JP2002031031A - Variable vane pitch mechanism of windmill - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a variable vane pitch mechanism of a windmill capable of shortening the total length of a nacelle and reducing the loss of an actuator. SOLUTION: In this windmill having a rotor head 14 on a tip of a rotating shaft 13, and varying a pitch angle of a vane 10 through a converting mechanism 60 by sliding a push pull rod 21, a hydraulic cylinder 56 is inclined to the rotating shaft 13, and the push pull rod 21 comprises a screw shaft cover 23, a rod body 30 slidably inserted into the cover 23 and connected to the converting mechanism 60 at its tip, a screw shaft 25 engaged with a nut part 26 mounted on the rod body 30, a clutch for permitting and inhibiting the rotation of the screw shaft 25, and a spring 37 for energizing the rod body 30 in the tip direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wind turbine, and more particularly to a variable blade pitch mechanism of a wind turbine.

[0002]

2. Description of the Related Art For example, a windmill used for wind power generation, etc.
Especially in large wind turbines, the startup torque is increased by the variable pitch blades, and the number of revolutions is controlled according to the wind speed.
At the time of strong wind, the resistance is reduced by feathering which makes the wing parallel to the wind direction.

This variable blade pitch mechanism is disclosed in, for example,
As disclosed in Japanese Patent Publication No. 4344 and schematically shown in FIG. 10, a movable shaft 102 extending within a main shaft 101 passes through the inside of a parallel gear 103, and has a radial bearing 1 at an end.
The radial bearing 104 is connected to a hydraulic cylinder 106 disposed coaxially with the movable shaft 102 via a spring receiver 105. Parallel gear 1
An axial driving force of a spring 107 and a hydraulic cylinder 106 disposed between the spring 03 and the spring receiver 105 is transmitted to the movable shaft 102 via a radial bearing 104, and is converted into a rotational motion of the wing 109 by a link 108. It is configured as follows.

Accordingly, when hydraulic pressure is supplied to the hydraulic cylinder 106, the driving force of the hydraulic cylinder 106 is transmitted to the movable shaft 102 via the radial bearing 104 that supports the end of the movable shaft 102, and the driving force is transmitted to the movable shaft 102 by this driving force.
Slides in the axial direction, and the blade pitch is changed by a link 108 connected to the movable shaft 102.

When the hydraulic pressure of the hydraulic cylinder 106 is lost, the spring 107 slides the movable shaft 102 in the reverse direction, so that the blade pitch converted by the action of the hydraulic cylinder 106 is restored to its original state, that is, the feathering position. Side.

[0006]

SUMMARY OF THE INVENTION The above-mentioned Japanese Patent Application Laid-Open No. 7-434.
According to Japanese Patent Publication No. 4 (1994) -104, the blade pitch is variably controlled by the operation of the hydraulic cylinder 106, and even when the hydraulic pressure of the hydraulic cylinder 106 is lost, the blades 109 are
Can be changed to the feathering position side.

However, the hydraulic cylinder 106 and the variable shaft 10
2 is arranged coaxially and connected, there is a concern that the effect of wind pressure acting on the nacelle increases with the increase in the nacelle length direction of the nacelle of the wind turbine and the increase in the size of the nacelle.
The urging force of the spring 107 mounted between the parallel gear 103 and the spring receiver 105 is constantly applied to the hydraulic cylinder 10.
6, the urging force may cause a large loss of the hydraulic pressure of the hydraulic cylinder 106.

Accordingly, a first object of the present invention, which has been made in view of the above points, is to provide a variable blade pitch mechanism of a wind turbine which can reduce the size of the nacelle by shortening the length of the nacelle in the nacelle. . Further, the second aspect of the present invention
It is an object of the present invention to provide a wind turbine blade pitch variable mechanism capable of greatly reducing the hydraulic pressure loss of an actuator.

[0009]

According to a first aspect of the present invention, there is provided a wind turbine blade pitch varying mechanism for achieving the first object.
A rotor head that supports the base end of the wing so that the pitch angle can be changed is provided at the tip of a cylindrical rotating shaft that is rotatably supported on the base, and the rotor head is provided by a control actuator that is arranged on the base end side of the rotating shaft. A wind turbine blade pitch variable mechanism that slides a push-pull rod slidably inserted into a rotation shaft and changes a pitch angle of the blade via a conversion mechanism that connects the push-pull rod and a base end of the blade. The control actuator is an actuator that expands and contracts and is arranged so that the expansion and contraction direction is inclined with respect to the axial direction of the rotation shaft. And a link mechanism.

