JP2523280B2 - Rotor support structure for propeller type wind turbine - Google Patents

Description

Description: TECHNICAL FIELD OF THE INVENTION The present invention relates to a rotor support structure for a propeller-type wind turbine.

[Prior art]

A propeller-type wind turbine used as a power source of a wind power generator or the like is configured by fixing a rotor having a plurality of blades to a horizontal rotation shaft, and supporting the other end of the rotation shaft by a cantilever on a support portion. ing. Since the rotating shaft is cantilevered with the rotor fixed at one end as described above, a large bending moment is applied, and therefore, the rotating shaft has a large rigidity so as to suppress the deformation due to this bending moment to a low level. Is designed to.

On the other hand, since the wind turbine uses the energy of natural wind, torque fluctuations associated with wind speed fluctuations are transmitted to the rotary shaft. It is known that this torque fluctuation is as many as N times the rotational speed in a two-blade type rotor normally used in a large wind power generator. However, in a rotating shaft having a large rigidity as described above, since the amount of torsional deformation is small even when such a large torque fluctuation occurs, the torque as it is can be applied to a driven system device such as a gearbox or a generator. Will be transmitted.

Therefore, in the conventional propeller-type wind turbine, in order to ensure the strength and rigidity of the gears, shafts, etc. of the driven system equipment so as to have the durability and reliability that sufficiently endure the above torque fluctuation, it is inevitably large. However, as a result, it has been a cause of increasing the weight and capacity of the driven system equipment.

[Object of the Invention]

An object of the present invention is to provide a rotor support structure in a propeller-type wind turbine that can reduce the influence of wind speed fluctuations and can achieve reliability while ensuring weight reduction and size reduction.

[Structure of Invention]

The present invention to achieve the above object is a propeller-type wind turbine in which a rotor having a plurality of blades is fixed to a tip portion of a rotating shaft in a lateral direction, and the rear end side of the rotating shaft is cantilever-supported in a nacelle, The rotating shaft is concentrically arranged and has a double structure composed of a straight inner shaft and an outer shaft, and the outer shaft is attached to the nacelle through bearings which are spaced apart from each other on the front end side and the rear end side thereof. The rotor is rotatably supported, the rotor is fixed to the tip of the outer shaft, the inner shaft is made up of a flexible shaft, and the rear end side is arranged in the vicinity of a bearing on the rear end side supporting the outer shaft. Characterized in that it is rotatably supported in the outer shaft via a bearing, the front end side of the inner shaft is fixed to the outer shaft, and only the rear end side of the inner shaft is connected to the driven system. Is.

〔Example〕

FIG. 2 shows a wind power generator using a propeller type wind turbine according to the present invention. Reference numeral 1 is a column extending vertically, and a rotor 3 is attached to the upper end of the column via a nacelle 2. The rotor 3 is constructed by installing two blades 5 and 5 on a hub 4 in a pair, and the nacelle 2 is supported rotatably around the axis of the support column 1 and is shown in FIG. The horizontal rotation shaft 9 as shown in FIG. Outside the hub 4 of the rotor 3 and the nacelle 2, cowlings 7 and 8 are provided, respectively.
Is covered.

The rotor 3 is fixed to the front end of a rotary shaft 9 supported in the nacelle 2, and the rotation of the rotor 3 is transmitted from the rotary shaft 9 to a generator (not shown) provided in the yoke case 6. In this structure, the rotor 3 has the wind W in the arrow direction.
On the other hand, the nacelle 2 is moved to the leeward side while being rotated around the support column 1, and the rotation of the rotor 3 itself is changed to the yoke case 6.
It is transmitted to the generator inside.

FIG. 1 is a cross-sectional view of the support portion of the rotor 3 with the cowlings 7 and 8 removed.

Reference numeral 9 denotes a rotary shaft supported by the nacelle 2 described above, and the hub 4 of the rotor 3 is fixed to a mounting portion 9a at the tip thereof.
Ring-shaped bearings 10 and 10 are fixed to the outer sides of the two opposite surfaces of the hub 4, respectively. On the other hand, at the base ends of the two blades 5, 5, the ring-shaped internal gear 11,
11 are fixed, and these ring-shaped internal gears 11 and 11 are coaxially fitted inside the ring-shaped bearings 10 and 10, respectively, and by this fitting, the blades 5 and 5 are rotatable with respect to the hub 4. Supported by.

