Vertical axis wind turbine

Abstract

To provide a horizontal axis wind turbine capable of generating large drag to rotate blades vigorously when wind hits an opening / closing member.SOLUTION: Since horizontal plates 7 are formed on the upper and lower ends of a blade 5, a space S between an opening / closing member 10 in an open state and an inner surface 5a of the blade 5 is blocked by the horizontal plates 7. Therefore, wind W hitting the opening / closing member 10 is less likely to escape to the outside from both top and bottom of the opening / closing member 10, to increase a pressure (drag) of the wind W hitting the opening / closing member 10 and allow the blade 5 to rotate vigorously. The horizontal plates 7 have an effect of rectifying the wind W passing along the inner surface 5a and an outer surface 5b of the blade 5. Since opening / closing control means 20 is hidden behind a horizontal shaft 4, it does not generate air resistance.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a vertical axis wind turbine. [Background technology]

[0002] One type of wind turbine for wind power generation is the vertical axis wind turbine, which has multiple horizontal shafts extending radially from a vertical axis of rotation, and has lift-type blades attached to the tips of the shafts that rotate in a certain direction.The rotational component of the lift generated by the blades is used as rotational force, and this has the advantage of good energy conversion efficiency.

[0003] In the medium to high wind speed range, when the tip speed ratio between the rotation speed and the wind speed of this type of vertical axis wind turbine is 1 or more, lift is generated on the blades and the turbine continues to rotate. However, if the tip speed ratio is less than 1, no lift is generated to rotate the turbine, and no rotational energy is obtained.

[0004] For this reason, in the past, an opening / closing member was attached to the inner surface of the blade, which opens a certain angle from the front end when the peripheral speed ratio was less than 1. Wind was blown against this opening / closing member to generate resistance on the blade, which then caused the blade to rotate (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2008-202508 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, in such conventional technology, the blades were rotated by blowing wind against a plate-shaped opening / closing member attached to the inner surface of the blade. However, because this structure simply blows wind against a plate-shaped opening / closing member, the wind that hit the opening / closing member immediately escapes to both the top and bottom sides from the top and bottom ends of the opening / closing member, so it was not possible to obtain a large resistance and to rotate the blades with sufficient force.

[0007] The present invention has been made with attention to such conventional techniques, and aims to provide a horizontal axis type wind turbine that can generate a large resistance when the wind hits the opening and closing members, thereby rotating the blades vigorously. [Means for solving the problem]

[0008] According to a first technical aspect of the present invention, a vertical axis type wind turbine has a plurality of horizontal shafts extending radially from a plurality of positions in the up and down direction of a vertical rotation shaft, lift-type blades that rotate in a fixed direction are attached to the tips of the horizontal shafts, and opening / closing members having a vertical size corresponding to the blades and whose front ends are journalled on the inner surface of the blades are attached to the inner surface of the blades behind the horizontal shafts in the rotational direction, and the entirety can be opened and closed within a predetermined angular range with respect to the inner surface of the blades around the front end side, and the opening and closing operation of the opening / closing members is controlled by an opening / closing control means in accordance with the circumferential speed ratio between the rotational speed of the blades and the wind speed, characterized in that at the upper and lower ends of the blades, horizontal plates are formed which close the spaces between the inner surfaces of the blades and the opening / closing members from above and below when the opening / closing members are open.

[0009] According to a second technical aspect of the present invention, the horizontal plate is formed around the entire outer edge of the cross-sectional shape at the upper and lower ends of the blade.

[0010] According to a third technical aspect of the present invention, the opening / closing control means is formed by pins respectively attached to the inner surface of the blade and the opening / closing member, and a tension spring provided between the two pins, and is characterized in that the opening / closing control means is formed on the rear side in the rotation direction of the horizontal shaft. Effect of the Invention

[0011] According to the first technical aspect of the present invention, horizontal plates are formed on the upper and lower ends of the blade, so that the space between the open / close member and the inner surface of the blade in the open state is blocked by the horizontal plates, making it difficult for the wind hitting the open / close member to escape from both the upper and lower sides of the open / close member, increasing the pressure (resistance) of the wind hitting the open / close member and allowing the blade to rotate vigorously.