According to the first aspect of the present invention, since the actuator is arranged so that the direction of expansion and contraction of the actuator is inclined with respect to the axial direction of the rotation shaft, the drive unit can be shortened in the direction of the rotation axis and the nacelle can be reduced in size. Is brought about.

According to a second aspect of the present invention, in the wind turbine blade pitch varying mechanism according to the first aspect, the actuator comprises:
A hydraulic cylinder supported at the base by the base, wherein the link mechanism is configured such that a distal end of a first arm extending from a boss portion rotatably supported by the base has a base end of a push-pull rod. And a tip end of a second arm extending to the boss portion is a bell crank slidably connected to a tip of the hydraulic cylinder.

According to the second aspect of the present invention, the actuator is formed by a hydraulic cylinder which is arranged to be inclined with respect to the rotation axis, and the link mechanism is constituted by a bell crank which connects between the hydraulic cylinder and the push-pull rod. Thereby, the inclined arrangement of the hydraulic cylinder is facilitated, the stroke of the push-pull rod can be easily changed by changing the link ratio of the bell crank, and the thrust by the wing can be changed.

According to a third aspect of the present invention, in the wind turbine blade pitch varying mechanism of the first or second aspect, the actuator has a base end on the rotor head side with respect to a tip end, and
It is characterized by being arranged obliquely so as to intersect with the rotation axis in a side view.

According to the third aspect of the present invention, by arranging the actuator obliquely so as to intersect with the rotation axis in a side view state, it is possible to shorten the drive unit in the direction of the rotation axis, and to reduce the size of the nacelle. Is brought about.

According to a fourth aspect of the present invention, there is provided a variable blade pitch mechanism for a wind turbine, wherein a pitch angle can be freely changed at a tip of a cylindrical rotary shaft rotatably supported by a base. A rotor head for supporting the base end of the wing is provided, and a push-pull rod slidably inserted into the rotation shaft is slid toward the rotor side by a control actuator disposed on the base end side of the rotation shaft, whereby the push-pull rod is provided. A wind turbine blade pitch variable mechanism that changes the pitch angle of the blade to the feathering side via a conversion mechanism that connects the tip end of the blade to the base end of the blade, wherein the push-pull rod extends along the axial direction of the push-pull rod. And a hollow first shaft portion, a base end of which is slidably inserted into the first shaft portion and opened, and a tip end of which is the first shaft portion.
A hollow second shaft portion protruding from the distal end of the shaft portion and connected to the conversion mechanism; a nut portion provided at a base end portion of the second shaft portion; A third shaft rotatably supported by the shaft, fixing means for allowing and preventing rotation of the third shaft with respect to the first shaft, and bridging between the first shaft and the second shaft; And the second from the tip of the first shaft
And a biasing means for biasing the tip of the shaft portion toward the protruding side.

According to the fourth aspect of the present invention, when the control actuator becomes inoperable, the fixing of the third shaft portion by the fixing means is released at any pitch position of the wing, so that the urging means can be released. The urging force is released and the second shaft is urged in the projecting direction from the first shaft to extend the push-pull rod to change the wing to the feathering side via the conversion mechanism, and to perform normal operation. Sometimes, the urging force of the urging means does not act on the control actuator, the loss of the operating force of the control actuator is suppressed, and the required capacity of the control actuator can be set low, which leads to downsizing of the control actuator. .

According to a fifth aspect of the present invention, in the wind turbine blade pitch varying mechanism according to the fourth aspect, the nut portion and the third shaft portion are configured such that the biasing means causes the second shaft portion to have a feather pitch angle. It is characterized by being extended to the ring position.

According to the fifth aspect of the present invention, the wind turbine can be quickly stopped by changing the wing to the feathering position by the urging means.

According to a sixth aspect of the present invention, in the wind turbine blade pitch variable mechanism according to the fourth or fifth aspect, the fixing means allows the rotation of the third shaft when the operating force of the control actuator is lost. When the operating force of the control actuator is lost and the pitch angle of the blade is at the feathering position, the rotation of the third rotation shaft is prevented.

According to the sixth aspect of the present invention, when the rotation of the third shaft is permitted when the operating force of the control actuator is lost, the second shaft is urged in the projecting direction from the first shaft by the urging means and pushed. The pull rod extends, the wing is changed to the feathering side via the conversion mechanism, and the rotation of the third rotating shaft is prevented at the feathering position, so that the push-pull rod stops extending and the wing moves to the feathering position. Will be retained.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a wind turbine blade pitch varying mechanism according to the present invention will be described below with reference to FIGS.

FIG. 1 is a sectional view of a main part of a blade pitch variable mechanism showing an outline of the present embodiment, and FIG. 2 is a view taken in the direction of arrow A in FIG. In the figure, reference numeral 1 denotes a tower formed in a cylindrical shape, and a base 2 is provided at the upper end of the tower 1 so as to be rotatable on the axis of the tower 1, and the base 2 is a base such as a hydraulic motor or an electric motor. It is rotationally driven by the table rotation actuator 3. The casing 6 of the generator 5 is supported on the base 2 by the nacelle frame 4, and a driving unit 11 that supports the blade 10 is provided. In the drawing, reference numeral 8 denotes a nacelle that covers the drive unit 11, the generator 5, and the like.

The driving section 11 has a cylindrical housing 12 provided in the nacelle frame groove 4 and having an axis extending substantially horizontally, and a cylindrical rotating shaft 13 extending through the housing 12. It is rotatably supported by a bearing 12a.

A hollow rotor head 14 is provided at the tip of the rotating shaft 13, and a bearing 15 a is attached to the rotor head 14.
A wing connecting shaft 15 to which the base of the wing 10 is connected via the shaft is rotatably supported, and a rotor 7 of the generator 5 is connected to the rotating shaft 13.

The variable blade pitch mechanism 2 extends from the inside of the rotor head 14 through the inside of the rotating shaft 13 to the base end side of the rotating shaft 13.
0 is provided.

The blade pitch variable mechanism 20 is disposed within the rotary shaft 13 and is slidable in the axial direction.
A control actuator 50 for sliding the push-pull rod 21 in the axial direction of the rotating shaft 13; and a push-pull rod 21 disposed in the rotor head 14.
And a conversion mechanism 60 for converting the reciprocating motion of the wing connection shaft 15 into a rotary motion. These push-pull rod 21, control actuator 50,
Although the conversion mechanism 60 operates in conjunction with each other, each configuration will be described for convenience of description, and then the operation state will be described.

The push-pull rod 21 has a pin 3
4, the base is connected to the movable shaft 61 of the conversion mechanism 60, and the base end protrudes from the rotation shaft 13, is swingably connected to the arm link 51 of the control actuator 50, and is slidably disposed in the rotation shaft 13.

The push-pull rod 21 will be described in detail with reference to FIGS. FIG. 3 shows the push rod 21
FIG. 4 is a cross-sectional view of FIG. 3, and FIG.
FIG. 2 is a sectional view taken along line II of FIG.

The push-pull rod 21 has a base member 22 formed on both sides with a protruding pin portion 22a to which the bell crank 51 of the control actuator 50 is swingably connected. The base end of a screw shaft cover 23 which is a first shaft part formed in a rectangular pipe shape having a rectangular cross section extending along the axial direction, that is, a cylindrical shape, is further joined.
The base end of the screw shaft 25 which becomes a third shaft extending in the axial direction through the base is penetrated and rotatably supported.

A helical ball groove 25a is formed on the outer periphery of the screw shaft 25, and a cylindrical nut portion 26 having a helical ball groove 26a formed on the inner periphery is fitted to the outer periphery of the screw shaft 25. The ball 27 is fitted between the ball grooves 25a and 26a of the screw shaft 25 and the nut portion 26 to form a ball screw mechanism. More specifically, the nut portion 26 has a ball groove 26
A ball return path (not shown) which is continuous with the ball a is formed, and an endless circulation path of the ball 27 is formed by the ball groove 26a and the ball return path. A large number of balls 27 are arranged and housed in the endless circulation path.

On the distal end side of the nut portion 26, a rotation prevention member 28 having a rectangular cylindrical shape is provided on the inner periphery of the screw shaft cover 23, which is axially movable via a roller 28a and whose rotation is restricted in the circumferential direction. Are joined to prevent rotation of the nut portion 26. In such a configuration, each ball 2
Numerals 7 roll and circulate while receiving a load on the ball groove 25a while rotating the screw shaft 25 with the movement of the nut portion 26 in the axial direction.