In addition, the ring-shaped bearings 10, 10 are provided on the outer surface of the hub 4.
Stays 12 and 12 are fixed to the inner part surrounded by the inside of
Servo motors 13, 13 are attached to these stays 12, 12, respectively. The servomotors 13, 13 mesh the pinions 14, 14 fixed to their output shafts with the ring-shaped internal gears 11, 11 respectively, and the ring-shaped bearings 10, 10 are moved by a fixed amount according to a command from a control unit (not shown). By rotating, the pitch angles of the blades 5 and 5 are changed, and the rotor 3 is controlled to a constant rotation speed.

The rotating shaft 9 having the rotor 3 fixed to the tip is arranged concentrically and has a double structure including an inner shaft 15 and an outer shaft 16 which are straight and tubular. Of these two inner and outer axes,
The inner shaft 15 has a high strength against a shear stress due to torsion, but is made of a steel material having a small torsional rigidity, and is a so-called quill shaft. The outer shaft 16 is composed of a tubular shaft having a large outer diameter and a large bending rigidity. The outer shaft 16 is a bearing arranged on the front end side and the rear end side of the outer shaft 16 with a space therebetween.
The rotor 3 is rotatably supported in the nacelle 2 via 18, 19 and the rotor 3 is fixed to the tip of the outer shaft 16 via the mounting portion 9a. On the other hand, the inner shaft 15 composed of a flexible shaft
Is rotatably supported in the outer shaft 16 via a bearing 17 arranged in the vicinity of a rear end side bearing 19 supporting the outer shaft 16 and a front end side fixed to the outer shaft 16 and from the outer shaft 16. A rear end portion 15a of the protruding inner shaft 15 is supported by the nacelle 2 via a bearing 20.

In the rotating shaft 9 having the above-described structure, the outer shaft 16 supports the radial load from the rotor 3 and receives the bending moment, and the inner shaft 15 receives the rotating torque from the rotor 3 and transmits it to the rear speed increaser 25. It is supposed to do. The gearbox 25 connected to the rear end portion 15a of the inner shaft 15 is composed of gears 21, 22 and 23, 24, and is connected to the transmission shaft 28 via a pair of bevel gears 26, 27. The rotational torque transmitted to the inner shaft 15 as described above is transmitted to a generator (not shown).

In addition, on the side where the hub 4 is connected to the rotating shaft 9, the outer shaft 16
A rotation speed sensor 29 is provided so as to face the above, and another rotation speed sensor 30 that faces the rear end portion 15a of the inner shaft 15 is provided on the side connected to the speed increaser 25. The former rotational speed sensor 29 mainly detects the rotational speed of the rotor 3 and is used for controlling the rotational speed of the rotor by converting the pitch of the blades. The latter rotational speed sensor 30 mainly controls the rotational speed proportional to the rotational speed of the generator. It is used to control the output of the generator for detection.

As described above, in the propeller type wind turbine, the rotor 3
The bending load applied to the rotating shaft 9 due to the load is mainly supported by the outer shaft 16 having a large rigidity, and therefore, reliable support that does not cause bending deformation is enabled. On the other hand, the rotational torque from the rotor 3 is transmitted to the driven system such as the speed increaser 25 and the generator via the inner shaft 15 and is not transmitted from the outer shaft 16. Since the inner shaft 15 is composed of the flexible shaft, the strength against the torsional moment due to the transmission torque is the same as that of the other parts, but the torsional rigidity is small and the torque fluctuation is easily absorbed.

Therefore, when the rotor 3 receives a gust of wind and a rapid torque fluctuation is transmitted to the rotating shaft 9, the inner shaft 15 is twisted and deformed to absorb the torque fluctuation, thereby increasing the speed increaser.
Propagation to the 25 side can be mitigated. Further, since the inner shaft 15 absorbs the torque fluctuation when the wind speed fluctuates, an additional load over the entire system of the wind power generator can be reduced.

For example, when a wind gust is generated when the wind power generator is operated at the rated output, which changes the torque-rotation speed characteristic on the rotor 3 side, in the case of the conventional hard shaft, the torque is immediately increased. After being transmitted to the generator, the number of rotations increases with a torsional moment. On the other hand, in the case of the rotating shaft 9 having the double structure of the present invention, the inner shaft 15
Due to the torsional deformation of the rotor 3, the number of rotations of the rotor 3 is increased, and the pitch conversion of the blades is performed while absorbing the energy. Therefore, the original rated output rotation can be returned early. Further, at this time, the inner shaft 15 (flexible shaft) has a long torsional vibration cycle and delays the transmission of the increased torque to the generator side, so that the start of acceleration on the generator side can also be delayed. Therefore, due to the synergistic effect of the above two, it is possible to stop the fluctuation of the rotation speed on the generator side to an extremely small value.

