JP2012067737A - Wind power generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wind power generator that efficiently generates electric power according to a window force over a wide range, and also efficiently suppresses the overrotation of the generator.SOLUTION: The wind power generator 10 drives the generator 12 by rotating a propeller 20, which has a plurality of blades 32 radially arranged in the periphery of a hub 30, using the force of window. The wind power generator includes: a pivot shaft 34 arranged in one of the hub 30 and the blade 32; a guide 36 arranged in the other of the hub and the blade and housing the pivot 34 freely movably; a clamping angle adjustment device changing the clamping angle α of the blades 32 to the rotary shaft of the hub 30, according to a radial movement to the hub 30 of the blades 32; and a spring 40 biasing the blades 32 inward in the radial direction of the hub 30 against the centrifugal force of the blade 32. When the blades 32 move outward in the radial direction against the biasing force of the spring, the blades are moved in the direction where the clamping angle α becomes smaller, through the clamping angle adjustment device.

Description

  The present invention relates to a wind power generator that obtains electric power by driving a power generator with wind power.

  Various types of wind power generators have been developed. In particular, a small variable-speed wind power generator that can generate power even when the wind strength is weak, according to the wind speed, to respond to fluctuations in the rotation speed of the impeller from low speed rotation to high speed rotation, Some output of the generator is converted to a constant frequency of commercial power, for example, via an AC-DC-AC inverter. In the case of such a variable speed type wind power generator, if the impeller is excessively rotated, an overcurrent flows through the armature on the stationary side of the generator, and the generator may be burned out. Further, the impeller itself may be physically damaged by centrifugal force due to over rotation. For this reason, under strong winds, it is common to protect the wind power generator from damage by stopping power generation or suppressing the rotational speed of the power generator.

  Usually, as a method of suppressing the rotation speed of the generator to prevent over-rotation, a method of mechanically braking using frictional force (see, for example, Patent Document 1), and a generator using the generated power There is an electromagnetic braking method (see, for example, Patent Document 2).

  JP2003-343419   JP2008-228570

  However, when braking mechanically, heat due to friction is generated between the members that move relative to the rotating side and the fixed side, and particularly when braking while maintaining a certain degree of rotation over a long period of time, Wear between rotating members also increases. Also, the electromagnetic braking method consumes the rotation of the impeller by the generator, which increases the power generation cost, and at this time, heat is generated inside the generator. The generation of such heat reduces the service life of the generator and causes damage. For this reason, even if it is a case where a wind speed fluctuates over a wide range, without generating unnecessary heat, the wind power generator which can generate electric power stably is desired.

  The present invention has been made based on such circumstances, and is capable of efficiently generating electric power according to wind strength over a wide range and capable of efficiently suppressing over-rotation of the generator. The purpose is to provide.

  In order to achieve the above object, according to the present invention, there is provided a wind power generator that drives a power generator by rotating a propeller having a plurality of blades radially arranged on a peripheral portion of the hub by the force of wind. A pivot shaft provided on one of the blades, a guide provided on the other of the hub and the blade for movably receiving the pivot shaft, and a radial movement of the blade relative to the hub according to the radial movement of the blade relative to the hub. A mounting angle adjusting device that changes a mounting angle of the blade; and a biasing device that biases the blade inward in the radial direction of the hub against centrifugal force, the blade resisting the biasing force of the biasing device. Thus, there is provided a wind power generator that moves the blade in a direction in which the mounting angle is reduced via the mounting angle adjusting device when moved outward in the radial direction.

The cam mechanism preferably includes a protrusion protruding from the outer peripheral surface of the pivot shaft and a groove provided on the inner peripheral surface of the guide and into which the protrusion is fitted.
The pivot may be attached integrally to the blade at the radially inner end of the blade, and the biasing device may include a spring having one end rotatably attached to the pivot. .

  According to the wind power generator of the present invention, when the wind force becomes stronger, the rotation speed of the propeller increases, and each blade moves radially outward by the centrifugal force, the blade moves radially outward. Accordingly, the cam mechanism moves in the direction of decreasing the blade mounting angle with respect to the rotation shaft of the hub, thereby suppressing the rotation speed of the propeller from increasing. Thereby, while being able to generate electric power efficiently according to the intensity | strength of the wind over a wide range, the excessive rotation of a generator can be suppressed efficiently.