[0012] According to a second technical aspect of the present invention, the horizontal plate is formed not only in the portion corresponding to the opening and closing member but also all around the outer edge of the cross-sectional shape of the upper and lower ends of the blade, so that when the blade rotates due to lift, the wind passing along the inner and outer surfaces of the blade is rectified, and lift can be generated more reliably.

[0013] According to a third technical aspect of the present invention, an opening / closing control means consisting of two pins and a tension spring is formed on the rear side of the horizontal shaft in the rotational direction, and when the opening / closing member is rotated by lift in a closed state, the opening / closing control means is hidden on the rear side of the horizontal shaft, so that the opening / closing control means does not cause air resistance. [Brief description of the drawings]

[0014] [Figure 1] FIG. 2 is an overall perspective view showing a vertical axis wind turbine rotating by lift with the opening / closing members closed. [Diagram 2] Cross-sectional view of the blade taken along the line SA-SA in Figure 1. [Diagram 3] 3 is a cross-sectional view corresponding to FIG. 2 showing the blade rotating due to resistance when the opening / closing member is open. [Figure 4] FIG. 4 is an enlarged cross-sectional view showing the leading end of the blade during rotation due to drag. [Diagram 5] FIG. 4 is an exploded perspective view showing the mounting structure of the front end portion of the blade. [Figure 6] FIG. 4 is a perspective view, partially in section, showing the blade during rotation due to drag. [Figure 7] FIG. 4 is a plan view showing the blade during rotation due to drag force. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] 1 to 7 are diagrams showing a preferred embodiment of the present invention.

[0016] The vertical axis wind turbine 1 according to this embodiment has a vertical shaft 3 that rotates in a constant rotation direction R relative to a base 2. Hereinafter, in this embodiment, the direction along the rotation direction R will be described as the front side, and the opposite side as the rear side.

[0017] Four horizontal shafts 4 extending radially are formed at the upper end of the vertical shaft 3 and two points below it. Lift-type blades 5 that rotate in the direction of rotation R are attached to the ends of the horizontal shafts 4. The blades 5 are streamlined airfoils with inner and outer surfaces 5a and 5b, and have a composite structure in which a metal plate is bonded to the surface of a resin-molded body.

[0018] The blade 5 is hollow and has three ribs 6 formed inside to maintain the overall rigidity. Horizontal plates 7, also made of a composite material of resin and metal plate, are formed at the top and bottom ends of the blade 5. These horizontal plates 7 basically have a shape that is an approximately similar, enlarged version of the cross-sectional shape of the blade 5, and are formed around the entire outer edge of the cross-sectional shape of the blade 5. There is a part that protrudes from the inside rear of the horizontal plate 7, and stoppers 8 are formed there on the parts that face each other in the vertical direction.

[0019] A plate-shaped opening / closing member 10 that can be opened and closed freely around its front end 9 is attached to the inner surface 5a of the blade 5 rearward of the horizontal shaft 4. This opening / closing member 10 is also made of a composite material of resin and metal plate. The opening / closing member 10 has a surface shape that can be brought into close contact with the inner surface, and has the same vertical size as the inner surface 5a.

[0020] A recess 11 having a cylindrical inner surface that is partially open in the vertical direction is formed on the inner surface 5a of the blade 5 slightly behind the horizontal axis 4. A round rod-shaped shaft 12 with fixed upper and lower ends is attached to the center of the recess 11. Four hinges 13 that are rotatable within the recess 11 around the shaft 12 are provided at the top and bottom of the shaft 12.

[0021] A cover 15 is placed on the front end 9 of the opening / closing member 10 against a flat portion 14 (see FIG. 5) formed on the hinge 13, and is fixed thereto by a screw 16 that penetrates through the cover 15. Therefore, the opening / closing member 10 can be opened and closed freely around the front end 9 side by the structure of the shaft 12, hinge 13, etc.

[0022] Of the four top and bottom covers 15 and hinges 13, two on the top and bottom sides are located behind the horizontal shaft 4, and a pin 18 is attached in a protruding state to the two top and bottom covers 15. In addition, another pin 17 is attached to the inner surface 5a, which is also located behind the horizontal shaft 4. A tension spring 19 is provided between these two pins 17, 18, and a constant tension force is applied to bring the pins 17, 18 closer to each other. The two pins 17, 18 and the tension spring 19 constitute an opening / closing control means 20.

