JP2008175176A - Vertical axis drag type windmill - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a small-sized windmill of a vertical axis drag type, which efficiently rotates stably from starting to operation with strong winds in order to offer service, installed in an urban district, in which such an arrangement is introduced that starting is made at a low wind speed, a good power generating efficiency is obtained in rotating, and the windmill and generator are protected by controlling the rotating speed in operating with strong winds. <P>SOLUTION: The windmill is equipped with a plurality of blades 3 arranged symmetrically about a windmill rotary shaft 2, in which each blade 3 is supported with its peripheral end 7 rotatable, while the internal end 10 is displaced according to the rotating speed of the windmill, whereby the wind receiving surface assumes a paddle shape at starting in the standstill condition while it assumes a Savonius form in rotating, and when exceeding the rated rotating speed, the section shape in the axial direction assumes a cylindrical shape, which assures enhancement of the starting characteristic at starting and the power generating efficiency in rotating, and also suppression of the rise of the rotating speed in operating with strong winds, and thereby the power generator and/or the windmill is protected. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a configuration for protecting a device in a vertical axis drag type wind turbine used for wind power generation using natural energy by improving start-up characteristics and suppressing an increase in the rotational speed of the wind turbine during a strong wind.

  In recent years, as the development of small wind power generators, which are expected as an independent and distributed energy source, has progressed, vertical axis drag type wind turbines are less affected by the wind direction and have low noise even when the rotational speed increases. This is a windmill that is suitable for use with a Savonius type windmill.

  Various improvements have been proposed for this type of Savonius-type wind turbine in order to improve the start-up characteristics at low wind speeds and to suppress the increase in the rotational speed during strong winds. For example, Patent Document 1 discloses an improvement in starting characteristics at a low wind speed. This Savonius type windmill is characterized in that the starting force of the windmill is increased by providing small blades that increase the rotational torque on the outer peripheral side of the blades.

For example, Patent Document 2 discloses the suppression of the increase in the number of rotations in a strong wind. In this Savonius type windmill, by attaching the central part of the arc length of the blades arranged on the windmill so as to rotate around the pivot, the area where the blades receive wind pressure changes and the shaft rotates extremely even in strong winds. There is a feature that the rotational speed of the windmill can be controlled. Further, in the Savonius type windmill of Patent Document 3, the outer end portion of the blade is supported by the turning shaft, and the distance adjustment member for adjusting the distance from the windmill shaft is attached to the inner end, and the wind pressure area is increased or decreased in response to the wind speed change. Some control the rotational speed of the windmill.
JP 2005-171872 A JP 58-170864 A JP 09-2222070 A

  In such a conventional Savonius type windmill, at the time of start-up, the action of increasing the rotational direction torque acts on the outer periphery of the windmill and the windmill starting force increases, but in the rotational speed range where the wind speed increases and the power generation operation is performed. By dividing the blade surface into small blades, the wind pressure surface that can receive wind and smoothly guide the flow to the adjacent blade is reduced, and the center distance of the rotational force from the shaft center is shortened, so the rotational torque is also reduced. There is a problem that the power generation efficiency decreases due to a decrease.

  In addition, in the conventional Savonius type windmill, when the rotation speed of the windmill increases, the area receiving wind pressure changes due to the action of centrifugal force and suppresses the increase in the rotation speed, but the central part of the wing can be rotated by the pivot. The outer diameter of the wind turbine formed by the blades is reduced. It is generally known that the relationship between the wind speed and the rotational speed of a Savonius wind turbine depends on the wind turbine outer diameter, and that the rotational speed at the same wind speed increases as the wind turbine outer diameter decreases. For this reason, there is a problem that a phenomenon in which the rotational speed increases when the area receiving the wind pressure changes occurs. Moreover, in the conventional Savonius type windmill, although the outer peripheral end of the blade is supported by the swivel shaft, the change range of the blade wind pressure area depends on the length of the distance adjustment member, so that the change range is small and starts. There is a problem that the range from time to time exceeding the rated rotation cannot be optimized. In addition, an example in which a wire or the like is used for the drum as the distance adjusting member in order to increase the increase / decrease amount of the wind pressure area is shown, but there is a problem that the structure of the entire apparatus becomes complicated.

  The present invention solves such a conventional problem, and by changing the position of the inner peripheral end of the blade according to the rotational speed of the windmill, the startup characteristics are improved at the time of startup, and the power generation efficiency is improved at the time of rotation. The object of the present invention is to provide a vertical axis drag type wind turbine that can protect the equipment by suppressing an increase in the number of revolutions in a strong wind.

  In order to achieve the above object, the vertical axis drag type wind turbine according to the present invention includes a plurality of blades arranged symmetrically with respect to the wind turbine rotating shaft, and the outer peripheral side end of the blade and the wind turbine rotating shaft are connected by a connecting means. The position of the inner peripheral edge of the blade is displaced depending on the number of rotations of the windmill, so that the startup characteristics are improved when starting from a stopped state, and the power generation efficiency is improved during rotation. It is characterized by.

  By this means, even if it is installed in a weak wind area such as an urban area, it can be started from a low wind speed, and at the time of rotation, it can operate with improved power generation efficiency. Here, the outer peripheral side end of the blade is an end portion that is far from the wind turbine rotation axis in the radial direction when the wind turbine is stopped, and the inner peripheral side end of the blade is an end portion that is close to the radial direction from the wind turbine rotation axis. Say that.

  In addition, when the rotational speed of the windmill exceeds the rated speed, the position of the inner peripheral side end of the blade is displaced so as to suppress the increase in the rotational speed. Can no longer rise and protect equipment such as windmills and generators.

  In addition, as a means to improve the start-up characteristics of the windmill, it has become a paddle type at the start from the stop state, and a Savonius type from the start to the rated rotation, so that the start-up characteristic at low wind speed is maintained and the Savonius at the time of rotation. The power generation efficiency can be improved by increasing the rotational speed of the shape.

  In addition, when the rotational speed of the windmill exceeds the rated speed, the cross-sectional shape viewed from the windmill rotation axis direction formed by the disposed blade is cylindrical, so that the position of the blade inner peripheral end is Displacement, the radial distance from the windmill rotation axis coincides with the value on the blade outer peripheral side and the blade wind pressure surface faces the inside of the windmill, so the rotational force generated by receiving wind from the outside decreases and the rotation speed The wind turbines and generators can be protected.

  In addition, since the outer peripheral side end of the blade is rotated about the movable shaft and the position of the inner peripheral end of the blade is changed, when the centrifugal force acts on the center of gravity of the blade by rotation, the outer peripheral side of the blade Since the position of the blade inner peripheral side end can be smoothly displaced with the end as a fulcrum, even if the blade material is a highly rigid material such as a metal, the wind turbine configuration can be easily changed according to the rotational speed.

  Further, the cross section of the blade is formed by one circular arc, and the radius of curvature thereof is the same as the radius of the wind turbine outer diameter, so that the center of gravity of the blade becomes the central portion of the circular arc shape, and the position of the inner peripheral edge of the blade Is displaced, the radial distance from the windmill rotating shaft coincides with the value of the blade outer peripheral side end, and the cylindrical shape when the blade wind pressure surface faces the inside of the windmill becomes a perfect circle. Therefore, the centrifugal force generated by the rotation of the blade is uniform in all phases in the windmill rotation direction, and the fixed point reaction force acting on the blade inner peripheral end and the blade outer peripheral end is equal to the centrifugal force. The vibration at the time can be kept low, and at the same time, the stress generated in the blade and the support member can be made uniform, and the shape is advantageous in terms of strength.

  The blade has a cross-section in which one arc or a plurality of arcs are tangentially continuous, and a linear distance connecting the inner peripheral side end and the outer peripheral side end of the blade is the wind turbine rotating shaft and the blade outer peripheral end. And the position of the inner peripheral side end with the outer peripheral end of the blade as a fulcrum is set to be a range shorter than the length of the polygonal side formed with the outer peripheral side end of the blade as a vertex. By simply displacing it, a paddle shape is formed at startup, and a Savonius shape is formed at rotation. Therefore, the power generation efficiency can be improved by increasing the rotational speed of the Savonius shape during rotation while maintaining and improving the starting characteristics at a low wind speed.

  Further, as another means for changing the shape of the windmill, the outer peripheral side end of the blade is fixed using a flexible elastic material as a material of the blade, and the curvature of the blade is deformed so as to increase according to the number of rotations. Since the position of the inner peripheral side end is displaced, when the centrifugal force is applied, the position of the inner peripheral side end of the blade can be smoothly displaced to the outer peripheral side by elastic deformation of the blade. A simple structure in which a hinge mechanism or the like is not provided at the outer peripheral side end can be achieved.