The anti-rotation member 28 has a cylindrical rod body 3 whose base end is slidably disposed in the screw shaft cover 23 and serves as a second shaft extending in the axial direction.
0 is joined at the base end.

The rod body 30 includes a proximal rod 31 joined to the rotation preventing member 28 and a distal rod 3 joined to a distal end of the proximal rod 31 via a connecting fitting 32.
The distal end of the rod 33 is connected to the movable shaft 61 of the conversion mechanism 60 by a pin 34 or the like.

A spring 37 fitted to the outer periphery of the proximal rod 31 is compressed between a spring receiver 35 formed on the connection fitting 32 and a spring receiver 36 disposed at the distal end of the screw shaft cover 23. It is mounted in a state. The outer periphery of the spring 37 is covered by a spring cover 38.

Further, the base member 22 and the screw shaft 2
5 is provided with a clutch 40 for controlling the rotation of the screw shaft 25. Clutch 40
For example, when the clutch power supply is turned on, the clutch plate 41 attached to the base end of the screw shaft 25 is opened to allow the screw shaft 25 to rotate, and when the clutch power supply is turned off, the clutch plate 41 is closed to prevent the screw shaft 25 from rotating. It is constituted by an electromagnetic clutch. Reference numeral 42 denotes a rod detection switch that detects the retreat position of the rod body 30 when the end of the nut 26 contacts.

Next, the control actuator 50 will be described with reference to FIG. 6 showing an enlarged view of a portion B in FIG. 1 and FIG.

The control actuator 50 includes a support bracket 5 attached to the casing 6 of the generator 5.
A boss portion 5 pivotally supported by a support shaft 53 extending above the rotation shaft 13 and perpendicular to the axis thereof in plan view;
1a, a first arm 51b extending substantially downward from the boss 51a and having a branched tip pivotally coupled to a pin 22a formed in the base member 22, and a boss 51a.
And a second arm 51c extending in a direction away from the generator 5 along the axis extending direction from the bell crank 5.
1 is provided, and the distal end of the second arm 51c is connected to the actuator 55.

The actuator 55 has its base end supported by a bracket 57 provided below the casing 6 of the generator 5 via a support shaft 58 extending perpendicularly to the axis of the rotation shaft 13 in plan view. Is supported by the second arm 51c by the support shaft 59.
And a hydraulic supply device 56 such as a hydraulic pump for supplying hydraulic pressure to the hydraulic cylinder 56.
The hydraulic cylinder 56 is disposed so as to be inclined so as to intersect the axis of the rotation shaft 13 in a side view so that the base end is closer to the rotor head 14 than the front end.

Next, the conversion mechanism 60 will be described with reference to FIG.

The conversion mechanism 60 disposed in the hollow rotor head 14 has a movable shaft 61 connected to the distal end of the distal rod 33 by a pin 34 or the like. The movable shaft 61 is supported by the rotor head 14. A plurality extending in the axial direction,
For example, a slider arm 63 slidably supported in the axial direction by three guide rails 62 is rotatably supported via a thrust bearing 64.

An arm link 65 is provided between the slider arm 63 and the blade connection shaft 15. By moving the movable shaft 61 in the distal direction along the axis, the slider arm 63 moves in the distal direction along the guide rail 62 via the thrust bearing 64, and the arm link 6 is moved.
5, the linear motion is converted into the rotary motion, and the blade connection shaft 1 is converted.
5 is moved to the feathering side, and the movable shaft 61 is moved in the proximal direction, so that the slider arm 63 is moved to the proximal side along the guide rail 62 and the arm link 65 is moved.
As a result, the blade connection shaft 15 is turned to the flat side.

Further, at the tip of the movable shaft 61, a proximity switch 66 for detecting a flat position in proximity to the projection 14a formed on the rotor head 14 for detecting a flat position, and
A feathering position detection proximity switch 67 for detecting a feathering position in proximity to the projection 14b is attached.

Next, the operation of the variable blade pitch mechanism configured as described above will be described.

First, during normal use, the rotation of the screw shaft 25 is prevented by the clutch 40 with the push rod 21 contracted as shown in FIGS. The ball 27 fitted between the ball grooves 25a and 26a without any rotation prevents the axial movement of the screw shaft 25 and the nut portion 26 in the axial direction, thereby preventing the push-pull rod 21 from expanding and contracting in the axial direction. I have.

Now, the blade 10 receives the wind, the rotating shaft 13 is rotated via the blade connecting shaft 15 and the rotor head 14, and the generator 5 is driven. When hydraulic pressure is supplied to the hydraulic cylinder 56 during this operation, the bell crank 51 rotates around the support shaft 53 in the direction of the arrow FL shown in FIG. Second of bell crank 51
The push rod 21 connected to the distal end of the arm 51c slides to the proximal end side, and the slider arm 63 moves to the proximal end along the guide rail 62 by the movable shaft 61 connected to the distal end of the push-pull rod 21 by the pin 34. Then, the linear motion is converted into the rotary motion by the arm link 65, and the blade connection shaft 15 is rotated to the flat side, so that the blade 10 can be changed to the operating position moved from the feathering side to the flat side.

Similarly, when the bell crank 51 rotates in the direction of arrow FE shown in FIG. 1 by the contraction of the hydraulic cylinder 56, the push-pull rod 21, the movable shaft 61 and the slider arm 65 are pushed to the distal end side, and the arm link 65. As a result, the linear motion is converted into a rotary motion, and the blade connection shaft 15 is turned to the feathering side, and the blade 10 is changed to the operating position in which the blade 10 is moved from the flat side to the feathering side.

In the flat position shown by the solid line in FIG. 9, the wing 10 has a flat position detecting proximity switch 66 provided at the end of the movable shaft 61 close to the projection 14a formed on the rotor head 14. At the feathering position indicated by the broken line in FIG. 9, the feathering position detecting proximity switch 67 provided at the tip of the movable shaft 51 approaches the projection 14b, and the feathering position is detected. The variable range of the pitch of the wing 10 is restricted by detecting these positions. That is, the sliding range of the push rod 21 due to the expansion and contraction of the hydraulic cylinder 56 is restricted.

When the actuator 55 becomes inoperable due to a loss of the hydraulic pressure supplied to the hydraulic cylinder 56, power is supplied to the clutch 40 from a power source provided separately, and the power is supplied to the proximal end of the screw shaft 25. The attached clutch plate 41 is released, and the screw shaft 25 becomes rotatable.

When the rotation of the screw shaft 25 is permitted, the screw shaft 25 and the nut portion 26 screwed by the ball screw mechanism formed by the ball grooves 25a and 26a and the ball 27 and the like can expand and contract in the axial direction. And the spring receiver 3 provided on the connection fitting 32
5 and a spring 37 elastically mounted between a spring receiver 36 disposed at an end of the screw shaft cover 23.
The push-pull rod 21 is extended while rotating the screw shaft 25 by the urging force.

With the extension of the push-pull rod 21, the slider arm 63 is moved toward the distal end along the guide rail 62 by the movable shaft 61 connected to the distal end of the push-pull rod 21 by the pin 34.
Is turned to the feathering side to change the wing 10 to the feathering side.

When the feathering position detecting proximity switch 67 provided on the movable shaft 51 detects the feathering position by approaching the projection 14b, the power supply of the clutch 40 is turned off.
The switching clutch 40 is operated to stop and hold the rotation of the screw shaft 25, that is, the push-pull rod 21
Is stopped, the wing 10 is fixed at the feathering position, and the windmill is stopped.

With the wind turbine stopped, the hydraulic cylinder 5
6 to repair the actuator 55
Restore 5

Thereafter, electric power is supplied to the clutch 40 and the clutch plate 4 attached to the screw shaft 25 is supplied.
1 is released to allow the screw shaft 25 to rotate freely,
The hydraulic cylinder 56 is contracted to push the proximal end of the push-pull rod 21 toward the distal end via the bell crank 51.
With the pushing of the base end, the screw shaft 25 is rotated by the ball screw mechanism while the screw shaft 25 is contracted against the urging force of the spring 37, the screw shaft 25 is completely contracted, and the nut portion 42 is inserted into the rod. The clutch current is interrupted by contacting the detection switch 42, the rotation of the screw shaft 25 is prevented by the clutch 40, and the screw shaft 25 is returned to the initial state.

According to the embodiment described above, since the hydraulic cylinder 56 and the push-pull rod 21 are connected via the bell crank 51, the bell rank 51
By changing the link ratio between the first arm 51b and the second arm 51c, the stroke of the push-pull rod 21 can be easily changed, and the change of the thrust by the wing 10 becomes easy. The control actuator 50
Is attached to the cover 6 of the generator 5, the support rigidity of the control actuator 50 is secured, the influence on the blade pitch control due to the elastic deformation of the support portion is avoided, and the hydraulic cylinder 56 and the bell clamp Since the connecting portion 51 and the connection between the bell crank 51 and the push-pull rod 21 are disposed outside the rotary shaft 13, maintenance such as replacement of the hydraulic cylinder 56 and the control actuator 50 such as the bell crank 51 becomes easy.

Further, by disposing the actuator, in particular, the hydraulic cylinder 56 at an angle so as to intersect with the push-pull rod 21 in a side view, the total length of the drive unit 11 can be reduced, and the total length of the nacelle 8 can be suppressed. it can.

Further, the constituent members of each push-pull rod 21 such as the screw shaft 25, the nut portion 26, the spring 37 and the clutch 40 can be mounted separately from the control actuator 50 such as the bell crank 51 and the hydraulic cylinder 56. Assembly becomes easy.

On the other hand, when the actuator 55 such as the hydraulic cylinder 56 becomes inoperable, the urging force of the spring 37 is released by releasing the fixing of the screw shaft 25 by the clutch 40 at any pitch position of the blade 10. When released, the push-pull rod 21 starts to elongate, the blade 10 can be changed to the feathering side to quickly stop the windmill, and the urging force of the spring 37 acts on the hydraulic cylinder 56 during normal operation. In addition, the hydraulic pressure loss of the hydraulic cylinder 56 is suppressed, and the required capacity of the hydraulic cylinder 56 can be set low, so that the hydraulic cylinder 56 can be downsized.

The expansion and contraction characteristics of the push-pull rod 21 can be adjusted by appropriately changing the leads of the ball grooves 25a and 26a of the screw shaft 25 and the nut portion 26. By using the nut portion 26 and the like screwed by a ball screw mechanism, the outer diameter is particularly reduced, and the rotary shaft 13 is compactly housed. Further, the clutch 40 that controls the rotation of the screw shaft 25 can use many general-purpose clutches that stop and allow the rotational movement.

The present invention is not limited to the above embodiment, but can be variously modified without departing from the spirit of the invention. For example, in the above-described embodiment, the rod body 30 is formed by connecting the proximal rod 31 and the distal rod 33 with the connecting fitting 32.
And the distal rod 33 can be formed in a continuous and integral pipe shape, and other types of telescopic actuators such as an electric actuator that expands and contracts by an electric motor can be used instead of the hydraulic cylinder 56. .

[0060]

According to the wind turbine blade pitch varying mechanism of the present invention described above, a rotor head for supporting the base end of the blade so that the pitch angle can be changed is provided at the tip of the rotary shaft, and the base end side of the rotary shaft is provided. In a blade pitch variable mechanism that slides a push-pull rod that is slidably inserted into a rotary shaft by a control actuator disposed in a rotary shaft, and changes a pitch angle of the blade via a conversion mechanism, an actuator is arranged in the axial direction of the rotary shaft. By arranging such that the direction of expansion and contraction of the drive unit is inclined, the drive unit can be shortened in the rotation axis direction, and the total length of the nacelle can be shortened.

Further, when the control actuator becomes inoperable, the urging force of the urging means is released by releasing the fixing of the third shaft portion by the fixing means at any pitch position of the blade. The shaft portion is urged in the protruding direction from the first shaft portion so that the push-pull rod extends and can be changed to the feathering side, and the urging force of the urging means does not act on the actuator during normal operation, The loss of the operating force of the control actuator is suppressed, so that the required performance of the control actuator can be set low, and the size of the control actuator can be reduced.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a main part showing an outline of an embodiment of a blade pitch varying mechanism of a wind turbine according to the present invention.

FIG. 2 is a view taken in the direction of arrow A in FIG. 1;

FIG. 3 is a side view showing an outline of a push-pull rod.

FIG. 4 is a sectional view of FIG. 3;

FIG. 5 is a sectional view taken along line II of FIG. 4;

FIG. 6 is an enlarged view of a portion B in FIG. 1;

FIG. 7 is a view as viewed in the direction of arrow C in FIG. 6;

FIG. 8 is an enlarged view of a portion D in FIG. 1;

FIG. 9 is an explanatory diagram showing an operating state of the wing, where a solid line indicates a flat state and a broken line indicates a feathering state.

FIG. 10 is a sectional view of a main part of a variable blade pitch mechanism in a conventional wind turbine.

[Explanation of symbols]

 2 Nacelle base (base) 4 Nacelle frame (base) 5 Generator 6 Casing 8 Nacelle 10 Blade 11 Drive unit 12 Housing 13 Rotary shaft 14 Rotor head 15 Blade connection shaft 20 Blade pitch variable mechanism 21 Push-pull rod 22 Base end Member 23 Screw shaft cover (first shaft portion) 25 Screw shaft (third shaft portion) 25a Ball groove 26 Nut portion 26a Ball groove 27 Ball 28 Rotation preventing member 30 Rod body (second shaft portion) 31 Base end rod 32 Connection fitting 33 Tip rod 37 Spring (biasing means) 40 Clutch (fixing means) 41 Clutch plate 42 Rod detection switch 50 Control actuator 51 Bell crank 51a Boss 51b First arm 51c Second arm 52 Support bracket 53 Support shaft 55 Actuator Tab 56 Hydraulic cylinder 58 Support shaft 59 Support shaft 60 Conversion mechanism 61 Movable shaft 62 Guide rail 63 Slider arm 64 Thrust bearing 66 Flat position detection proximity switch 67 Feathering position detection proximity switch

Claims (6)

[Claims] 1. A rotor head for supporting a base end of a blade so that a pitch angle can be freely changed is provided at a tip of a cylindrical rotary shaft rotatably supported on a base, and is disposed on a base end side of the rotary shaft. A control actuator that slides a push-pull rod slidably inserted into the rotary shaft and changes a pitch angle of the wing via a conversion mechanism that connects the push-pull rod and a base end of the wing. In the variable mechanism, the control actuator includes an actuator that expands and contracts and extends and contracts with respect to the axial direction of the rotation shaft, and converts the operation of the actuator into a slide driving force of the push-pull rod and pushes the actuator. A variable blade pitch mechanism for a wind turbine, comprising a link mechanism for sliding a pull rod. 2. The hydraulic actuator according to claim 1, wherein the actuator is a hydraulic cylinder having a base end supported by the base, and the link mechanism is extended by a boss portion rotatably supported by the base. A bell crank having a distal end of the arm swingably connected to a base end of the push-pull rod and a distal end of a second arm extending from the boss portion swingably connected to a distal end of the hydraulic cylinder. The blade pitch variable mechanism for a wind turbine according to claim 1, wherein: 3. The actuator according to claim 1, wherein the actuator has a base end inclined with respect to a tip end on the rotor head side and crossing the rotation axis in a side view. Wind turbine blade pitch variable mechanism. 4. A rotor head for supporting a base end of a blade so that a pitch angle can be freely changed is provided at a distal end of a cylindrical rotary shaft rotatably supported on a base, and is disposed on a base end side of the rotary shaft. The control actuator moves a push-pull rod slidably inserted into the rotary shaft toward the rotor side, so that the pitch angle of the wing is converted via a conversion mechanism that connects the tip of the push-pull rod and the base end of the wing. The push-pull rod comprises: a hollow first shaft portion continuous along the axial direction of the push-pull rod; and a base end slidable in the first shaft portion. A hollow second shaft connected to the conversion mechanism with a distal end protruding from the distal end of the first shaft and being connected to the second shaft; A pivoted nut portion, a third shaft portion screwed to the nut portion and rotatably supported by the first shaft portion, and allowing and preventing rotation of the third shaft portion with respect to the first shaft portion. Fixing means; and urging means provided between the first shaft part and the second shaft part to urge the tip of the second shaft part from the front end of the first shaft part to project from the front end of the first shaft part. A variable pitch mechanism for wind turbine blades. 5. The windmill according to claim 4, wherein the nut portion and the third shaft portion extend the second shaft portion by the urging means until the pitch angle of the blades reaches the feathering position. Wing pitch variable mechanism. 6. The fixing means allows the rotation of the third shaft portion when the operating force of the control actuator is lost, the operating force of the control actuator is lost, and the pitch angle of the wing is a feathering position. 6. The blade pitch varying mechanism for a wind turbine according to claim 4, wherein the rotation of the third rotating shaft is sometimes prevented.