Further, since both the inner shaft 15 and the outer shaft 16 of the rotating shaft 9 are straight and have a double structure, the rotating shaft 9 supported in a cantilever manner is not lengthened more than necessary, and therefore the rotating shaft 9 The bending moment can be reduced as much as possible, and unnecessary increase in strength at the rotary shaft support portion of the nacelle 2 can be avoided.

In addition, a straight outer shaft 16 for fixing the rotor 3 is supported on the nacelle 2 by bearings 18 and 19 which are separated from each other on the front end side and the rear end side, and a straight inner shaft 15 whose front end is attached to the outer shaft 16 is A bearing 17 placed near the rear end bearing 19
Since it is supported by the nacelle 2, it reliably supports the nacelle 2 for a long period of time against a large load acting on the outer shaft 16 and the inner shaft 15 while holding the outer shaft 16 and the inner shaft 15 in a concentric double structure. can do.

〔The invention's effect〕

As described above, the present invention is a propeller-type wind turbine in which a rotor having a plurality of blades is fixed to the tip of a horizontal rotation shaft, and the rear end side of the rotation shaft is cantilever-supported in a nacelle. The shafts are arranged concentrically and have a double structure consisting of a straight inner shaft and an outer shaft, and the outer shaft is rotated by the nacelle via bearings that are spaced apart on the front end side and the rear end side thereof. A bearing that is freely supported, the rotor is fixed to the tip of the outer shaft, the inner shaft is formed of a flexible shaft, and the rear end side is arranged near the rear end bearing that supports the outer shaft. Since it is rotatably supported in the outer shaft via the, and the tip side of the inner shaft is fixed to the outer shaft, and only the rear end side of the inner shaft is connected to the driven system, the following excellent It has a great effect.

That is, the rotating shaft that fixes the rotor has a double structure consisting of an inner shaft made of a flexible shaft and an outer shaft arranged outside thereof, and only the inner shaft side is connected to the driven system. While the outer shaft takes charge, the rotational torque can be taken by the inner shaft having low rigidity. Therefore, the torque variation applied to the rotary shaft from the rotor due to the wind speed variation can be absorbed by the torsional deformation of the inner shaft, and thereby the propagation to the driven system can be mitigated. It is not necessary to unnecessarily increase the weight or the capacity to secure the strength and rigidity of the device, and the reliability can be secured while achieving the weight reduction and the compactness.

In addition, since the straight inner shaft and the outer shaft both have a double structure, it is possible to avoid unnecessarily increasing the length of the cantilever-supported rotating shaft, and to bend the rotating shaft. Since the moment can be made as small as possible, unnecessary increase in strength of the rotary shaft supporting portion of the nacelle is not caused.

Further, a straight outer shaft for fixing the rotor is supported by the nacelle by bearings separated from each other on the front end side and the rear end side, and a straight inner shaft whose front end is fixed to the outer shaft is supported by the outer shaft. Since the bearing arranged near the rear end bearing supports the outer shaft, the outer shaft and the inner shaft are kept in a double structure of concentric circles against a large load acting on the outer shaft and the inner shaft.
The nacelle can be reliably supported for a long time.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a rotor supporting portion of a wind turbine generator using a propeller-type wind turbine according to an embodiment of the present invention, and FIG. 2 is a perspective view showing a main portion of the wind turbine generator using the propeller-type wind turbine. 2 ... Nacelle, 3 ... Rotor, 5 ... Blade, 9 ... Rotation axis,
15 ... Inner shaft, 16 ... Outer shaft, 17,18,19 ... Bearing, 25 ... Gearbox (driven system).

Claims (2)

(57) [Claims] 1. A propeller-type wind turbine in which a rotor having a plurality of blades is fixed to a front end portion of a horizontal rotation shaft, and the rear end side of the rotation shaft is cantilever-supported in a nacelle. In a double structure composed of a straight inner shaft and an outer shaft, both of which are rotatably supported by the nacelle via bearings that are spaced apart on the front end side and the rear end side of the outer shaft. With the above, the rotor is fixed to the tip of the outer shaft, the inner shaft is made up of a flexible shaft, and the rear end side of the outer shaft is supported by a bearing arranged near the rear end bearing that supports the outer shaft. A rotor for a propeller-type wind turbine, wherein the rotor is rotatably supported in an outer shaft, the front end side of the inner shaft is fixed to the outer shaft, and only the rear end side of the inner shaft is connected to a driven system. Support structure. 2. The rotor support structure for a propeller-type wind turbine according to claim 1, wherein the driven system is a gearbox and a generator.