JP2001099045A - Blade pitch variable mechanism for wind mill - Google Patents

Abstract

PROBLEM TO BE SOLVED: To uniformly control each pitch of a plurality of blades without using any hydraulic cylinder in a blade pitch mechanism for wind mill. SOLUTION: A pitch controlling servo motor 12 is fixed to the tip center of a hollow rotor head 5 in a wind generating device, and a main gear 13a that is a bevel gear is mounted on a motor shaft turned into the rotor head 5. A blade 4 is mounted on the rotor head 5 through a blade bearing 6, and a sub-gear 14a that is a bevel gear is mounted on the base end side of the blade 4. The rotating shaft of the sub-gear 14a is arranged on the central axis of the blade 4, and the blade 4 is rotatable to the rotor head 5 by the effect of the blade bearing 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a variable blade pitch mechanism of a wind turbine used for wind power generation and capable of stably generating electric power.

[0002]

2. Description of the Related Art FIGS. 7 and 8 show a wind turbine 1 used for conventional wind power generation. The wind turbine 1 is provided with a rotor section 3 in front of a wind turbine main body 2, and the rotor section 3 is composed of a blade 4 and a rotor head 5 that supports the blade 4. Usually, two or three blades 4 are provided on a windmill, and a connecting pipe 4 a of the blade 4 is rotatably attached to a rotor head 5 via a blade bearing 6. The rotor head 5 is attached to the wind turbine main body 2 via a rotor head bearing 7, and is configured to be rotatable with respect to the wind turbine main body 2. The inside of the rotor head 5 is hollow, and the same number of hydraulic cylinders 8 as the blades 4 are arranged on the front wall thereof.

As shown in FIG. 8, a rod 9 is provided on a hydraulic cylinder 8, and the tip of the rod 9 is
The other end of the arm 10 is rotatably connected to a connecting shaft 11 integrally attached to the blade 4, and the other end of the arm 10 is rotatably connected to the connecting shaft 11. Construct a link mechanism. With such a configuration,
When the rod 9 of the hydraulic cylinder 8 is expanded and contracted, the linear motion of the rod 9 is converted into a rotational motion of the connecting shaft 11 by the link mechanism. When the connecting shaft 11 rotates, the blade 4 connected to the connecting shaft 11 rotates to change the mounting angle of the blade 4 with respect to the rotor head 5, that is, the blade pitch.

[0004]

As described above, the blade pitch variable mechanism is provided in the wind turbine because it is necessary to control the rotation speed of the rotor head 5 in order to keep the power generated by the wind turbine used for wind power generation constant. This is because it is necessary to change the blade pitch according to the wind speed. However, in a structure in which the blade pitch is changed using the hydraulic cylinder 8 as in the related art, since the rotor head 5 has a hydraulic system, if an oil leak occurs, the oil scatters to the outside,
There is a possibility that the problem of contamination of the wind turbine 1 and ground contamination may occur.
Further, since one blade 4 uses one hydraulic cylinder 8 independently, there is a possibility that an error occurs in the pitch of each blade.

The present invention has been made in view of the above problems, and has as its object to provide a blade pitch variable mechanism of a wind turbine capable of eliminating oil leakage and uniformly controlling the pitches of a plurality of blades. .

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a rotor head at the tip of a rotating shaft of a wind turbine, supports the rotor with a plurality of blade bearings interposed therebetween, and mounts the blade. In a blade pitch variable mechanism of a wind turbine provided with a means for displacing a pitch, the displacing means includes a sub gear connected to a base end of the blade,
A motor fixed to the rotor head side; and a main gear attached to a drive shaft of the motor and driven by the auxiliary gear.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a variable blade pitch mechanism for a wind turbine according to a first embodiment of the present invention will be described with reference to FIGS. Note that the same parts as those in the related art are described with the same reference numerals. FIG. 1 is a cross-sectional view of a blade pitch variable mechanism of a wind turbine according to the present invention, as viewed from the side of the wind turbine, and FIG. 2 is a cross-sectional view of the same from the front of the wind turbine. As shown in FIG.
A servomotor 12 for blade pitch control is fixed to the center of the tip of the hollow rotor head 5 connected to the rotor head 5a, and a drive shaft 12a of the motor directed into the rotor head 5 is a bevel gear. A (drive) gear 13a is mounted. The wind turbine 1 is provided with a sensor for monitoring the pitch of the blades 4 and a control device for driving a servomotor.

Three blades 4 (only one blade is shown) are attached to the rotor head 5 at 120-degree intervals via blade bearings 6, and a bevel gear (a bevel gear) is provided at the base end side of each blade 4. Driven) gear 14a is mounted. Each sub gear 14a is arranged at right angles to the main gear 13a. The rotation axis of the auxiliary gear 14 a is arranged on the center axis of the blade 4, and the blade 4 is rotatable with respect to the rotor head 5 by the action of the blade bearing 6.

According to the wind turbine blade pitch varying mechanism of the present embodiment, in order to control the power of the wind turbine and the like, when the pitch of the blades 4 is varied, the servo motor 12 is driven by a command from a control unit (not shown). , Main gear 1
3a rotates in a predetermined direction. Since the main gear 13a meshes with the three sub-gears 14a, the sub-gears 14a simultaneously rotate in the same direction by the same amount of pitch. As a result, the three blades 4 rotate by the same pitch, thereby varying the blade pitch. Thus, the main gear 13a is
Each of the blades 4
Can be displaced by the same pitch. Also, since the motor control is used, the pitch can be displaced instantaneously.

