possible to suppress the over rotation of the wing portion of the wind turbine without moving the arm in the axial direction, reduce the influence of friction, and reduce It is an object of the present invention to provide a lift-type vertical axis wind turbine capable of suppressing an increase in the size of a rotation suppressing mechanism.

  The lift type vertical axis wind turbine of the present invention is a lift type vertical axis wind turbine including a rotating hub and a plurality of wind turbine blades rotating around a vertical axis, wherein each of the plurality of wind turbine blades is An arm supported by the hub for rotation and extending in the horizontal direction perpendicular to the vertical axis, and a blade provided at one end of the arm, wherein the arm is rotated by the rotation hub and extends in the horizontal direction. The arm and the blade are supported so as to be rotatable around an axis and are twisted around the rotation axis of the arm so as to reduce the wind receiving area of the blade. When twisting, the arm does not move in the axial direction of the rotation axis of the arm, and the lift-type vertical axis windmill further moves the arm and blade of each of the plurality of windmill blades so that the twist angles of the arms are different from each other. A tuning mechanism for tuning the rotation of the arms around the rotation axis so as to be equal to each other, and a biasing mechanism for urging the arms in a direction in which the blade receiving area increases when the arms are twisted. And a biasing member.

  Further, it is preferable that the arm is configured to be twisted around the rotation axis by an air force applied to the blade and / or the arm when the blade rotates around the vertical axis.

  Further, the cross section of the blade is a streamline having a curved front edge and a sharp rear edge, and when the blade is viewed in the axial direction of the arm, the rotation axis of the arm is rotated by the rotation of the arm. It is preferable that the arm is provided so as to be located on the trailing edge side of the blade with respect to a line connecting two aerodynamic center points located equidistant from the axis.

  Further, it is preferable that the arm is formed flat in a direction parallel to the vertical axis when the blade is not twisted (twist angle is 0 °).

  Further, the initial position of the blade corresponding to the time of a windless state is set such that a line connecting the two aerodynamic center points is inclined at a predetermined initial twist angle with respect to a vertical line, In the initial position, it is preferable that the blade is held in a state where a preload is applied by a predetermined urging force from the urging member.

  Further, a positioning member defining an initial position of the blade is provided so that the blade is held in a state of being inclined at the predetermined initial twist angle in a state where the blade is urged by the urging member. Is preferred.

  Further, when the blade has been twisted from the initial position to a second position where the wind receiving area of the blade has decreased, a second twist that regulates further twisting of the blade and defines a maximum twist angle of the blade. It is preferable to have a positioning member.

  In addition, the tuning mechanism includes a plurality of arm-side gears respectively provided at the other ends of the arms of the plurality of wind turbine blades, and one hub provided on the rotation hub and meshing with the plurality of arm-side gears. It is preferable to have a side gear.

  Further, it is preferable that the urging member urges the arm indirectly by urging the hub-side gear of the tuning mechanism.

  Further, the rotating hub has a weight member movable with respect to the rotating hub when the rotating hub rotates and a predetermined centrifugal force is applied, and the weight member is connected to the tuning mechanism. Connected via a member, the biasing member is configured to directly or indirectly bias the weight member in a direction to suppress movement of the weight member due to centrifugal force, and a twist moment due to the aerodynamic force and When the force applied to the weight member by the centrifugal force overcomes the urging force of the urging member and the weight member moves, the tuning mechanism operates by the operation of the connecting member interlocked with the movement of the weight member. In addition, it is preferable that the blade is configured to be twisted in a direction to reduce a wind receiving area of the blade.

  In addition, the tuning mechanism includes a plurality of arm-side gears respectively provided at the other ends of the arms of the plurality of wind turbine blades, and one hub provided on the rotation hub and meshing with the plurality of arm-side gears. A side gear, wherein the connecting member is attached to the rotating hub so as to be swingable around an axis parallel to the vertical axis, and the connecting member is connected to the weight member by a swing shaft of the connecting member. A second extension extending toward the hub-side gear from the pivot shaft of the connecting member, and being attached to the hub-side gear. The part has an elongated hole at an end attached to the hub-side gear, the hub-side gear has a shaft member inserted into the elongated hole, the weight member moves by centrifugal force, and the (2) The end of the extension portion swings about the swing axis of the connecting member. To come, it is preferable that the hub-side gear by said shaft member receives a force from the edge of the long hole of the second extending portion is rotated.

  In addition, the tuning mechanism includes a plurality of arm-side gears respectively provided at the other ends of the arms of the plurality of wind turbine blades, and one hub provided on the rotation hub and meshing with the plurality of arm-side gears. A side gear, wherein the connecting member is attached to the rotating hub so as to be swingable around an axis parallel to the vertical axis, and the connecting member is connected to the weight member by a swing shaft of the connecting member. And a connecting member side gear provided coaxially with the swing axis of the connecting member, wherein the tuning mechanism meshes with the connecting member side gear and is coaxial with the hub side gear. A tuning mechanism-side gear provided above, wherein the hub-side gear is configured to rotate in accordance with rotation of the tuning mechanism-side gear, the weight member moves by centrifugal force, and the coupling member is When swinging around the swing axis, By rotation of the serial tuning mechanism side gear, it is preferable that the hub-side gear is rotated.

  In addition, when a predetermined centrifugal force is applied to the blade by rotation of the blade around the vertical axis, a maximum deformation occurs in a radially outward direction of the blade when the blade is deformed, and the blade extends between the tuning portion and the tuning mechanism. A reinforcing member, one end of the reinforcing member is connected to the deformed portion of the blade, the other end of the reinforcing member is connected to the tuning mechanism via a connecting member, and the urging member is connected to the connecting member. Via a member, the tuning mechanism is urged so that the reinforcing member applies a radially inward tension to the deformed portion of the blade, a predetermined centrifugal force is applied to the blade, and the reinforcing member When the deformed portion is displaced radially outward against the urging force of the urging member, the tuning mechanism is operated via the connecting member by the displacement of the reinforcing member. It is preferable that the blades are configured to twist in a direction to decrease the swept area of the blades.

  In addition, the tuning mechanism includes a plurality of arm-side gears respectively provided at the other ends of the arms of the plurality of wind turbine blades, and one hub provided on the rotation hub and meshing with the plurality of arm-side gears. A side gear, one end of the connecting member is attached to the hub side gear so as to be swingable about an axis parallel to the vertical axis, and the other end of the connecting member is the other end of the reinforcing member. Is attached to the blade so that a predetermined centrifugal force is applied to the blade, and when the reinforcing member and the deformed portion are displaced radially outward, the hub-side gear rotates due to the movement of the connecting member, It is preferable that the rotation of the hub-side gear causes the rotation of the arm-side gear, and the blade twists in a direction to reduce the wind receiving area of the blade.

  ADVANTAGE OF THE INVENTION According to this invention, in a vertical axis wind turbine of a lift type, without rotating the arm in the axial direction, the over rotation of the wing of the wind turbine is suppressed, the influence of friction is reduced, and the over rotation suppressing mechanism is enlarged. Can be suppressed.

It is a side view of a lift type vertical axis windmill of one embodiment of the present invention. It is a perspective view which shows a part of windmill of FIG. FIG. 3 is a top view of the windmill of FIG. 2. It is a side view of the windmill in the state where some windmill blade parts were removed. FIG. 5 is a schematic cross-sectional view taken along line VV of FIG. 4, showing an example of a blade cross-sectional shape. It is the schematic which shows the state before and after the twist of the blade in the windmill of one Embodiment of this invention. FIG. 4 is a diagram illustrating an attachment portion to which a positioning member for changing a twist angle of a blade is attached. FIG. 5 is a schematic diagram showing aerodynamic center points equidistant from a rotation axis and aerodynamic forces acting on the aerodynamic center points in a linear portion located radially outward of a blade. Positions as viewed from the vertical axis direction of two aerodynamic center points A and B at symmetric positions with respect to the arm with the blade twisted when the arm is shifted rearward in the rotational direction from the aerodynamic center point. It is a figure showing a relation. It is a figure which shows the dependence of a dimensionless twist moment on a blade mounting position and a twist angle. 4 is a graph showing a relationship between a windmill rotation speed and a windmill shaft torque when an initial twist angle changes. (A)-(C) is a schematic diagram showing an example of assembling work of a windmill of one embodiment. It is a perspective view of a lift type vertical axis windmill of another embodiment of the present invention. It is a top view of the windmill of FIG. It is a perspective view of a lift type vertical axis windmill of yet another embodiment of the present invention. It is a top view of the windmill of FIG. FIG. 14 is a schematic side view showing a connection member side gear and a tuning mechanism side gear of the wind turbine of FIG. 13. It is a figure showing the relation between the shaft torque of the windmill of case 6, and windmill rotation speed. FIG. 14 is a diagram illustrating a relationship between a shaft torque of a windmill and a windmill speed in a case 7; It is a figure showing the relation between the shaft torque of the windmill of case 8, and windmill rotation speed. It is a figure which shows the comparison of the wind speed dependence of the generated electric power in case 6,7,8. It is the result of having simulated the deformation of the triangular wing by the structural analysis based on the finite element method. It is the schematic which shows the blade to which the reinforcement member for suppressing the deformation of a blade was attached. FIG. 14 is a perspective view of a lift-type vertical axis wind turbine according to a fourth embodiment in which a deformation force of a blade acting via a reinforcing member is used as a force for driving the twist of the blade. FIG. 23 is a top view of the lift-type vertical axis wind turbine shown in FIG. 22.

  Hereinafter, a lift type vertical axis wind turbine according to an embodiment of the present invention will be described with reference to the drawings. The embodiment described below is merely an example, and the lift-type vertical axis wind turbine of the present invention is not limited to the following embodiment.

<First Embodiment>
As shown in FIG. 1, a lift-type vertical axis wind turbine 1 of the present embodiment (hereinafter, simply referred to as a wind turbine 1) rotates around a vertical axis X with respect to the base 2 having a power generation unit 21. The rotating hub 3 includes a plurality of wind turbine blades 4 that rotate about the vertical axis X together with the rotating hub 3.

  The base 2 is a portion serving as a base of the wind turbine 1. Although the structure of the base 2 is not particularly limited, in the present embodiment, as shown in FIG. 1, the base 2 is formed at a predetermined height in order to position the wind turbine blade 4 of the wind turbine 1 at a predetermined height from the installation surface. Leg 22 is provided.

  The rotation hub 3 rotates with respect to the base 2 when the wind turbine blades 4 receive wind. In the present embodiment, the rotating hub 3 is connected to a shaft (not shown) that rotates around the vertical axis X, and the wind turbine blades 4 receive wind, and the rotating hub 3 and the shaft are connected to the vertical axis X. Power is generated by rotating around.

  The wind turbine blade part 4 is a part which rotates by receiving wind. In the present embodiment, the windmill blade section 4 is a butterfly-type windmill blade obtained by improving a Darrieus-type windmill blade. In the present embodiment, a lift-type vertical axis wind turbine will be described as an example of a butterfly-type wind turbine obtained by improving a Darrieus-type wind turbine, but a lift-type vertical-axis wind turbine may be a non-butterfly-type wind turbine. Alternatively, a windmill other than the Darrieus-type windmill may be used. As shown in FIGS. 2 and 3, a plurality of (three in FIG. 2 and FIG. 3) wind turbine blades 4 are provided at equal intervals around the vertical axis X. In addition, the number of the wind turbine blades 4 is not particularly limited. Although the material of the wind turbine blade part 4 is not particularly limited, a lightweight material having a predetermined strength such as aluminum is preferably used.

  As shown in FIGS. 2 and 3, each of the plurality of wind turbine blades 4 is supported by the rotating hub 3 and extends in a horizontal direction perpendicular to the vertical axis X and at one end of the arm 41. And a blade 42 provided.

  In the present embodiment, the windmill 1 is of a lift type, and the cross section of the blade 42 has an airfoil shape in which a front edge LE is curved and a rear edge TE has a sharp streamline as shown in FIG. In FIG. 5, the wing section is hollow and has no ribs. However, one or more ribs may be provided, or the wing section may be solid. In this embodiment, the wind turbine blade part 4 is a butterfly type as shown in FIGS. 2 and 4, and the blade 42 provided at the tip of the arm 41 forms a loop. More specifically, the blade 42 is formed in a substantially triangular shape. In addition, the shape of the wind turbine blade part 4 is not limited to the shapes shown in FIGS. 2 to 5 as long as it is suitable for a vertical axis wind turbine of a lifting type. For example, the windmill blade 4 may have a blade used for an H-type Darius windmill, a non-linear blade, or a circular butterfly blade.

  The arm 41 is supported by the rotation hub 3 so as to be rotatable around a rotation axis Y (see FIG. 4) extending in the horizontal direction. The rotation axis Y is a line serving as the rotation center of the arm 41. The arm 41 only needs to be supported by the rotation hub 3 so as to be rotatable about the rotation axis Y, and the method of supporting the arm 41 is not particularly limited. In the present embodiment, the arm 41 is rotatably supported around the rotation axis Y via a bearing (not shown) on the support portion 31 provided on the rotation hub 3. Specifically, the support portion 31 has an insertion hole through which the arm 41 can be inserted, and the arm 41 is supported via a bearing in an insertion hole formed in the support portion 31. It is preferable that the support portion 31 is supported at two or more positions along the axial direction of the arm 41.

  In the present embodiment, a blade 42 is provided at one end (an end farther from the vertical axis X of the wind turbine 1) of the arm 41. Further, the arm 41 has a bevel gear (an arm-side gear described later) G1 described below on the other end side (an end closer to the vertical axis X of the windmill 1) of the arm 41. In this embodiment, as shown in FIGS. 2 and 4, the arm 41 is formed flat at one end of the arm 41 in a direction parallel to the vertical axis X at a twist angle of 0 °. . In this case, twisting of the blade 42 by pneumatic force described later is further facilitated. When the arm 41 has a flat shape, the cross-sectional shape of the arm 41 may be the same wing shape as the blade 42 (see FIG. 5), or may be a flat rectangular shape. In the present embodiment, one end of the arm 41, that is, a portion corresponding to a radially outer side of the bearing of the supporting portion that supports the arm 41 is formed flat, and the other end of the arm 41 is formed in a cylindrical shape. However, the shape of the arm 41 is not particularly limited. For example, the arm 41 may be entirely flat, only a part of the arm 41 may be flat, or the whole may be columnar.

  The arm 41 is twisted around the rotation axis Y of the arm 41 so as to reduce the wind receiving area of the blade 42 by an air force applied to the blade 42 and / or the arm 41 when the blade 42 rotates around the vertical axis X. Is provided. Note that the wind receiving area of the blade 42 refers to a projected area of a portion swept when the blade 42 makes one rotation around the vertical axis X. Accordingly, in FIG. 6A, when the blade surface indicated by the solid line is substantially perpendicular to the horizontal plane, the air receiving area is maximum, and when the blade surface is indicated by the two-dot chain line, the air receiving surface is horizontal. The area is minimized. In addition, “twist by aerodynamic force” in this specification means, as described in another embodiment described later, an action on a weight member described later in addition to an aerodynamic force applied to the blade 42 and / or the arm 41. This also includes the case where the blade 42 is twisted due to the centrifugal force generated or the tension of the reinforcing member caused by the deformation of the blade. When the wind turbine blade 4 of the wind turbine 1 rotates around the vertical axis X, a rotational moment about the rotation axis Y of the arm 41 is generated by the air force acting on the wind turbine blade 4. The rotation moment of the arm 41 about the rotation axis Y is referred to as a twist moment in this specification.

FIG. 7 shows the aerodynamic forces F _pA and F _pB acting on the aerodynamic center point A and the aerodynamic center point B equidistant with respect to the rotation axis Y in the linear portion located radially outward of the blade 42. It is a schematic diagram. When the blade 42 is inclined by the twist angle η with respect to the vertical line VT, for example, the relative wind velocity Vp _A incident parallel to the blade section passing through the aerodynamic center point _A is, as shown in FIG. The wind V and the aerodynamic center point A are determined by the synthesis of the relative wind speed r _A ω accompanying the motion given by the product of the radial distance r _A from the rotation axis (vertical axis X) of the wind turbine 1 and the rotation angular velocity ω. In FIG. 7, the combined relative wind speed is indicated as (V + rω) _A. When the angle between the direction of the synthetic relative wind speed Vp _{A and} the direction of the chord length of the wing is defined as the angle of attack α in the wing cross section including the aerodynamic center point A, the magnitude of the angle of attack α and the relative wind speed Vp _A , A lift L and a drag D occur in the direction shown in FIG. However, in the case of the vertical axis wind turbine, even if it is assumed that the direction of the natural wind V is constant, the direction of the chord of the blade section changes 360 ° with respect to the direction of the natural wind V during one rotation of the wind turbine. Therefore, the direction of the angle of attack α with respect to the chord direction always changes, and a state in which the directions of the lift L and the drag D shown in FIG. 7 are opposite to the chord direction may occur. The aerodynamic component F _pA for rotating the wing in the wing cross section including the aerodynamic center point A is given as the sum of the projections of the lift L and the drag D in the chord direction. The magnitude and orientation of F _pA varies within constraints within the chord direction.