[0023] The tension spring 19 pulls the pin 18 on the opening / closing member 10 in the direction of the pin 17 on the inner surface 5a, causing the front end 10 of the opening / closing member 10 to open inward together with the hinge 13, centered on the shaft 12, until the opening / closing member 10 hits the stopper 8 of the horizontal plate 7 and stops, taking up an open position of approximately 30 degrees.

[0024] When the opening / closing member 10 is in the open state, even when the wind speed is low and the peripheral speed ratio is less than 1, the wind W hits the opening / closing member 10 in the open state, and the blades 5 rotate due to the pressure (resistance) of the wind W. Furthermore, horizontal plates 7 are formed on the upper and lower ends of the blades 5, and the space S between the inner surface 5a of the blades 5 in the open state and the opening / closing member 10 is blocked by these horizontal plates 7, so that the wind W that hits the opening / closing member 10 is less likely to escape to the outside from both the upper and lower sides of the opening / closing member 10. Therefore, the pressure (resistance) of the wind W hitting the opening / closing member 10 increases, and the blades 5 can rotate vigorously.

[0025] When the rotation of the opening / closing member 10 due to the resistance increases, the peripheral speed ratio becomes 1 or more, and lift is generated on the blade 5, the opening / closing member 10 rotates in the closing direction against the tension spring 19 due to centrifugal force and comes into close contact with the inner surface 5a of the blade 5. Therefore, the blade 5 takes on its original streamlined airfoil shape, and lift is generated on the blade 5, causing it to rotate vigorously.

[0026] Since the horizontal plate 7 is formed not only in the portion corresponding to the opening / closing member 10 but also around the entire outer edge of the cross-sectional shape of the blade 5, a straightening effect is achieved for the wind W passing along the inner surface 5a and outer surface 5b of the blade 5, thereby enabling lift to be generated more reliably.

[0027] When the opening / closing member 10 is in a closed state, the opening / closing control means 20 consisting of two pins 17, 18 and a tension spring 19 protrudes from the blade 5. However, since this opening / closing control means 20 is formed on the rear side of the horizontal shaft 4 and is hidden behind the horizontal shaft 4, the opening / closing control means 20 does not create air resistance during rotation. [Explanation of symbols]

[0028] 1 Vertical axis wind turbine 3 vertical axis 4 horizontal axis 5 Blades 5a Inner surface 5b External surface 7 horizontal plate 9 Front end 10 Opening and closing members 17, 18 pin 19 Extension Spring 20 Opening and closing control means R Rotation direction W Wind S space

Claims

1. A plurality of horizontal shafts are formed so as to extend radially from a plurality of positions above and below the vertical rotating shaft, and lifting blades that rotate in a fixed direction are attached to the tips of the horizontal shafts, An opening / closing member having a vertical size corresponding to the blade and a front end portion pivotally supported on the inner surface of the blade is attached to the rear side of the horizontal axis in the direction of rotation on the inner surface of the blade, and the opening / closing member as a whole is freely openable and closable within a predetermined angular range with respect to the inner surface of the blade, centered on the front end side; A vertical axis wind turbine in which the opening and closing operation of the opening and closing member is controlled by an opening and closing control means in accordance with a peripheral speed ratio between a rotation speed of the blade and a wind speed, A horizontal axis wind turbine characterized in that horizontal plates are formed at the upper and lower ends of the blades to close the space between the inner surface of the blade and the opening / closing member from above and below when the opening / closing member is open.

2. 2. The horizontal axis wind turbine according to claim 1, wherein the horizontal plate is formed over the entire circumference of the outer edge of the cross-sectional shape at the upper and lower ends of the blade.

3. 3. The vertical axis wind turbine according to claim 1 or 2, characterized in that the opening and closing control means is formed by pins erected on the inner surface of the blade and the opening and closing member, and a tension spring provided between the two pins, and the opening and closing control means is formed on the rear side in the rotation direction of the horizontal axis.

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