Vertical axis windmill

Abstract

To provide a vertical axis windmill comprising an overrotation suppression mechanism that has higher strength to adapt the enlargement of the windmill, and also facilitates attachment and detachment of movable vanes to facilitate maintenance inspection.SOLUTION: There is provided a vertical axis windmill that comprises a base part which has an electric generation part, a rotation part which rotates on a vertical axis relative to the base part, and a plurality of windmill vanes which are coupled to the rotation part through a fixed arm 14 and rotate on the vertical axis, wherein a pair of vertical arms 17 are vertically mounted on the fixed arm, a movable arm 15 for overrotation suppression rotatable around an axis of a rotary shaft 35 connecting both the vertical arms 17 is provided, and an auxiliary vane 16 which tilts the movable arm 15 around the axis of the rotary shaft 35 with the action of a centrifugal force generated during the rotation of the windmill and puts the movable arm 15 back into an initial state at a rotation stop of the windmill is provided in the movable arm 15.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] This invention relates to a vertical axis wind turbine that generates electricity by rotating using lift generated by vertically arranged wind turbine blades, and more specifically to a vertical axis wind turbine equipped with an over-rotation suppression mechanism. [Background technology]

[0002] Conventionally, vertical axis wind turbines have a base with a power generating unit, a rotating unit that rotates about a vertical axis relative to the base, and a number of wind turbine blades (main blades) that are connected to the rotating unit via arms and rotate about the vertical axis. Because their performance is not dependent on wind direction, vertical axis wind turbines have a simple structure and are considered to be suitable for reducing costs. Recently, it has been shown that by closely arranging small vertical axis wind turbines, it is possible that the output per unit installation area can be greater than that of a wind power plant (wind farm) using large horizontal axis wind turbines, and there are high hopes for the realization of wind farms using small vertical axis wind turbines in promoting the introduction of renewable energy.

[0003] On the other hand, vertical axis wind turbines have the characteristic that their performance is not dependent on wind direction, which makes braking control difficult.In other words, with horizontal axis wind turbines, over-rotation can be prevented relatively easily by using tail fins (side wings) to deflect the rotor surface (the surface on which the blades rotate) away from the wind direction (furling), but with vertical axis wind turbines, furling is not possible because they are not dependent on wind direction.

[0004] Therefore, an over-rotation suppression mechanism that generates an aerodynamic brake torque that opposes the rotation direction of the vertical axis wind turbine according to the rotation speed of the vertical axis wind turbine is described in Patent Document 1. The over-rotation suppression mechanism described in Patent Document 1 is composed of a movable blade that rotates around the rotation axis centered on the longitudinal direction of an arm connected to the rotating part and the main blade, and an over-rotation suppression inductor that hangs down vertically from the leading edge side or the trailing edge side of the movable blade.

[0005] Therefore, the centrifugal force acting on the over-rotation suppression inducer according to the rotation speed of the vertical axis wind turbine acts on the movable blade as a moment in a direction that rotates the leading edge of the movable blade upward or downward in the vertical direction. Also, the moment due to the aerodynamic force acting on the movable blade, the moment due to the weight of the movable blade, the moment due to the aerodynamic force acting on the over-rotation suppression inducer, the moment due to the weight of the over-rotation suppression inducer, and the moment due to the centrifugal force acting on the movable blade act on the movable blade to change the angle of attack of the movable blade.

[0006] That is, the vertical axis wind turbine described in Patent Document 1 is configured such that the angle of attack of the movable blades changes depending on the magnitude relationship of the moment acting on the movable blades, generating a resistance torque that opposes the torque that rotates the vertical axis wind turbine, thereby suppressing over-rotation of the vertical axis wind turbine. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Patent Publication No. 2022-108917 Summary of the Invention [Problem to be solved by the invention]

[0008] However, in the vertical axis wind turbine described in Patent Document 1, the movable blades are connected in series to the fixed arms, and the movable blades rotate around the longitudinal direction of the arms as the center of rotation axis. This means that the rotation axis of the movable blades needs to bear a load equivalent to that of the fixed arms, and there is a concern that if the wind turbine itself is made larger, the structural strength of the rotation axis of the movable blades may not be sufficient to manufacture one with the strength to accommodate it. In addition, because the movable blades are attached coaxially with the arms, removing the movable blades is difficult, which raises concerns that problems may arise with the maintenance and inspection of the wind turbine itself.

[0009] The present invention has been made in view of the above circumstances, and has an object to provide a vertical axis wind turbine equipped with an over-rotation suppression mechanism that is stronger in order to accommodate the increase in size of the wind turbine itself and that facilitates the attachment and detachment of movable blades and therefore maintenance and inspection. [Means for solving the problem]

[0010] In order to achieve the above object, the present invention provides a vertical axis wind turbine comprising a base having a power generating unit, a rotating unit which rotates around a vertical axis relative to the base, and a plurality of wind turbine blades which are connected to the rotating unit via a fixed arm and rotate around the vertical axis, the vertical axis wind turbine comprising: a pair of vertical arms suspended from the fixed arm; a movable arm for suppressing over-rotation which is rotatable around a rotation axis connecting both vertical arms; and an over-rotation suppression inductor which is provided on the movable arm and tilts the movable arm around the axis of the rotation axis by the action of centrifugal force generated when the wind turbine rotates, and returns the movable arm to its initial state when the wind turbine stops rotating (Claim 1).