If the distance xa from the leading edge LE of the blade 42 to the wing attachment position (the position of the rotation axis Y of the arm 41) is equal to the distance xc from the leading edge LE of the blade 42 to the aerodynamic center point A (xa = xc), when the average values of the aerodynamic forces F _pA and F _pB acting on the arbitrary aerodynamic center point A and the aerodynamic center point B located at the same distance h from the position of the rotation axis Y in one rotation of the windmill are the same ( At F _pA = F _pB ), no twist moment TM about the rotation axis Y of the blade 42 and / or the arm 41 is generated irrespective of the magnitude of the twist angle η of the blade 42. However, the distance xa from the leading edge LE of the blade 42 to the wing mounting position is different from the distance xc from the leading edge LE of the blade 42 to the aerodynamic center point. For example, as shown in FIG. When viewed in the direction of the rotation axis Y, the rotation axis Y of the arm 41 is parallel to a line LN connecting two aerodynamic center points A and B located at the same distance from the rotation axis Y of the arm 41. When the arm 41 is provided so as to be located on the trailing edge TE side of the blade 42, the aerodynamic forces F _pA and F _pB acting on the aerodynamic center points A and B in a state where the blade 42 is twisted. Are not the same, and a twist moment TM is generated. More specifically, as shown in FIG. 7, the horizontal distance from the position of the rotation axis Y to the aerodynamic center point A when viewed from the vertical axis X direction of the wind turbine 1 is S _A , and the aerodynamic center is if the horizontal distance to the point B and S _B, a relationship of S _a> S _B. This is because the radial distance r _A of the aerodynamic center point _A from the vertical axis X is equal to the radius of the aerodynamic center point B from the vertical axis X, as clearly shown in the positional relationship viewed from the vertical axis X direction in FIG. 8A. It means that it is longer than the distance r _B. Accordingly, the relative wind speed r _A ω associated with the rotational movement of the aerodynamic center point A is greater than the relative wind speed r _B ω associated with the rotational movement of the aerodynamic center point B. At the same time, due to the twist of the blade 42, the phase of the aerodynamic center point A is advanced with respect to the aerodynamic center point B with respect to the rotational azimuth angle 参照 (see FIG. 8A) with respect to the rotation axis Y direction. The magnitude V of the natural wind flowing into the wind turbine is reduced when approaching the wind turbine rotor, and the wind velocity flowing into the central portion of the rotor has a velocity distribution in which the velocity is lower than the surrounding area. It is also generally known that the speed decreases as a whole on the downstream side (180 ° ≦ Ψ <360 °) compared to the upstream side (0 ° ≦ Ψ <180 °). Therefore, the angle of attack α, which is determined by the synthesis of the relative wind speed (rω) and the natural wind (V), the magnitude of the lift L and the way of changing the direction of the drag D are determined by two cross sections including the aerodynamic center point A and the aerodynamic center point B. As a result, the average value of the aerodynamic forces F _pA and F _pB during one rotation of the windmill also differs, and the twist moment TM shown in FIG. 7 is generated.

  As described above, in the present embodiment, the blade 42 can be twisted by the pneumatic force acting on the blade 42 and / or the arm 41 so that the wind receiving area of the blade 42 is reduced. Thereby, the rotational force of the blade 42 can be reduced during a strong wind, and the over rotation of the blade 42 can be suppressed, the breakage of the wind turbine 1 can be suppressed, and the safety can be improved. Further, the blade 42 is twisted by air force, not by using the radial outward movement of the arm 41 due to centrifugal force. Therefore, in the present embodiment, the arm 41 and the blade 42 do not move in the axial direction (radially outward) of the rotation axis Y of the arm 41 when the arm 41 twists around the rotation axis Y. Therefore, it is possible to reduce the influence of friction without requiring a complicated non-linear guide groove. Also, there is no need to increase the over-rotation suppression mechanism in the radial direction.

  With respect to the position of the rotation axis Y of the arm 41 with respect to the blade 42, as described above, the position of the rotation axis Y of the arm 41 is set at two aerodynamic center points A located at the same distance from the rotation axis Y of the arm 41. , B, is provided on the trailing edge TE side of the blade 42. As for the position of the rotation axis Y of the arm 41, the twist moment increases as the position of the rotation axis Y of the arm 41 shifts toward the trailing edge TE of the blade 42, and the effect of inclining the blade 42 increases. Specifically, the distance xa from the leading edge LE of the blade 42 to the position of the rotation axis Y of the arm 41 is 40 to 85% of the distance c from the leading edge LE of the blade 42 to the trailing edge TE. And more preferably 55 to 75%.

FIG. 8B is a diagram comparing the difference in the change of the twist moment depending on the blade mounting position with respect to three twist angles (η = 5 °, 10 °, 15 °). The vertical axis is the dimensionless twist moment Ctm obtained by dividing the twist moment TM by 0.5 ρV ² RH (H / 2) to make the dimensionless. The horizontal axis is the tip peripheral speed ratio λ, which is defined by λ = Rω / V. Here, ρ is the air density, V is the upstream wind speed, R is the radius of the windmill rotor, H is the height of the windmill, and ω is the rotational angular velocity of the windmill rotor.

  In FIG. 8B, the wind turbine is the butterfly wind turbine shown in FIGS. 1 to 5, and has a rotor diameter (diameter of the outermost rotation locus of the blade 42 of the wind turbine 1) of 12.5 m (radius R = 6.25 m); It is assumed that the rotating hub 3 has a diameter of 0.9 m, a blade height H (see FIG. 4) of 7.8 m, and three blades. The wing section shape was NACA 0018 (symmetric wing type), and the chord length was calculated as 412 mm. Regarding the wing mounting position, the distance xa from the leading edge LE of the blade 42 to the position of the rotation axis Y of the arm 41 is 44.2% of the distance c from the leading edge LE of the blade 42 to the trailing edge TE. (Hereinafter referred to as 44.2% c), 55% c, 60% c, and 72% c.

  As shown in FIG. 8B, at xa = 44.2% c, the dimensionless twist moment increases in the negative direction in the range of λ = 0.8 to 2.8. In the case of η = 5 ° and η = 10 ° at xa = 55% c and η = 5 ° at xa = 60% c, the dimensionless twist moment is slightly increased around λ = 1.9 to 2.5. It has a negative value. However, at xa = 55% c, η = 15 °, at xa = 60% c, 10 ° and 15 °, and at xa = 72% c, for all values of η, the dimensionless twist moment is positive at all values of λ. The dimensionless twist moment tends to increase as the value of the distance xa from the leading edge LE of the blade 42 to the position of the rotation axis Y of the arm 41 increases.

Further, in the present embodiment, the initial position of the blade 42 corresponding to the time of the windless state is such that a line connecting the two aerodynamic center points A and B is predetermined with respect to the vertical line VT (a line parallel to the vertical axis X). Is set to be inclined at the initial twist angle of. Thereby, when the wind turbine blade part 4 of the wind turbine 1 starts rotating around the vertical axis X, a twist moment can be generated in the blade 42. The blade 42 inclined at the initial twist angle is inclined such that the horizontal center distance A from the rotation axis Y is longer in the vertical aerodynamic center point A than the aerodynamic center point B in the vertical direction. I have. If the initial twist angle η ₀ is larger than 0 ° (η ₀ > 0 °), a twist moment is generated by the aerodynamic force on the blade 42. Therefore, the initial twist angle η ₀ is not particularly limited if it is larger than 0 °, for example, 0.1 ° ≦ It is preferable that η ₀ ≦ 5 °.

FIG This initial twist angle eta _0, the five cases where the initial twist angle eta ₀ is different (see Table 1), three wind speeds (8m / s, 23m / s , 40m / s) the comparison of shaft torque Q in the state It is shown in FIG.

The wind turbine is a butterfly wind turbine shown in FIGS. 1 to 5, having a rotor diameter of 7 m, a rotating hub 3 having a diameter of 0.89 m, a blade height of 2.7 m, and five blades. Was used. The wing section shape was NACA 0018 (symmetric wing type), and the chord length was calculated as 242.3 mm. The distance xa is 57% c. The maximum allowable windmill rotation speed (rated rotation speed) of the windmill was 120 rpm. As shown in FIG. 9, when the initial twist angle η ₀ is 3 ° (Case 4) or 4 ° (Case 5), it has an operating point at a lower rotational speed than the other cases, It can be seen that the effect of is effectively obtained. When the initial twist angle η ₀ is 1 ° (Case 2) or 2 ° (Case 3), the torque characteristics are desirable in three wind speeds (8 m / s, 23 m / s, and 40 m / s). It can be said that it has. When the initial twist angle η ₀ is 0 ° (Case 1), when the load becomes zero due to a control trouble or the like at a wind speed of 8 m / s, the characteristic slightly exceeds the allowable rotation speed (120 rpm). Therefore, the initial twist angle is preferably 0.1 ° ≦ η ₀ ≦ 4 °, and more preferably 0.1 ° ≦ η ₀ ≦ 2.5 °.

