JP2009299518A - Wind mill - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize reduction of the entire weight and to reduce the manufacturing cost by automatically controlling a pitch angle of a blade 15 via a simple and inexpensive mechanism and reducing bending load applied to the blade 15. <P>SOLUTION: A base end of the blade 15 is separated from an outer peripheral face of a rotary shaft part 14, and the base end and the rotary shaft part 14 are connected by an elastic support member 17 that supports the base end and the rotary shaft part 14 in a twisted state. When centrifugal force is applied to the blade 15, twisting of the elastic support member 17 acts to increase the pitch angle of the blade 15 by rotating the blade 15 with the twisting center as an axis of the pitch angle upon the twisting of the elastic support member 17 being released so that the elastic support member 17 is elastically deformed to allow outward displacement of the blade 15. Further, a support shaft 19 projected forward to extend from the rotary shaft part 14 is provided, and the support shaft 19 and the blade 15 are connected by a wire 20. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a windmill used for power generation.

  A windmill having blades whose pitch angle can be changed is known, for example, in Patent Documents 1 to 4.

  In the conventional windmill, in order to change the pitch angle of the blades, a control mechanism such as electricity or hydraulic pressure is built in the rotating shaft of the windmill to rotate the angle of the blade surface with respect to the wind direction. Since the number of parts in the rotating shaft increases, dust or the like carried by the wind may enter the rotating shaft and deteriorate its function. In order to prevent such dust from entering, the structure is further complicated by having a seal structure.

Japanese Patent Publication No. 63-37000 JP 2003-65205 A JP 2003-254221 A Japanese Patent Laid-Open No. 2007-9898

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a wind turbine that can automatically control the blade pitch through a simple and inexpensive mechanism.

  In order to achieve the above object, the present invention provides a wind turbine having a rotating shaft portion and a blade capable of changing a pitch angle projecting outward from the rotating shaft portion in the radial direction of rotation, and the base end portion of the blade is the rotating shaft portion. In contrast, an elastic support member is provided which is supported in a state of being twisted around the center of the pitch angle and resists by an elastic force in a direction in which the twist is unwound.

  According to the present invention, the elastic support member in a twisted state is placed outside the rotating shaft, and the pitch angle of the wings can be changed by unwinding the torsion, so the dust enters the rotating shaft, There is no need to install a mechanism that hinders the change of the pitch angle, and a reduction in weight and a reduction in manufacturing cost can be realized.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a perspective view showing a horizontal axis wind turbine for power generation provided with blades according to the present embodiment. Reference numeral 1 denotes an upright support shaft that extends upward from a foundation structure formed on the ground. Reference numeral 2 denotes an upright support shaft 1 around a cylindrical member 3 that is externally fitted to the upper end of the upright support shaft 1. This is a main body base that is rotatably mounted. The main body base 2 includes a front substrate portion 2a and a tail portion 2b extending rearward therefrom. A pair of front and rear bearings 4a and 4b and a pair of left and right generators 5a and 5b are fixed on the upper surface of the housing base 2a, and a flat wind direction plate 6 is provided along the front-rear direction f1 at the rear of the tail 2b. Are fixed upright.

  Reference numeral 7 denotes a rotary shaft that is rotatably supported through a pair of front and rear bearings 4a and 4b. A drive pulley 8 is provided at a central position between the pair of front and rear bearings 4a and 4b in the longitudinal direction of the rotary shaft 7. A transmission belt 10a is wound between the driving pulley 8 and a driven pulley 9a fixed to the input shaft of the generator 5a located on one side of the driving pulley 8. The transmission belt 10b is also wound around the driven pulley 9b fixed to the input shaft of the generator 5b located on the other side. The generators 5a and 5b, the driven pulleys 9a and 9b, and the transmission belts 10a and 10b are arranged symmetrically with respect to the drive pulley 8 when viewed from the front, and the respective rotation centers of the driven pulleys 9a and 9b and the drive pulley 8 are arranged. Are arranged in a straight line when viewed from the front. 12 is a nacelle for covering each part 4a, 4b, 5a, 5b, 7, 8, 9a, 9b, 10a, 10b on the board | substrate part 2a, and is fixed on the board | substrate part 2a as shown by the virtual line a0.