Next, a variable blade pitch mechanism of a wind turbine according to a second embodiment of the present invention will be described with reference to FIGS. Note that the same parts as those in the related art are described with the same reference numerals. FIG. 3 is a cross-sectional view of the blade pitch variable mechanism of the wind turbine according to the present invention as viewed from the side of the wind turbine, and FIG. 4 is a cross-sectional view of the mechanism seen from the front of the wind turbine. As shown in the figure, a servo motor 12 for pitch control is fixed to the center of the tip of the hollow rotor head 5, and a main gear, which is a bevel gear, is mounted on a drive shaft 12 a of the motor directed into the rotor head 5. 13b is attached.

A gear mounting plate 15b is fixed to the servo motor 12, and intermediate gears 16b, which are bevel gears, are mounted on the servo motor 12 at three positions at 120 degree intervals corresponding to the blades 4. Each of the intermediate gears 16b is arranged on the same plane as the main gear 13b and meshes with each other. In addition,
As for the intermediate gear 16b, a gear mounting plate may be provided on the rotor head 5 side. Three blades 4 (only one blade is shown) are attached to the rotor head 5 via a blade bearing 6, and a sub gear 14 b which is a bevel gear is attached to the base end side of each blade 4. Each sub gear 14b is arranged at right angles to the pair of intermediate gears 16b.
The rotation axis of the auxiliary gear 14b is arranged on the center axis of the blade 4, and the blade 4 is actuated by the action of the blade bearing 6.
It is rotatable with respect to the rotor head 5. in this way,
In the present embodiment, since the intermediate gear 16b is provided, the gear ratio of the gear can be changed. In particular, in the first embodiment, the diameter (number of teeth) of the main gear 13a is large, and the slight rotation of the motor shaft of the servomotor 12 greatly changes the pitch angle of the blade 4, making it difficult to perform delicate control. However, in the present embodiment, since the diameter of the main gear 13b is reduced, the blade pitch can be controlled more accurately.

Next, a variable blade pitch mechanism of a wind turbine according to a third embodiment of the present invention will be described with reference to FIGS. Note that the same parts as those in the related art are described with the same reference numerals. FIG. 3 is a cross-sectional view of the blade pitch variable mechanism of the wind turbine according to the present invention as viewed from the side of the wind turbine, and FIG. 4 is a cross-sectional view of the mechanism seen from the front of the wind turbine. This embodiment is different from the second embodiment in that a main gear 13c, an auxiliary gear 14c, and an intermediate gear 16
That is, the gear ratio of c is changed. In the second embodiment, the number of teeth of the main gear 13b> the number of teeth of the auxiliary gear 14b, but in the present embodiment, the number of teeth of the main gear 13c <the number of teeth of the auxiliary gear 14c. Thus, more precise blade pitch control can be performed.

Although the embodiments of the present invention have been described above, the present invention is, of course, not limited thereto, and various modifications can be made based on the technical concept of the present invention. In each of the above embodiments, the pitch of the three blades 4 is made variable by one servo motor 12, but a servo motor 12 may be provided for each blade 4. In such a case, each of the main gear and the auxiliary gear may be a spur gear, or a combination of a worm gear and a worm wheel.

[0014]

As described above, according to the wind turbine blade pitch variable mechanism of the present invention, the problem of oil leakage is eliminated because no hydraulic cylinder is used. Since the auxiliary gear on each blade side is rotated by one main gear, a plurality of blade pitch displacements become uniform, so that accurate control becomes possible.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a rotor portion of a variable blade pitch mechanism of a wind turbine according to a first embodiment of the present invention, as viewed from a side of the wind turbine.

FIG. 2 is a cross-sectional view taken along line XX of FIG.

FIG. 3 is a cross-sectional view of a rotor part of a variable blade pitch mechanism of a wind turbine according to a second embodiment of the present invention, as viewed from a side of the wind turbine.

FIG. 4 is a sectional view taken along the line YY in FIG. 3;

FIG. 5 is a cross-sectional view of a rotor portion of a blade pitch variable mechanism of a wind turbine according to a third embodiment of the present invention as viewed from a side of the wind turbine.

FIG. 6 is a sectional view taken along the line ZZ in FIG. 5;

FIG. 7 is a partially cutaway sectional view of a conventional wind turbine.

8 is a perspective view of a blade pitch variable mechanism using a hydraulic cylinder of the wind turbine of FIG. 7;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Windmill 2a Rotating shaft of a windmill 3 Rotor part 4 Blade 4a Connecting pipe 5 Rotor head 6 Blade bearing 7 Rotor head bearing 12 Servo motor 12a Drive shaft 13a-13c Main gear 14a-14c Secondary gear 15b, 15c Gear mounting plate 16b , 16c Intermediate gear

Claims (4)

[Claims] 1. A wind turbine blade pitch variable mechanism comprising: a rotor head provided at a tip end of a rotation shaft of a wind turbine, supported by bearings of a plurality of blades, and having means for displacing a mounting pitch of the blade. The displacement means includes a sub gear connected to a base end of the blade, a motor fixed to the rotor head side, and a main gear attached to a drive shaft of the motor and driven by the sub gear. A variable blade pitch mechanism for a wind turbine. 2. The mechanism according to claim 1, wherein said main gear and said auxiliary gear are bevel gears meshing with each other. 3. Each of the blades is provided with an auxiliary gear,
The mechanism according to claim 2, wherein the auxiliary gears mesh with the main gears. 4. The blade pitch varying mechanism for a wind turbine according to claim 1, wherein an intermediate gear is interposed between the main gear and the auxiliary gear.