In the present embodiment, the wind turbine 1 is held in a state in which the blade 42 is held in a state of being inclined at a predetermined initial twist angle η _{0 (} in a state where the blade 42 is biased by a biasing member SP described later), as shown in FIGS. And as shown in FIG. 6A, it has a positioning member 51 that defines an initial position of the blade 42. By having the positioning member 51, for example, the blade 42 is held in a state where there is no wind and the initial twist angle η ₀ , and when the wind turbine blade part 4 rotates around the vertical axis X, the blade 42 has a twist moment. Can be generated. In the present embodiment, the positioning member 51 is a positioning pin provided on the support portion 31 that supports the arm 41. The positioning member 51 initializes the blade 42 by engaging with an engaging portion (engaging pin) 41a protruding from the arm 41. It can be held at the initial position inclined at the twist angle η ₀ . The positioning member 51 is not limited to the positioning pin, but may be engaged with a part of the arm 41 or the blade 42 to hold the arm 41 and the blade 42 at an initial position inclined at a predetermined initial twist angle η _0. If possible.

  Further, in the present embodiment, when the wind turbine 1 is twisted from the initial position to the second position where the wind receiving area of the blade 42 is reduced, as shown in FIGS. 2 to 4 and 6A, It has a second positioning member 52 that regulates further twist of the blade 42 and defines a maximum twist angle ηm of the blade 42. By having the second positioning member 52, when the wind receiving area of the blade 42 is to be maintained in a reduced state during strong wind, the engagement portion ( The engagement pin 41a is engaged, and the blade 42 is held in a twisted state to the second position where the wind receiving area is reduced. In the present embodiment, the second positioning member 52 is a positioning pin, like the positioning member 51. However, the second positioning member 52 is not limited to the positioning pin, and is engaged with a part of the arm 41 or the blade 42 to hold the arm 41 and the blade 42 at the second position inclined at the predetermined maximum twist angle ηm. I just want to be able. Note that the maximum twist angle ηm corresponding to the second position is not particularly limited, but is preferably, for example, 20 ° ≦ ηm ≦ 30 °. Note that the positioning member 51 and the second positioning member 52 may be provided so as to be position-adjustable, and may be configured to be able to change the initial twist angle and the maximum twist angle. In the present embodiment, as shown in FIG. 6B, the second positioning member 52 can be attached to a plurality of attachment portions 53 such as a plurality of insertion holes provided in the support portion 31. By changing the mounting position, the maximum twist angle can be changed. Further, as shown in FIG. 6A, the engagement portion 41a of the arm 41 and the second positioning member 52 may be configured to be engaged with the blade 42 being horizontal. In this case, for example, the engagement portion 41a of the arm 41 is sandwiched between the two second positioning members 52 inserted into the two attachment portions 53 (see FIG. 6B) so that the blade 42 is held in a horizontal state. Thereby, as described later, workability at the time of assembling the wind turbine 1 is improved.

  As shown in FIGS. 2 to 4, the wind turbine 1 of the present embodiment is configured to rotate around the rotation axis Y of the arm 41 so that the twist angles of the arm 41 and the blade 42 of the plurality of wind turbine blades 4 are equal to each other. And a tuning mechanism 6 for tuning the rotations of the two. Since the wind turbine 1 has the tuning mechanism 6, the twist operations of the plurality of blades 42 are linked, and the twist angles are equal. Therefore, even if there is a variation in aerodynamic force (area force) acting on the surface of the blade 42 depending on the rotation azimuth angle of the wind turbine 1 or an imbalance in aerodynamic force due to a manufacturing error of a member used for the wind turbine 1, Are tuned. Therefore, the plurality of blades 42 do not move unbalanced, and the windmill 1 can obtain stable rotation.

  In this embodiment, as shown in FIGS. 2 to 4, the tuning mechanism 6 includes a plurality of arm-side gears G <b> 1 provided at the other ends of the arms 41 of the plurality of wind turbine blades 4, and the rotation hub 3. And one hub-side gear G2 that meshes with the plurality of arm-side gears G1. Specifically, in this embodiment, three small arm bevel gears G1 engage with one large diameter bevel gear hub side gear G2, and the three arm gears G1 are mutually connected. It rotates at the same rotation angle in conjunction. Therefore, the arm 41 rotates at the same rotation angle around the rotation axis Y, the twist angle becomes uniform among the plurality of wind turbine blades 4, and the wind turbine 1 rotates stably. Further, by using gears for the tuning mechanism 6, the durability of the tuning mechanism 6 is enhanced, the safety of the wind turbine 1 is increased, and the life of the wind turbine 1 can be extended.

  Further, in the present embodiment, as shown in FIGS. 2 to 4, when the arm 41 is twisted, the urging member SP that urges the arm 41 toward the direction in which the wind receiving area of the blade 42 increases is used. Have. The urging member SP has a direction in which the wind receiving area of the blade 42 increases when the wind is weakened after the arm 41 and the blade 42 are twisted, such as in a strong wind, that is, the blade 42 is in an inclined state of the initial twist angle. Energize in a certain direction. Thereby, after the wind becomes weak, the wind receiving area of the blade 42 is increased again, and the wind turbine 1 can obtain a high output.

  The urging member SP may directly urge the arm 41 or may indirectly urge the arm 41. In the present embodiment, the arm 41 is indirectly biased by the biasing member SP biasing the hub-side gear G2 of the tuning mechanism 6. Specifically, the biasing member SP biases the hub-side gear G2 in the direction of rotation about the vertical axis X with respect to the rotation hub 3 (hereinafter, also referred to as torsion spring SP). ). One end of the torsion spring SP is held by a first holding portion (a pin in this embodiment) Ha provided on the rotation hub 3, and the other end of the torsion spring SP is provided on the hub side gear G2. The second holding portion (pin in this embodiment) is held by the second holding portion Hb. As a result, the hub-side gear G2 biases the arm 41 in a direction to bring the arm 41 into the inclined state with the initial twist angle.

  The type of the urging member SP is a torsion spring in the present embodiment, but may be another spring such as a coil spring as long as the arm 41 can be energized, or may be a hydraulic / pneumatic type. An actuator or an electric actuator such as a servomotor may be used. In addition, by using an elastic body such as a spring as the urging member SP, the elastic body such as the spring is broken and the urging force is lost, so that when the blade 42 is applied with pneumatic force, the blade 42 immediately twists. . Therefore, when the urging member SP is broken, the blade 42 is easily twisted when the wind blows, and the blade 42 is not maintained in a state close to the initial twist angle (that is, a state in which the wind receiving area is large). Therefore, it is possible to avoid a situation where the urging member SP is damaged and the wind turbine 1 is in a dangerous state in which over-rotation cannot be suppressed, and the wind turbine 1 can have fail-safe characteristics.

  Further, at the initial position of the blade 42, the blade 42 may be held in a state where a preload is applied by a predetermined urging force from the urging member SP. When a preload is applied to the blade 42 by the urging member SP, the blade 42 is held at the initial position until a predetermined amount of twist moment is applied to the blade 42. Therefore, the wind turbine blade part 4 rotates around the vertical axis X while maintaining the state in which the blade 42 does not twist around the rotation axis Y and has a large wind receiving area until the wind reaches a predetermined level. Therefore, the wind turbine 1 can be maintained at a high output until the wind power reaches a predetermined level. When a predetermined or more twist moment is applied to the blade 42, the blade 42 twists from the initial position side in a direction to reduce the wind receiving area of the blade 42. Accordingly, when the wind becomes stronger than a predetermined value, the blades 42 are twisted in a direction to reduce the wind receiving area, and the rotating force of the blades 42 is reduced in a strong wind, so that excessive rotation of the blades 42 can be suppressed. Therefore, breakage of the wind turbine 1 can be suppressed, and safety can be improved.

