JPS6354144B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a variable pitch device for blades, and more particularly, the present invention relates to a variable pitch device for blades, and in particular, a support shaft is provided on a transmission shaft through a hub, extending outward in the radial direction and exposed. The base end of the blade is rotatably supported on this support shaft, and a movable body is provided on the transmission shaft so as to be movable back and forth, and one end of this movable body extends outward from the hub and the base end of the blade. The blade is connected to one side by a connecting rod, and the movable body follows the rotation of the transmission shaft and moves in the axial direction to rotate the blade on the support shaft and change its pitch angle. This invention relates to a variable pitch device.

[Prior Art] When the wind speed changes, the angle of attack of the blades of a wind turbine or the like inevitably changes. Therefore, even if the pitch angle of the blade is set so that the blade rotates with the highest efficiency for a given wind speed (the pitch angle at this time is generally called the critical angle), as the wind speed increases, the lift coefficient of the blade will decrease. decreases rapidly, and conversely, the drag coefficient increases. Furthermore, if the wind speed decreases below a predetermined wind speed, the drag coefficient decreases, but the lift coefficient also decreases at the same time. As a result, the efficiency of wind turbines and the like decreases. As a means to solve such problems, the pitch angle of the blades of wind turbines, etc. is changed according to the wind speed, so that the lifting force or rotational force acting on the blades due to wind power is always maximized, increasing the efficiency of wind turbines, etc. Alternatively, means are already known to limit the output exceeding the rating or the force acting on the blades during strong winds.

[Problems to be Solved by the Invention] By the way, since the blade rotates together with the transmission shaft, there is a mechanical constraint that the drive means for changing the pitch angle of the blade must necessarily rotate together with the blade. . Therefore, conventional blade variable pitch devices have been installed inside the transmission shaft. The base end of the blade extending inside the transmission shaft was driven by a variable pitch device to change its pitch angle. However, installing a blade variable pitch device inside a generally narrow transmission shaft is not only extremely difficult in terms of processing and assembly, but also requires miniaturization of the variable pitch device itself, resulting in a complicated structure and failure. The problem was that it was easy to do. In order to repair a malfunctioning part, it is necessary to remove the entire variable pitch device from the transmission shaft, which is also undesirable from the viewpoint of maintenance. Furthermore, the inside of the transmission shaft must be made hollow in order to install the variable pitch device, which poses a problem in that the mechanical strength of the transmission shaft is reduced.

The present invention has been devised to effectively solve the above-mentioned problems in conventional blade variable pitch devices.

The purpose of the present invention is to facilitate the processing, assembly, and maintenance of the variable pitch device by arranging the blade variable pitch device on the outer periphery of the transmission shaft, and to improve its mechanical strength by making the transmission shaft a solid shaft. There is a particular thing.

[Means for solving the problem] A variable pitch device for a blade in which the base end of the blade is rotatably supported on a hub that rotates integrally with a transmission shaft in order to change the pitch angle of the blade, A spindle is provided on the hub to extend outward in the radial direction and is exposed and rotatably supports the base end of the blade, and a spindle is provided on the outer periphery of the transmission shaft so as to be movable back and forth along the axial direction. a movable body having one end extending outward in the axial direction of the hub; a drive mechanism having one end attached to a fixed system and the other end connected to the movable body so as to be relatively rotatable to reciprocate the movable body;
A connecting rod that connects one end of the hub of the movable body extending outward and one side of the base end of the blade to transmit the moving force of the movable body to the base end of the blade. .

[Function] Describing the function of the present invention, a movable body provided on the outer periphery of a transmission shaft so as to be reciprocally movable is reciprocated by a drive mechanism provided on a fixed body, and the movable body is extended outward from the hub of the movable body. One end of the blade and one side of the proximal end of the blade, which is pivotally supported on a support shaft that extends outward in the radial direction of the hub, are connected to the outside of the hub using a connecting rod that transmits the moving force of the movable body. The driving force is transmitted from the fixed system to the blades outside the transmission shaft and outside the hub to change the pitch.

[Embodiment] A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

The figure shows a blade variable pitch device according to the present invention applied to a wind turbine blade.
Reference numeral 1 designates a common bed as a fixed system, and a cylindrical rotor spindle 2 is fixed at the tip thereof with its axis horizontal. This rotor spindle 2
A hub 4 is fitted through a rotor main bearing 3, and the tip of the rotor spindle 2 is covered by a side plate 4a extending radially inward from one side of the hub 4. Note that this side plate 4a is attached to the hub 4.
It is integrally molded with. A cylindrical support shaft 5 is provided on the outer periphery of the hub 4, extending outward in the radial direction and exposed.
is provided, and a base end portion of a blade 9 is rotatably supported on this support shaft 5. Specifically, a blade hub outer cylinder 8 is fitted to the outside of the support shaft 5 via a blade support bearing 6, and the base end of the blade 9 is connected to the tip of this blade hub outer cylinder 8, so that the blade 9 is configured to be rotatable around the support shaft 5.

A transmission shaft 10 is provided in the rotor spindle 2 along the axis of the rotor spindle 2, passing through the side plate 4a of the hub 4 from the common bed 1 side and protruding outward as appropriate. A flange portion 10a is formed on the transmission shaft 10 outside the side plate 4a, and the flange portion 10a and the side plate 4a are fixed with bolts (not shown). and transmission shaft 1
0 is rotatably supported by a transmission shaft bearing 11 in a common bed 1 and a rotor main bearing 3. A moving body is provided on the outer periphery of the transmission shaft 10 so as to be able to reciprocate along the axial direction. In particular, this moving body consists of an inner moving body 16 provided inside the hub 4 and an outer moving body 13 provided on the protrusion 10b of the transmission shaft 10 extending axially outward of the hub 4. The outer movable body 13 constitutes one end of the movable body extending axially outward of the hub 4. Specifically, an outer movable body 13 that is fitted onto the transmission shaft 10 via a slide key 12 and extends radially outward is provided on the protrusion 10b of the transmission shaft 10 that protrudes to the outside of the side plate 4a. It is being
The tip of the outer moving body 13 forming one end of the moving body hub 4 extending outward, and the base end of the blade hub outer cylinder 8 exposed to the outside of the hub 4 forming the base end of the blade 9. The blade hub outer cylinder 8 is connected to the outside of the hub 4 by a connecting rod 14 that transmits the moving force of the moving body, and the blade hub outer cylinder 8 is supported by the movement of the outer moving body 13 along the transmission shaft 10. It is configured to rotate around a shaft 5. Therefore, blade 9
Most of the drive structure of the hub 4 is exposed outside the hub 4, making assembly, inspection, and repair easy, and the structure inside the hub 4 is simplified. The rotating direction at this time is such that the pitch angle of the blade 9 increases when the outer movable body 13 moves toward the side plate 4a. Further, the connecting rod 14 and the outer movable body 13 and the connecting rod 14 and the blade hub outer cylinder 8 are pin-coupled via a universal joint (not shown).
is designed to rotate smoothly.

On the other hand, a cylindrical inner moving body 16 constituting a moving body is fitted into the transmission shaft 10 in the rotor spindle 2, and an outer cylinder 18 is connected to the inner moving body 16 via a thrust bearing 17 that enables relative rotation. are fitted. One end of a plurality of hydraulic cylinders 19 is connected to the outer cylinder 18, the other end of which is installed in the common bed 1 serving as a fixed system and provided parallel to the transmission shaft 10. is configured to be able to reciprocate in the axial direction of the transmission shaft 10. That is, the outer cylinder 18 and the hydraulic cylinder 19 constitute a drive mechanism for the inner movable body 16. The inner movable body 16 and the outer movable body 13 are connected by a plurality of rods 20 that pass through the side plate 4a of the hub 4 and are provided parallel to the transmission shaft 10. In particular, the hydraulic cylinder 1 constituting the drive mechanism
9 is fixedly provided between the common bed 1, which is a fixed system, and the outer cylinder 18, which is rotatable relative to the movable body, so that it does not rotate together with the transmission shaft 10, and can be used for hydraulic piping or other control purposes. Wiring and the like can be easily arranged, and the cylinder 19 can be inspected and repaired easily.

Further, in this embodiment, since the outer moving body 13 is supported by a plurality of rods 20, even when the outer moving body 13 moves to the end of the transmission shaft 10,
It is possible to reduce the load on the transmission shaft 10 while supporting it with sufficient strength, stabilize the rotation of the rotating transmission shaft 10, and effectively control torsional vibrations and the like. Note that the peripheral edge of the outer cylinder 18 is engaged with a slide key 21 in a slide key groove formed in the inner wall of the rotor spindle 2 along its axial direction, and the rotation of the outer cylinder 18 is prevented by the slide key 21. At the same time, the outer cylinder 18 guides the movement of the transmission shaft 10 in the axial direction. Therefore, the drive mechanism can smoothly reciprocate the moving body without following the rotation of the moving body.

Next, the operation of the above embodiment will be described.

When a rotational force is applied to the blade 9 by wind force, the force is transmitted to the hub 4 via the support shaft 5, and is further transmitted from the side plate 4a of the hub 4 to the flange portion 10 of the transmission shaft 10.
a and drives the transmission shaft 10. At this time,
Since the outer movable body 13 is engaged with the protrusion 10b of the transmission shaft 10 by the slide key 12, it rotates following the rotation of the transmission shaft 10. In addition, the inner moving body 1 is connected to the outer moving body 13 by the rod 20.
6 rotates in the same manner. In this state, hydraulic cylinder 1
When the transmission shaft 9 is driven, the driving force is transmitted to the inner movable body 16 via the outer cylinder 18 and the thrust bearing 17, and the inner movable body 16 and the outer movable body 13 rotate together with the transmission shaft 10 and move in the axial direction thereof. The blade hub outer cylinder 8 connected to the outer movable body 13 by the connecting rod 14 rotates about the support shaft 5, and the blade 9 also rotates together with this, changing its pitch angle. Therefore, the pitch angle of the blade 9 can be maintained at the optimum angle depending on the wind speed. In addition, when strong winds such as a typhoon blow against the blades 9, the hydraulic cylinder 19 is driven to move the outer movable body 13 to the side plate 4.
It is better to move it to the a side and set the pitch angle of the blade 9 to 90 degrees to prevent excessive force from acting on the blade 9. (This is generally referred to as feathering.) At this time, as shown in FIG. Alternatively, the blade 9 may be locked to ensure that the blade 9 is stopped.

Reference numeral 23 in FIG. 2 is a fluid pressure cylinder for releasing the engagement between the feather lock 22 and the outer cylinder 18. In addition, when it is necessary to quickly change the pitch angle of the blade 9 in the event of an abnormality, the hydraulic cylinder 1
It is preferable to switch the hydraulic circuit No. 9 to an emergency circuit and change the pitch angle at two to three times the normal speed.

[Effects of the Invention] As is clear from the above configuration, the present invention provides the following effects.

(1) Since the driving force is transmitted from the fixed system to the blade outside the transmission shaft and outside the hub, processing, assembly, repair and inspection of the device can be accomplished extremely easily.

(2) Since the transmission shaft can be made into a solid shaft, it is easy to manufacture it and its mechanical strength can be improved.

(3) In particular, one side of the proximal end of the blade provided outside the hub via a support shaft and one end of the movable body extending outside the hub are connected by a connecting rod outside the hub. Because of this structure, most of the drive structure can be located outside the hub, making assembly, inspection, and repair easy.

(4) In addition, one end of the drive mechanism is attached to a fixed system, and the other end is connected to the movable body so that it can rotate relative to it, so the drive mechanism does not rotate together with the transmission shaft, making it easy to install various piping, etc. In addition, inspection, repair, etc. can be performed easily.

[Brief explanation of the drawing]

FIG. 1 is a sectional side view showing a preferred embodiment of the present invention, and FIG. 2 is a sectional side view of a main part showing another embodiment of the invention. In the figure, 1 is a common bed which is a fixed system, 4 is a hub, 5 is a support shaft, 9 is a blade, 10 is a transmission shaft, 1
3 and 16 are the outer moving body and the inner moving body, 1
4 is a connecting rod, and 18 and 19 are an outer cylinder and a hydraulic cylinder which are drive mechanisms.

Claims (1)

[Claims] 1. In a blade variable pitch device in which the base end of the blade is rotatably supported on a hub that rotates integrally with a transmission shaft in order to change the pitch angle of the blade, a supporting shaft that is provided to extend and be exposed in the direction and rotatably supports the proximal end of the blade; and one end of the supporting shaft that is provided on the outer periphery of the transmission shaft so as to be able to reciprocate along the axial direction thereof. a movable body extending axially outward from the hub; a drive mechanism having one end attached to the fixed system and the other end connected to the movable body so as to be relatively rotatable to reciprocate the movable body; a connecting rod that connects one end of the movable body extending outward from the hub and one side of the proximal end of the blade to transmit the moving force of the movable body to the proximal end of the blade; A variable blade pitch device characterized by: