KR20210022943A - Wind turbine - Google Patents

Abstract

The present invention provides a wind power generator capable of increasing energy production without increasing the blade size. According to the present invention, the wind power generator comprises: a multi-stage tower in which a plurality of tubular members are stacked; a nacelle located on an upper part of the tower and rotatably coupled to a lower part of the tower; a rotor rotatably installed in front of the nacelle; a blade spaced apart along the circumferential direction and coupled to an outer circumferential surface of a hub disposed in front of the rotor, and having a space therein; and a mass part disposed in an inner space of the blade and configured to be movable in the inner space. A relative position of the mass part with respect to the hub is changed in the inner space so that the rotational torque of the blade becomes high while the blade rotates.

Description

Wind power generator {WIND TURBINE}

The present invention relates to a wind power generator. Specifically, the present invention relates to a wind power generator capable of increasing or decreasing the rotational torque of the blades.

Wind power generation refers to a power generation method that converts wind energy into mechanical energy (rotation power) using a windmill, and this mechanical energy is converted into electrical energy by driving a generator to obtain power.

Wind power generation is not only the most economical among renewable energy sources developed to date, but also has the advantage of being able to generate electricity using wind, which is an infinite, no-cost clean energy source.Therefore, active investment is being made not only in Europe, but also in the Americas and Asia. to be.

Wind power generators for such wind power generation may be classified into a vertical axis wind power generator and a horizontal axis wind power generator according to the direction of the rotation axis. Until now, horizontal axis wind generators are more efficient and stable compared to vertical axis, so horizontal axis wind generators are mostly applied to commercial wind farms.

On the other hand, although the blades are enlarged to increase the energy output of wind power generators, there is a problem that a production facility for producing a blade needs to be replaced according to the increase in the blade size and a problem that requires a large investment in the blade production facility. In addition, there is a problem of transporting large-sized blades, and it is difficult to install the transported blades on the top of the tower.

Republic of Korea Patent Publication No. 10-2011-0127346 (2011.11.25)

The present invention provides a wind power generator capable of increasing energy production without increasing the blade size.

A wind turbine generator according to an aspect of the present invention includes a multi-stage tower in which a plurality of tubular members are stacked, a nacelle positioned at the top of the tower and rotatably coupled to a lower portion of the tower, and a rotor rotatably installed in front of the nacelle. , A blade spaced apart from and coupled to an outer circumferential surface of a hub disposed in front of the rotor and having a space therein, and a mass portion disposed in the inner space of the blade and movable in the inner space, and the blade The relative position of the mass portion with respect to the hub changes within the inner space so that the rotation torque of the blade increases while the is rotated.

In the wind power generator according to an aspect of the present invention, the mass unit may be moved by gravity by changing a position of the inner space of the blade with respect to the direction of gravity as the blade rotates.

In the wind power generator according to an aspect of the present invention, the blade may rotate at a low speed so that the mass portion is movable by gravity within the inner space while the blade rotates.

In the wind power generator according to an aspect of the present invention, the mass portion may be moved in the inner space such that the blade inner space is perpendicular to the gravitational direction and then disposed close to the hub when it is directed in a direction opposite to the gravitational direction.

In the wind power generator according to an aspect of the present invention, the mass portion may be moved in the inner space so as to be away from the hub when the blade inner space is perpendicular to the gravity direction and then is directed in the same direction as the gravity direction.

In the wind power generator according to an aspect of the present invention, when any one blade rotates in the same direction as the direction of gravity along the rotation direction of the blade, the mass portion applies the rotation torque of the blade to gravity in the inner space of the blade. It can move in the direction of raising.

In the wind turbine generator according to an aspect of the present invention, the blade may further include a guide portion disposed in the inner space of the blade and guiding the movement of the mass portion.

In the wind power generator according to an aspect of the present invention, the blade may further include end supports disposed at both ends of the inner space so that the moving area of the mass portion along the guide portion is limited.

In the wind power generator according to an aspect of the present invention, the guide portion may extend through the mass portion or may be formed to surround the mass portion.

In the wind turbine generator according to an aspect of the present invention, the blade may further include a damper disposed at both ends of the guide portion and reducing the impact of the mass portion colliding with the end support.

In the wind turbine generator according to an aspect of the present invention, the blade may further include an elastic body interposed between the end support and the mass portion, and to alleviate an impact when the mass portion is moved toward the end support by gravity.

In the wind power generator according to an aspect of the present invention, to reduce the starting torque of the blade, it is disposed on the opposite side of the inner space of the end support, it may further include a motor for moving the mass portion toward the hub.

In the wind power generator according to an aspect of the present invention, the motor may be operated when the blade stops rotating.

In the wind power generator according to an aspect of the present invention, as the motor is operated, the mass portion may further include a connecting member connecting the motor and the mass portion so that the mass portion moves toward the hub along the guide portion.

As described above, according to one aspect of the present invention, according to the position of the rotating blade, the mass portion is moved by gravity, and the rotation torque of the rotor may be increased by the force generated at this time. This makes it possible to reduce the size of the blades of wind power generators that produce similar amounts of energy.

According to another aspect of the present invention, by arranging the movable mass portion in the inner space of the blade, it is possible to increase the torque of the rotor due to aerodynamic force and the torque of the rotor due to gravity. This can maximize the energy output of the wind power generator.

According to another aspect of the present invention, when the rotor is stopped, there is an effect of reducing a high starting torque that may occur when the mass part is located at the end of the blade by moving the mass part located at the end of the blade closer to the rotor through the motor. .

1 is a perspective view showing a wind power generator according to an embodiment of the present invention.
FIG. 2 is a diagram schematically illustrating a yawing system installed under the nacelle of FIG. 1.
3 is a diagram schematically showing the interior of the nacelle of FIG. 1.
FIG. 4 is a conceptual diagram illustrating an inner state of the blade of FIG. 1.
5 is a conceptual diagram illustrating a state in which a mass part inside the blade moves according to each position of the blade.
6 is a conceptual diagram illustrating a state in which a mass part is moved by a motor according to another embodiment of the present invention.

The present invention is intended to illustrate specific embodiments and to be described in detail in the detailed description, since various transformations may be applied and various embodiments may be provided. However, this is not intended to limit the present invention to a specific embodiment, it should be understood to include all conversions, equivalents, and substitutes included in the spirit and scope of the present invention.

The terms used in the present invention are used only to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In the present invention, terms such as'include' or'have' are intended to designate the presence of features, numbers, steps, actions, components, parts, or a combination thereof described in the specification, but one or more other features. It is to be understood that the presence or addition of elements or numbers, steps, actions, components, parts, or combinations thereof does not preclude in advance.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In this case, it should be noted that in the accompanying drawings, the same components are indicated by the same reference numerals as much as possible. In addition, detailed descriptions of known functions and configurations that may obscure the subject matter of the present invention will be omitted. For the same reason, some elements in the accompanying drawings are exaggerated, omitted, or schematically illustrated.

Hereinafter, a wind power generator according to an embodiment of the present invention will be described with reference to FIGS. 1 to 5. 1 is a perspective view showing a wind power generator according to an embodiment of the present invention, FIG. 2 is a schematic view showing a yawing system installed under the nacelle of FIG. 1, and FIG. 3 is a view showing the interior of the nacelle of FIG. It is a schematic diagram. FIG. 4 is a conceptual diagram illustrating an internal state of the blade of FIG. 1, and FIG. 5 is a conceptual diagram illustrating a state in which a mass part inside the blade moves according to each position of the blade.

Referring to FIGS. 1 to 3, the wind power generator 10 according to the present embodiment includes a tower 110, a nacelle 120, and a rotor 130. The wind power generator 10 according to the present embodiment may be made of a direct type wind power generator that does not have a gearbox, and in particular, may be made of an offshore wind power generator installed on the sea. Meanwhile, as another embodiment of the present invention, it may be applied to a multi-type wind power generator having a plurality of unit power generation units. However, the present invention is not limited thereto.

The tower 110 is erected and installed at a constant height on the ground and at sea, and supports the nacelle 120 and the rotor 130. The tower 110 may have a tubular shape whose diameter increases from the top to the bottom. In this case, the tower 110 may be formed in a multi-stage shape in which a plurality of tubular members are stacked. Meanwhile, a staircase, a conveyor, or an elevator may be installed inside the tower 110 to transport workers or work tools for maintenance.

The nacelle 120 may be installed at the top of the tower 110 to enable yawing with respect to the tower 110. The nacelle 120 is located above the tower 110 and may be rotatably coupled to the lower portion of the tower 110. The nacelle 120 to which the power generation unit 140 is coupled may be rotated so that the blade 132 faces the wind. The yaw system 300 may include a yaw bearing (not shown), a yaw drive motor 310, a pinion gear 330, and a tooth row 350.

The tower 100 and the nacelle 120 are connected to each other through a yaw bearing (not shown), and the nacelle 120 rotates with respect to the tower 100 fixedly installed on the ground by a yaw bearing (not shown), that is, yaw You can exercise. The yaw bearing (not shown) includes an outer ring and an inner ring. The outer ring of the yaw bearing (not shown) is fixed to the tower 100, and the inner ring of the yaw bearing (not shown) may be fixed to the nacelle 120. However, the present invention is not necessarily limited thereto, and the outer ring of the yaw bearing may be fixed to the nacelle 120 and the inner ring of the yaw bearing may be fixed to the tower 100.

The yaw drive motor 310 may be fixedly coupled to one side of the nacelle 120, and a pinion gear 330 may be coupled to the lower end of the yaw drive motor 310. Meanwhile, a tooth row 350 is formed on the outer circumferential surface of the tower 100 to which the outer ring of the yaw bearing (not shown) is fixed, so that the pinion gear 330 of the yaw drive motor 310 can be geared to the tooth row 350. have. However, the present invention is not limited thereto, and the tooth row is formed on the outer or inner ring of the yaw bearing, and the pinion gear may be directly connected to the yaw bearing.

At this time, the pinion gear 330 rotates according to the driving of the yaw drive motor 310 and the pinion gear 330 rotates along the teeth 350. Therefore, when the yaw drive motor 310 rotates, the nacelle 120 to which the yaw drive motor 310 is coupled performs a yaw motion on the tower 100.

The rotor 130 is composed of a hub 131 and a plurality of blades 132, and the hub 131 is rotatably installed on the front surface of the nacelle 120. In addition, the plurality of blades 132 are coupled to the outer peripheral surface of the hub 131 by being spaced apart at predetermined intervals along the circumferential direction.

The power generation unit 140 is installed inside the nacelle 120 to generate electricity, and includes a main shaft 144, a gearbox 145, a brake 146, and a generator 147.

The rotor 130 is rotatably installed in front of the nacelle 120, and the rotational force generated from the rotor 130 is transmitted to the gearbox 145 through the main shaft 144. The rotor 130 is composed of a hub 131 and a plurality of blades 132, the hub 131 is coupled to one end of the main shaft 144 is rotatably installed on the front of the nacelle 120. In addition, the plurality of blades 132 are coupled to the outer peripheral surface of the hub 131 by being spaced apart at predetermined intervals along the circumferential direction.

The hub 131 may have a conical shape protruding convexly forward to reduce wind resistance. The blade 132 rotates about the central axis of the hub 131 by the wind. The blade 132 has a streamlined cross section in the width direction, and a space portion may be formed therein.

The nacelle 120 is a housing for accommodating the gearbox 145, the generator 147, and the like, and may have a hexahedral shape. However, the shape of the nacelle 120 is not necessarily limited thereto, and may be formed in a cylindrical shape or the like.

The main shaft 144 transmits the rotational force of the rotor 130 to the gearbox 145, and the main shaft 144 rotating at high speed is rotatably supported by a main bearing (not shown).

The gearbox 145 is a device that converts the rotational speed of the main shaft 144 rotated by the blade 132 using a gear into a rotational speed suitable for power generation, and includes a plurality of gears inside the gearbox 145. There is an increase gear (not shown). On the other hand, in the gearbox 145 for lubrication and cooling of a plurality of gears in the gearbox part, oil for a gearbox (not shown) may be provided.

The brake 146 is disposed at a position adjacent to the gearbox 145 to control the rotational force of the main shaft 144. At this time, the brake 146 may be mainly used in a disk type.

The generator 147 is a device that generates electricity using input rotational energy, and includes a rotor (not shown) and a stator (not shown) connected to a rotating shaft therein. The rotor generates electricity by rotating at high speed around the stator.

4 and 5, the mass part 210 is disposed in the inner space 132a of the blade 132 and is movable in the inner space 132a. Specifically, the mass portion 210 has a relative position of the mass portion 210 with respect to the hub 131 in the inner space 132a so that the rotation torque of the blade 132 increases while the blade 132 rotates. Change. For example, as shown in Figure 4 (a), the mass portion 210 may be disposed inside the blade 132 close to the hub 131, as shown in Figure 4 (b), the mass portion 210 ) May be disposed at the end of the blade 132 far from the hub 131.

As the blade 132 rotates, the mass part 210 may change the position of the inner space 132a of the blade 132 with respect to the direction of gravity. Specifically, (a) of FIG. 4 shows that the blade 132 is disposed in the opposite direction of the tower 110 around the hub 131. That is, (a) of FIG. 4 may indicate that the blade 132 is disposed in the 12 o'clock direction when viewed around the hub 131. In addition, (b) of FIG. 4 may indicate that the blade 132 is disposed around the hub 131 in the 6 o'clock direction. At this time, gravity acts in the -z-axis direction. That is, the mass part 210 receives gravity in the -z-axis direction.

Since the mass part 210 moves by gravity, the mass part 210 in FIG. 4A may be disposed close to the hub 131. In addition, in (b) of FIG. 4, the mass part 210 may be disposed farther from the hub 131. On the other hand, the mass portion 210 is disposed close to or far from the hub 131 is the same as the mass portion 210 is disposed close to or far from the rotor 130. That is, when the mass portion 210 is disposed away from the hub 131, the rotation torque of the rotor 130 may be increased. Specifically, as shown in FIG. 4B, when the mass portion 210 is disposed away from the hub 131 by gravity, the rotational torque of the rotor 130 may be increased.

Meanwhile, the blade 132 may further include a guide part 220 disposed in the inner space 132a of the blade 132 and guiding the movement of the mass part 210. In addition, the guide part 220 may extend through the mass part 210 or may be formed to surround the mass part 210. Specifically, as shown in FIG. 4, the guide part 220 may be disposed between end supports 132b disposed at both ends of the inner space 132a of the blade 132. In addition, the mass part 210 may be moved from one end of the inner space 132a of the blade 132 to the other end along the guide part 220.

The end support 132b supports the guide part 220. At the same time, the end support 132b may serve to limit the movable area of the mass part 210 in the inner space 132a of the blade 132.

Meanwhile, the blade 132 rotates in a direction from the z-axis of FIGS. 4 and 5 toward the y-axis. 5, the blade 132 rotates in a direction from (a) to (b), and from (b) to (c), that is, in a clockwise direction.

The mass part 210 may be moved in the inner space 132a so that the blade 132 is disposed close to the hub 131 when the inner space 132a of the blade 132 is perpendicular to the direction of gravity and then faces in a direction opposite to the direction of gravity. . Specifically, (a) in FIG. 5 may be referred to as a 9 o'clock direction from the direction facing the wind power generator 10. At this time, the blade 132 rotates toward (b). That is, in (a), the inner space 132a of the blade 132 is perpendicular to the direction of gravity (-z direction), and due to the rotation of the blade 132 (from (a) to (b) direction), the direction of gravity It is directed in the opposite direction.

At this time, the mass portion 210 disposed in the inner space 132a of the blade 132 moves from the end of the blade 132 to the inside of the blade 132 by gravity as the blade 132 rotates. That is, the mass part 210 may be disposed close to the hub 131.

At this time, the blade 132 may rotate at a low speed so that the mass portion 210 can be moved by gravity in the inner space 132a of the blade 132 while the blade 132 rotates. That is, when the blade 132 rotates from (a) to (b), gravity and centrifugal force may simultaneously act on the mass part 210. Gravity acts in a direction toward -z, and centrifugal force is in a direction toward the outside of the circle. If the rotational speed of the blade 132 is high, the force of the centrifugal force is greater than the force of gravity acting on the mass portion 210, so the mass portion 210 may not move close to the hub 131 by gravity. have.

Meanwhile, while the blade 132 rotates from (b) to (c), the mass portion 210 may be disposed inside the blade 132 close to the hub 131. In this case, the blade 132 may further include a damper 230 for reducing the impact of the mass part 210 colliding with the end support 132b. That is, the dampers 230 may be disposed inside the end supports 132b at both ends to reduce the impact of the mass part 210 moved by gravity colliding with the end supports 132b. The damper 230 may be disposed at both ends of the guide part 220 where the guide part 220 meets the end support 132b.

At this time, the device inside the blade 132 including the mass part 210, the guide part 220, and the damper 230 described above may be referred to as the rotation torque increasing/decreasing device 200. Further, referring to FIG. 6, the rotation torque increasing/decreasing device 200 may further include a motor 240, a connecting member 242, and an elastic body 250. This will be described later with reference to FIG. 6.

The wind turbine generator 10 according to an embodiment of the present invention described above has an advantage of being able to perform power generation even at a low wind speed. In addition, the wind power generator 10 according to an embodiment of the present invention increases the torque by aerodynamic force through the movement of the mass part 210 in the blade 132 inner space 132a while performing power generation even at a low wind speed. There is an advantage that a smaller blade 132 can be applied.

As the blade 132 passes through (c), the gravity acting on the mass portion 210 gradually decreases. Accordingly, the mass part 210 may be moved to the outside of the guide part 220 by centrifugal force. That is, the mass part 210 may be moved in the inner space 132a so as to be away from the hub 131 when the blade 132 inner space 132a is perpendicular to the direction of gravity and then is directed in the same direction as the direction of gravity. have.

For example, while the blade 132 passes through the position of (e), both centrifugal force and gravity are directed to the outside of the guide unit 220, so the mass unit 210 quickly moves to the outside of the guide unit 220 Can be. That is, the mass part 210 may be disposed at a position far from the hub 131.

When the blade 132 rotates in the same direction as the gravity direction along the rotation direction of the blade 132, the mass part 210 is the inner space 132a of the blade 132 In the direction of increasing the rotation torque of the blade 132 due to gravity can be moved. As described above, as the blade 132 passes through the (e) position, both centrifugal force and gravity are directed downward. Accordingly, the mass part 210 may be rapidly moved in the direction of increasing the rotational torque of the blade 132 by gravity in the inner space 132a of the blade 132, that is, toward the outer periphery of the guide part 220.

In the path in which the blade 132 moves from the (g) position to the (a) position, the centrifugal force and the gravity direction approximately coincide. Accordingly, the blade 132 may rotate while the mass part 210 is located at the outermost part of the guide part 220. In addition, the rotation torque value of the blade 132 may be increased to the maximum.

As described above, according to an embodiment of the present invention, according to the position of the rotating blade 132, the mass part 210 is moved by gravity, and the rotation torque of the rotor 130 is increased by the force generated at this time. I can make it. Through this, it is possible to reduce the size of the blade 132 of the wind power generator 10 that produces energy of a similar size.

In addition, according to an embodiment of the present invention, the movable mass portion 210 is disposed in the inner space 132a of the blade 132 to increase the torque of the rotor 130 by aerodynamic force, and/or gravity As a result, the torque of the rotor 130 may be increased. because of this. It is possible to maximize the energy output of the wind power generator 10.

6 is a conceptual diagram illustrating a state in which a mass part is moved by a motor according to another embodiment of the present invention. The embodiment shown in FIG. 6 differs only in that the wind generator 10 further includes a motor 240, a connecting member 242 and an elastic body 250 when compared to the embodiment shown in FIG. 4. , Since the other components are the same and similar, a description thereof will be omitted.

Referring to FIG. 6, the blade 132 may include a motor 240. The motor 240 may be disposed outside the end support 132b to reduce the starting torque of the blade 132, and may be disposed to move the mass part 210 toward the hub 131.

Specifically, FIG. 6 shows a state in which the blade 132 is disposed at the position (g) of FIG. 5. The mass part 210 is disposed to be moved in the -z-axis direction by weight. On the other hand, as the motor 240 is operated, the connecting member 242 connecting the motor 240 and the mass part 210 so that the mass part 210 is moved along the guide part 220 toward the hub 131 is May be included more.

In this case, in order to reduce the high starting torque that may occur when the mass part 210 is located at the end of the blade 132 by moving the mass part 210 close to the rotor 130, the motor 240 is operated. The mass part 210 may be moved in the z-axis direction from a position far from the hub 131. For example, when it is placed in the 6 o'clock direction as shown in FIG. 5(g), it is disposed close to the end of the blade 132, so that the starting torque increases. Therefore, in order to reduce this, it is necessary to arrange the mass part 210 close to the hub 131.

That is, when the blade 132 stops rotating, in order to reduce the starting torque required to rotate the blade 132 again, the motor 240 is operated so that the mass part 210 is placed near the hub 131. You can do it.

For example, the blade 132 is disposed at a position similar to that of (a), (b), (e), (f), (g) and (h) of FIG. 5, and the rotation of the blade 132 should have stopped. When the motor 240 described above can be operated.

According to an embodiment of the present invention, when the rotor 130 is stopped, the mass part 210 located at the end of the blade 132 is moved close to the rotor 130 through the motor 240 to move the mass part 210 ) Has the effect of reducing the high starting torque that may occur when the blade 132 is positioned at the end.

On the other hand, the blade 132 is interposed between the end support (132b) and the mass portion 210, the elastic body 250 to relieve the impact when the mass portion 210 is moved toward the end support (132b) by gravity. ) May be further included.

For example, when the elastic body 250 moves so that the mass part 210 approaches the hub 131 while rotating from (a) to (c) of FIG. 5, the impact applied to the end support (132b) can be alleviated. I can. In addition, as well as the impact reduced by the damper 230, there is an effect of additional impact reduction. Through this, it is possible to increase the durability of the rotation torque increasing/decreasing device 200. In addition, since the mass portion 210 inside the blade 132 is moved by gravity, if the blades 132 are not formed to be symmetrical to each other, the impact in any one direction may continue to occur, so that such an impact is prevented. There is an effect of reducing.

As described above, one embodiment of the present invention has been described, but those of ordinary skill in the relevant technical field add, change, delete or add components within the scope not departing from the spirit of the present invention described in the claims. It will be possible to variously modify and change the present invention by means of the like, and it will be said that this is also included within the scope of the present invention.

10: wind generator
110: tower
120: Nacelle
130: rotor
131: hub
132: blade
132a: inner space
132b: end support
140: power generation unit
144: main shaft
145: gearbox
146: brake
147: generator
200: rotation torque increase/decrease device
210: mass part
220: guide part
230: damper
240: motor
242: connecting member
250: elastic body
300: yawing system
310: yaw drive motor
330: pinion gear
350: dentition

Claims (14)

tower;
A nacelle positioned above the tower and rotatably coupled to a lower portion of the tower;
A rotor rotatably installed in front of the nacelle;
A blade spaced apart from and coupled to an outer circumferential surface of a hub disposed in front of the rotor along a circumferential direction, and having a space therein; And
It is disposed in the inner space of the blade and includes a mass portion made movable in the inner space,
A wind generator in which the relative position of the mass part with respect to the hub changes within the inner space. The method of claim 1,
The mass part,
As the blade rotates, the position of the inner space of the blade with respect to the direction of gravity changes. The method of claim 2,
The blade,
While the blade rotates, the mass portion rotates at a low speed so as to be movable by gravity within the inner space. The method of claim 3,
The mass part,
After the inner space of the blade is perpendicular to the direction of gravity, when it is directed in a direction opposite to the direction of gravity, it is moved in the inner space to be disposed close to the hub. The method of claim 3,
The mass part,
After the inner space of the blade is perpendicular to the direction of gravity, when it is directed in the same direction as the direction of gravity, it is moved in the inner space to move away from the hub. The method of claim 3,
The blade,
When any one of the blades rotates in the same direction as the direction of gravity along the rotational direction of the blades, the mass portion moves in a direction in which the rotational torque of the blades is increased by the gravity in the inner space of the blades. . The method of claim 1,
The blade,
It is disposed in the inner space of the blade, further comprising a guide portion for guiding the movement of the mass portion, wind power generator. The method of claim 7,
The blade,
Further comprising end supports disposed at both ends of the inner space so that the moving area of the mass part along the guide part is limited. The method of claim 8,
The guide part,
Extending through the mass portion, or formed to surround the mass portion, wind power generator. The method of claim 9,
The blade,
It is disposed at both ends of the guide portion, further comprising a damper for reducing the impact of the mass portion colliding with the end support, wind power generator. The method of claim 10,
The blade,
The wind generator further comprising an elastic body interposed between the end support and the mass portion, and for alleviating an impact when the mass portion is moved toward the end support by gravity. The method of claim 8,
The wind generator further comprises a motor disposed on the opposite side of the inner space of the end support to reduce the starting torque of the blade, and moving the mass portion toward the hub. The method of claim 12,
The motor is operated when the blade stops rotating. The method of claim 13,
The wind generator further comprises a connecting member connecting the motor and the mass portion so that the mass portion is moved toward the hub along the guide portion as the motor is operated.

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