  Further, in the present embodiment, the urging member SP may include an urging force adjusting mechanism that switches the presence or absence of the preload applied to the blade 42 or adjusts the magnitude of the preload. The biasing force adjusting mechanism enables the position of the first holding portion Ha (spring holding) holding one end of the torsion spring SP to be changed, or the plurality of first holding portions (spring holding) to the rotation hub 3. By providing and switching the position where one end of the torsion spring SP is engaged, the presence or absence of the preload and the magnitude of the preload can be adjusted. The structure of the urging force adjusting mechanism is not particularly limited as long as the urging force can be adjusted. For example, in a state where the engagement between the arm-side gear G1 and the hub-side gear G2 is released, the torsion spring SP is compressed by rotating the hub-side gear G2 with respect to the rotation hub 3, and then the arm-side gear G2 is rotated. The preload applied by the torsion spring SP may be adjusted by engaging the gear G1 with the hub-side gear G2. When the windmill 1 has an urging force adjusting mechanism, the preload applied by the urging member SP is adjusted according to conditions such as the installation location and size of the windmill 1 to optimize the timing at which the blade 42 is twisted. Can be

  In addition, when the above-described biasing force adjusting mechanism is provided, as shown in FIG. 10, the assembling work of the windmill 1 can be facilitated, and the windmill installation cost can be reduced. Since it is difficult to attach the wind turbine blades 4 at a high place above the base 2, it is practical to attach the wind turbine blades 4 to the rotating hub 3 on the ground. In this case, when the windmill blade 4 is large, when the height from the ground to the rotating hub 3 is increased, the height of the base on which the rotating hub 3 is mounted from the ground is increased, and a scaffold is assembled. Work can be difficult. However, the biasing force adjusting mechanism temporarily disables the biasing force applied to the biasing member SP, and rotates the direction of the blade 42 by about 90 ° from the original initial twist angle (the blade 42 indicated by the two-dot chain line in FIG. If the wing surface is attached to the rotating hub 3 with the wing surface parallel to the ground as shown in FIG. 10A, the workability is improved. After assembling all the windmill blades 4 to the rotating hub 3, the entire windmill rotor (a unit including the rotating hub 3 and the windmill blades 4) is lifted up to a height above the base 2 using a crane or the like, It is installed on the rotating shaft of the base 2 (see FIG. 10B). In this case, in order to prevent the blade 42 from rotating from the horizontal state, the wind turbine 1 restricts the rotation of the blade 42 around the rotation axis Y and holds the blade 42 in the horizontal state. A regulating member (not shown) may be provided.

  When the connection between the rotation hub 3 and the base 2 is completed, the regulation of the rotation of the blade 42 by the above-described rotation regulating member is released, and the direction of the blade 42 is changed from the horizontal state to the inclined state with the initial twist angle. (See FIG. 10C). After that, the urging force is applied to the blade 42 by operating the urging force adjusting mechanism, and the blade 42 is held at the initial twist angle. Thereby, the assembly of the wind turbine 1 is completed.

<Embodiment 2>
Next, a windmill according to the second embodiment will be described. The points described in each configuration of the first embodiment can be similarly applied to the second embodiment. In the following description, the points described in the first embodiment will be omitted, and differences will be mainly described.

  In the present embodiment, as shown in FIGS. 11 and 12, in order to twist the blade 42 around the rotation axis Y, in addition to the air force applied to the blade 42, the weight member 7 provided on the rotation hub 3 The centrifugal force applied to is used. The illustration of the blade 42 is omitted in FIGS. 11 and 12.

  In the wind turbine 1 of the present embodiment, as shown in FIGS. 11 and 12, the rotation hub 3 is movable with respect to the rotation hub 3 when the rotation hub 3 rotates and a predetermined centrifugal force is applied. Weight member 7. The weight member 7 is connected to the tuning mechanism 6 via a connecting member 8. The urging member SP is configured to directly or indirectly urge the weight member 7 in a direction to suppress the movement of the weight member 7 due to centrifugal force.

  In this embodiment, when the weight applied to the weight member 7 due to the twist moment due to the aerodynamic force and the centrifugal force overcomes the urging force of the urging member SP and the weight member 7 moves, the connection linked to the movement of the weight member 7 is connected. The operation of the member 8 causes the tuning mechanism 6 to operate. Thus, the blade 42 is configured to be twisted in a direction to reduce the wind receiving area of the blade 42. Therefore, in the present embodiment, until the predetermined centrifugal force is applied to the weight member 7, the weight member 7 does not move with respect to the rotating hub 3, and the twist of the blade 42 is suppressed even if an air force is applied. Therefore, in the present embodiment, in addition to the effects obtained in the first embodiment, the blade 42 can maintain a large wind receiving area in a wider range of wind speed, and can increase power generation efficiency. Thereafter, when a predetermined centrifugal force is applied to the weight member 7 in addition to the air force applied to the blade 42, the rotation speed of the wind turbine blade portion 4 increases, and the weight member 7 resists the urging force of the urging member SP. Moves, and the blade 42 is twisted via the tuning mechanism 6. Thus, power generation can be performed in a state where the wind receiving area of the blade 42 is large until the rotation speed of the wind turbine blade 4 is within a predetermined range, and when the rotation speed of the wind turbine blade 4 exceeds the predetermined range, the blade The blade 42 is twisted by both the aerodynamic force applied to the weight 42 and the centrifugal force applied to the weight member 7, thereby suppressing over-rotation.

  The weight member 7 has a predetermined weight, and moves by centrifugal force due to an increase in the number of rotations of the wind turbine blade portion 4 around the vertical axis X, and the blade 42 moves around the rotation axis Y by the movement of the weight member 7. Rotate. The weight member 7 is supported by the connecting member 8 such that the bottom of the weight member 7 is separated from the upper surface of the rotation hub 3.

  In the present embodiment, the weight member 7 is connected to the tuning mechanism 6 by the connecting member 8. The connecting member 8 operates in accordance with the movement of the weight member 7 so that the tuning mechanism 6 can be operated in the direction of rotating the blade 42 around the rotation axis Y. Are connected. In addition, if the connecting member 8 connects the weight member 7 and the tuning mechanism 6 so that the tuning mechanism 6 can be operated in a direction of rotating the blade 42 around the rotation axis Y, the present embodiment is applicable. It is not limited to the shape and structure.

  In the present embodiment, as shown in FIGS. 11 and 12, the connecting member 8 is attached to the rotating hub 3 so as to be swingable about an axis Ax parallel to the vertical axis X. The connecting member 8 extends from the swing axis Ax of the connecting member 8 toward the weight member 7 and extends from the swing axis Ax of the connecting member 8 toward the hub-side gear G2. And a second extension 82 attached to G2. The second extension 82 has an elongated hole 82a at an end attached to the hub-side gear G2, and the hub-side gear G2 has a shaft member G21 inserted into the elongated hole 82a. The connecting member 8 having the first extension portion 81 and the second extension portion 82 is formed in a substantially L-shape, and when a centrifugal force is applied to the weight member 7 as shown in FIG. It swings around the swing axis Ax in the direction of the arrow AR1 against the biasing force of the biasing member SP. Thereby, the first extension portion 81 and the second extension portion 82 swing integrally about the swing axis Ax, and the end of the second extension portion 82 is moved in the direction of the arrow AR2 in FIG. Rocks.

  The position at which the urging member SP is provided is not particularly limited as long as the urging member SP can directly or indirectly urge the weight member 7 in a direction that suppresses the movement of the weight member 7 due to centrifugal force. In the present embodiment, the urging member SP has a structure in which the urging member support member 32 extending along the vertical axis X of the rotation hub 3 (a portion where one end of a spring is attached to the rotation hub 3 rotates). ) And the weight member 7. More specifically, the tension spring is shown on the locking portion 71 provided on the cylindrical weight member 7 and the locking portion 32a provided on the biasing member support 32 shown as a support pin. The urging member SP is locked. It is preferable that the biasing member SP be preloaded as described above. The biasing member SP may be provided between the tuning mechanism 6 such as the hub-side gear G2 and the rotating hub 3 so as to resist the centrifugal force of the weight member 7.

  In the present embodiment, as shown in FIG. 12, the weight member 7 moves due to the centrifugal force, and the end of the second extending portion 82 swings around the swing axis Ax of the connecting member 8 in the direction of the arrow AR2. Then, when the shaft member G21 receives a force from the edge of the elongated hole 82a of the second extension 82, the hub-side gear G2 is configured to rotate in the direction of the arrow AR3. Thereby, the arms 41 of the plurality of wind turbine blades 4 are synchronized and rotated around the rotation axis Y via the arm-side gear G1. Thereby, the blade 42 is twisted around the rotation axis Y, the wind receiving area of the blade 42 is reduced, and the overturn of the wind turbine blade 4 is suppressed.

<Embodiment 3>
Next, a windmill according to the third embodiment will be described. The points described in the respective configurations of the first and second embodiments can be similarly applied to the third embodiment. In the following description, the points described in the first and second embodiments will be omitted, and differences will be mainly described.