When the cam mechanism has a protrusion protruding from the outer peripheral surface of the pivot shaft and a groove provided on the inner peripheral surface of the guide and into which the protrusion fits, the cam mechanism can be formed into a very simple structure. Reliable operation can be ensured.
When the pivot shaft is mounted integrally with the blade at the radially inner end of the blade, and the biasing device has a spring with one end rotatably mounted on the pivot shaft, the rotation of the pivot shaft is Smooth operation can be ensured without hindering.

Explanatory drawing which shows the wind power generator by embodiment of this invention. Explanatory drawing of the attachment part of the braid | blade of a propeller and a hub when the rotation speed of the wind power generator of FIG. 1 is small. Explanatory drawing of the attachment part of a braid | blade and a hub when the rotation speed of a propeller is large. Explanatory drawing when seeing a propeller from the front end side.

The cam mechanism which adjusts the attachment angle of a braid | blade is shown, (A) is explanatory drawing of the protrusion provided in the pivot pin, (B) is explanatory drawing of the groove | channel which this pivot pin fits.

1 to 5 show a wind power generator 10 according to a preferred embodiment of the present invention. In the figure, similar parts are denoted by the same reference numerals.
As shown in FIG. 1, the wind power generator 10 includes a propeller 20 disposed at the front end by a wind directional blade 18 disposed at the rear end of a housing 14 housing the power generator 12 that is rotatably supported by a column 16. Oppose to the wind. The generator 12 accommodated in the housing 14 includes a rotor 24 rotated by a horizontally disposed propeller shaft 22 and a stator 26 fixed to the housing 14 side, and a current generated in the stator 26 is led. 28 to a normal frequency converter (not shown).

  As shown in FIGS. 2 to 5, the propeller 20 includes a hub 30 that is integrally fixed to the tip of the propeller shaft 22, and three blades 32 in the present embodiment. They are arranged at equal intervals along the circumference of the hub 30. The illustrated blade 32 is formed in a so-called lift type, the thickness gradually decreases from the leading edge 32a side to the trailing edge 32b side, one side surface is formed into a smooth curved surface, and a smooth air flow is generated. Can be formed. As the shape of the blade 32, an appropriate shape is adopted as long as the rotational driving force of the propeller shaft 22 can be changed by changing the pitch, that is, the mounting angle with respect to the propeller shaft 22 which is the rotation shaft of the hub 30. It is possible.

  The hub 30 holding these blades 32 has a cone-like outer shape with rounded tips, and each blade 32 can be moved along the radial direction and the pitch can be changed via a coupling mechanism arranged inside. It is attached to. As long as the hub 30 can rotate integrally with the propeller shaft 22, the hub 30 is not limited to an integral structure, and can be assembled from a plurality of members. In any case, it is preferable that the outer shape has a smooth curved shape that does not hinder the air flow.

The propeller 20 of the present embodiment is a pivot shaft 34 that projects radially inward from the inner end of the blade 32, that is, the end on the hub 30 side, as a mounting angle adjusting device that changes the mounting angle of the blade 32 to the hub 30. And a guide 36 recessed in the hub 30.
The guide 36 has a cylindrical inner surface whose central axis extends along the radial direction of the propeller shaft 22, and slidably accommodates the blade 32 via the pivot shaft 34. The pivot shaft 34 moves in the axial direction within the guide 36 and can rotate within the guide 36 about the central shaft 34a. By rotating the blade 32 about the pivot 34, the reference line P of the blade 32 and the propeller shaft 22 pass through the central axis 34 a of the pivot shaft 34 and the rear edge 32 b of the blade 32 at the inner end portion of the blade 32. The mounting angle α formed between the central axis 22a and the central axis 22a can be changed.

  This attachment angle adjusting device is provided with a cam mechanism 38 that changes the attachment angle α (see FIG. 2) of the blade 32 in accordance with the radial movement of the blade 32 relative to the hub 30. The cam mechanism 38 is formed by a short shaft-shaped protrusion 35 protruding radially outward from the cylindrical side surface of the pivot shaft 34 and a groove 37 formed on the inner peripheral surface of the guide 36. Is formed by a groove 37 that rotates in the groove 37 about its central axis. The groove 37 opens outward on the inner end side close to the propeller shaft 22 and closes the outer end side, so that the projection 35 is fitted into the groove 37 from the inner end side, and along the groove 37. In addition to being movable in the radial direction, it is possible to prevent the protrusion 35 and thus the pivot shaft 34 from being pulled out radially outward from the closed outer end side.

  Such a pivot 34 has an end face on the inner end side of the blade 32 formed in a flat shape, protrudes from the flat surface toward the propeller shaft 22, and a guide 36 is formed of a hollow cylindrical cylinder member. It can be formed by being fixed inside the hub 30 formed in the above. In this case, it can be formed in a very simple structure and can be easily aligned. The inner end of the blade 32 is preferably not projected from the cone-shaped outer surface of the hub 30 when the pivot 34 moves most radially outward in the guide 36. Thereby, it is possible to prevent the pivot 34 from being exposed to the outside.

In the cam mechanism 38 having the projections 35 and the grooves 37, the grooves 37 may be formed on the pivot shaft 34 and the projections 35 may be formed on the inner surface of the guide 36. It is also possible to provide a cam mechanism in which a plurality of pairs of protrusions 35 and grooves 37 are provided.
In any case, when the projection 35 is disposed at the inner end side of the groove 37, that is, at a position close to the propeller shaft 22, the above-described mounting angle α is the largest and the smallest angle when the projection 35 is disposed at the outer end side. Is formed. The attachment angle α varies depending on the blade surface shape of the blade 32, but is preferably formed to be in the range of about 45 ° ± 5 ° within a range of 30 ° to 60 °, for example. When the mounting angle α is the smallest, it is preferable that the propeller 20 hardly rotates or only a slight driving force is formed in order to prevent the generator 12 from being burned out.

  Further, the propeller 20 is provided with a spring 40 as a biasing device that biases each blade 32 inward in the radial direction of the hub 30 against the centrifugal force during rotation. In the illustrated embodiment, the spring 40 is formed by a coil spring having one end attached to the inner end of the pivot 34. However, any blade spring can be used as long as each blade 32 can be urged radially inward of the hub 30. Etc. Further, instead of being directly attached to the pivot shaft 34, the blade 32 may be biased via a separate member such as a link mechanism. In any case, the urging device 40 is provided with a connecting portion that causes only the force along the direction of the central axis of the pivot shaft 34 to act on the blade 32 so as not to hinder the rotation of the pivot shaft 34 in the guide 36. Is preferred. For example, it is possible to insert a ball joint (not shown) between the inner end of the pivot shaft 34 and the spring 40, and such a connection portion is provided outward from the hub 30 instead of the pivot shaft 34. Any part that does not protrude can be provided at an appropriate position on the inner end side of the blade 32.

The wind power generator 10 thus formed operates as follows.
As shown in FIG. 1, the wind power generator 10 is supported by the upper end of the support | pillar 16 arrange | positioned in the orthogonal | vertical direction. The wind direction blades 18 arranged on the rear side move around the support column 16 in accordance with the direction of the wind so that the propeller 20 on the tip side always faces the direction in which the wind blows in the horizontal plane. For example, when the wind speed is weak, such as 1 m / sec, the propeller 20 hardly rotates or rotates at a low speed. Therefore, as shown in FIG. Arranged in a state of being pulled inward.

  Accordingly, the protrusion 35 of the pivot shaft 34 is disposed at a position closest to the propeller shaft 22 in the groove 37 of the guide 36. The blade 32 is disposed in the state where the mounting angle α is the largest. The blade 32 is arranged with the largest surface facing the wind. Thereby, even if it is a weak wind, the propeller 20 is rotated and the electric power formed with the generator 12 can be taken out via a frequency converter.

  When the wind speed increases and the rotation speed of the propeller 20 increases, the centrifugal force acting on the blade 32 increases, and moves outward in the radial direction of the hub 30 against the biasing force of the spring 40, that is, the biasing device (see FIG. 3). The pivot shaft 34 rotates while being guided by the groove 37 in the groove 37, moves in the guide 36 outward in the axial direction, and rotates the blade 32 in a direction in which the mounting angle α decreases.

  When the attachment angle α of the blade 32 is reduced, the area that receives the wind is reduced, the lift force that is formed is also reduced, and the rotation of the propeller 20 is suppressed even when the wind speed is increased. When the centrifugal force acting on the blade 32 is reduced by suppressing the rotation of the propeller 20, the blade 32 is moved inward in the radial direction by the biasing force of the spring 40, and again approaches the propeller shaft 22. As a result, the mounting angle α of the blade 32 is automatically adjusted to a magnitude balanced by the rotational speed of the propeller 20 and the urging force of the urging device such as the spring 40. Therefore, it is possible to reliably prevent the propeller 20 and therefore the generator 12 from over-rotating.

  Therefore, according to the wind power generator 10, when the wind force is increased, the rotation speed of the propeller 20 is increased, and each blade 32 is moved radially outward by the centrifugal force, the blade 32 is radially outward. The cam mechanism 38 of the mounting angle adjusting device moves in a direction to decrease the mounting angle α of the blade 32 with respect to the propeller shaft center line 22a of the hub 30 in accordance with the movement to the angle, thereby suppressing the rotation speed of the propeller 20 from increasing. To do. Thereby, while being able to generate electric power efficiently according to the intensity | strength of the wind over a wide range, the excessive rotation of a generator can be suppressed efficiently.

Even under strong winds, it is not necessary to provide an electrical or mechanical brake that stops power generation or suppresses over-rotation of the generator 12, and thus cooling of the heat during braking by such a brake is unnecessary.
When the cam mechanism 38 has a protrusion 35 protruding from the outer peripheral surface of the pivot shaft 34 and a groove 37 provided on the inner peripheral surface of the guide 36 and into which the protrusion 35 is fitted, the cam mechanism 38 is formed in a very simple structure. Therefore, the reliable operation can be ensured.

  If the pivot shaft 34 is attached to the radially inner end of the blade 32 integrally with the blade 32 and the biasing device has a spring 40 which is rotatably attached to the pivot shaft 34 at one end, the pivot A smooth operation can be ensured without the spring 40 hindering the rotation of the shaft 34.

  It should be noted that the present invention is not limited to the above-described embodiment, and it is obvious that various changes or modifications can be made within the scope of the invention described in the claims. For example, when the blade 32 moves radially outward by centrifugal force, the tip can be tilted backward, that is, toward the wind vane 18 side.

DESCRIPTION OF SYMBOLS 10 ... Wind generator 12 ... Generator 20 ... Propeller 30 ... Hub 32 ... Blade 34 ... Pivot shaft 36 ... Guide 40 ... Spring alpha ... Mounting angle

Claims (3)

A wind power generator that drives a power generator by rotating a propeller having a plurality of blades radially arranged around the hub by the force of wind,
A pivot shaft provided on one of the hub and the blade, a guide provided on the other of the hub and the blade to movably accommodate the pivot shaft, and a radial movement of the blade with respect to the hub A mounting angle adjusting device that changes a mounting angle of the blade with respect to the hub, and a biasing device that biases the blade inward in the radial direction of the hub against a centrifugal force. A wind power generator characterized by moving a blade in a direction in which the mounting angle is reduced via the mounting angle adjusting device when moving outward in the radial direction against an urging force.   2. The wind power generation according to claim 1, wherein the cam mechanism includes a protrusion protruding from an outer peripheral surface of the pivot shaft and a groove provided on an inner peripheral surface of the guide and into which the protrusion is fitted. Machine.   The pivot is attached to the blade at a radially inner end thereof integrally with the blade, and the biasing device includes a spring having one end rotatably attached to the pivot. Or the wind power generator of 2.

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