[0011] With this configuration, the over-rotation suppression guide can be attached to a movable arm that can rotate around a rotation axis that connects a pair of vertical arms suspended from a fixed arm. Also, when the wind turbine rotates, the rotational component of the centrifugal force acting on the over-rotation suppression guide causes the movable arm to tilt around the rotation axis as the angle (hereinafter referred to as the inclination angle) between the over-rotation suppression guide and the vertical direction changes, and a braking force due to aerodynamic force acts on the movable arm. Also, when the wind turbine stops rotating, the movable arm automatically returns to its original initial state.

[0012] In the present invention, it is preferable that the over-rotation suppression guide is provided at a position offset toward the leading edge or trailing edge in the rotation direction with respect to the rotation shaft at the lower part of the movable arm (claim 2). With this configuration, the inclination angle between the over-rotation suppression inductor and the vertical direction increases, and a large aerodynamic braking force acts on the movable arm.

[0013] In the present invention, it is preferable that the wind turbine blade, the fixed arm, the vertical arm, the movable arm and the over-rotation suppression guide are formed into an airfoil cross section having a hollow portion of the same shape (claim 3).

[0014] By configuring in this manner, the wind turbine blade, fixed arm, vertical arm, movable arm and over-rotation suppression guide are formed into an airfoil cross-sectional shape having a hollow portion of the same shape as the wind turbine blade, so that a rotational component is generated by aerodynamic force, i.e., lift force directed in the horizontal direction, thereby increasing the propulsive force of the wind turbine.

[0015] In this invention, when the fixed arm and the vertical arm are formed in an airfoil cross-sectional shape having the same hollow shape, it is preferable that the vertical arm has a vertical bracket that is inserted and fixed longitudinally into the hollow, and the vertical bracket is connected by a fixing member that penetrates the bracket that is inserted and fixed into the hollow of the fixed arm (Claim 4).In this case, it is preferable that the vertical bracket and the bracket that is inserted and fixed into the hollow of the fixed arm are formed in the same cross-sectional shape that is inserted and fixed into a partitioned hollow that constitutes a part of the hollow (Claim 5).

[0016] With this configuration, the fixed arm and the vertical arm can be easily and firmly fixed together while maintaining the light weight of the fixed arm and the vertical arm.

[0017] In addition, in this invention, when the movable arm and the over-rotation suppression guide are formed in an airfoil-shaped cross section having the same hollow, it is preferable that the over-rotation suppression guide has a lower reinforcing bracket inserted and fixed in the hollow at the top of the over-rotation suppression guide, and the lower reinforcing bracket is connected by a fixing member penetrating an upper reinforcing bracket inserted and fixed in the hollow of the movable arm (claim 6). In this case, it is preferable that the lower reinforcing bracket and the upper reinforcing bracket are formed in the same cross section and inserted and fixed in a partitioned hollow constituting a part of the hollow (claim 7). Also, it is preferable that the fixing member penetrating the upper reinforcing bracket is inserted into a cylindrical spacer interposed between the movable arm and the over-rotation suppression guide (claim 8).

[0018] With this configuration, the movable arm and the over-rotation suppression guide can be easily and firmly fixed to each other while maintaining the light weight of the movable arm and the over-rotation suppression guide. Also, by inserting the fixing member penetrating the upper reinforcing bracket into the cylindrical spacer interposed between the movable arm and the over-rotation suppression guide, the fixing member connecting the movable arm and the over-rotation suppression guide can be prevented from being exposed to the outside.

[0019] In the present invention, it is preferable that the rotating shaft further comprises a damper mechanism that is integrated with either the vertical arm or the movable arm, is formed to be rotatable relative to the other of the vertical arm and the movable arm, and generates a reaction torque against a moment that rotates the rotating shaft and the other member relatively (Claim 9).In this case, it is preferable that the damper mechanism is an oil damper in which the reaction torque increases according to the relative speed at which the rotating shaft and the other member rotate relatively (Claim 10).

[0020] With this configuration, when the movable arm rotates with an increase in the rotation speed of the wind turbine, a reaction force acts against the direction in which the movable arm rotates. Therefore, it is possible to prevent the amount of rotation of the movable arm from becoming excessive, and it is not necessary to provide multiple stoppers that limit the amount of rotation of the movable arm, or to prevent abnormal noise and vibration caused by contact between such stoppers and the movable arm. Similarly, when the rotation speed of the rotating shaft decreases and the amount of rotation of the movable arm decreases, a reaction force acts against the direction in which the movable arm rotates toward the initial position. Therefore, it is possible to prevent abnormal noise and vibration caused by contact between the movable arm and the stopper that positions the movable arm at the initial position due to a sudden decrease in the amount of rotation of the movable arm.

[0021] In addition, in this invention, stoppers are provided at opposing positions of the vertical arm and the movable arm, and when the two stoppers come into contact with each other, the movable arm is in an initial state, and if the over-rotation suppression guide is provided on the leading edge side in the rotation direction of the wind turbine with respect to the wind turbine rotation shaft, it is preferable that the leading edge side in the rotation direction of the wind turbine is supported in an upward position, and if the over-rotation suppression guide is provided on the trailing edge side in the rotation direction of the wind turbine with respect to the wind turbine rotation shaft, it is preferable that the leading edge side in the rotation direction of the wind turbine is supported in a downward position (Claim 11).

[0022] By configuring it in this manner, it is possible to prevent the movable arm from tilting forward (lowering) in the initial state when the over-rotation suppression guide is provided on the leading edge side in the rotational direction of the wind turbine rotation shaft, and it is also possible to prevent the movable arm from tilting backward (raising) in the initial state when the over-rotation suppression guide is provided on the trailing edge side in the rotational direction of the rotation shaft. Effect of the Invention

[0023] According to the present invention, as configured above, the following effects can be obtained.

[0024] (1) According to the invention described in claims 1 and 2, an over-rotation suppression inductor can be attached to a movable arm that can rotate around an axis of rotation connecting a pair of vertical arms suspended from a fixed arm. This makes it possible to provide high strength in response to the increase in size of the wind turbine itself, and to facilitate the installation and removal of the movable arm, facilitating maintenance and inspection.

[0025] (2) According to the inventions described in claims 3 to 8, in addition to the above (1), a rotational component is generated by aerodynamic force, i.e., horizontal lift force, thereby increasing the propulsive force of the wind turbine. Also, the fixed arm, vertical arm, movable arm, and over-rotation suppression guide can be easily and firmly fixed while maintaining the light weight of the fixed arm, vertical arm, movable arm, and over-rotation suppression guide.

[0026] (3) According to the invention described in claims 9 and 10, in addition to the above (1), it is possible to prevent the fluctuation range of the rotation amount of the movable arm from becoming excessive, thereby eliminating the need to provide multiple stoppers to limit the rotation amount of the movable arm, and also suppressing the generation of abnormal noise and vibration due to contact between such stoppers and the movable arm.

[0027] (4) According to the invention described in claim 11, in addition to the above (1), it is possible to prevent the movable arm from tilting forward or backward in the initial state, thereby optimizing the initial posture of the movable arm and at the same time making it possible to reliably generate a tilting operation. [Brief description of the drawings]

[0028] [Figure 1] FIG. 1 is a schematic side view showing an example of a vertical axis wind turbine according to the present invention in use. [Diagram 2] FIG. 2 is a side view showing a partial cross section of the blade fixing part of the vertical axis wind turbine. [Diagram 3] FIG. 2 is a plan view of a blade fixing part of the vertical axis wind turbine. [Figure 4] FIG. 2 is a side view of a wing according to the present invention. [Figure 4A]1A is a plan view showing a cross section of a part of a wing bracket according to the present invention, FIG. 1B is a side view, and FIG. 1C is a cross-sectional view taken along line II in FIG. [Diagram 5] FIG. 1 is a schematic front view showing a main part of a vertical axis wind turbine according to the present invention. [Figure 6] 6 is an enlarged partial cross-sectional view of a portion II in FIG. 5. [Figure 6A] 3A is a front view showing a rotation shaft stopper according to the present invention, and FIG. 3B is a cross-sectional view taken along line III-III in FIG. [Figure 6B] 4A is a front view, FIG. 4B is a side view, FIG. 4C is a rear view, and FIG. 4D is a cross-sectional view taken along line IV-IV in FIG. 4A. [Figure 6C] 1A is a schematic diagram showing a stopper portion that maintains the initial state of a movable arm in this invention, FIG. 1A is a state in which the stopper is maintained, FIG. 1B is a rotary shaft stopper, and FIG. [Figure 7] 7 is a plan view showing a part in cross section along the movable arm of FIG. 6. [Figure 7A] FIG. 2 is a cross-sectional view showing a mounting state of a rotary bearing according to the present invention. [Figure 8] FIG. 7 is a left side view of FIG. 6. [Figure 9] FIG. 6 is an enlarged partial cross-sectional view of a portion V in FIG. 5. [Figure 10] 10 is a plan view showing a cross section of a part of the main part of FIG. 9. FIG. [Figure 11] FIG. 10 is a right side view of FIG. [Figure 12] FIG. 12 is a cross-sectional view taken along line VI-VI in FIG. [Figure 13] 1 is a front view showing a partially cutaway view of an over-rotation suppression guide according to the present invention in a mounted state; [Figure 14] FIG. 14 is a plan view of FIG. [Figure 15] 7 is a cross-sectional view taken along line VII-VII of the over-rotation suppression guide. FIG. [Figure 16] 5A and 5B are a schematic plan view and a schematic side view, respectively, showing the relationship of forces acting in an over-rotation suppression mechanism using the above-mentioned over-rotation suppression inductor. [Figure 17]FIG. 2 is a perspective view showing a movable arm and an over-rotation suppression guide in a low rotation speed state of the vertical axis wind turbine according to the present invention. [Figure 18] FIG. 13 is a perspective view showing the movable arm and the over-rotation suppression guide when the wind turbine is in a high rotation speed state. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0029] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

[0030] As shown in FIG. 1, a vertical axis wind turbine 1 (hereinafter simply referred to as wind turbine 1) according to this invention comprises a rotating shaft 2 which rotates around an axis Z (hereinafter referred to as vertical axis Z) which is perpendicular to the direction in which the wind is received, in other words, perpendicular to the installation surface 4 (ground surface), a power generating unit 6 connected to the rotating shaft 2 via a bearing unit 3, a plurality of (for example, three) wind turbine blades 10 (hereinafter referred to as blades 10) which are connected to the rotating shaft 2 and rotate around the vertical axis Z, and support legs 5 which support the wind turbine 1.

[0031] The wing 10 is fixed to the rotating shaft 2 via a first bracket 21 constituting a wing mounting member 20 fixed to the rotating shaft 2, and a second bracket 22 fixed to the first bracket 21. In other words, the wing 10 is fixed to the rotating shaft 2 via the wing mounting member 20 consisting of the first bracket 21 and the second bracket 22. The wing 10 has upper diagonal wings 11A and lower diagonal wings 11B that extend obliquely up and down as they move away from the vertical axis Z, a main wing 12 that extends along a direction approximately parallel to the vertical axis Z of the wing 10, and a connecting member 13 that connects the upper diagonal wing 11A and lower diagonal wing 11B to the main wing 12 in a curved shape. Specifically, the wing 10 is formed in a substantially triangular shape that is formed approximately symmetrically with respect to the horizontal axis X in a side view. Note that the substantially triangular shape here means that the overall shape of the wing 10 is close to a triangle, and includes a shape in which any one of the three sides is curved.

[0032] The wing 10 is provided with a fixed arm 14 extending horizontally, one end of which is fixed to the rotating shaft 2 via a first bracket 21 and a second bracket 22, and the other end of which is connected to the main wing 12. As shown in Fig. 5, a pair of vertical arms 17 are suspended from the fixed arm 14 on the side of the main wing 12, and a movable arm 15 is provided at the lower end of each of the vertical arms 17, which is rotatable around a rotating shaft 35 connecting both vertical arms. An aileron 16 is provided at the center of the movable arm 15 as an over-rotation suppression inducer that tilts the movable arm 15 around the rotating shaft 35 due to the action of centrifugal force generated when the wind turbine 1 rotates, and returns the movable arm 15 to its initial state when the wind turbine 1 stops rotating.

[0033] The upper diagonal wing 11A, the lower diagonal wing 11B, the main wing 12, the connecting member 13, the fixed arm 14, the movable arm 15, the vertical arm 17, and the aileron 16 that form the wing 10 are formed of aluminum extruded shapes having hollows 10a to 10d of the same cross-sectional shape, and as shown in FIG. 4, they have a streamlined cross section with a curved leading edge and a sharp trailing edge, and the hollows 10a to 10d are defined by a plurality of ribs 10e. In FIG. 4, the upper and lower sides of the second defined hollow 10b from the leading edge (hereinafter referred to as the second hollow 10b) are flat, and are formed into a rectangular shape by both ribs 10e. The upper and lower sides of this hollow 10b are formed thick. Note that FIG. 4 shows a case in which there are four hollows 10a, 10b, 10c, and 10d defined by three ribs 10e, but the shape and number of the hollows are arbitrary.

[0034] The blade mounting member 20 is partially formed of a plurality (three pieces) of first brackets 21 each having a protruding strip 21a that fits into a recessed strip 2a that is provided along the longitudinal direction at three equally spaced positions on the outer circumferential surface of the rotating shaft 2. The first brackets 21 are connected to each other by bolts and nuts. The first brackets 21 are formed of an aluminum extruded member.

[0035] 3, the second bracket 22 is fixed to the first bracket 21 via bolts and nuts. The second bracket 22 is formed from an aluminum extruded member having a wing mounting piece 22a extending at a predetermined angle in a direction approaching each other from the tips of a pair of standing pieces that stand on both sides in the width direction leaving flanges, and a fixed arm mounting piece 22b that is approximately parallel to the rotation shaft 2 and connects the tips of both the wing mounting pieces 22d.

[0036] The upper diagonal wing 11A, the lower diagonal wing 11B, the connecting member 13 and the fixed arm 14 formed as described above are bolted to the wing bracket 24 and the second bracket 22 which are inserted and fixed in the second hollow portion 10b.

[0037] The wing bracket 24 is formed of an aluminum extrusion. As shown in FIG. 4A, the wing bracket 24 has an upper contact portion 24a and a lower contact portion 24b that contact the flat surfaces of the upper and lower sides of the second hollow portion 10b from the front edge of the wing 10 (including the fixed arm 14) and the upper and lower ends of the ribs 10e on both sides, screw receiving portions 24c that protrude at three locations corresponding to the three mounting holes 10f provided in the second hollow portion 10b of the wing 10 on the upper contact portion 24a and the lower contact portion 24b, and a pair of connecting portions 24d that connect the screw receiving portions 24c on both the left and right sides. In this case, the screw receiving portion 24c has a tip formed in an arc shape, and a through hole 24e with a circular cross section is provided along the longitudinal direction of the wing bracket 24. Also, the screw receiving portion 24c has a screw hole 24f provided from the upper and lower parts toward the through hole 24e. Further, the screw receiving portion 24c at one end in the longitudinal direction of the wing bracket 24 is provided with a fastening screw hole 24g into which a wing connecting bolt (not shown) is screwed.

[0038] 2, the bearing unit 3 includes a bearing 3c formed of a tapered roller bearing that rotatably supports the rotating shaft 2, and a cylindrical housing 3d that holds the bearing 3c at the upper and lower parts in the longitudinal direction. The power generating unit 6 connected to the rotating shaft 2 via the bearing unit 3 includes a speed increaser 6a and a generator 6b.

[0039] A housing support member 25 divided into three parts along the longitudinal direction of the rotating shaft 2 is fixed to the outer peripheral surface of the housing 3d of the bearing unit 3 configured as described above so as to surround the housing 3d. In addition, a support leg support member 26 is fixed to the outer peripheral surface of the housing support member 25 by fixing bolts and nuts along the circumferential direction of the rotating shaft 2, and the end faces of the support legs 5 are fixed in contact with the support leg support member 26.

[0040] In the wind turbine 1 constructed as described above, one end of the fixed arm 14 is fixed to the rotating shaft 2 by the blade bracket 24 and the second bracket 22 being bolted together as described above. The other end of the fixed arm 14 is fixed to the blade bracket 24 inserted and fixed in the second hollow portion 10b of the fixed arm 14 and to the blade bracket 24 inserted and fixed in the second hollow portion 10b of the main wing 12 by a bolt 27 penetrating the main wing 12 (see Figures 5 and 9).

[0041] The main wing 12 is divided into two parts, an upper wing 12a and a lower wing 12b, and the wing brackets 24 inserted into the second hollow portions 10b of the upper wing 12a and the lower wing 12b are fixed by bolts 27 and nuts 27a to be connected. The bolts 27 are covered from the outside by a spacer ring 28, which is a cylindrical spacer, between the fixed arm 14 and the main wing 12. An aluminum washer 29, whose contact surface with the main wing 12 is formed into a concave curved surface, is interposed at the contact portion between the bolts 27 and the spacer ring 28 and the main wing 12. The washer 29 is made of an aluminum member because if the bolts 27 and the spacer ring 28 are made of different metals, the main wing 12 may corrode due to the potential difference between the different metals.

[0042] A pair of vertical arms 17 are vertically attached to the fixed arm 14 on the side of the main wing 12. As shown in Fig. 6 and Figs. 7 to 10, the fixed arm 14 and the vertical arm 17 are connected by a bracket 30A inserted and fixed in the second hollow portion 10b of the fixed arm 14 by a bolt 31 and a nut 32, and a vertical bracket 30B inserted and fixed in the second hollow portion 10b of the vertical arm 17 by a bolt 31 and a nut 32, and a connecting bolt 33, which is a fixing member passing through the fixed arm 14 and the bracket 30A, being screwed into the vertical bracket 30B. In this case, the bracket 30A and the vertical bracket 30B are formed of an aluminum extrusion material having the same shape, i.e., the same cross-sectional shape, as the wing bracket 24. The vertical bracket 30B is inserted and fixed in the second hollow portion 10b of the vertical arm 17 through its length. Aluminum washers 29, whose contact surfaces with the fixed arm 14 and the vertical arm 17 are formed into concave curved surfaces, are interposed between the bolt 31 and the nut 32, and the connecting bolt 33 and the fixed arm 14 and the vertical arm 17. By interposing the aluminum washers 29 in this manner, it is possible to prevent the fixed arm 14 and the vertical arm 17 from corroding due to the potential difference between the dissimilar metals.

[0043] The movable arm 15 is attached to the lower end of each of the vertical arms 17 suspended from the fixed arm 14 as described above via a rotating shaft 35 so as to be rotatable around the axis of the rotating shaft 35. The rotating shaft 35 is integrated with either one of the vertical arm 17 or the movable arm 15, for example the movable arm 15, and is formed so as to be rotatable relative to the other member of the vertical arm 17 and the movable arm 15, and is provided with a damper mechanism 40 which generates a reaction torque against the moment which rotates the rotating shaft 35 relative to the other member.

[0044] The rotating shaft 35 has small diameter shaft portions 35b, 35c having threaded portions extending from both axial ends of a large diameter shaft portion 35a, and a square shaft portion 35d extending from the axial end of the small diameter shaft portion 35c arranged on the movable arm 15 side, to which an oil damper 41 described later is attached.

[0045] The rotating shaft 35 thus formed is connected to a rotating bearing 36 inserted and fixed in the third hollow portion 10c of the movable arm 15 and the fourth hollow portion 10d adjacent to the third hollow portion 10c. As shown in FIG. 6B, the rotating bearing 36 is formed to have a substantially trapezoidal cross section, and is inserted and fixed in the third hollow portion 10c of the movable arm 15 and the fourth hollow portion 10d communicating with the third hollow portion 10c via the notched rib 10e. A stepped through hole 36a into which the rotating shaft 35 is inserted is formed in the rotating bearing 36, and the rotating shaft 35 inserted into the through hole 36a is rotatably supported by a tapered roller bearing 36c supported by an oil seal 36b arranged in the through hole 36a. A stopper 37 capable of coming into contact with a stopper 52 of a stopper member 50 described later is protrudingly provided at the front of the rotating bearing 36 facing the vertical arm 17 at the front edge side position of the movable arm 15.

[0046] The damper mechanism 40 generates a damper torque (reaction torque) against the torque that rotates the movable arm 15, and in the example shown here, an oil damper 41 is used. That is, the oil damper 41 is composed of a housing 41a for storing oil having a predetermined viscosity, and a rotor 41b that is accommodated in the housing 41a and is provided so as to be rotatable relative to the housing 41a, and is configured to generate a damper torque against the torque that rotates the rotor 41b by the flow resistance of the oil caused by the rotation of the rotor 41b. Therefore, the rotor 41b in the oil damper 41 is connected to the rotating shaft 35 so as to be rotatable together with the rotating shaft 35, and the housing 41a is connected to a rotary bearing 36 that is inserted and fixed in the second hollow portion 10b of the movable arm 15 and the third hollow portion 10c adjacent to the second hollow portion 10b.

[0047] Specifically, the housing 41a is formed by an annular bottom and a bottomed cylindrical cover part with a through hole formed in the center, and two mounting parts protruding to the outer periphery are integrated with the bottom. Through holes are formed in the mounting parts, and the mounting parts are fixed to the rotary bearing 36 by bolts 42. The rotor 41b is formed of, for example, an oval or elliptical plate member with a cylindrical part integrated in the center. That is, by assembling the rotor 41b to the housing 41a, the oil in the housing 41a is sealed in a liquid-tight manner by the bottom, the cover part, and the cylindrical part formed on the rotor 41b. The cylindrical parts and the rotary shaft 35 are integrated.

[0048] The oil damper 41 generates a damper torque according to the viscosity of the oil, the amount of oil, the angular velocity of the rotor 41b, and the like, so the magnitude of the generated damper torque depends on the specifications of the oil damper 41, such as the size and shape. Therefore, the magnitude of the damper torque required for the rotor shaft 35 is obtained by experiments, simulations, and the like, and the number of oil dampers 41 that can generate the damper torque is provided. In the example shown in Figures 6, 7, 9, and 10, four oil dampers 41 are provided in line in the axial direction of the rotor shaft 35. In order to arrange the oil dampers 41 in line in this way, annular spacers 41c according to the height of the housing 41a are arranged between the oil dampers 41, more specifically, between the bottoms.

[0049] The rotary bearing 36 is formed with a communication hole 36d (see FIG. 6B) extending from the rear edge side of the movable arm 15 toward the through hole 36a, and a grease nipple 43 is attached to the opening of the communication hole 36d. This is for supplying lubricating oil to the tapered roller bearing 36c. The rear surface of the rotary bearing 36 is formed with a screw hole 36e into which a fixing bolt 42 of the oil damper 41 is screwed.

[0050] The rotating shaft 35, the damper mechanism 40, and each tapered roller bearing 36c configured as described above are attached to the movable arm 15 together with the rotating bearing 36 by nuts 39 screwed to the threaded portions of the small diameter portions 35b, 35c via bearing holders 38 on both sides of the large diameter portion 35a. After that, the rotating shaft 35 is passed through a through hole 50a provided in a stopper member 50, which is fixed to the vertical arm 17 via a stopper mounting member 55 (described later), and the nuts 39 are screwed to the threaded portions on both sides of the stopper member 50 to fix it. In this way, the vertical arm 17 and the movable arm 15 are connected. As shown in FIG. 8, the movable arm 15 is disposed so as to protrude in the rotation direction of the wind turbine 1 from the vertical arm 17. That is, the movable arm 15 is disposed so as to protrude in the rotation direction of the wind turbine 1 from the fixed arm 14 and the main wing 12, which are disposed in the same row as the vertical arm 17.

[0051] The stopper member 50 is made of an aluminum member, and as shown in Fig. 6A, a through hole 50a through which the small diameter portion 35b of the rotating shaft 35 is inserted is provided at the center of a disk 51, and six bolt insertion holes 53 are provided at equal intervals at positions on a concentric circle on the outer periphery side of the disk 51. An arc-shaped stopper 52 protrudes from one surface of the disk 51. The stopper 52 is formed by cutting out a cylindrical portion formed integrally with the disk 51, and the angle formed by both end surfaces 52a, 52b in the circumferential direction is formed to be about 95°. That is, one end surface 52a is formed vertically when viewed from the front, and the other end surface 52b is formed inclined by 5° from the horizontal plane. The reason for setting the angle of attack at 5° in this manner is that, as shown in Fig. 6C, contact between stopper 37 protruding from rotary bearing 36 and end face 52b of stopper 52 allows movable arm 15 to be supported in an upward position with the leading edge side in the rotation direction of wind turbine 1 facing upward in the initial state, preventing movable arm 15 from tilting forward (lowering) in the initial state, and optimizing the initial position of movable arm 15. Note that, although the angle of attack is set to 5° here, the angle of attack may be set in the range of 4° to 8° within the range in which tilting of movable arm 15 occurs reliably.

[0052] The stopper member 50 formed as described above is fixed to a stopper mounting member 55, which is fixed to the vertical arm 17 by a bolt 56 and a nut 57, by a bolt 58 passing through the bolt insertion hole 53 and a nut 59 screwed onto the bolt 58. The surface of the stopper mounting member 55 that comes into contact with the vertical arm 17 is formed into a concave curved surface similar in shape to the outer shape of the vertical arm 17, and the opposite surface is formed flat.

[0053] The vertical arm 17 and the stopper mounting member 55 are attached by screwing nuts 57 onto bolts 56 which pass through the vertical bracket 30B, which is inserted and fixed in the second hollow portion 10b of the vertical arm 17, and the core 30C, which is inserted and fixed in the third hollow portion 10c of the vertical arm 17. An aluminum washer 29 is interposed between the bolt 56 and the vertical arm 17 to prevent corrosion of the vertical arm 17 due to the potential difference between the dissimilar metals.

[0054] The aileron 16 is vertically attached to the center side of the movable arm 15. As shown in Figs. 13 to 15, the movable arm 15 and the aileron 16 are connected to each other by an upper reinforcing bracket 30D, which is inserted and fixed by a bolt 31 and a nut 32 into the second hollow portion 10b of the movable arm 15, and a first lower reinforcing bracket 30E, which is inserted and fixed by a bolt 31 and a nut 32 into the second hollow portion 10b at the top of the aileron 16, being connected by a connecting bolt 33, which is a fixing member that penetrates the movable arm 15 and the upper reinforcing bracket 30D, being screwed into the first lower reinforcing bracket 30E. At this time, the connecting bolt 33 that penetrates the upper reinforcing bracket 30D is inserted into a spacer ring 28, which is a cylindrical spacer interposed between the movable arm 15 and the aileron 16. In this way, by inserting the connecting bolt 33 into the spacer ring 28 interposed between the movable arm 15 and the aileron 16, the connecting bolt 33 that connects the movable arm 15 and the aileron 16 can be prevented from being exposed to the outside.

[0055] The upper reinforcing bracket 30D and the first lower reinforcing bracket 30E are formed of aluminum extrusions having the same shape, i.e., the same cross-sectional shape, as the wing bracket 24. The second lower reinforcing bracket 30F is inserted into the third hollow portion 10c of the aileron 16 and fixed by a bolt 31 and a nut 32 that penetrate the aileron 16 and the second lower reinforcing bracket 30F. An aluminum washer 29, whose contact surface with the fixed arm 14 and the vertical arm 17 is formed into a concave curved surface, is interposed between the bolt 31 and the nut 32, the connecting bolt 33, and the movable arm 15 and between the aileron 16 and the aileron 16. By interposing the aluminum washer 29 in this way, it is possible to prevent the fixed arm 14 and the vertical arm 17 from corroding due to the potential difference between the different metals.

[0056] Next, the operation of the wind turbine 1 having the over-rotation suppression mechanism configured as above will be described with reference to Figs. When the wind speed increases and the wind turbine 1 rotates at a high speed, the rotational direction component F1 of the centrifugal force Fc acting on the aileron 16 increases. At this time, a net moment acts on the movable arm 15 in a downward direction (a direction in which the leading edge moves downward) due to the sum ((1)+(2)+(3)+(4)) of (1) the moment due to the aerodynamic force acting on the movable arm 15 around the rotation axis of the movable arm 15 (moment around the mounting position due to drag and lift FL), (2) the moment due to gravity FG1 of the movable arm 15, (3) the moment due to the aerodynamic force acting on the aileron 16 and the aileron 16 (drag Fr), and (4) the moment due to gravity FG2 of the aileron 16 and the aileron 16. If the head-up moment due to the rotational direction component F1 of the centrifugal force Fc acting on the aileron 16 increases compared to this net moment, the inclination angle α increases. In addition, in the aileron 16, depending on the rotation azimuth angle (azimuth angle) of the wind turbine blade 10, a rotation direction component F1 due to an aerodynamic force Fa (lift force directed in the horizontal direction) is generated, which becomes the propulsive force of the wind turbine 1. Therefore, in a low rotation speed state, this contributes to improving the performance of the wind turbine 1.

[0057] As a result, as shown in Figures 16(b) and 18, the inclination angle α becomes very large, the projected area of ​​the movable arm 15 seen from the direction of rotation of the wind turbine becomes large, and a large braking force F2 due to aerodynamic forces acts on the movable arm 15, suppressing over-rotation of the wind turbine 1. However, in strong wind conditions, even at low rotation speeds, the moment of aerodynamic forces acting on the movable arm 15 (1) becomes large in the lifting direction (the direction in which the leading edge moves upward), and becomes dominant compared to the rotation moment in the lifting direction due to the centrifugal force Fc acting on the aileron 16 (5), generating a large braking force F2. As a result, in strong wind conditions, the wind turbine 1 is suppressed to a low rotation speed.

[0058] According to the vertical axis wind turbine of the embodiment configured as described above, the ailerons 16 can be attached to the movable arm 15 which is rotatable around the axis of the rotation shaft 35 connecting the pair of vertical arms 17 suspended from the fixed arm 14. This makes it possible to provide high strength corresponding to the increase in size of the wind turbine itself, and to facilitate attachment and detachment of the movable arm 15, thereby facilitating maintenance and inspection.

[0059] Furthermore, the wind turbine blade 10, the fixed arm 14, the vertical arm 17, the movable arm 15, and the aileron 16 are formed of an aluminum extrusion material with an airfoil-shaped cross section having a hollow portion of the same shape as the wind turbine blade 10, so that a rotational component due to aerodynamic force, i.e., lift force directed in the horizontal direction, is generated, and the propulsive force of the wind turbine 1 can be increased. Furthermore, the fixed arm 14, the vertical arm 17, the movable arm 15, and the aileron 16 can be fixed firmly while maintaining a light weight. Furthermore, the fixed arm 14, the vertical arm 17, the movable arm 15, and the aileron 16 can be fixed using the bracket 30A, the vertical bracket 30B, the upper reinforcing bracket 30D, and the first lower reinforcing bracket 30E formed of an aluminum extrusion material with the same cross section, which are inserted and fixed in the second hollow portion 10b of the same shape. Therefore, the number of components can be reduced, and the efficiency of the installation work can be improved.

[0060] Moreover, the brackets 30A, 30B, 30D, and 30E are fixed by bolts 31 and nuts 32 via aluminum washers 29, while the fixed arm 14 and the vertical arm 17 and the movable arm 15 and the aileron 16 are fixed by connecting bolts 33 via aluminum washers 29. Therefore, it is possible to prevent corrosion due to the potential difference between dissimilar metals in the components of the wind turbine 1, and to increase the lifespan of the wind turbine 1.

[0061] Furthermore, since the fluctuation range of the rotation amount of the movable arm 15 can be prevented from becoming excessive, there is no need to provide multiple stoppers to limit the rotation amount of the movable arm 15, and the generation of abnormal noise and vibration due to contact between such stoppers and the movable arm 15 can be suppressed.

[0062] In the above embodiment, a butterfly-type wind turbine has been described in which the shape of the wind turbine blade 10 is formed into a substantially triangular shape having upper diagonal wing 11A and lower diagonal wing 11B extending from the rotating part 2, a main wing 12 extending in a direction substantially parallel to the vertical axis Z of the wind turbine blade 10, and a connecting member 13 that connects the upper diagonal wing 11A, lower diagonal wing 11B and the main wing 12 in a curved shape. The wind turbine 1 according to the present invention is not limited to this, and can also be applied to an H-type Darrieus wind turbine in which a vertical main wing 12 is attached to the tip of a fixed arm 14. [Explanation of symbols]

[0063] 1 windmill 2 Rotation Axis 10 Wings (windmill wings) 10b 2nd hollow part 11A Upper diagonal wing 11B Lower diagonal wing 12 Wing 13 Connecting members 14 Fixed Arm 15 Movable Arm 16 Aileron (overspeed suppression derivative) 17 Vertical Arm 24 Wing bracket 28 Spacer ring (cylindrical spacer) 29 Aluminum washer 30A Bracket 30B Vertical bracket 30D Upper Reinforcement Bracket 30E 1st lower reinforcement bracket 33 Connecting bolt (fixing member) 35 Rotational Axis 36 Rotary bearing 37 Stopper 40 Damper mechanism 41 Oil damper 50 Stopper member 52 Stopper α Inclination Fa Air Force F1 Rotational component F2 braking force C Rotation center X horizontal axis Z vertical axis

Claims

1. A vertical axis wind turbine comprising: a base having a power generating unit; a rotating unit that rotates about a vertical axis relative to the base; and a plurality of wind turbine blades that are connected to the rotating unit via fixed arms and rotate about the vertical axis, A pair of vertical arms suspended from the fixed arm; a movable arm for suppressing excessive rotation that is rotatable around a rotation axis connecting both of the vertical arms; and an over-rotation suppression inductor provided on the movable arm, which inclines the movable arm around the axis of the rotation shaft by the action of centrifugal force generated when the wind turbine rotates, and returns the movable arm to its initial state when the wind turbine stops rotating. A vertical axis wind turbine.

2. 2. The vertical axis wind turbine according to claim 1, The over-rotation suppression inductor is provided at a position offset toward a leading edge side or a trailing edge side in a rotation direction with respect to the rotation shaft at a lower part of the movable arm. A vertical axis wind turbine.

3. 2. The vertical axis wind turbine according to claim 1, The wind turbine blade, the fixed arm, the vertical arm, the movable arm, and the over-rotation suppression guide are formed in an airfoil cross-sectional shape having a hollow portion of the same shape. A vertical axis wind turbine.

4. 4. The vertical axis wind turbine according to claim 3, The vertical arm has a vertical bracket that is inserted and fixed longitudinally into the hollow portion, The vertical bracket is connected by a fixing member that passes through the bracket and is inserted and fixed in the hollow portion of the fixed arm. A vertical axis wind turbine.

5. 5. The vertical axis wind turbine according to claim 4, the vertical bracket and the bracket inserted and fixed in the hollow portion of the fixed arm are formed in the same cross-sectional shape and inserted and fixed in a partitioned hollow portion constituting a part of the hollow portion; A vertical axis wind turbine.

6. 4. The vertical axis wind turbine according to claim 3, The over-rotation suppression guide has a lower reinforcing bracket that is inserted and fixed into the hollow portion at the top of the over-rotation suppression guide, The lower reinforcing bracket is connected to an upper reinforcing bracket by a fixing member that penetrates the upper reinforcing bracket, the upper reinforcing bracket being inserted and fixed in the hollow portion of the movable arm. A vertical axis wind turbine.

7. 7. The vertical axis wind turbine according to claim 6, The lower reinforcing bracket and the upper reinforcing bracket are formed to have the same cross-sectional shape and are inserted and fixed into a partitioned hollow portion that constitutes a part of the hollow portion. A vertical axis wind turbine.

8. 7. The vertical axis wind turbine according to claim 6, The fixing member penetrating the upper reinforcing bracket is inserted into a cylindrical spacer interposed between the movable arm and the over-rotation suppression guide. A vertical axis wind turbine.

9. 2. The vertical axis wind turbine according to claim 1, the rotation shaft is integrated with either the vertical arm or the movable arm, and is formed to be relatively rotatable with the other of the vertical arm and the movable arm; The rotary shaft and the other member may be rotated relative to each other by a damper mechanism that generates a reaction torque against the moment. A vertical axis wind turbine.

10. 10. The vertical axis wind turbine according to claim 9, the damper mechanism includes an oil damper in which the reaction torque increases according to a relative speed at which the rotating shaft and the other member rotate relative to each other, A vertical axis wind turbine.

11. 2. The vertical axis wind turbine according to claim 1, A stopper is provided at each of the opposing portions of the vertical arm and the movable arm, When the two stoppers come into contact with each other, the front edge side of the movable arm in the rotation direction of the wind turbine is supported in an upward or downward position in the initial state. A vertical axis wind turbine.

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