  In the wind turbine 1 of the present embodiment, the connecting member 8 that connects the weight member 7 and the tuning mechanism 6 has a gear. Specifically, as shown in FIGS. 13 to 15, the connecting member 8 includes an extending portion 81 extending from the swing axis Ax of the connecting member 8 toward the weight member 7, and a swing axis of the connecting member 8. Ax and a connecting member-side gear 83 provided coaxially. As shown in FIG. 15, the tuning mechanism 6 is provided with a tuning mechanism side gear G3 which meshes with the coupling member side gear 83 and is provided coaxially with the hub side gear G2.

  The weight member 7 has the same configuration as that of the second embodiment, and moves by centrifugal force due to an increase in the number of rotations of the wind turbine blade section 4 of the wind turbine 1 around the vertical axis X. When a predetermined centrifugal force is applied, the weight member 7 swings with the extension 81 around the swing axis Ax. As shown in FIG. 14, when the weight member 7 swings around the swing axis Ax in the direction of the arrow AR4, the connecting member side gear 83 connected to the swing axis Ax also swings so as to rotate with the swing axis Ax. It rotates in the direction of the arrow AR5 around the moving axis Ax.

  As shown in FIG. 15, the coupling member-side gear 83 is arranged so as to mesh with the tuning mechanism-side gear G3, and is configured so that when the coupling member-side gear 83 rotates, the tuning mechanism-side gear G3 also rotates. ing. The hub-side gear G2 is configured to rotate according to the rotation of the tuning mechanism-side gear G3. The structure and arrangement position of the tuning mechanism side gear G3 are not particularly limited as long as the hub side gear G2 can be rotated by rotation of the tuning mechanism side gear G3. In the present embodiment, as shown in FIG. 15, the tuning mechanism side gear G3 is disposed coaxially with the hub side gear G2, and is provided so as to rotate with the hub side gear G2. The tuning mechanism side gear G3 may be formed integrally with the hub side gear G2, or may be separately fitted to the hub side gear G2. Another gear may be interposed between the tuning mechanism side gear G3 and the hub side gear G2.

  In the present embodiment, similarly to the second embodiment, when the weight applied to the weight member 7 due to the twist moment due to the aerodynamic force and the centrifugal force overcomes the urging force of the urging member SP and the weight member 7 moves, The tuning mechanism 6 operates by the operation of the connecting member 8 interlocked with the movement of the member 7. Thus, the blade 42 is configured to be twisted in a direction to reduce the wind receiving area of the blade 42. Therefore, in the present embodiment, until the predetermined centrifugal force is applied to the weight member 7, the weight member 7 does not move with respect to the rotating hub 3, and the twist of the blade 42 is suppressed even if an air force is applied. Therefore, in the present embodiment, in addition to the effects obtained in the first embodiment, the blade 42 can maintain a large wind receiving area in a wider range of wind speed, and can increase power generation efficiency. Thereafter, when the rotation speed of the wind turbine blade portion 4 increases and a predetermined centrifugal force is applied to the weight member 7 in addition to the air force applied to the blade 42, the weight member 7 resists the urging force of the urging member SP. Then, as shown in FIG. 14, the connecting member 8 swings around the swing axis Ax in the direction of the arrow AR4. When the connecting member 8 swings about the swing axis Ax in the direction of the arrow AR4, the connecting member side gear 83 rotates around the swing axis Ax in the direction of the arrow AR5. When the coupling member-side gear 83 rotates in the direction of the arrow AR5, the tuning mechanism-side gear G3 rotates in the opposite direction. As a result, the hub-side gear G2 rotates in the direction of the arrow AR6. When the hub-side gear G2 rotates, the arms 41 of the plurality of wind turbine blades 4 synchronize with each other and rotate around the rotation axis Y via the arm-side gear G1. Thereby, the blade 42 is twisted around the rotation axis Y, the wind receiving area of the blade 42 is reduced, and the overturn of the wind turbine blade 4 is suppressed. Further, in the present embodiment, since the weight member 7 and the tuning mechanism 6 are connected by the gears (the connecting member side gear 83 and the tuning mechanism side gear G3), the swing of the weight member 7 to which the centrifugal force is applied. Can be smoothly transmitted to the tuning mechanism 6, and damage to the connecting member 8 and the tuning mechanism 6 is suppressed.

  In the first embodiment shown in FIGS. 2, 3, and 4, the case where there is no preload of the spring (referred to as Case 6) and the case where there is a preload (referred to as Case 7), and the embodiment illustrated in FIGS. In the case of Embodiment 3 (hereinafter referred to as Case 8), the rotational speed dependence of the shaft torque in an expected optimum state (a state in which overspeed is prevented and the annual power generation amount increases) is shown in FIGS. Are shown below. In each case, the wind speed V was assumed to be in three states of 5 m / s, 10 m / s, and 18 m / s. Table 2 summarizes the values of each parameter in the optimal state in each case.

  The wind turbine assumed in FIGS. 16, 17, and 18 is the butterfly wind turbine shown in FIG. 1, having a rotor diameter of 12.5 m (radius R = 6.25 m), a rotating hub 3 having a diameter of 0.9 m, and a blade It is assumed that the height H is 7.8 m and the number of blades is three. The wing section shape was NACA 0018 (symmetric wing type), and the chord length was calculated as 412 mm. The wind turbines of Cases 1 to 5 whose characteristics are shown in Table 1 and FIG. 9 have a rotor diameter of 7 m, and the diameter of the rotation hub 3, that is, the size of the over-rotation suppression mechanism is 0.89 m. In cases 6 to 8 in which the diameter of the rotor is increased to 12.5 m, the diameter of the rotating hub 3 is almost the same (0.9 m), so that the enlargement of the excessive rotation suppressing mechanism can be suppressed. I understand.

  In case 6 shown in FIG. 16 with no torsional spring and no preload, the parameters are adjusted so as to match as much as possible the torque characteristics without twist at a wind speed V = 5 m / s, and the wind speed is 10 m / s or 18 m / s. In the strong wind condition of s, the optimum condition is selected so as to have an intersection (operating point) with the power generation control target (torque characteristic of the generator) at a rotation speed lower than about 40 rpm assumed as the rated rotation speed. The over-rotation is suppressed. However, in case 6, when a trouble of the controller or the like occurs, at a wind speed of 5 m / s, it is expected that the windmill rotation speed will be 50 rpm or more, which exceeds the rated rotation speed.

  In case 7 shown in FIG. 17 with a torsion spring and a preload, at a wind speed V = 5 m / s, the maximum value (rotational speed 30 rpm) of the torque characteristic without twist is as close as possible to the rated rotational speed. At a rotational speed of 40 rpm or less, the parameters were adjusted so as to have an intersection with the 0Nm line on the horizontal axis. Even in a strong wind state at a wind speed of 10 m / s or 18 m / s, at a rotation speed lower than the rated rotation speed of 40 rpm, there is an intersection (operating point) with the power generation control target (torque characteristic of the generator).

  In case 8 using the tension spring and the coupling member side gear shown in FIG. 18, at a wind speed V = 5 m / s, the torque characteristics almost match the torque characteristics in the case where there is no twist up to the rated speed of 40 rpm, and are higher than that. The parameters were adjusted so that the twist angle rapidly changed to a maximum angle of 30 ° defined by the second positioning member and the rotational torque (axial torque) of the wind turbine rotor became negative at the rotational speed. In a strong wind condition of a wind speed of 10 m / s or 18 m / s, from the low speed to the rated speed of 40 rpm, there is no intersection (operating point) with the power generation control target (torque characteristic of the generator), and the twist angle is initially set. Although the rotation speed increases while maintaining the value, when the rotation speed exceeds the rated rotation speed, the twist angle rapidly changes up to the maximum angle 30 ° defined by the second positioning member, and the rotation torque (shaft torque) of the wind turbine rotor is increased. ) Is negative, and the over-speed is suppressed.

  FIG. 19 compares the wind speed dependence of the generated power in cases 6 to 8 predicted from the rotational torque (axial torque) of the wind turbine rotor shown in FIGS. Since the natural wind fluctuates, it is expected that the generated power of the windmill always changes, but in FIG. 19, for convenience, the torque of the windmill when assuming a constant wind speed as shown in FIGS. The intersection of the curve and the torque characteristic curve of the generator (power generation control target) was determined, and the power was generated at a specific wind speed. In FIG. 19, when the wind speed is 18 m / s or more, the wind speed appearance rate is predicted to be almost 0% even if the generated power is high, and thus does not contribute to the annual power generation amount. The drop in the generated power in the range of the wind speed of 6 to 8 m / s in Case 6 and the drop in the generated power in the range of the wind speed of 7 to 9 m / s in Case 8 are caused when the twist angle η shown in FIG. In this case, the situation corresponds to the peak of the dimensionless twist moment seen in the range of the tip peripheral speed ratio λ of 3 to 4.