  Reference numeral 13 denotes a windmill disposed in front of the main body 2. As shown in FIG. 2, the windmill is smaller than the blade 15 in addition to the rotating shaft portion 14 and a plurality of (three in the illustrated example) large blades 15. A plurality (three in the illustrated example) of small blades 16 are provided. The rotating shaft portion 14 has a larger diameter than the rotating shaft 7 and a central portion 14a having a right cylindrical outer peripheral surface, a front portion 14b tapered forward from the front end surface of the central portion 14a, and a rear portion of the central portion 14a. The rear portion 14c is tapered from the end face toward the rear, and is fixed concentrically with the rotary shaft 7.

  The three blades 15 are radially positioned on the outer peripheral surface of the rotary shaft portion 14 in an equiangular arrangement around the rotation center a1. Each blade 15 is straight in the radial direction of the rotating shaft 7, and the blade width is gradually reduced as it moves away from the rotating shaft 7. The blade 15 can change the pitch angle. If the rotation center axis of the pitch angle is “pitch angle center a2”, the width center a2 of the blade 15 coincides with the position of the pitch angle center a2. The blade 15 is manufactured by cutting a uniform thickness metal plate or synthetic resin plate into a blade-deployed shape and then bending it in the blade width direction as necessary. Alternatively, FRP (fiber reinforced plastic) can be used. Alternatively, a small blade having a wing length of approximately 2 m to 2.5 m may be manufactured using a flooring plywood or the like. By using a plate with a uniform thickness, it can be manufactured at a lower price than that with a blade thickness adjusted.

  Each blade 15 and the rotary shaft portion 14 are separated from each other, and both of them are separated in the rotational radius direction of the rotary shaft portion 14. The base end portion of each blade 15 and the 14 rotating shaft portions opposed thereto are coupled via an elastic support member 17. The elastic support member 17 supports the corresponding wing 15 in a state where the elastic rod members 17a and 17b are twisted as an initial state around the plane including the pitch angle center a2 of the wing 15, and the wing 15 has an outer side in the direction a2. When the centrifugal force is applied, the elastic support member 17 is untwisted by the centrifugal force, and the blade 15 is displaced outward in the axial direction of the pitch angle center a2, so that the blade 15 is untwisted. It functions to increase the pitch angle (θ in FIG. 7). Here, the pitch angle θ is an inclination angle in the rotation direction of the blade 15 with respect to the rotation radius surface of the rotation shaft portion 12.

  The structure of the torsional coupling between the base end portion of each blade 15 and the 14 rotating shaft portions opposed thereto by the elastic support member 17 will be described with reference to FIG. In FIG. 3, 18a is a virtual circle hypothesized at the front part of the central part 14a of the rotating shaft part 14 and forms a part of the rotating shaft part 14 and uses the rotation center of the rotating shaft 7 as the rotation center. In addition, 18b is an imaginary circle imaginary at the rear of the central portion 14a of the rotating shaft portion 14 and forms a part of the rotating shaft portion 14 and has the rotation center of the rotating shaft 7 as its rotation center. In FIG. 3, d <b> 1 indicates a rotation locus circle at the radially outermost portion of the blade 15, and d <b> 2 indicates a rotation locus circle at the base end of the blade 15.

FIG. 4 shows a positional relationship in which one blade 15 is attached. In the figure, a plane C including a rotation center a1 and a pitch angle center a2 is virtually defined, and the left side of the plane C is referred to as “front” and the right side is referred to as “rear”. The elastic support member 17 has elastic rod members 17a and 17b. The elastic rod member 17 a has one end 17 a-1 connected to the front edge portion 15 a of the base end portion of the blade 15, and the other end 17 a-2 of the front virtual circle 18 a forming the peripheral wall of the rotating shaft portion 14. It is couple | bonded with the back side part 15c. The elastic rod member 17 b has one end 17 b-1 connected to a rear edge portion 15 d of the base end of the wing 15, and the other end 17 b-2 is a rear side forming the peripheral wall of the rotating shaft 14. It is coupled to the front portion 15f of the virtual circle 18b. As a result, the elastic rod members 17a and 17b are coupled to the surface C so as to cross one end and the other end in the front-rear direction (front and back).

  In the figure, the positions where the extension lines of the leading edge or the trailing edge of the blade 15 abut against the cylindrical surface including the virtual circles 18a and 18b are indicated by 15b and 15e, respectively. The portion 15a near the front edge of the blade 15 is not connected to the rotary shaft portion 14 by extending to 15b, but is twisted to the position 15c as indicated by the arrow indicated by "I". A portion 15d near the rear edge of the base end is also connected to 15f in a twisted connection state. The rotation center of both torsion is the pitch angle center a2. This “twisted state” means that the combined shape of the elastic rod members 17a and 17b can be observed as a “looks twisted” as a result. It is not intended that the elastic rod members 17a and 17b must be attached to the peripheral walls of the blade 15 and the rotary shaft portion 14 after being twisted with internal stress.

  Each elastic rod member 17a, 17b is formed of a cross-sectional circle such as a piano wire, a hard steel wire, or a phosphor bronze wire, or a pipe-like linear material for a spring or a similar material. The end portions of the elastic rod members 17 a and 17 b are fixed to the base end portion of the blade 15 and the rotary shaft portion 14. The angle φ (FIG. 6) at which each elastic rod member 17 a, 17 b in the stationary state of the rotating shaft portion 14 faces the blade 15 from the virtual circles 18 a, 18 b is rotated and the centrifugal force g 1 is applied to the blade 15. Even at this time, there is no change in the roots of the virtual circles 18a and 18b. Since deformation of the elastic rod members 17a and 17b occurs in the length range of the elastic rod members 17a and 17b, it is necessary to prevent the formation of elastic discontinuities on the line of the elastic rod members 17a and 17b. Good. The elastic rod members 17a and 17b support the proximal end of the blade 15 with the surface C interposed therebetween, and this state is an initial state where the blade is twisted. The torsion center by the elastic rod members 17a and 17b is set at the position of the pitch angle center a2. Further, the elastic bar members 17a and 17b are given elastic force so as to resist the direction of untwisting from the initial state.

  As shown in FIG. 5, the three small blades 16 are fixed to the outer peripheral surface of the rotating shaft portion 14 in an equiangular arrangement around the rotation center a <b> 1. The total length of each small blade 16 is equal to or slightly longer than the distance between the rotary shaft portion 14 and the blade 15. The wingspan is gradually reduced as it goes to the outside of the turning radius. In the illustrated example, each small blade 16 is positioned between two adjacent blades 15 in the rotation direction of the rotary shaft portion 14 and coincides with the rotation center point c1 of the blade 15 on the rotation center a1 direction of the rotary shaft portion 14. Is positioned to be. Note that the position of the small blade 16 on the rotation center a1 may be arbitrarily changed. For example, each small blade 16 may be positioned immediately behind each blade 15. In FIG. 5, d <b> 3 indicates a rotation locus circle at the radially outermost portion of the small wing 16, and d <b> 4 is a rotation locus circle at the base end of the small wing 16 and matches the outer peripheral surface of the rotating shaft portion 14. is there. The small wing 16 uses the wind passing through the range in which the elastic support member 17 is present as rotational power.

  In FIG. 2, the support shaft 19 is an upwind portion provided so as to extend the rotating shaft 7, and is fixed in the same shape as the rotating shaft portion 14. A portion in the vicinity of the tip of the support shaft 19 and each blade 15 are connected by a wire 20 such as a nylon string or a wire. The tension direction of these wires 20 is set so that the tension generated in each of the wires 20 when the blade 15 receives wind from the front crosses in the vicinity of one point p1 on the center line of the support shaft 14. .

  As shown in FIGS. 1 and 2, one end of each wire 20 on the blade 15 side is a front surface of the blade at two different positions p01 and p02 in the range from the position near the proximal end of the corresponding blade 15 to the outermost position. It is fastened to the front edge part. The connection position of the wire on the blade 15 side is on the leading edge side (or on the leading edge) rather than on the central axis of the pitch angle. And it is good for the included angle (theta) of each wire 20 and the support shaft 19 to be in the range up to 60 degree | times. The reason why the upper limit of the included angle θ1 is set to 60 degrees is that if the angle is larger than this, the blade 15 cannot be effectively pulled forward even though the tension of the wire 20 is increased.

  Next, the operation of the horizontal axis wind turbine described above will be described with reference to FIGS.

  FIG. 6 is a front view showing the vicinity of the proximal end of the blade 15, FIG. 7 is a side view showing the vicinity of the proximal end of the blade 15, and FIG. 8 is a plan view showing the vicinity of the proximal end of the blade 15.

  The wind direction plate 6 rotates the main body 2 around the upright support shaft 1 by the energy of the wind, and makes the front surface of the windmill 13 face the windward side. Thereby, the windmill 13 is given a rotational force corresponding to the size of the blades 15 and the small blades 16 and the pitch angle θ by the energy of the wind, and rotates around the rotation center a <b> 1 together with the rotation shaft portion 14. The rotation of the windmill 13 is transmitted to the input shafts of the generators 5a and 5b via the rotating shaft 7, and the generators 5a and 5b generate electric power.

In FIG. 6, when the wind speed toward the windmill 13 changes to large or small, and the amount of power generated by the generators 5 a and 5 b changes to large or small, the rotational speed of the windmill 13 also changes depending on those changes. Now, assuming that the rotational speed of the windmill 13 increases, the centrifugal force g1 applied to the blade 15 increases. The wing 15 is pulled outward by the centrifugal force g1. The elastic rod members 17a and 17b are arranged such that the ends 17a-1 and 17b-1 on the blade 15 side approach a plane C including the rotation center a1 and the pitch angle center a2 of the blade 15 to thereby twist the elastic rod members 17a and 17b. (In this embodiment, the torsion center is set at the position of the pitch angle center a2.) The blade 15 is rotated in a direction in which the twisted state is unwound. As the ends 17a-1 and 17b-1 of the elastic rod members 17a and 17b approach the surface C, the pitch angle θ increases. When the pitch angle θ increases, the blade 15 is displaced so as to approach the position indicated by the imaginary line e1. That is, the twist is unwound by the centrifugal force g1, the elastic indicating member 17 is extended, and the wing 15 is moved outward. On the other hand, since the elastic rod members 17a and 17b develop a spring force in an attempt to maintain a twisted state, the pitch angle is determined at a position where the centrifugal force g1 and the spring force are balanced. As a result of adjusting the pitch angle θ, an increase in rotation is suppressed. Further, although the wire 20 pulls the vicinity of the front edge of the blade 15 forward and holds the position of the front edge, even if the pitch angle θ increases and the front edge of the blade 15 moves to the windward side, the blade 15 Is stretched to the outside of the turning radius, and the coupling position with the blade 15 is also moved to the outside of the turning radius, so that the blade 15 is hardly distorted.
When the wing 15 is twisted, the ends 17a-1 and 17b-1 of the elastic rod members 17a and 17b may pass through the surface C.

  On the other hand, when the rotational speed of the windmill 13 decreases, the centrifugal force g1 applied to the blade 15 decreases. The force pulling the wing 15 outwardly of the radius of rotation decreases, and the elastic rod members 17a and 17b are restored to the torsional state by the elasticity, and by this restoration, the wing 15 approaches the position indicated by the phantom line e2. Displace. When the twisted state is restored, the pitch angle θ decreases. As a result, the rotation reduction is suppressed.

  In this way, since the change in the rotational speed of the windmill 13 is suppressed despite the change in the wind speed, the rotational speed of the input shafts of the generators 5a and 5b is stabilized, and the generators 5a and 5b generate stable power. It becomes like this.

  Next, the operation of the windmill 13 when the wind speed increases rapidly due to a gust of wind or the like will be described. In this case, the wind pressure applied to each blade 15 increases without increasing the rotational speed of the windmill 13. The wind pressure applies an external force directed backward to the blade 15, and the external force acts intensively near the center of the projected shape when the blade 15 is viewed from the front. On the other hand, the wire 20 pulls the vicinity of the front edge of the blade 15 and holds the position near the front edge. As a result, a large rotational force around the pitch angle center a2 due to the tension of the wire 20 and the external force is generated. The rotational force causes the elastic rod members 17a and 17b to bend and deform against the elastic force so as to reduce the rotational force, and the bending deformation causes the blade 15 to be displaced in the vicinity of the position indicated by the imaginary line e1 and to produce a pitch angle θ. Will be increased. As a result, a large external force applied to the blade 15 due to a gust or the like is instantly reduced, and the blade 15 is prevented from applying an excessive load regardless of the centrifugal force. Further, the pitch angle θ is changed depending on the strength of the wind regardless of the centrifugal force. Therefore, the rotational speed of the windmill 13 is kept constant before the rotational speed of the blades 15 is changed by the change in wind force. The effect is obtained.

  Returning to FIG. 1, the generators 5a and 5b, the driven pulleys 9a and 9b, and the transmission belts 10a and 10b are arranged in a symmetrical manner with respect to the drive pulley 8 as viewed from the front, and the driven pulleys 9a and 9b and the drive pulley. The respective rotation centers 8 are arranged in a line when viewed from the front. When the windmill 13 is driven to rotate, rotation is transmitted from the drive pulley 8 to the generators 5a and 5b. At this time, the transmission belts 10a and 10b are subjected to a tensile force in the left-right direction perpendicular to the rotation shaft 7. Works. The tensile forces applied to the transmission belts 10a and 10b cancel each other because the two driven pulleys 9a and 9b are arranged in a positive symmetry with respect to the drive pulley 8 and are arranged in a straight line when viewed from the front. Thus, the rotating shaft 7 rotates without receiving a lateral load from the transmission belts 10a and 10b.

  Further, when the wind power is small, the rotational speed of the windmill 13 may decrease, and the voltage generated by the generators 5a and 5b may decrease. In such a case, the two generators 5a and 5b are connected in series. By performing the electric circuit control, a necessary voltage can be stably secured.

  Furthermore, the small wings 16 function to supplement the rotational force generated by the wings 15 due to the wind. In particular, in the present invention, since the base end of the blade 15 and the rotary shaft portion 14 are separated from each other, the wind passes through the rotation region of the separated portion without being converted into rotational energy by the blade 15. Thus, the energy of the passing wind is effectively converted into rotational energy. As a result, the energy conversion efficiency of the windmill 13 is increased, and the rotational driving force generated by the windmill 13 is increased.

  In the present embodiment, since the pitch angle can be changed depending on the wind strength in addition to the centrifugal force, for example, when the wind strength is different between the upper portion and the lower portion of the windmill 13, It becomes possible to automatically change the pitch angle between the blades 15 located at the lower part. As a result, the fast rotational force received by the upper wing 15 does not work so that the lower wing 15 cancels out, and the wind can be efficiently converted into electric power.

  Next, a modification of the above embodiment will be described.

  (1) The support shaft 19 and each of the blades 15 are connected by one or more wires 20, and one end of each of the wires 20 on the blade 15 side is fixed to a different location on the pitch angle center a <b> 2 of the blade 15. It may be configured.

  In this modification, one end of the plurality of wires 20 on the support shaft 19 side may be fixed to a plurality of points on the support shaft 19 at two or more points.

  (2) The number of blades 15 and small blades 16 provided on the rotating shaft 14 may be arbitrarily changed.

  (3) One end side (rotating shaft portion 14 side) of the elastic rod members 17a and 17b is provided on virtual circles 18a and 18b provided outside the surface C including the rotation center a1 and the pitch angle center a2. It may be provided on C. The torsional magnitude is the torsional magnitude from the position 15b to the position of the surface C in FIG. In this case, the positions 15a and 15d on the other end side (wing 15 side) of the elastic rod members 17a and 17b are not on the surface C.

  (4) The number of generators is not limited to two, and may be an arbitrary number of one or more.

  (5) In the above-described embodiment, the wing 15 has a uniform thickness using a plate material. However, instead of this, a blade whose thickness is adjusted like a propeller of an airplane may be used.

  (6) In the above embodiment, the windmill 13 is disposed on the windward side and the main body 2 is disposed on the leeward side, but this may be reversed. That is, the main body 2 is arranged on the windward side and the windmill 13 is arranged on the leeward side. In this case, the blade 15 is disposed on the leeward side from the point P1 to which the wire 20 is connected. That is, the rotation shaft 7, the support shaft 19, the rotation shaft portion 14, and the blade 15 are in a positional relationship from the main body 2 toward the leeward side, and the P1 position where the wire 20 is fixed is on the windward side of the blade 15.

  (7) In the above embodiment, since the blade 15 uses a plate material, the pitch angle center and the width center of the blade 15 are set at the same position in order to balance the leading edge side and the trailing edge side. Obviously it is not necessary to match.

Second Embodiment
FIG. 9 is a diagram showing a windmill in the second embodiment.

  In the elastic support member 17 of the previous embodiment, the wing 15 is held in an elastic torsional state by the spring force of the elastic rod members 17a and 17b and in the torsional state. This is realized by separate members.

  In the present embodiment, the elastic support member 17 has support bar members 17c and 17d that are coupled to the front edge and the rear edge of the base end portion of each blade 15. The elastic rod member 17c coupled to the location near the front edge of the base end portion of each blade 15 is fixed to the front virtual circle 18a, and the location near the rear edge of the base end portion of each blade 15 includes the support rod member 17d. Via the rear virtual circle 18b. Refer to FIG. 3 for the positional relationship between the virtual circles 18a and 18b on the rotation center a1. If a plane including the rotation center a1 and the pitch angle center a2 in FIG. 9 is hypothesized, one support rod member 17c is formed into a virtual circle 18a on the front side that forms the rotation shaft portion 14 with one end thereof guided to the rear side of the plane. The other support rod member 17d is coupled to a rear virtual circle 18b that forms the rotary shaft portion 14 while being guided to the front side of the surface. Furthermore, the other end of one elastic rod member 17c is guided to the front side of the surface and coupled to a position near the front edge of the base end portion of the blade 15, and the other end of the other support rod member 17d is directed to the rear side of the surface. It is guided and connected to a portion near the rear edge of the base end portion of the blade 15. Each connection point b is a universal joint.

  A shaft portion 17f extends from the rotary shaft portion 14 in the direction of the pitch angle center a2, and has a flange 17g at the tip thereof. Further, on the blade 15 side, a spring holder 17e extends toward the rotary shaft portion 14, and the spring holder 17e can slide the shaft portion 17f in the direction of the pitch angle center a2. A coil spring 17h made of an elastic body is contained inside the spring holder 17e. The coil spring 17h is in contact with the flange 17g and the bottom of the spring holder 17e, and urges the blade 15 toward the rotating shaft 14 side.

  When the rotation of the blade 15 is accelerated in the horizontal axis wind turbine formed in this way, centrifugal force acts on the blade 15 and the blade 15 moves in a direction away from the rotation center a1. At this time, the blades 15 change the pitch angle around the pitch angle center a2 by the action of the support rod members 17c and 17d and the universal joint b. The pitch angle is determined at a position where the coil spring 17h is balanced with the magnitude of the centrifugal force g1. Thus, in the present embodiment, the elastic force of the elastic support member 17 is realized by the coil spring 17h, and the torsional action is realized by the support rod members 17c and 17d. In the case of the present embodiment, the number of parts is increased as compared with the previous embodiment. On the other hand, since the coupling relationship between the blade 15 and the rotating shaft portion 14 becomes stronger, the wire 20 used in the previous embodiment may be omitted. When the support rod members 17c and 17d are provided with a spring property, they can be directly fixed to the blade 15 or the rotary shaft portion 14 without using the universal joint b. Further, it is not necessary to provide both the support rod members 17c and 17d, and a modification having either one of the support rod members is also possible. In the above embodiment, the coil spring 17h is used as the elastic body, but an elastic body using the compression and extension of rubber may be used.

  In addition, although the wing | blade of each above-mentioned embodiment does not specifically limit the magnitude | size, stable intensity | strength is obtained and it is a factory by implementing on the thing of the diameter of a rotation diameter of about 5m-15m. It is useful when used for generators for home use or residential use.

It is a perspective view which shows the horizontal axis type windmill for electric power generation of 1st Embodiment. It is a perspective view of a windmill. It is a perspective explanatory view showing the attachment structure of a wing typically. It is explanatory drawing which shows the attachment positional relationship about one blade. It is a side view which shows typically the attachment structure of the wing | blade of the said wing | blade and a small wing | blade. It is a front view which shows the base end vicinity of a wing | blade. It is a side view which shows the base end vicinity of a wing | blade. It is a top view which shows the base end vicinity of a wing | blade. It is a perspective view which shows the wing | blade of 2nd Embodiment which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 13 Windmill 14 Rotating shaft part 15 Wings 16 Small wings 17 Elastic support member 17a Elastic bar member 17b Elastic bar member 19 Support shaft 20 Wire a1 Center of rotation a2 Center of pitch angle (width center of blade 15)
θ Pitch angle

Claims (5)

In a windmill having a rotating shaft part and a blade capable of changing the pitch angle projecting outward from the rotating shaft part in the radial direction of rotation,
An elastic support member that supports the base end portion of the blade with respect to the rotating shaft portion in a twisted state around the center of the pitch angle in an initial state and resists the twisting direction with an elastic force; A characteristic windmill.   The wind turbine according to claim 1, wherein the rotating shaft portion has a portion on the windward side from a position where the blade is supported, and the windward portion and the blade are coupled by a wire.   The elastic support member is formed of a plurality of elastic rod members, and one elastic rod member has one end closer to the leading edge of the base end portion of the blade with respect to a plane including the rotation axis and the central axis of the pitch angle. And the other end is coupled to the position of the rotary shaft on the plane or the opposite side, and one end of the other elastic rod member is coupled to a position near the rear edge of the base end of the blade. The wind turbine according to claim 1, wherein the other end is coupled to the plane shaft or the position of the rotating shaft on the opposite side.   The elastic support member includes a plurality of support bar members and an elastic member that urges the blade in the direction of the rotation shaft portion, and one elastic plane with respect to a plane including the rotation shaft and the central axis of the pitch angle. One end of the support rod member is coupled to a position near the front edge of the base end portion of the blade, and the other end is coupled to the position of the rotary shaft on the plane or the opposite side, and the other elastic rod member is The one end is coupled to a position near the rear edge of the base end portion of the blade, and the other end is coupled to the position of the rotary shaft portion on the plane or opposite side thereof. The described windmill. The wind turbine according to claim 2, wherein the connection position of the wire on the blade side is provided closer to the leading edge side of the blade than on the central axis of the pitch angle.