  Further, the chord length of the blade is not less than 1.9 times the distance from the windmill rotating shaft to the blade outer peripheral side and shorter than the value obtained by dividing the circumferential length of the windmill outer diameter by the number of blades. As a result, a paddle shape is formed when the blade is stopped, and a Savonius shape is formed when the blade is rotated simply by changing the curvature of the blade. Therefore, the power generation efficiency can be improved by increasing the rotational speed of the Savonius shape during rotation while maintaining and improving the starting characteristics at a low wind speed.

  In addition, when the rotational speed of the wind turbine reaches the maximum rotational speed, a small plate-like piece that fills a gap formed between the position of the inner peripheral side end of the blade and the outer peripheral side end of the adjacent blade is attached. Since the gap formed in the cylindrical shape formed by the blade can be eliminated, it is possible to prevent the wind from the outside from hitting the blade wind pressure surface facing inward, thereby enhancing the effect of suppressing the increase in the rotational speed. .

  In addition, since the wind turbine is provided with a means for suppressing the ventilation of the portion where the blade inner peripheral side contact with the adjacent blade at the time of start-up from the stop state, the surface receiving the paddle-shaped wind pressure formed by the blade Since air leakage can be eliminated, the wind pressure of natural wind can be received to the maximum and the starting characteristics can be improved.

  Further, as a means for suppressing ventilation, the blade inner peripheral side end is provided in a portion where the blade inner peripheral end contacts the adjacent blade, so that the rotation increases even after starting. Air leakage can be eliminated in the low wind speed range.

  In addition, by providing a flexible material at the inner peripheral side edge of the blade as a means for suppressing ventilation, in addition to eliminating air leakage in the low wind speed range from the start up until the rotation increases, the wind stops. When the rotation speed is lowered and stopped, the impact when the position of the end on the inner peripheral side of the blade is displaced to contact the adjacent blade can be reduced.

  In addition, a circular plate is provided on one or both end faces of the blade in the windmill rotation axis direction, the outer diameter of the circular plate is larger than the windmill outer diameter, and the center is coupled to the windmill axis, and the windmill rotation axis And also serves as a connecting means between the blade outer peripheral end and the wind force can be prevented from always escaping from the blade axial end regardless of the blade inner peripheral position. Both power generation efficiency can be improved.

  In addition, by providing a blade connecting member in which the radial distance between the windmill rotating shaft and the inner peripheral side ends of all the blades arranged is the same, variation in wind pressure and centrifugal force received by each blade is averaged. Therefore, it is possible to suppress a variation in the number of rotations and maintain stable rotation.

  Further, the blade connecting member is a disc having a spiral guide groove from the inner side to the outer side in the radial direction, and a protrusion provided on the inner peripheral side end of the blade fits into the guide groove and is rotatable inside the blade. Since the position of the peripheral end is displaced, the movable range of the blade inner peripheral position can be increased with a simple structure.

  According to the present invention, without changing the configuration, the position of the inner peripheral side end of the blade is changed according to the rotation speed of the windmill, thereby improving the start-up characteristics at start-up, improving the power generation efficiency at the time of rotation, In some cases, it is possible to provide a vertical axis drag type wind turbine that can protect the device by suppressing an increase in the rotational speed.

  The vertical axis drag type wind turbine according to claim 1 of the present invention includes a plurality of blades arranged symmetrically with respect to the wind turbine rotating shaft, and the outer peripheral side end of the blade and the wind turbine rotating shaft are connected by a connecting means, The position of the inner peripheral side edge of the blade is displaced depending on the number of rotations of the windmill, so that the startup characteristics are improved when starting from a stopped state, and the power generation efficiency is improved during rotation. Thus, even if it is installed in a weak wind area such as an urban area, it can be started from a low wind speed, and it can operate with improved power generation efficiency during rotation. Here, the outer peripheral side end of the blade is an end portion that is far from the wind turbine rotation axis in the radial direction when the wind turbine is stopped, and the inner peripheral side end of the blade is an end portion that is close to the radial direction from the wind turbine rotation axis. Say that.

  The vertical axis drag type wind turbine according to claim 2 of the present invention is the vertical axis drag type wind turbine according to claim 1, wherein the position of the inner peripheral side end of the blade is displaced when the rotational speed of the wind turbine exceeds the rated rotation. The shape is designed to suppress the increase in the rotational speed, and has the effect that the rotational speed of the windmill does not increase during strong winds and equipment such as a windmill and a generator can be protected.

  The vertical axis drag type wind turbine according to claim 3 of the present invention is the vertical axis drag type wind turbine according to claim 1, wherein the vertical axis drag type wind turbine is of a paddle type at the start from the stop state and a Savonius type at the rated rotation from the start. The power generation efficiency can be improved by increasing the rotational speed of the Savonius shape during rotation while maintaining and improving the starting characteristics at low wind speeds.

  The vertical axis drag type wind turbine according to claim 4 of the present invention is the vertical axis drag type wind turbine according to claim 2, wherein the wind turbine rotation formed by the blades arranged when the rotational speed of the wind turbine exceeds the rated rotation. The cross-sectional shape seen from the axial direction is a cylindrical shape, the position of the inner peripheral end of the blade is displaced, and the radial distance from the wind turbine rotating shaft matches the value of the outer peripheral end of the blade. Since the wind pressure surface faces the inside of the windmill, the rotational force generated by receiving wind from the outside is reduced, the rotational speed is not increased, and equipment such as a windmill and a generator can be protected.

  The vertical axis drag type wind turbine according to claim 5 of the present invention is the vertical axis drag type wind turbine according to claim 3 or 4, wherein the outer peripheral side end of the blade is rotationally movable around the movable axis, and the blade inner peripheral end When the centrifugal force acts on the center of gravity of the blade by rotation, the position of the blade inner peripheral end can be smoothly displaced with the blade outer peripheral end as a fulcrum. Even if the material is a highly rigid material such as a metal, the windmill configuration can be easily changed in accordance with the rotational speed.

  The vertical axis drag type wind turbine according to claim 6 of the present invention is the vertical axis drag type wind turbine according to claim 5, wherein the blade has a cross section formed by one circular arc, and the radius of curvature thereof is the radius of the wind turbine outer diameter. The center of gravity of the blade is the center of the arc shape, the position of the blade inner peripheral edge is displaced, and the radial distance from the windmill rotation axis is the value of the blade outer peripheral edge. The cylindrical shape when the blade wind pressure surface coincides and faces the inside of the windmill becomes a perfect circle.

  Therefore, the centrifugal force generated by the rotation of the blade is uniform in all phases in the windmill rotation direction, and the fixed point reaction force acting on the blade inner peripheral end and the blade outer peripheral end is equal to the centrifugal force. The vibration at the time can be suppressed to a low level, and at the same time, the stress generated in the blade and the support member can be made uniform and the strength can be advantageously improved.

  The vertical axis drag type wind turbine according to claim 7 of the present invention is the vertical axis drag type wind turbine according to claim 5 or 6, wherein the blade has a cross-section in which one arc or a plurality of arcs are tangent continuous. A linear distance connecting the inner peripheral side end and the outer peripheral side end of the blade is 1.2 times or more the distance from the wind turbine rotating shaft to the blade outer peripheral side end, and the blade is formed with the outer peripheral side end as a vertex. The range is shorter than the length of the side of the square, and a paddle shape is formed at start-up and a Savonius shape is formed at rotation simply by displacing the position of the inner peripheral end with the outer peripheral end of the blade as a fulcrum. Therefore, the power generation efficiency can be improved by increasing the rotational speed of the Savonius shape during rotation while maintaining and improving the starting characteristics at a low wind speed.

  The vertical axis drag type wind turbine according to claim 8 of the present invention is the vertical axis drag type wind turbine according to claim 3 or 4, wherein the outer peripheral side end of the blade is fixed using a flexible elastic material. The blade is deformed so that the curvature of the blade increases in accordance with the rotational speed, and the position of the inner peripheral side end is displaced, and when the centrifugal force is applied, the blade is elastically deformed to cause the inner peripheral side of the blade to be displaced. Since the end position can be smoothly displaced to the outer peripheral side, the blade outer peripheral side end has a simple structure in which a hinge mechanism or the like is not provided.