  Table 3 shows the annual power generation amounts of cases 6 to 8 that are predicted based on the wind speed dependence of the generated power in FIG. The wind speed appearance rate assumed a Rayleigh distribution with an average wind speed of 5 m / s. In case 8 where the generated power has the highest characteristic in the low wind speed range of 6 m / s or less, the predicted annual power generation is the largest.

<Embodiment 4>
Next, a windmill according to the fourth embodiment will be described. The points described in each of the first to third embodiments can be similarly applied to the fourth embodiment. In the following description, the points described in the first to third embodiments will be omitted, and differences will be mainly described.

  Generally, when the blades of a vertical axis wind turbine are rotated at a high speed, centrifugal force acting on the blades causes the blades to deform radially outward as shown in FIG. FIG. 20 shows the result of simulating the deformation of a triangular wing by a structural analysis based on the finite element method. Since the own weight of the wing is taken into account, a vertical downward displacement is also shown. The wind turbine is a butterfly wind turbine shown in FIGS. 1 to 5, and in the present embodiment, the calculation is performed assuming that the rotor diameter is 7 m and the blade height is 2.7 m. The blade section shape was NACA 0018 (symmetric blade type), the chord length was 242.3 mm, and the blade material was calculated as aluminum. The amount of deformation at the maximum radial position is substantially proportional to the rotation speed, and in the example of FIG. 20, deformation of about 80 mm is expected outward in the radial direction at the rated rotation speed of 120 rpm. In FIG. 20, the amount of deformation is displayed ten times.

  In order to suppress the deformation of the wings and increase the upper limit rotation speed, at the expense of a slight reduction in output (the expected output reduction is several%), in the present embodiment, as shown in FIGS. A deformed portion 42a of the blade 42 in which a maximum deformation occurs radially outside (the right side in FIGS. 20 and 21) of the blade 42 when a predetermined centrifugal force is applied to the blade 42 by rotation of the blade 42 around the vertical axis X; There is a reinforcing member 9 between the tuning mechanism 6. The reinforcing member 9 applies a tension toward the inside in the radial direction to the deformed portion 42a.

  FIG. 22 is a perspective view of a lift-type vertical axis wind turbine according to the fourth embodiment in which the deformation force of the wing acting via the reinforcing member (brace) 9 is used as the force for driving the twist of the blade 42. FIG. 23 is a top view of the lift-type vertical axis wind turbine shown in FIG. In FIGS. 22 and 23, a part of the blade 42 and the reinforcing member 9 is omitted.

  One end 91 of the reinforcing member 9 is connected to a deformed portion 42a of the blade 42 (see FIG. 21), and the other end 92 of the reinforcing member 9 is connected to the tuning mechanism 6 via a connecting member 80 (FIGS. 22 and 23). reference). As shown in FIGS. 22 and 23, the urging member SP is provided with a tuning mechanism such that the reinforcing member 9 applies a radially inward tension to the deformed portion 42 a of the blade 42 via the connecting member 80. 6 are energized. As shown in FIGS. 22 and 23, the tuning mechanism 6 is provided on a plurality of arm-side gears G <b> 1 provided at the other ends of the arms 41 of the plurality of wind turbine blade parts 4, and provided on the rotation hub 3, respectively. And one hub-side gear G2 that meshes with the arm-side gear G1. One end 80a of the connecting member 80 is swingably attached to the hub-side gear G2 around an axis parallel to the vertical axis X, and the other end 80b of the connecting member 80 is swingable to the other end 92 of the reinforcing member 9. Attached to.

  More specifically, in the present embodiment, as shown in FIGS. 22 and 23, the reinforcing member 9 is rod-shaped, and penetrates a hole provided in the support portion (frame) 31 to radially extend. At the other end 80b of the reinforcing member 9 on the vertical axis X side, the link member (the connecting member 80) and the hinge can swing with respect to the upper surface of the hub-side gear G2. Is joined to. One end 80a of the link rod (connection member 80) is swingably connected to a pin (such as a reamer bolt) attached so as to protrude vertically upward from the hub-side gear G2. When the windmill is rotated at a high speed and a predetermined centrifugal force is applied to the blade 42, a large tension acts on the reinforcing member 9. When the reinforcing member 9 and the deformed portion 42a are displaced radially outward against the urging force of the urging member SP, the tuning mechanism 6 is operated via the connecting member 80 by the displacement of the reinforcing member 9, and the blade 42 is displaced. Twists in a direction to reduce the wind receiving area of the blade 42. More specifically, when a predetermined centrifugal force is applied to the blade 42 and the reinforcing member 9 and the deformed portion 42a are displaced outward in the radial direction, the movement of the connecting member 80 causes the hub-side gear G2 to rotate. The rotation of the hub-side gear G2 rotates the arm-side gear G1, and the blade 42 twists in a direction to reduce the wind receiving area of the blade 42.

  In this embodiment, in order to prevent the blade 42 from twisting when the rotation speed is relatively small, an attachment member (such as an eyebolt) is attached to the side surface of the hub-side gear G2 and the side surface of the support portion (frame) 31. A tension spring (biasing member SP) is provided between the two mounting members (eye bolts or the like) to apply a preload.

  In order to suppress over-rotation in a strong wind at a wind speed of about 60 m / s, it is sufficient that the maximum twist angle of the blade 42 is about 25 ° to 30 °. In the examples of FIGS. 22 and 23, since the ratio of the number of teeth between the hub-side gear G2 and the arm-side gear G1 is 3: 1, when the maximum twist angle of the blade 42 is 30 °, the rotation angle of the hub-side gear G2 Is 10 °. The rotational moment about the vertical axis X acting on the hub-side gear G2 via the reinforcing member (brace) 9 and the connecting member 80 changes depending on the size of the windmill and the upper limit rotational speed, but the maximum twist angle at the desired rotational speed is reduced. What is necessary is just to adjust the proportional constant, initial displacement, etc. of the urging member SP (a tension spring, a compression spring, etc.) so that it may be realized.

  In the examples of FIGS. 22 and 23, even when the blade is in a 30 ° twist angle state, the interference between the root portion of the inclined blade 42 and the member (not shown) connecting the blade 42 and the arm 41 is present. The installation position of the reinforcing member (brace) 9 on the support portion (frame) 31 is set so as not to occur. If it is possible to make a hole through the reinforcing member (brace) 9 at the center of the arm 41, the installation position of the reinforcing member 9 can be matched with the central axis of the arm 41.

  In the example of FIGS. 22 and 23, when the twist angle is set to 90 ° at the time of assembling as shown in FIG. Interference between the root portion of the blade 42 and the member connecting the blade 41 and the arm 41 is temporarily avoided, the assembly of the blade 42 is completed, and the reinforcing member (brace) 9 is connected with the twist angle set to 0 °. Then, a predetermined tension may be applied.

  In the fourth embodiment, when the blade 42 is twisted, the reinforcing member 9 is twisted. When the reinforcing member 9 is sufficiently long, the torsion can be absorbed within a range of elastic deformation. If the torsion of the reinforcing member 9 is not absorbed within the range of the elastic deformation, a universal joint rotatable around the central axis of the reinforcing member 9 is provided at any position including the end of the reinforcing member 9. (Not shown) can be inserted to avoid the torsion.

  In the fourth embodiment, one end 91 of the reinforcing member 9 is displaced vertically downward with respect to the position of the other end 92 due to the own weight of the blade 42 or the own weight of the reinforcing member 9. It is ideal that the one end 91 of the reinforcing member 9 is attached to the deformed portion 42a of the blade 42 at a position close to the extension of the rotation axis Y. However, the own weight of the blade 42 or the own weight of the reinforcing member 9 is preferable. If the installation position of the reinforcing member 9 is not coincident with the central axis (rotation axis Y) of the arm 41 as shown in the example of FIGS. Therefore, when the blade 42 is twisted, the reinforcing member 9 bends. When the reinforcing member 9 is sufficiently long, the bending can be absorbed within a range of elastic deformation. If the bending of the reinforcing member 9 is not absorbed within the range of the elastic deformation, a universal joint (FIG. 5) that can deflect with respect to the central axis of the reinforcing member 9 is provided at any position including the end of the reinforcing member. (Not shown) can be inserted to avoid said bending.

  When the lift-type vertical axis wind turbine of the fourth embodiment is used, the weight member 7 required in the second and third embodiments becomes unnecessary, and the setting of the initial twist angle required in the first embodiment may be omitted. . Further, in the present embodiment, since the action of the centrifugal force is greater than the aerodynamic force, it is not necessary to move the blade mounting position in the trailing edge direction required in the first to third embodiments, or It becomes possible to reduce. In the fourth embodiment, the reinforcing member (brace) 9 moves outward in the radial direction by a very small amount (about 10 mm), but does not require a guide groove having a complicated shape, and the arm 41 does not move in the radial direction. Therefore, even if the size of the wind turbine increases, the size of the over-rotation suppression mechanism becomes compact.

1 lift type vertical axis windmill (windmill)
DESCRIPTION OF SYMBOLS 2 Base part 21 Power generation part 22 Leg 3 Rotation hub 31 Support part 32 Energizing member support 32a Locking part 4 Windmill blade part 41 Arm 41a Engaging part (engaging pin)
42 Blade 42a Deformation part of blade 51 Positioning member 52 Second positioning member 6 Tuning mechanism 7 Weight member 71 Locking part 8, 80 Connecting member 80a One end of connecting member 80b The other end of connecting member 81 Extension (first extension) Ide)
82 second extension portion 82a elongated hole 83 connecting member side gear 9 reinforcing member 91 one end of reinforcing member 92 other end of reinforcing member Ax swing shaft G1 arm side gear G2 hub side gear G21 shaft member G3 tuning mechanism side gear Ha 1 holding part Hb second holding part LE front edge SP biasing member (torsion spring / tension spring)
TE Trailing edge X Vertical axis Y Rotation axis

Claims (16)

A rotating vertical axis wind turbine having a rotating hub and a plurality of wind turbine blades rotating around a vertical axis,
Each of the plurality of wind turbine blades is supported by the rotating hub, and has an arm extending in a horizontal direction perpendicular to the vertical axis, and a blade provided at one end of the arm,
The arm is
The rotation hub is rotatably supported around the rotation axis extending in the horizontal direction, and is provided so as to be twisted around the rotation axis of the arm so as to reduce the wind receiving area of the blade,
The arm and the blade, when the arm twists around the rotation axis, does not move in the axial direction of the rotation axis of the arm,
The lifting vertical axis windmill further comprises:
A tuning mechanism that synchronizes the rotation of the arms around the rotation axis with each other such that the twist angles of the arms and the blades of each of the plurality of wind turbine blades are equal to each other;
A lifting-type vertical axis wind turbine, comprising: a biasing member that biases the arm in a direction in which the wind receiving area of the blade increases when the arm is twisted. The lifting vertical axis according to claim 1, wherein the arm is configured to twist about the rotation axis by an air force applied to the blade and / or the arm when the blade rotates about the vertical axis. Windmill. The cross section of the blade is a streamline with a curved leading edge and a sharpened trailing edge,
When the blade is viewed in the axial direction of the arm,
The arm is provided such that the rotation axis of the arm is located on the trailing edge side of the blade with respect to a line connecting two aerodynamic center points located equidistant from the rotation axis of the arm. The lift-type vertical axis wind turbine according to claim 2, which is provided. The lift type vertical axis wind turbine according to claim 3, wherein the arm is formed to be flat in a direction parallel to the vertical axis when the blade is not twisted. The initial position of the blade corresponding to the windless state is set so that a line connecting the two aerodynamic center points is inclined at a predetermined initial twist angle with respect to the vertical line, and the initial position of the blade is set. The lift type vertical axis wind turbine according to claim 3 or 4, wherein, in the position, the blade is held in a state where a preload is applied by a predetermined urging force from the urging member. A positioning member for defining an initial position of the blade so that the blade is held in a state inclined at the predetermined initial twist angle in a state where the blade is urged by the urging member. 5. A lift-type vertical axis wind turbine according to 5. A second positioning member that regulates further twisting of the blade when the blade is twisted from the initial position to a second position where the wind receiving area of the blade is reduced, and defines a maximum twist angle of the blade; The lift-type vertical axis wind turbine according to claim 6, comprising: The tuning mechanism,
A plurality of arm-side gears provided at the other end of the arm of the plurality of wind turbine blades,
The lift-type vertical axis wind turbine according to any one of claims 1 to 7, further comprising one hub-side gear provided on the rotating hub and meshing with the plurality of arm-side gears. The lifting vertical axis wind turbine according to claim 8, wherein the urging member indirectly urges the arm by urging the hub-side gear of the tuning mechanism. The rotating hub has a weight member movable relative to the rotating hub when the rotating hub rotates and a predetermined centrifugal force is applied,
The weight member is connected to the tuning mechanism via a connecting member,
The biasing member is configured to directly or indirectly bias the weight member in a direction to suppress movement of the weight member due to centrifugal force,
When the twisting moment due to the aerodynamic force and the force applied to the weight member due to the centrifugal force overcome the urging force of the urging member and the weight member moves, the coupling member interlocks with the movement of the weight member. The lift-type vertical shaft according to any one of claims 1 to 9, wherein the tuning mechanism is operated by an operation, and the blade is configured to twist in a direction to reduce a wind receiving area of the blade. Windmill. The tuning mechanism,
A plurality of arm-side gears provided at the other end of the arm of the plurality of wind turbine blades,
One hub-side gear provided on the rotating hub and meshing with the plurality of arm-side gears,
The connecting member is swingably attached to the rotating hub around an axis parallel to the vertical axis,
A first extension extending from the pivot axis of the coupling member toward the weight member, and a first extension extending from the pivot axis of the coupling member toward the hub-side gear; A second extension to be attached,
The second extension has an elongated hole at an end attached to the hub-side gear,
The hub-side gear has a shaft member inserted into the long hole,
When the weight member moves due to centrifugal force and the end of the second extension portion swings about the swing axis of the connection member, the shaft member is formed as a long hole of the second extension portion. The lift-type vertical axis wind turbine according to claim 10, wherein the hub-side gear rotates by receiving a force from an edge. The tuning mechanism,
A plurality of arm-side gears provided at the other end of the arm of the plurality of wind turbine blades,
One hub-side gear provided on the rotating hub and meshing with the plurality of arm-side gears,
The connecting member is swingably attached to the rotating hub around an axis parallel to the vertical axis,
The coupling member includes an extending portion extending from the pivot axis of the coupling member toward the weight member, and a coupling member-side gear provided coaxially with the pivot axis of the coupling member,
The tuning mechanism is
It comprises a tuning mechanism side gear that is meshed with the coupling member side gear and is provided coaxially with the hub side gear, and the hub side gear is configured to rotate according to the rotation of the tuning mechanism side gear,
The lift according to claim 10, wherein when the weight member moves by centrifugal force and the connecting member swings around the swing shaft, the hub-side gear rotates by rotation of the tuning mechanism-side gear. Type vertical axis windmill. When a predetermined centrifugal force is applied to the blade by rotation of the blade around the vertical axis, a reinforcing member extending between a deformed portion of the blade where maximum deformation occurs radially outward of the blade and the tuning mechanism Further having
One end of the reinforcing member is connected to the deformed portion of the blade, and the other end of the reinforcing member is connected to the tuning mechanism via a connecting member,
The urging member urges the tuning mechanism via the connecting member so that the reinforcing member applies a tension inwardly in the radial direction to the deformed portion of the blade.
A predetermined centrifugal force is applied to the blade, and when the reinforcing member and the deformed portion are displaced radially outward against the urging force of the urging member, the displacement of the reinforcing member through the connecting member The lift vertical axis wind turbine of claim 1, wherein the tuning mechanism is operated to cause the blade to twist in a direction that reduces the wind receiving area of the blade. The tuning mechanism,
A plurality of arm-side gears provided at the other end of the arm of the plurality of wind turbine blades,
One hub-side gear provided on the rotating hub and meshing with the plurality of arm-side gears,
One end of the connecting member is swingably attached to the hub-side gear around an axis parallel to the vertical axis, and the other end of the connecting member is swingably attached to the other end of the reinforcing member. ,
A predetermined centrifugal force is applied to the blade, and when the reinforcing member and the deformed portion are displaced radially outward, the hub-side gear rotates due to the movement of the connecting member,
14. The lift-type vertical axis wind turbine according to claim 13, wherein the rotation of the hub-side gear rotates the arm-side gear, and the blade twists in a direction to reduce the wind receiving area of the blade. In the state where the blade is urged by the urging member, a positioning defining an initial position of the blade is maintained such that the blade is held inclined at a predetermined initial twist angle where the wind receiving area of the blade is maximized. The lift type vertical axis wind turbine according to claim 13 or 14, comprising a member. A second positioning member that regulates further twisting of the blade when the blade is twisted from the initial position to a second position where the wind receiving area of the blade is reduced, and defines a maximum twist angle of the blade; The lift type vertical axis wind turbine according to claim 15, comprising: