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Title:
WIND TURBINE, ROTARY MACHINE AND METHOD FOR PREVENTING DAMAGE TO ROTARY MACHINE FOR WIND TURBINE
Document Type and Number:
WIPO Patent Application WO/2019/115729
Kind Code:
A1
Abstract:
A rotary machine for a wind turbine includes: a rotor; and a casing for housing the rotor and supported by a base portion so as to constitute a stator of the rotary machine. At least a part of the casing is configured to be rotatable together with the rotor while permitting relative rotation with respect to the base portion when a rotational force equal to or greater than a threshold torque value is applied to the rotor.

Inventors:
NUMAJIRI, Tomohiro (Dusager 4, Aarhus N, DK-8200, DK)
Application Number:
EP2018/084838
Publication Date:
June 20, 2019
Filing Date:
December 13, 2018
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
MHI VESTAS OFFSHORE WIND A/S (Dusager 4, Aarhus N, DK-8200, DK)
International Classes:
F03D7/02; F03D15/00; F03D80/00; F16D7/02; H02K5/26
Foreign References:
US4586400A1986-05-06
DE102011105345A12012-12-27
US20130272842A12013-10-17
US20110269554A12011-11-03
US20110140439A12011-06-16
Attorney, Agent or Firm:
HENKEL, BREUER & PARTNER (Maximiliansplatz 21, M√ľnchen, 80333, DE)
Download PDF:
Claims:
[CLAIMS]

1. A rotary machine for a wind turbine, comprising:

a rotor;

a stator composed of a casing for housing the rotor; and

a base portion supporting the casing,

wherein at least one part of the casing is configured to be rotatable together with the rotor while permitting relative rotation with respect to the base portion when a rotational force equal to or greater than a threshold torque value is applied to the rotor.

2. The rotary machine for a wind turbine according to claim 1, further comprising

a friction engagement element provided between the base portion and the at least one part of the casing,

wherein the friction engagement element is configured to permit relative rotation of the at least one part of the casing with respect to the base portion when a rotational force equal to or greater than the threshold torque value is applied to the rotor.

3. The rotary machine for a wind turbine according to claim 2,

wherein the friction engagement element includes a friction pad provided between the base portion and the at least one part of the casing.

4. The rotary machine for a wind turbine according to claim 2,

wherein the friction engagement element includes

a first wedge member provided at a side of the base portion, and

a second wedge member which faces to the first wedge member and is provided at a side of the at least one part of the casing.

5. The rotary machine for a wind turbine according to any one of claims 1 to 4, further comprising

an adjusting section configured to adjust the threshold torque value.

6. The rotary machine for a wind turbine according to claim 5, further comprising

a friction engagement element provided between the base portion and the at least one part of the casing,

wherein the adjusting section is configured to be capable of adjusting the friction fastening force of the friction engagement element. 7. The rotary machine for a wind turbine according to claim 1 , further comprising

a clutch provided between the base portion and the at least one part of the casing, wherein the clutch is configured to permit relative rotation of the at least one part of the casing with respect to the base portion when a rotational force equal to or greater than the threshold torque value is applied to the rotor.

8. The rotary machine for a wind turbine according to claim 1 , further comprising

a latch element provided between the base portion and the at least one part of the casing, wherein the latch element is configured to permit relative rotation of the at least one part of the casing with respect to the base portion when a rotational force equal to or greater than the threshold torque value is applied to the rotor.

9. The rotary machine for a wind turbine according to any one of claims 1 to 8, further comprising

a cable which is provided between a sensor for monitoring the rotary machine or a condition of the rotary machine and a cable connection end at a side of the base portion and connects the sensor and the cable connecting end,

wherein the cable is configured so that a connecting condition between the sensor and the cable connection end is released when the at least one part of the casing relatively rotates with respect to the base portion.

10. The rotary machine for a wind turbine according to any one of claims 1 to 8 further comprising

a first cable and a second cable each provided between a sensor for monitoring the rotary machine or a condition of the rotary machine and a cable connection end at a side of the base portion, and

a slip ring provided between the first cable and the second cable. 11. The rotary machine for a wind turbine according to any one of claims 1 to 10,

wherein the rotary machine is a motor including a reduction gear,

the casing includes a gear casing which covers the reduction gear, and

at least the gear casing is configured to be permitted to relatively rotate with respect to the base portion when a rotational force equal to or greater than the threshold torque value is applied to the rotor.

12. The rotary machine for a wind turbine according to any one of claims 1 to 11,

wherein the rotary machine is a yaw drive for adjusting yaw angle of the wind turbine, and

the yaw drive includes:

a motor;

a reduction gear disposed between the motor and a ring gear for yaw rotation; and a pinion which is disposed between the reduction gear and the ring gear and is connected to an output shaft of the reduction gear.

13. The rotary machine for a wind turbine according to any one of claims 1 to 12,

wherein the rotary machine is any one of a motor for adjusting a yaw angle of the wind turbine or a motor for adjusting a blade pitch angle, a drive train component device of the wind turbine, or a generator of the wind turbine.

14. A wind turbine comprising the rotary machine according to any one of claims 1 to 13. 15. A method for preventing a rotary machine for a wind turbine from being damaged, comprising:

releasing a fixed state between at least a part of a casing of the rotary machine and a base portion on which the rotary machine is mounted so that relative rotation of the at least a part of the casing with respect to the base portion is permitted and that the at least a part of the casing is rotated together with the rotor when a torque greater than a threshold value is applied to the rotor of the rotary machine.

Description:
[DESCRIPTION]

WIND TURBINE, ROTARY MACHINE AND METHOD FOR PREVENTING DAMAGE

TO ROTARY MACHINE FOR WIND TURBINE

[Technical Field]

[0001] This disclosure relates to a wind turbine, a rotary machine for a wind turbine and a method for preventing damage to a rotary machine for a wind turbine. [Background Art]

[0002] Conventionally, there is known a configuration in which a torque limiter is provided at a rotating portion of a wind turbine to release a certain load or more. For example, U.S. Patent Publication No. 2011/0140439 (hereinafter referred to as Patent Document 1) discloses a structure in which a hollow conical torque limiter is provided between a pinion for applying a driving force to a ring gear for yaw rotation and a yaw drive shaft for transmitting torque to the pinion.

[0003] However, in Patent Document 1, it is necessary to set the torque limiter to have high rigidity in order to transmit sufficient design torque between the pinion and the drive shaft at the time of normal operation, and a large-sized pinion having a larger volume than usual is necessary. Further, when a gear ratio between the pinion and the ring gear is set low, it is necessary to increase the number or the size of the yaw drive.

[0004] Further, in a gear box, tooth spillage and sticking are likely to occur at a high speed stage as compared with a low speed stage, but there is a possibility that sticking may occur also at a low speed stage (for example, a pinion and a drive shaft). Unforeseen events such as when sticking occurs at the low speed stage or where sticking occurs between the rotational system (rotor) including shafts and gears and the stationary system (stator) accommodating them, it is desirable to protect, in particular, parts which are relatively low in mechanical strength and which require a great deal of labor for replacement and maintenance. [Summary of Invention]

[0005] The present invention has been made in view of the above problems, and at least one embodiment of the present invention aims to protect rotary machine from damage during overload.

[0006] (l)According to at least one embodiment of the present invention, there is provided a rotary machine for a wind turbine, which includes:

a rotor;

a stator composed of a casing for housing the rotor; and

a base portion supporting the casing,

wherein at least one part of the casing is configured to be rotatable together with the rotor while permitting relative rotation with respect to the base portion when a rotational force equal to or greater than a threshold torque value is applied to the rotor.

[0007] In the conventional torque limiter, the torque transmission between an element of the rotational system and an element of the rotational system in contact therewith (that is, in the rotational system) is blocked, whereas in the configuration shown in the present disclosure, a part of the fixed system can be rotated together with the rotational system. That is, according to the rotary machine for the wind turbine according to the above-described embodiment, it is possible to switch a part of the fixed system between a case where the fixed system acts as a fixed system with a predetermined threshold torque as a boundary and a case where the fixed system behaves as a rotational system.

[0008] According to the above configuration, at least a part of the casing installed, at the time of normal operation of the wind turbine, as the stationary stator internally accommodating the rotational system such as the rotor or the like rotates together with the rotor when a torque equal to or larger than the threshold value acts on the rotor, with relative rotation with respect to the base portion being permitted. That is, at the time of normal operation of the wind turbine, since at least a part of the casing functions as the stator integrated with the base portion, smooth operation of the rotor accommodated therein can be secured. On the other hand, when a rotational force equal to or greater than the threshold torque is applied to the rotor, at least a part of the casing can rotate relative to the base portion and can rotate together with the rotor. Therefore, it is possible to relieve the load acting on the rotary machine at the time of overload and protect the rotary machine from damage.

[0009] In addition, by allowing a fixed system interface which has conventionally been fastened and fixed by bolts and nuts, for example, to rotate with a torque equal to or larger than the threshold value while holding the interface with the brake applied during normal operation, as described above, it is possible to adequately protect the rotary machine and its surrounding elements without requiring measures such as actions or treatment by an operator when engaging or fixing of the gear inside the rotary machine or excessive torque thereto occurs.

[0010] (2)In some embodiments, according to the above configuration (1), the rotary machine may include a friction engagement element provided between the base portion and the at least one part of the casing, wherein the friction engagement element is configured to permit relative rotation of the at least one part of the casing with respect to the base portion when a rotational force equal to or greater than the threshold torque value is applied to the rotor.

[0011] According to the configuration including the frictional engagement element in this manner, it is possible to arbitrarily set the threshold torque at which the relative rotation of the casing with respect to the base portion is allowable, so that the rotary machine can be appropriately protected.

[0012] (3)In some embodiments, according to the above configuration (2), the friction engagement element may include a friction pad provided between the base portion and the at least one part of the casing.

[0013] According to this configuration, it is possible to achieve the effects shown in some embodiments of the present disclosure with a simple configuration by processing a friction material having an appropriate coefficient of friction, abrasion resistance, thickness, and the like according to the threshold torque into a shape suitable for the opposing surface between the casing and the base portion, to form the friction pad.

[0014] (4)In some embodiments, according to the above configuration (2), the friction engagement element may include a first wedge member provided at a side of the base portion, and a second wedge member which faces to the first wedge member and is provided at a side of the at least one part of the casing.

[0015] According to this configuration, the degree of freedom of design can be improved in consideration of the work space in the nacelle and the tower, the maintainability, and the tightening direction of the fastening work.

[0016] (5)In some embodiments, according to any one of the above configurations (1) to (4), the rotary machine may further comprise an adjusting section configured to adjust the threshold torque value.

[0017] With this configuration, it is possible to appropriately adjust the threshold torque at the time of incorporating the rotary machine in the wind turbine or thereafter. Thereby, for example, even in the case where there is a design error or an incorporation error between the casing and the base portion, or even when the initial assembling state or the threshold torque changes in accordance with the use situation or aged deterioration of the wind turbine, it is possible to appropriately set the threshold torque allowing the relative rotation of at least a part of the casing with respect to the base portion by adjusting the threshold torque adjusting portion.

[0018] (6)In some embodiments, according to the above configuration (5), the rotary machine may further comprise a friction engagement element provided between the base portion and the at least one part of the casing, wherein the adjusting section is configured to be capable of adjusting the friction fastening force of the friction engagement element.

[0019] By adopting such a configuration, as the threshold torque adjuster, various members or devices that can adjust the frictional engagement force by the frictional engagement element and can keep the adjusted fastening force constant are adopted.

[0020] (7)In some embodiments, according to the above configuration (1), the rotary machine may further comprise a clutch provided between the base portion and the at least one part of the casing, wherein the clutch is configured to permit relative rotation of the at least one part of the casing with respect to the base portion when a rotational force equal to or greater than the threshold torque value is applied to the rotor.

[0021] According to this configuration, by the clutch configured so as to permit relative rotation of at least a part of the casing with respect to the base portion when a rotational force equal to or greater than the threshold torque is applied to the rotor, it is possible to obtain the same effect as in some embodiments of the present invention.

[0022] (8)In some embodiments, according to the above configuration (1), the rotary machine may further comprise a latch element provided between the base portion and the at least one part of the casing, wherein the latch element is configured to permit relative rotation of the at least one part of the casing with respect to the base portion when a rotational force equal to or greater than the threshold torque value is applied to the rotor.

[0023] According to this configuration, by the latch element configured to permit relative rotation of at least a part of the casing with respect to the base portion when a rotational force equal to or greater than the threshold torque is applied to the rotor, it is possible to obtain the same effect as in some embodiments of the present invention.

[0024] (9)In some embodiments, according to any one of the above configurations (1) to

(8), the rotary machine may further comprise a cable which is provided between a sensor for monitoring the rotary machine or a condition of the rotary machine and a cable connection end at a side of the base portion and connects the sensor and the cable connecting end, wherein the cable is configured so that a connecting condition between the sensor and the cable connection end is released when the at least one part of the casing relatively rotates with respect to the base portion.

[0025] According to this configuration, when a rotational force equal to or greater than the threshold torque is applied to the rotor and at least a part of the casing rotates relative to the base portion, the connection state between the sensor and the cable connection end is canceled. Therefore, such cases in which the cable itself is cut due to the twisting of the wiring such as the cable due to the relative rotation, the sensor pulled by the cable and the cable connection end come off, and the rotary machine is damaged can be effectively prevented. Also, at the time of restoration, since the cable can be reconnected easily, it is possible to improve the maintainability.

[0026] (lO)In some embodiments, according to any one of the above configurations (1) to (8), the rotary machine may further comprise a first cable and a second cable each provided between a sensor for monitoring the rotary machine or a condition of the rotary machine and a cable connection end at a side of the base portion, and a slip ring provided between the first cable and the second cable.

[0027] According to this configuration, when a rotational force equal to or greater than the threshold torque is applied to the rotor and at least a part of the casing rotates relative to the base portion, even if the first cable and the second cable between the sensor and the cable connection end are twisted, the slip ring can absorb or eliminate the twisting and maintain the electrical connection. Therefore, such case in which the first cable or the second cable is cut by the twist of the wiring such as the cable due to the relative rotation, the sensor and the cable connection end connected to the cables are disconnected so that damage to the rotary machine can be effectively prevented.

[0028] (l l)In some embodiments, according to any one of the above configurations (1) to

(10), the rotary machine may be a motor including a reduction gear, the casing includes a gear casing which covers the reduction gear, and at least the gear casing may be configured to be permitted to relatively rotate with respect to the base portion when a rotational force equal to or greater than the threshold torque value is applied to the rotor.

[0029] ln this way, by applying the rotary machine to the combination of the speed reduction gear and the motor so as to make the gear casing of the casing relatively rotatable with respect to the base portion, the components of the wind turbine among the many driving units including the motor and the speed reduction gear, advantageous effects shown in the present disclosure can be enjoyed.

[0030] ( 12)In some embodiments, according to any one of the above configurations (1) to

(11), the rotary machine may be a yaw drive for adjusting yaw angle of the wind turbine, and the yaw drive may include: a motor; a reduction gear disposed between the motor and a ring gear for yaw rotation; and a pinion which is disposed between the reduction gear and the ring gear and is connected to an output shaft of the reduction gear.

[0031] According to the configuration in which the yaw drive is applied as the rotary machine as described above, in the yaw drive that performs the yaw rotation of the wind turbine, it is possible to obtain benefits of the action and the effect shown in some embodiments of the present disclosure. In particular, the ring gear, which is a relatively large member among the constituent elements of the rotary system, tends to have a lower mechanical strength as compared with other members due to limitation in size and the like in heat treatment such as quenching and tempering, and it requires a great deal of labor for replacement and maintenance. Therefore, at least a part of the casing of the yaw drive to be meshed with the ring gear via the pinion can be rotated integrally with the rotor such as the motor and the speed reduction gear as described above, the torque from the ring gear can be released regardless of where in the motor or the speed reduction gear biting or sticking occurs. Therefore, it is possible to properly and effectively protect the rotary machine and its surrounding elements from overload.

[0032] (l3)In some embodiments, according to any one of the above configurations (1) to (12), the rotary machine may be any one of a motor for adjusting a yaw angle of the wind turbine or a motor for adjusting a blade pitch angle, a drive train component device of the wind turbine, or a generator of the wind turbine.

[0033] That is, the rotary machine can also be applied to a single motor, and it is possible to enjoy the advantageous effect shown in the present disclosure in relation between the rotor and the casing inside the motor or the motor. Further, for example, in the gear train constituting device and the speed increasing gear in the generator, these rotary machines can be protected from damage during overload.

[0034] (l4)According to at least one embodiment of the present invention, there is provided a wind turbine comprising the rotary machine according to any one of the above configuration. [0035] (15)According to at least one embodiment of the present invention, there is provided a method for preventing damage to a rotary machine for a wind turbine, the method includes:

releasing a fixed state between at least a part of a casing of the rotary machine and a base portion on which the rotary machine is mounted so that relative rotation of the at least a part of the casing with respect to the base portion is permitted and that the at least a part of the casing is rotated together with the rotor when a torque greater than a threshold value is applied to the rotor of the rotary machine.

[Brief Description of Drawings]

[0036] FIG. 1 is a schematic view showing a structure of a wind turbine according to an embodiment.

FIG. 2 is a schematic perspective view showing a structure of a rotary machine for a wind turbine according to one embodiment.

FIG. 3 is a longitudinal sectional view showing a structure of a rotary machine for a wind turbine according to one embodiment.

FIG. 4 is a longitudinal sectional view showing the structure of a rotary machine for a wind turbine according to another embodiment.

FIG. 5A is a view showing a threshold torque adjustment unit (elastic member and bolt) in a rotary machine for a wind turbine according to one embodiment.

FIG. 5B is a diagram showing a threshold torque adjustment unit (wedge member and bolt) in a rotary machine for a wind turbine according to one embodiment.

FIG. 6 is a schematic diagram showing a wiring state of a rotary machine in one embodiment.

FIG. 7 is a schematic diagram showing a wiring state of a rotary machine according to another embodiment.

FIG. 8 is a schematic diagram showing a rotary machine for a wind turbine according to another embodiment. [Description of Embodiments]

[0037] Embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It is intended, however, that unless particularly specified, dimensions, materials, shapes, relative positions and the like of components described in the embodiments shall be interpreted as illustrative only and not limitative of the scope of the present invention.

[0038] First, the structure of a rotary machine for a wind turbine according to at least one embodiment of the present invention will be described with reference to FIG. 1 to FIG. 4. The rotary machine 10 for windmill is a constituent device of the wind turbine 1 and can be applied to a wind turbine 1 installed on land or offshore.

[0039] As shown in FIG. 1 , the wind turbine 1 includes a wind turbine rotor 4 including a plurality of wind turbine blades 2 and a hub 3 to which the wind turbine blade 2 is attached, a nacelle 7 rotatably supporting the rotor 4 via a drive train component device 5 including a main shaft and a main bearing, a generator 6 driven by receiving the rotational force of the main shaft, a tower 8 supporting the nacelle 7 so as to be horizontally tumable, and a platform 9 on which the tower 8 is installed. The wind turbine blade 2 is configured so that a pitch angle can be adjusted by a rotation of the motor 50A installed in the hub 3. When the wind turbine 1 receives wind by the wind turbine blade 2, the rotor 4 rotates, and power is generated by the generator 6 connected to the rotor 4. The wind turbine 1 is configured so that a yaw angle of the wind turbine 1 can be adjusted by rotation of the motor 50.