  The vertical axis drag type wind turbine according to claim 9 of the present invention is the vertical axis drag type wind turbine according to claim 8, wherein the blade chord length is 1 of the distance between the wind turbine rotating shaft and the blade outer peripheral side end. .9 times or more and within a range shorter than the value obtained by dividing the circumference of the wind turbine outer diameter by the number of blades. Paddle type when stopped and Savonius when rotating just by changing the curvature of the blade Formed shape. Therefore, the power generation efficiency can be improved by increasing the rotational speed of the Savonius shape during rotation while maintaining and improving the starting characteristics at a low wind speed.

  The vertical axis drag type wind turbine according to claim 10 of the present invention is the vertical axis drag type wind turbine according to any one of claims 5 to 9, wherein when the rotational speed of the wind turbine reaches the maximum rotational speed, the inner peripheral side end of the blade A plate-shaped small piece that fills the gap formed between the position of the blade and the outer peripheral side edge of the adjacent blade is attached, and the gap can be eliminated from the cylindrical shape formed by the blade. In order to prevent the wind from the outside from hitting the blade wind pressure surface facing, the effect of suppressing the increase in the rotational speed can be enhanced.

  The vertical axis drag type wind turbine according to claim 11 of the present invention is the vertical axis drag type wind turbine according to any one of claims 5 to 10, wherein the wind turbine is adjacent to the blade inner peripheral end when the wind turbine is started from a stopped state. In order to eliminate air leakage at the paddle-shaped wind pressure surface formed by the blade, it is possible to receive the maximum wind pressure of the natural wind. And has the effect of improving the starting characteristics.

  The vertical axis drag type windmill according to claim 12 of the present invention is the vertical axis drag type windmill according to claim 11, wherein the blade inner peripheral side end and a blade adjacent to the blade are in contact with each other as a means for suppressing ventilation. The blade is provided with a recess having a shape into which the inner peripheral end of the blade fits, and has an effect that air leakage can be eliminated in a low wind speed range after the start-up until the rotation increases.

  The vertical axis drag type wind turbine according to claim 13 of the present invention is the vertical axis drag type wind turbine according to claim 11, wherein a flexible material is provided at the inner peripheral side end of the blade as means for suppressing ventilation. In addition to eliminating air leakage in the low wind speed range from the start up to the increase in rotation, the position of the inner peripheral edge of the blade is displaced when the wind stops and the rotation speed decreases and stops. It is possible to reduce the impact when contacting adjacent blades.

  The vertical axis drag type wind turbine according to claim 14 of the present invention is the vertical axis drag type wind turbine according to claims 5 to 13, wherein a circular plate is provided on one or both end faces of the blade in the wind turbine rotation axis direction, and the circular plate The outer diameter of the wind turbine is larger than the outer diameter of the wind turbine, and the center is coupled to the wind turbine shaft, and serves as a connection means between the wind turbine rotating shaft and the blade outer peripheral side. Regardless of the circumferential position, wind can always be prevented from escaping from the end in the blade axial direction, so that the generated drag increases, and both the starting characteristics and power generation efficiency can be improved.

  The vertical axis drag type wind turbine according to claim 15 of the present invention is the vertical axis drag type wind turbine according to claim 5 to 14, wherein the radial distance between the wind turbine rotating shaft and the inner peripheral side ends of all the blades arranged. The blade connecting members are made to be the same, and the variation in wind pressure and centrifugal force received by each blade can be averaged, so fluctuations in rotational speed are suppressed and stable rotation is achieved. Can be maintained.

  The vertical axis drag type wind turbine according to claim 16 of the present invention is the vertical axis drag type wind turbine according to claim 15, wherein the blade connecting member is a disc provided with a spiral guide groove from the inner side to the outer side in the radial direction. The projection provided on the inner peripheral end of the blade is fitted in the guide groove so that the position of the inner peripheral end of the blade is displaced while being rotatable. The movable range can be increased.

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

(Embodiment 1)
1 is an overall perspective sectional view of Embodiment 1 of the present invention, FIG. 2 is an axial sectional view, FIG. 3 is an axial sectional view showing a blade position at startup, and FIG. 4 is an axis showing a blade position at rotation. FIG. 5 is an axial sectional view showing the blade position when the rated rotation is exceeded.

  As shown in FIG. 1, the vertical axis drag type wind turbine 1 includes a wind turbine rotating shaft 2, a blade 3, a circular plate 4, a disk-shaped blade coupling member 5 having a guide groove 12, a plate A small piece 6 is provided. As shown in FIG. 2, the blade 3 has a hinge hole 8 at the outer peripheral end 7, and is inserted into the blade support rod 9 of the circular plate 4 and supported in a rotationally movable state. A protruding portion 11 protruding in the axial direction is formed at the inner peripheral side end 10 of the blade 3, and is fitted into the guide groove 12 of the blade connecting member 5 as a connecting means, and the inner peripheral side end of all three blades 3. The blade connecting member 5 can be rotated in the circumferential direction so that the positions of 10 are the same.

  Here, the outer peripheral side end 7 of the blade 3 is an end portion that is far from the wind turbine rotating shaft 2 in the radial direction when the wind turbine is stopped, and the inner peripheral side end 10 of the blade 3 is close to the radial direction from the wind turbine rotating shaft 2. It is defined as the end at the position. A flexible material 13 made of urethane rubber is affixed to the inner peripheral end 10 of the blade 3 as means for suppressing ventilation of a portion that comes into contact with the adjacent blade 3 when the windmill is stopped.

  Urethane rubber is used as the material for the flexible material, but other rubbers and sponges may be used. A spring member 14 that generates a resistance force in the circumferential direction is attached to the blade connecting member 5 as a connecting means, and when the windmill is not rotated by the resistance force, the inner peripheral side end 10 of the blade 3 is stopped. Is located on the innermost side, is in contact with the wind pressure surface 15 of the adjacent blade 3 and is in close contact with the flexible material 13 to form a paddle-shaped wind receiving surface. The radius of curvature of the blade 3 is formed by one arc and is 100 mm, which is the same as the radius of the windmill outer diameter. Further, the linear distance between the outer peripheral side end 7 and the inner peripheral side end 10 of the blade 3 is 135 mm, which is at least 1.2 times the distance 100 mm from the wind turbine rotating shaft 2 to the outer peripheral side end 7 of the blade 3, and the three blades 3. The length of the side of the triangle connecting the outer peripheral side ends 7 is shorter than 175 mm.

  A plate-shaped piece 6 having a radius of curvature of 100 mm, which is the same as the radius of the windmill outer diameter, is fixed between the upper and lower circular plates 4 at the outer peripheral end 7 of the blade 3. The blade 3 is made of polycarbonate resin mixed with glass fiber, but other resin or metal material may be used. For example, a highly rigid material that does not change the curvature of the blade 3 even when subjected to wind pressure such as FRP, CFRP, or aluminum is suitable.

  In the above configuration, when the wind blows as shown in FIG. 3, the vertical axis drag type wind turbine 1 receives the wind at the paddle-shaped wind receiving surface and starts at a low wind speed of approximately 1.0 m / s to 1.5 m / s. When it starts and starts rotating, as shown in FIG. 4, the outer peripheral side end 7 of the blade 3 is rotationally movable by the balance between the centrifugal force acting on the blade 3 and the resistance force of the spring material according to the number of rotations. The position of the inner peripheral side end 10 of the blade 3 is displaced outward while maintaining the curvature. The wind pressure surface 15 of the blade 3 adjacent to the inner peripheral side end of the blade 3 that is in contact with the blade 3 is separated to form a Savonius-type wind receiving surface.

Since the Savonius type produces a greater rotational force at the same wind speed than the paddle type, the power generation efficiency is improved compared with that at the time of startup. In this embodiment, the wind speed at which power generation is performed efficiently is 5 m / s to 15 m / s, and the rotational speed is in the range of about 300 min ^{−1 to} 1000 min ⁻¹ . When the wind speed is further increased and the rotational speed is increased, the centrifugal force acting on the blade 3 is increased, and the position of the inner peripheral side end 10 of the blade 3 is further displaced outward near the outer peripheral side end 7.

  As shown in FIG. 5, when the rated rotational speed is exceeded, the centrifugal force becomes very large, and the position of the inner peripheral side end 10 of the blade 3 is displaced outward to the same position as the outer peripheral side end 7. The formed cross-sectional shape is a cylindrical shape. At this time, the plate-shaped small piece 6 acts to close the cylindrical gap. When the cross-sectional shape is cylindrical, the wind pressure surface is less susceptible to wind and the rotational speed does not increase.

  After that, when the wind speed becomes weak, a Savonius-type wind receiving surface is obtained due to the balance between the centrifugal force acting on the blade 3 and the resistance force of the spring material 14, and when the wind speed is further lowered, the windmill stops and the inner peripheral end of the blade 3 is stopped. Comes into contact with the wind pressure surface of the adjacent blade 3 to form a paddle-shaped wind receiving surface. At this time, even when the wind suddenly stops from the strong wind, the impact when the blades 3 come into contact with each other due to the cushioning effect of the flexible material 13 can be avoided.

(Embodiment 2)
FIG. 6 is an axial sectional view showing the blade position at startup, FIG. 7 is an axial sectional view showing the blade position during rotation, and FIG. 8 is an axial direction showing the blade position when the rated rotation is exceeded. The same parts as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 6, the blade 3 is fixed by inserting the outer peripheral side end into a fixing rail 16 provided on the circular plate 4. In a stopped state where the windmill is not rotating, the inner peripheral side end 10 of the blade 3 is located on the innermost side, and is fitted into the recess 17 formed in the wind pressure surface 15 of the adjacent blade 3 so that the paddle-shaped wind receiving surface is Is formed. The indentation 17 functions as a means for suppressing ventilation of a portion that comes into contact with the adjacent blade 3 when the windmill is stopped from the stop state. The radius of curvature when the blade 3 is stopped is formed by one arc, and is, for example, 56 mm.

  The chord length of the blade 3 is 200 mm, which is 1.9 times or more of the radius of the windmill outer diameter of 100 mm and shorter than the value of 209 mm obtained by dividing the circumferential length by the number of blades. If the chord length deviates from the specified range, the paddle shape cannot be formed at the time of starting, and at the same time, it interferes with adjacent blades when the rated rotational speed is exceeded. The material of the blade 3 is urethane sponge, which is an elastic material, and the plate thickness is increased so that it can be self-supporting and maintain its rigidity. However, the frame is made of thin urethane rubber with a metal or resin frame around it. It may be configured to be self-supporting with the rigidity. The same effect can be obtained even if a thin metal material of about 0.3 mm is used.

  In the above configuration, when the wind blows, the vertical axis drag type wind turbine 1 starts by receiving the wind on the paddle-shaped wind receiving surface. When activated and started to rotate, as shown in FIG. 7, the curvature of the blade 3 is changed by the centrifugal force acting on the blade 3 in accordance with the rotational speed, and the position of the inner peripheral side end 10 of the blade 3 is changed. Is displaced outward.

  The indentation 17 of the blade 3 adjacent to the inner peripheral side end 10 of the blade 3 that is in contact with the blade 3 is separated to form a Savonius-shaped wind receiving surface. When the wind speed is further increased and the rotational speed is increased, the centrifugal force acting on the blade 3 is increased, the curvature radius of the blade 3 is increased, and the position of the inner peripheral side end 10 of the blade 3 is displaced outward. As shown in FIG. 8, when the rated rotational speed is exceeded, the centrifugal force becomes very large, and the position of the inner peripheral side end of the blade 3 is displaced outward to the same position as the outer peripheral side end 7. The radius is the same as the radius of the windmill outer diameter of 100 mm, and the cross-sectional shape formed by the blade 3 is a cylindrical shape. FIG. 8 shows an axial sectional view at that time. When the cross-sectional shape is cylindrical, the wind pressure surface is less susceptible to wind and the rotational speed does not increase.

Whole perspective sectional view of Embodiment 1 of the present invention Axial direction sectional view of Embodiment 1 of the present invention Cross-sectional view in the axial direction showing the blade position at start-up according to the first embodiment of the present invention Sectional view in the axial direction showing the blade position during rotation according to the first embodiment of the present invention Sectional view in the axial direction showing the blade position when the rated rotation of the first embodiment of the present invention is exceeded Sectional view in the axial direction showing the blade position at the time of start-up of Embodiment 2 of the present invention Sectional view in the axial direction showing the blade position during rotation according to the second embodiment of the present invention Sectional view in the axial direction showing the blade position when the rated rotation of the second embodiment of the present invention is exceeded

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vertical axis drag type windmill 2 Windmill rotating shaft 3 Blade 4 Circular plate 5 Blade connection member 6 Plate-shaped piece 7 Outer peripheral side end 8 Hinge hole 9 Blade support rod 10 Inner peripheral side end 11 Protrusion part 12 Guide groove 13 Flexible material 14 Spring material 15 Wind pressure surface 16 Fixing rail 17 Recess

Claims (16)

The blade includes a plurality of blades arranged symmetrically with respect to the windmill rotating shaft, the outer peripheral side end of the blade and the windmill rotating shaft are connected by a connecting means, and the position of the inner peripheral side end of the blade is determined by the rotational speed of the windmill. A vertical axis drag type wind turbine characterized in that it has a shape that improves its starting characteristics when it is displaced and starts from a stopped state, and has a shape that improves its power generation efficiency when it rotates. 2. The vertical shaft according to claim 1, wherein when the rotational speed of the wind turbine exceeds the rated rotational speed, the position of the inner peripheral side end of the blade is displaced to suppress the increase in the rotational speed. Drag type windmill. 2. The vertical axis drag type wind turbine according to claim 1, wherein the wind turbine is of a paddle type when starting from a stopped state and a Savonius type during starting and rated rotation. 3. The vertical axis drag according to claim 2, wherein when the rotational speed of the windmill exceeds a rated speed, a cross-sectional shape viewed from the windmill rotational axis direction formed by the blades arranged is a cylindrical shape. Type windmill. The vertical axis drag type wind turbine according to claim 3 or 4, wherein the outer peripheral side end of the blade is rotationally movable about the movable axis and the position of the inner peripheral side end of the blade is displaced. 6. The vertical axis drag type wind turbine according to claim 5, wherein a cross section of the blade is formed by one circular arc, and a radius of curvature thereof is the same as a radius of the wind turbine outer diameter. The cross section of the blade has a shape in which one arc or a plurality of arcs are tangent continuous, and a linear distance connecting the inner peripheral side end and the outer peripheral end of the blade is between the wind turbine rotating shaft and the blade outer peripheral end. The vertical axis drag type wind turbine according to claim 5 or 6, wherein the vertical axis drag type wind turbine is 1.2 times or more of the distance and shorter than a length of a side of a polygon formed with an outer peripheral side end of the blade as a vertex. The outer peripheral side end of the blade is fixed using a flexible elastic material as the material of the blade, and the position of the inner peripheral side end is displaced by deformation so that the curvature of the blade increases according to the number of rotations. The vertical axis drag type wind turbine according to claim 3 or 4, characterized in that: The chord length of the blade is in a range that is 1.9 times or more the distance between the windmill rotating shaft and the blade outer peripheral end and shorter than the value obtained by dividing the circumferential length of the windmill outer diameter by the number of blades. The vertical axis drag type wind turbine according to claim 8. When the rotational speed of the windmill is the maximum rotational speed, a plate-shaped piece is attached to fill a gap formed between the position of the inner peripheral side end of the blade and the outer peripheral side end of the adjacent blade. The vertical axis drag type wind turbine according to claim 5. The vertical axis drag type according to any one of claims 5 to 10, further comprising means for suppressing ventilation of a portion where the blade inner peripheral side end contacts with an adjacent blade when the windmill is started from a stopped state. Windmill. The vertical axis drag type according to claim 11, wherein the blade inner peripheral side end is fitted into a portion where the blade inner peripheral end contacts with a blade adjacent to the blade inner peripheral end as means for suppressing ventilation. Windmill. The vertical axis drag type wind turbine according to claim 11, wherein a flexible material is provided at an inner peripheral side end of the blade as means for suppressing ventilation. A circular plate is provided on one or both end faces of the blade in the windmill rotation axis direction, the outer diameter of the circular plate is larger than the windmill outer diameter, and the center is coupled to the windmill axis, and the windmill rotation axis and the The vertical axis drag type wind turbine according to claim 5, which also serves as a connecting means to the blade outer peripheral side end. The vertical axis drag type wind turbine according to claim 5, further comprising a blade connecting member configured such that a radial distance between the wind turbine rotating shaft and an inner peripheral side end of all the blades arranged is the same. The blade connecting member is a disc having a spiral guide groove from the inner side to the outer side in the radial direction, and a protrusion provided on the inner peripheral side end of the blade fits in the guide groove and is rotatable inside the blade. The vertical axis drag type wind turbine according to claim 15, wherein the position of the end is displaced.

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