JP2005151749A - Lightning protection device of wind turbine generator bearing and bearing of the device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lightning protection device of a wind turbine generator bearing that protects the bearing from lightning, suppress the generation of friction powder of a brush as much as possible, and can prevent the occurrence of early failure of the bearing due to the friction powder, and the bearing of the device. <P>SOLUTION: There is provided a conducting member 17 that conductibly contacts a pair of an outer ring 12 and a bearing housing and a pair of an inner ring 11 and a shaft so as to cover the whole of the pairs, and is switchable in contacting and non-contacting. There is provided a switch drive means 19 that switches the conducting member 17 into a contact state and a non-contact state. There is also provided a switch control means that gives a switching command to the switch drive means 9. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lightning strike protection device for a wind power generator bearing that prevents a raceway surface of a bearing that supports a main shaft of a wind power generator from being damaged by a lightning strike, and the bearing thereof.

  Due to environmental problems, a shift from fossil fuels to renewable energy is necessary. Therefore, wind power generation has attracted attention as a power generation device that has the least impact on the environment, does not generate any carbon dioxide, and does not cause natural destruction like hydropower generation. However, most of the troubles that occur in wind power generators are caused by lightning strikes, and the ratio is about 8 out of 100 in Europe. In Japan, it is said that it is more than doubled due to the difference in weather conditions. (For example, Non-Patent Document 1).

  As a countermeasure against lightning, it is common practice to provide a lightning rod, but even if a lightning rod is provided, lightning often strikes a blade or nacelle. In order to provide a lightning rod capable of sufficiently preventing this, a large number of high lightning rods surrounding the windmill are necessary, which is not practical. Since the efficiency of wind turbines increases as they increase in size, the size of wind turbines has been increased and those exceeding 100 m have been developed. Also, the higher the position from the ground surface, the faster the wind can be received, so it is often installed at a high place. For this reason, it is not possible to cope with a lightning rod.

If there is a lightning strike on the blades or nacelle (body) of the wind power generator, not only will the blades and nacelle be damaged, but current will also flow from the blades to the main shaft, causing damage to the bearings and electrical components that support the main shaft. To prevent this, grounding is applied, but since the power of lightning is large, the bearings and electrical components are also energized. In the bearing, melting of the metal material occurs between the rolling elements and the raceway surfaces of the races, and the bearing is damaged.
Various electro-erosion bearings for energizing inner and outer rings have been proposed as electro-corrosion prevention bearings used in parts where potential difference occurs, such as general electric corrosion prevention bearings other than wind power generators, such as motor bearings (for example, Patent Document 1).

In addition, if there is a possibility of lightning discharge in a specific area due to the proximity of thunderclouds, the thunderclouds can be detected for measures to determine whether laser-induced lightning operations or lightning strikes of various electrical facilities should be protected. An invention related to a thundercloud electric field detection device for judging the nature has been proposed (Patent Document 2).
Lecture distribution materials, 38th New Energy Lecture, “Rapidly growing wind power generation”, Organizer: Japan Electrical Manufacturers' Association, Wind Power Generation System Technical Committee, March 13, 2003 JP-A-11-082492 JP 2000-235082 A

  The current-carrying bearing connects the inner ring and the outer ring, and uses a brush for the contact portion. However, since the inner and outer rings make relative motion, the bearing generates wear powder from the contact portion with the brush. The wear powder penetrates into the bearing and the wear powder enters the raceway surface, thereby causing a bearing failure early. In addition, the use of the brush for many years may cause wear of the brush, which may reduce the reliability of energization. In general-purpose energized bearings, the above-mentioned problem of wear powder often has no practical problem, but wind power generators are difficult to maintain because they are installed in unmanned areas or installed in high places. Often. Therefore, it is desired that the bearings can be used without maintenance for several decades. Therefore, it is necessary to avoid as much as possible wear and abrasion powder generated at the contact portion of the brush.

  An object of the present invention is to protect a bearing from a lightning strike, suppress the generation of brush wear powder as much as possible, and prevent an early failure of the bearing due to the wear powder, and a lightning strike protection device for a wind power generator bearing, and its It is to provide a bearing.

