JPH0121185Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a rotating machine such as a wind turbine, and particularly to the structure of a joint at the root of a blade thereof.

Figures 1 and 2 show an example of a windmill as a rotating machine, in which the blades 1 are tilted forward, and the flange 2 at the joint end of the root of the blade 1 is connected to the rotating shaft supported by a bearing in the nacelle 6. It is connected to the flange 3 at the joint end of the blade attachment part 4 of No. 5.

Such a joint end of the root of the blade 1 and the rotating shaft 5
Conventionally, as a means of connecting the blade attachment part 4 to the joint end, the flanges 2 and 3 at both joint ends were firmly tightened and fixed with bolts 7, as shown in Fig. 3. .

By the way, due to the centrifugal force of the blade 1, an axial component force and an axis-perpendicular component force are generated in the blade 1.

The axial component force acts on the blade 1 as an axial force, while the axis-perpendicular component force acts as a bending load. Further, the wind load also acts on the blade 1 as a bending load.

Due to these bending loads, at the base of the blade 1,
A large bending moment is applied.

FIG. 4 is a graph showing the bending moment distribution of the blade 1 when the wind turbine is driven at a rotational speed of 100 rpm and a wind speed of 8 m/s, and the bending moment at the root of the blade 1 is extremely large.

Therefore, a large bending stress is generated at the base of the blade, and there is a possibility that the blade 1 may be damaged.

The present invention attempts to solve these problems, and is designed to provide a function for transmitting the axial component of centrifugal force and torque for changing the angle of attack at the attachment point of the blade to the rotating shaft of a rotating machine. To provide a blade joint structure for a rotating machine that reduces the generation of bending moment due to bending load without impairing the blades, and prevents blades from hanging down when stationary.

Therefore, the blade joint of the rotating machine of the present invention has a connecting shaft connected to the joint end at the root of the blade and extending in the longitudinal direction of the blade, and a connecting shaft connected to the joint end on the rotating shaft side and connected to the above-mentioned connection. It has an outer cylinder extending in the same direction as the shaft, and an inner cylinder pivotally connected to the outer cylinder through a pair of pins that are perpendicular to the cylinder axis direction of the outer cylinder. The above-mentioned connecting shaft is connected to the above-mentioned inner cylinder with the above-mentioned pair of pins so as to be connected so as to be relatively tiltable.
A flexible annular portion having a U-shaped vertical cross section is formed in the outer cylinder so as to be connected by a connecting pin having a phase difference of 90 degrees and to support the bending moment due to the weight of the blade when it is stationary. The present invention is characterized in that an elastic ring that can come into contact with the inner periphery of the annular portion is attached to the connecting shaft via a tightening nut that can adjust the outer diameter of the ring.

Hereinafter, a blade joint for a rotating machine as an embodiment of the present invention will be explained with reference to the drawings. FIG. 5 is a vertical sectional view showing the main parts, FIG. FIG. 3 is a cross-sectional view showing the operation of the embodiment.

As shown in FIGS. 5 and 6, in a wind turbine as a rotating machine, a connecting shaft extending in the longitudinal direction of the blade 1 is attached to a flange 2 at the joint end of the root of the blade 1 with a bolt 7. An outer cylinder 14 extending in the longitudinal direction of the blade 1 is attached to the flange 3 of the blade attachment part 4 at the joint end on the 5 side with bolts 7.

Further, an inner cylinder 12 is pivotally attached to the outer cylinder 14 via a pair of pins 11 that are perpendicular to the axis of the cylinder.

The connecting shaft 10 is connected to the inner cylinder 1 so as to freely allow relative tilting between the joint end at the base of the blade 1 and the joint end at the blade mounting portion 4 on the rotary shaft 5 side.
2 through a pin 13 having a phase difference of 90 degrees with the pin 11.

Incidentally, in order to support the bending moment due to its own weight when the blade 1 is at rest, the outer tube 14 is formed with a flexible annular portion 9 having a U-shaped longitudinal section. elastic ring 15
By tightening with the tightening nut 16 and deforming it by crowning, the elastic ring 15 is attached to the annular part 9.
It is designed to be in contact with the inner periphery of the

With the above-described configuration, when the blade 1 rotates, the centrifugal force causes the annular portion 9 to rotate as shown in FIG.
causes elastic deformation, creating a gap δ between the elastic ring 15 and the elastic ring 15.

At this time, the axial component of the centrifugal force generated by the rotation of the blade 1 is transmitted to the blade mounting portion 4 of the rotating shaft 5 via the connecting shaft 10, the inner cylinder 12, the outer cylinder 14, and the pins 11, 13. Ru.

Also, the torque for changing the angle of attack of blade 1 is:
It acts to twist the annular portion 9, but since the torsional rigidity of the annular portion 9 is high, the angle of attack of the blade 1 can be adjusted without any problem.

Furthermore, when the wind load acts, the blade 1 that was tilted forward rises and the flange 2 on the blade 1 side
and tilt the connecting shaft 10 connected thereto.

At this time, a gap δ is generated between the annular portion 9 and the elastic ring 15, and the pin 1 has a phase difference of 90 degrees between the connecting shaft 10, the inner cylinder 12, and the outer cylinder 15.
1 and 13, the tilting movement of the connecting shaft 10 is not restricted.

In other words, since the portion between the connecting shaft 10 and the outer cylinder 14 acts as a universal joint, the blade 1 can freely rise to a position where the moment due to centrifugal force and the moment due to wind load are balanced. Rotate in that position.

When the blade 1 is at rest, since the blade 1 is slightly inclined, a moment due to the blade 1's own weight acts, but this is supported by the reaction force generated at the contact portion between the annular portion 9 and the elastic ring 15. .

As described above, since the blade 1 can rise to a position where the moment due to centrifugal force and the moment due to wind load are balanced, no large bending stress is applied to the blade 1.

FIG. 8 shows the bending moment distribution in the blade 1 when using the blade joint according to the present invention. The bending moment at the root of the blade 1 is almost zero, and the bending moment near the radial center of the blade 1 is almost zero. The advantage is that the maximum bending moment generated in the blade is also much smaller than the maximum bending moment when the blade root is fixed as in the conventional case.

[Brief explanation of the drawing]

Figures 1 and 2 show the schematic structure of a wind turbine as a rotating machine. Figure 1 is a front view seen from the - arrow direction in Figure 2, and Figure 2 is a front view seen from the - arrow direction in Figure 1. FIG. 3 is a cross-sectional view showing the main parts of the conventional blade joint structure in the rotating machine, and FIG. 4 is a graph showing the bending moment distribution of the blade when the conventional blade joint structure is used. 5 to 7 show a blade joint for a rotating machine as an embodiment of the present invention, FIG. 5 is a vertical cross-sectional view showing the main part thereof, and FIG. 6 is a cross-sectional view of FIG. 7 are cross-sectional views showing the effect of the embodiment, and FIG. 8 is a graph showing the bending moment distribution of the blade according to the present invention. 1...Blade, 2,3...Flange, 4...Blade mounting portion, 5...Rotating shaft, 6...Nacelle, 7...Bolt, 9...Annular part, 10...Connection shaft, 11...
Pin, 12... Inner tube, 13... Pin, 14... Outer tube, 15... Elastic ring, 16... Tightening nut.

Claims (1)

[Scope of utility model registration request] A connecting shaft connected to the joint end at the root of the blade and extending in the longitudinal direction of the blade; an outer cylinder connected to the joint end on the rotating shaft side and extending in the same direction as the connecting shaft; The inner cylinder is pivotally connected to the outer cylinder through a pair of pins perpendicular to the cylinder axis direction of the outer cylinder, and the connecting shaft is connected to the inner cylinder by a connecting pin having a phase difference of 90 degrees from the pair of pins,
In order to support the bending moment due to the weight of the blade when it is stationary, a flexible annular portion having a U-shaped longitudinal section is formed in the outer cylinder, and an elastic ring that can come into contact with the inner periphery of the annular portion is formed in the outer cylinder. A vane joint for a rotating machine, characterized in that the blade joint is attached to the connecting shaft via a tightening nut that can adjust the outer diameter of the ring.