[0040] As illustrated non-limitingly in FIGS. 2 to 4, a rotary machine 10 for a wind turbine according to at least one embodiment of the present invention includes a rotor 14, a casing 12 which accommodates the rotor 14 and is supported on the base portion 18 so as to constitute a stator 16 of the rotary machine 10.

[0041] The casing 12 may include a step or flange on its outer surface and may be configured so that at least a part thereof faces the base portion 18.

[0042] The rotor 14 is configured to be rotatable relative to the stator 16, and is driven with being directly or indirectly supported by the stator 16. The rotor 14 may be a portion that mainly contributes to power transmission for driving the wind turbine 1 and changing its position by rotation. In the present disclosure, the rotor 14 that can be applied to various parts of the wind turbine 1 may also be collectively referred to as a rotational system.

[0043] The stator 16 may mainly include a body of the wind turbine 1 as a structure and a portion fixed to the wind turbine 1 to support other constituent elements. In the present disclosure, the stator 16 that can be applied to various parts of the wind turbine 1 may also be collectively referred to as a fixed system in some cases. As described above, the casing 12 may be supported by the base portion 18 to constitute the stator 16.

[0044] At least a part of the casing 12 is configured to be rotatable together with the rotor

14 by permitting relative rotation with respect to the base portion 18 when a rotational force equal to or greater than the threshold torque is applied to the rotor 14.

[0045] The threshold torque may be set in consideration of, for example, preventing damage to an element to be protected, mechanical strength of which is low among mechanical elements that perform power transmission directly or indirectly to the components of the rotary machine 10 or the rotary machine 10.

[0046] In the conventional torque limiter, the torque transmission between an element of the rotational system and an element of the rotational system in contact therewith (that is, in the rotational system) is blocked, whereas in the configuration shown in the present disclosure, a part of the fixed system can be rotated together with the rotational system. That is, according to the rotary machine 10 for the wind turbine 1 according to the above-described embodiment, it is possible to switch a part of the fixed system between a case where the fixed system acts as a fixed system with a predetermined threshold torque as a boundary and a case where the fixed system behaves as a rotational system.

[0047] According to the above configuration, at least a part of the casing 12 installed, at the time of normal operation of the wind turbine 1, as the stationary stator 16 internally accommodating the rotational system such as the rotor 14 or the like rotates together with the rotor 14 when a torque equal to or larger than the threshold value acts on the rotor 14, with relative rotation with respect to the base portion 18 being permitted. That is, at the time of normal operation of the wind turbine 1 , since at least a part of the casing 12 functions as the stator 16 integrated with the base portion 18, smooth operation of the rotor 14 accommodated therein can be secured. On the other hand, when a rotational force equal to or greater than the threshold torque is applied to the rotor 14, at least a part of the casing 12 can rotate relative to the base portion 18 and can rotate together with the rotor 14. Therefore, it is possible to relieve the load acting on the rotary machine 10 at the time of overload and protect the rotary machine 10 from damage.

[0048] In addition, by allowing a fixed system interface which has conventionally been fastened and fixed by bolts and nuts, for example, to rotate with a torque equal to or larger than the threshold value while holding the interface with the brake applied during normal operation, as described above, it is possible to adequately protect the rotary machine 10 and its surrounding elements without requiring measures such as actions or treatment by an operator when engaging or fixing of the gear inside the rotary machine 10 or excessive torque thereto occurs.

[0049] In some embodiments, the rotary machine 10 may be a yaw drive 10A for adjusting the yaw angle of the wind turbine 1. One or a plurality of yaw drives 10A may be arranged for one wind turbine 1. In an example shown non-limitingly in FIGS. 2 to 4, a plurality of (for example, 4 to 10) yaw drives 10A are arranged in one wind turbine 1. Each yaw drive 10A may be configured to be rotatable relative to the base portion 18 (nacelle base or base frame) via a hollow cylindrical bracket 13, for example. That is, the base portion 18 may include the bracket 13 that supports the yaw drive 10A in a relatively rotatable manner with respect to the base portion 18.

[0050] The yaw drive 10A may include a motor 50, a speed reduction gear 56 disposed between the motor 50 and a ring gear 54 for yaw rotation, and a pinion 52 disposed between the speed reduction gear 56 and the ring gear 54 and connected to the drive shaft 58 which is the output shaft of the reduction gear 56. That is, the yaw drive 10A may be configured such that an external force such as wind load acts in the order of the pinion 52, the speed reduction gear 56, and the motor 50 via the ring gear 54.

[0051] The bracket 13 may be configured to be fixed to the base portion 18 on the side of one end (for example, upper end portion) 13A in the axial direction of the cylinder, and may be configured to rotatably support the casing 12 of the yaw drive 10A by a flange 13C provided on the other end portion (for example, the lower end portion) 13B. The flange 13C may be, for example, an annular or arcuate inner flange (see FIGS. 3 and 4).

[0052] The motor 50 is electrically connected to a controller (not shown) and/or a power supply terminal of the wind turbine 1 and can be rotationally driven according to a control signal transmitted from the controller and/or an electric power transmitted from the power supply terminal.

[0053] The speed reduction gear 56 may include a multi-stage (multiple steps) or stepless speed change mechanism and may include, for example, four to five or more gear mechanisms (e.g. planetary gears etc.).

[0054] The rotor 14 in the yaw drive 10A may include, for example, an inner rotor including an output shaft of the motor 50 itself, a speed reduction gear 56 connected to the output shaft of the motor 50, a drive shaft 58, which is an output shaft of the yaw drive 10A, connected to the speed reduction gear 56, and a pinion 52 coupled to the drive shaft 58 and meshed with a ring gear 54 for yaw rotation.

[0055] According to the configuration in which the yaw drive 10A is applied as the rotary machine 10 as described above, in the yaw drive 10A that performs the yaw rotation of the wind turbine 1, it is possible to obtain benefits of the action and the effect shown in some embodiments of the present disclosure. In particular, the ring gear 54, which is a relatively large member among the constituent elements of the rotary system, tends to have a lower mechanical strength as compared with other members due to limitation in size and the like in heat treatment such as quenching and tempering, and it requires a great deal of labor for replacement and maintenance. Therefore, at least a part of the casing 12 of the yaw drive 10A to be meshed with the ring gear 54 via the pinion 52 can be rotated integrally with the rotor 14 such as the motor 50 and the speed reduction gear 56 as described above, the torque from the ring gear 54 can be released regardless of where in the motor 50 or the speed reduction gear 56 biting or sticking occurs. Therefore, it is possible to properly and effectively protect the rotary machine 10 and its surrounding elements from overload.

[0056] The motor 50 may be disposed below the ring gear 54. In this case, the speed reduction gear 56 may be disposed above the motor 50, and the pinion 52 may be disposed above the reduction gear 56 (see FIGS. 2 to 4). Further, the motor 50 may be disposed above the ring gear 54, in which case a reduction gear 56 is disposed below the motor 50 and a pinion 52 may be disposed below the reduction gear 56. Further, the threshold torque when the yaw drive 10A is applied as the rotary machine 10 may be set to a value that can prevent damage to the ring gear 54, for example.

[0057] In some embodiments, in the above configuration, the rotary machine 10 may include a frictional fastening element 20 (see FIG. 3) provided between at least a portion of the casing 12 and the base portion 18. At least one frictional engagement element 20 may be disposed at a position where at least a part of the casing 12 and the base portion 18 face each other.

[0058] The frictional engagement surface of the frictional engagement element 20 may be arranged in a direction orthogonal to the rotation axis of the rotor 14 (for example, a transmission such as a yaw gear) like a disk brake of a vehicle or the like (that is, arranged in a disk-like surface) (see, for example, FIG. 3). In this case, the frictional engagement element 20 may be disposed at a plurality of positions in the axial direction of the rotation axis of the rotor 14, or at least one of the casing 12 and the base portion 18 may be arranged to sandwich the friction engagement element 20 in a sandwich shape. Further, the frictional engagement element 20 may be in parallel with the rotation axis of the rotor 14 (that is, cylindrical surface arrangement) like the drum brake of a vehicle or the like (see, for example, FIG. 4). Further, the frictional engagement element 20 may be formed to match the shape of the opposing surface of at least a part of the casing 12 and the base portion 18, and may be annular or arcuate, for example.

[0059] The frictional engagement element 20 may be configured to permit relative rotation of at least a part of the casing 12 with respect to the base portion 18 when a rotational force equal to or greater than the threshold torque is applied to the rotor 14. The threshold torque in the case where such a frictional engagement element 20 is arranged appropriately sets the material of each of the casing 12, the base portion 18, the frictional engagement element 20, the friction coefficient of the surface, and the fastening force sandwiching the frictional engagement element 20 can be set to an arbitrary value. For example, a material having a value of a static friction coefficient close to a value of a dynamic friction coefficient may be adopted as the friction engagement element 20 as described above.

[0060] For example, a material used as a brake pad of a vehicle, such as a metal type, a plastic type, a carbon type, etc., may be adopted as the frictional engagement element 20.

[0061] According to the configuration including the frictional engagement element 20 in this manner, it is possible to arbitrarily set the threshold torque at which the relative rotation of the casing 12 with respect to the base portion 18 is allowable, so that the rotary machine 10 can be appropriately protected.

[0062] In some embodiments, in the above configuration, the frictional fastening element

20 may include a friction pad 22 provided between the base portion 18 and at least a portion of the casing 12 (see, for example, FIGS. 3 and 4). According to this configuration, it is possible to achieve the effects shown in some embodiments of the present disclosure with a simple configuration by processing a friction material having an appropriate coefficient of friction, abrasion resistance, thickness, and the like according to the threshold torque into a shape suitable for the opposing surface between the casing 12 and the base portion 18, to form the friction pad 22.

[0063] In some embodiments, the above configuration may further comprise a threshold torque adjuster 23 configured to adjust the threshold torque. With this configuration, it is possible to appropriately adjust the threshold torque at the time of incorporating the rotary machine 10 in the wind turbine 1 or thereafter. Thereby, for example, even in the case where there is a design error or an incorporation error between the casing 12 and the base portion 18, or even when the initial assembling state or the threshold torque changes in accordance with the use situation or aged deterioration of the wind turbine 1 , it is possible to appropriately set the threshold torque allowing the relative rotation of at least a part of the casing 12 with respect to the base portion 18 by adjusting the threshold torque adjusting portion 23.

[0064] In some embodiments, in the above configuration, the threshold torque adjuster 23 may be configured to be able to adjust the frictional engagement force by the frictional engagement element 20.

[0065] By adopting such a configuration, as the threshold torque adjuster 23, various members or devices that can adjust the frictional engagement force by the frictional engagement element 20 and can keep the adjusted fastening force constant are adopted. As such a member or device, for example, a structure using an elastic member 24 such as a spring (coil spring etc.) or rubber and a fastening element such as a bolt 25 (see FIG. 5A) may be adopted. In some embodiments, by advancing and retracting the bolt 25 in a direction intersecting the opposing surface of the casing 12 and the base portion 18 (for example, orthogonal in FIG. 5A), that is, in the pressing direction of the frictional engagement element 20, the frictional engagement may be configured to adjust the above described frictional engagement forces. Although not shown, a hydraulic system including an accumulator and a cylinder, an electromagnetic solenoid, a magnet, or the like may be adopted as the threshold torque adjuster 23. ln the case of adopting the hydraulic system, the function of adjusting the frictional engagement force can be achieved by adjusting a hydraulic pressure.

[0066] In some embodiments, in the above configuration, the frictional engagement element 20 includes a first wedge member 26 provided on the side of the base portion 18, and a second wedge member 27 which faces to the first wedge member 26 and is provided on the side of at least a part of the casing 12 (see, for example, FIG. 5B).

[0067] The first wedge member 26 and the second wedge member 27 may be configured to have a tapered shape in which the mutually contacting opposing faces are inclined with respect to the pressing direction of the frictional engagement element 20, and may be configured so that one of them may be tilted with respect to the other by a slide along the inclined face and the fastening force between the casing 12 and the base portion 18 can be adjusted. For example, by advancing and retracting the first wedge member 26 in a direction parallel to the opposing surface of the casing 12 and the base portion 18 with a bolt 25 or the like illustrated as non-limiting example in F1G. 5B, the frictional engagement element 20 may be configured so that the pressure (frictional engagement force) in the direction orthogonal to the moving direction can be adjusted.

[0068] According to this configuration, the degree of freedom of design can be improved in consideration of the work space in the nacelle 7 and the tower 8, the maintainability, and the tightening direction of the fastening work.

[0069] In some embodiments, in the above configuration, the rotary machine 10 may include a clutch (not shown) provided between the base portion 18 and at least a portion of the casing 12, and may be configured to permit relative rotation of at least a part of the casing 12 with respect to the base portion 18 (see FIG. 6, for example) when the rotational force equal to or greater than the threshold torque is applied to the rotor 14.

[0070] The clutch may include, for example, all of the mechanical elements that enable switching between the two members to be switched between a relatively non-rotatable state and a relatively rotatable state. For example, the clutch may include a mechanical clutch such as a dog clutch into which the claws of the two members mate or friction clutch.

[0071] According to this configuration, by the clutch configured so as to permit relative rotation of at least a part of the casing 12 with respect to the base portion 18 when a rotational force equal to or greater than the threshold torque is applied to the rotor 14, it is possible to obtain the same effect as in some embodiments of the present invention.

[0072] In some embodiments, the rotary machine 10 may include a latching element (not shown) provided between the base portion 18 and at least a portion of the casing 12. The latching element may be configured to permit relative rotation of the at least one portion with respect to the base portion 18 when the rotational force equal to or greater than the threshold torque is applied to the rotor 14.

[0073] According to this configuration, by the latch element configured to permit relative rotation of at least a part of the casing 12 with respect to the base portion 18 when a rotational force equal to or greater than the threshold torque is applied to the rotor 14, it is possible to obtain the same effect as in some embodiments of the present invention.

[0074] In some embodiments, the rotary machine 10 may include a cable 40 provided between a sensor (or a power supply terminal) 38 for monitoring the state of the rotary machine 10 or the rotary machine 10 and a cable connection end 46 on the side of the base portion 18, and connects the sensor 38 and the cable connection end 46 (see, for example, FIG. 6). The cable 40 may be configured so that the connection state between the sensor 38 and the cable connection end 46 is released when the cable 40 rotates relative to the base portion 18 of at least a part of the casing 12.

[0075] The sensor 38 may be, for example, an encoder or the like for detecting the rotational angle and the rotational speed of the motor.

[0076] The connection between the sensor 38 and the cable connection end 46 may be accomplished, for example, using a press fit connector or the like ln this case, the sensor 38 and the cable connection end 46 may be connected in a state in which the connection state can be released with a tensile force higher than a certain value without a locking function. Further, by separately connecting a wire or the like to the connector main body separately from the cable 40, a tensile force may not be added to the cable 40 itself, or the cable 40 itself may have a tensile resistance.

[0077] According to this configuration, when a rotational force equal to or greater than the threshold torque is applied to the rotor 14 and at least a part of the casing 12 rotates relative to the base portion 18, the connection state between the sensor 38 and the cable connection end 46 is canceled. Therefore, such cases in which the cable 40 itself is cut due to the twisting of the wiring such as the cable 40 due to the relative rotation, the sensor 38 pulled by the cable 40 and the cable connection end 46 come off, and the rotary machine 10 is damaged can be effectively prevented. Also, at the time of restoration, since the cable 40 can be reconnected easily, it is possible to improve the maintainability.

[0078] ln other embodiments, the cable 40 may be a cable that transmits electricity or information such as a control signal or a detection signal in an electrical or other manner (e.g. light via an optical fiber, etc.).

[0079] In some embodiments, in the above configuration, the rotary machine 10 may include a first cable 42 and a second cable 44 provided between a sensor (or a power supply terminal) 38 for monitoring the rotary machine 10 or the condition of the rotary machine 10 and a cable connection end 46 on the side of the base portion 18, and a slip ring 48 provided between the first cable 42 and the second cable 44 (see FIG. 7, for example).

[0080] According to this configuration, when a rotational force equal to or greater than the threshold torque is applied to the rotor 14 and at least a part of the casing 12 rotates relative to the base portion 18, even if the first cable 42 and the second cable 44 between the sensor 38 and the cable connection end 46 are twisted, the slip ring 48 can absorb or eliminate the twisting and maintain the electrical connection. Therefore, such case in which the first cable 42 or the second cable 44 is cut by the twist of the wiring such as the cable 40 due to the relative rotation, the sensor 38 and the cable connection end 46 connected to the cables 42, 44 are disconnected so that damage to the rotary machine 10 can be effectively prevented.

[0081 ] In some embodiments, rotary machine 10 may be a combination of a speed reduction gear (e.g. speed reduction gear 56) and a motor (e.g. motor 50). In this case, at least the gear casing 12 A (gear box) of the casing 12 covering the speed reduction gear 56 is allowed to rotate relative to the base portion 18 when a rotational force equal to or greater than the threshold torque is applied to the rotor 14 (see, for example, FIG. 8).

[0082] In this way, by applying the rotary machine 10 to the combination of the speed reduction gear 56 and the motor 50 so as to make the gear casing 12A of the casing 12 relatively rotatable with respect to the base portion 18, the components of the wind turbine 1 among the many driving units including the motor and the speed reduction gear, advantageous effects shown in the present disclosure can be enjoyed.

[0083] In some embodiments, in the above configuration, the rotary machine 10 includes a motor 50 for adjusting the yaw angle of the wind turbine 1 , a motor 50A for adjusting the blade pitch angle, a drive train component 5 of the wind turbine 1 , and/or the generator 6 of the wind turbine 1. [0084] That is, the rotary machine 10 can also be applied to a single motor, and it is possible to enjoy the advantageous effect shown in the present disclosure in relation between the rotor and the casing inside the motor 50 or the motor 50A. Further, for example, in the gear train constituting device 5 and the speed increasing gear in the generator 6, these rotary machines 10 can be protected from damage during overload.

[0085] A method for preventing damage to a rotary machine for a wind turbine according to at least one embodiment of the present invention is a method for preventing damage to a rotary machine 10 which is a component device of a wind turbine 1, the method includes releasing a fixed state between at least a part of a casing 12 of the rotary machine 10 and a base portion 18 on which the rotary machine 10 is mounted so that relative rotation of the at least a part of the casing 12 with respect to the base portion 18 is permitted and that the at least a part of the casing is rotated together with the rotor 14 when a torque greater than a threshold value is applied to the rotor 14 of the rotary machine 10. [Industrial Applicability]

[0086] At least one embodiment of the present invention can be used to protect rotary machines from damage in the event of overload in the field of rotary machines for wind turbines, wind turbines and methods of preventing damage thereof.