  A lightning strike protection device for a wind power generator bearing according to the present invention is an apparatus that is provided in a wind power generator and protects a rolling bearing having a pair of race rings and a plurality of rolling elements interposed between both race rings from lightning strikes. Switching between contact and non-contact is possible in such a way that one of the bearing rings and the set of members on which the bearing rings are installed and the other set of rings and the set of members supported by the other race ring are energized. A flexible energization member, a switching drive unit that switches the energization member between a contact state and a non-contact state, and a switching control unit that gives a switching command to the switching drive unit. The set of the one bearing ring and the member on which the bearing ring is installed is, for example, a bearing ring serving as an outer ring and a bearing housing. The other bearing ring and the set of members supported by the other bearing ring are, for example, a bearing ring that serves as an inner ring and a shaft such as a main shaft.

  According to this configuration, the current-carrying member is kept in a non-contact state at all times, and when lightning approaches or is expected to approach the wind power generator, the switching control unit is operated by the switching control unit to contact the current-carrying member. It can be made into an energized state. In other words, when there is a possibility that a lightning strike will occur, an energization path for protecting the bearing can be created by contacting the current-carrying member, so that it is possible to prevent energization through the rolling elements in the bearing even if a lightning strike occurs. . Therefore, damage to the raceway surface and rolling elements of the raceway is prevented. In addition, since the current-carrying member is not in contact normally and is in contact only when necessary, the generation of wear powder on the current-carrying member and the member that the current-carrying member contacts can be reduced as much as possible, and early failures due to wear powder can be prevented. The Moreover, since there is little abrasion of an electricity supply member, the reliable contact of an electricity supply member can be ensured even if it uses for many years, and the reliability of electricity supply becomes high. Furthermore, by contacting the energizing member only when necessary, frictional resistance due to the contact of the energizing member does not occur at all times, and an increase in rotational torque can be prevented.

In the lightning strike protection device for a wind turbine generator bearing according to the present invention, a thundercloud electric field detection device for detecting a thundercloud electric field in a predetermined area where the wind power generator is provided is provided, and the switching control means is a detection of the thundercloud electric field detection device. It is good also as what has an operation part which performs switching operation of a contact and non-contact by an operator near the installation position of a detection result display means where a result is displayed. The vicinity of the installation position of the detection result display means is a range in which the operator can recognize the thundercloud electric field from the detection result display means and operate the operation unit without delay, for example, the detection result display means and the operation unit are close to the same room to some extent. Say that. The detection result display means may be displayed on the screen, or may be displayed by a sound or light signal.
By providing the thundercloud electric field detection device, it is possible to accurately recognize that a thundercloud electric field has occurred in a limited area where the wind power generator is located. The operator can recognize the occurrence state of the thundercloud electric field by the detection result display means and operate the operation part of the replacement control means nearby to appropriately switch between contact and non-contact of the energization member. Since it is operated by the operator, it can be energized in a flexible manner corresponding to the occurrence of the thundercloud electric field. The said operation part may operate those switching drive means collectively about several wind power generators.

In the lightning strike protection device for a wind power generator bearing according to the present invention, when the thundercloud electric field detection device for detecting a thundercloud electric field in a predetermined area provided with the wind power generator is provided, the switching control means is always the switching The drive means may be in an operating state in which the energization member is not in contact, and the switching drive means may be brought into contact with the switching drive means in response to a detection signal from the thundercloud electric field detection device.
In the case of this configuration, it is possible to automatically switch to the energized state by the energizing member according to the thundercloud electric field detection status without requiring an operator.

In the lightning strike protection device for a wind power generator bearing according to the present invention, the rolling bearing may be a main shaft support bearing that supports the main shaft to which the blades of the wind power generator are attached.
Since the main shaft is a shaft with blades attached, it is most likely to be affected by lightning strikes among the bearings constituting the wind power generator. Therefore, each effect of the present invention, such as bearing protection from lightning strikes and prevention of generation of wear powder, is effectively exhibited.

A bearing for a wind power generator according to the present invention is a rolling bearing that is used in a wind power generator and has a pair of race rings and a plurality of rolling elements interposed between the race rings. It has a current-carrying member that can be switched between contact and non-contact so as to be able to conduct electricity over the set of installed members, the other raceway ring, and the set of members supported by the other raceway ring.
By providing the energization member that can be switched between contact and non-contact in this way, the energization member can be contacted only when necessary according to the approaching situation of the thundercloud electric field as described above. Therefore, while protecting a bearing from a lightning strike, generation | occurrence | production of the abrasion powder of a brush can be suppressed as much as possible, and the early malfunction of the bearing by abrasion powder can be prevented.

  The wind power generator of this invention may be provided with switching drive means for switching the energization member between a contact state and a non-contact state. The switching operation between the contact state and the non-contact state of the current-carrying member may be performed manually by using, for example, a mechanical transmission mechanism. However, by providing a switching drive means, automation or switching from a remote place is possible. Operation becomes possible.

  In the wind power generator bearing according to the present invention, the current-carrying member is a conductive elastic body attached to one of the race rings, and the conductive elastic body is not in contact with the other race ring in a natural state. It may be possible to contact the other race ring in a state where it is forcibly elastically deformed. When the energizing member is an elastic body, when the switching drive means is provided, simple switching drive means such as a single-acting solenoid or a cylinder device that applies a driving force only to the contact side is sufficient. Adjustment of the contact pressure of the current-carrying member is also easy. In addition, since the current-carrying member is attached to one of the bearing rings and comes into contact with the other raceway ring, the bearing alone is provided with a current-carrying member and its contact portion, and the incorporation of the bearing into the wind power generator is easy. is there.

In the bearing for a wind power generator according to the present invention, the energizing member is a conductive elastic body attached to one of the race rings, and the conductive elastic body is a member supported by the other race ring in a natural state. It may be non-contact with the member supported by the other race ring in a state in which it is elastically deformed forcibly.
Also in this configuration, the switching drive means is simple. Further, in this configuration, the energization member is not a bearing race, but a member such as a shaft supported by the race, so that the energization path can be further shortened.

In the wind turbine generator bearing according to the present invention, the energization member may be composed of a conductive metal member and a conductive brush.
In the case of this configuration, reliable contact can be obtained by the conductive brush.

  The wind power generator bearing of the present invention may be a main shaft support bearing that supports the main shaft to which the blades of the wind power generator are attached. As described above, the main shaft is most likely to be affected by lightning strikes, so that each effect of the present invention is effectively exhibited.

  The lightning strike protection device for a wind power generator bearing and the wind power generator bearing according to the present invention are supported by one raceway and a set of members on which the raceway is installed, the other raceway and the other raceway. In order to protect the bearing from lightning strikes, minimize the generation of brush wear powder as much as possible. Early failure of the bearing can be prevented.

  A first embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 2, the wind power generator 1 is configured such that a main shaft 3 to which a blade 2 serving as a windmill is attached is rotatably installed by a bearing 5 installed in a nacelle 4, and a speed increaser 6 is installed in the nacelle 4. And the generator 7 is installed. The speed increaser 6 increases the rotation of the main shaft 3 and transmits it to the input shaft of the generator 7. The nacelle 4 is rotatably installed on a support base 8 (FIG. 1) via a swivel bearing 20, and is turned via a speed reducer 10 by driving a turning motor 9 shown in FIG. The turning of the nacelle 3 is performed in order to make the direction of the blades 2 face the wind direction. Two spindle support bearings 5 are provided in the example of FIG. 2, but may be one.

  FIG. 3 shows the installation structure of the bearing 5 for supporting the main shaft. The bearing 5 includes an inner ring 11 and an outer ring 12 which are a pair of race rings, and a plurality of rolling elements 13 interposed between the inner and outer rings 11 and 12. The bearing 5 may be a radial bearing capable of thrust load, and may be an angular ball bearing, a tapered roller bearing, a deep groove ball bearing or the like in addition to the self-aligning roller bearing. Spherical roller bearings.

  The outer ring 12 of the bearing 5 has a raceway surface 12a having a spherical shape, and each rolling element 13 has a spherical roller whose outer peripheral surface follows the outer ring raceway surface 12a. The inner ring 11 is provided with a hook having the raceway surfaces 11a and 11a in each row individually. The rolling elements 13 are held by a holder 14 (see FIG. 4) for each row.

  In FIG. 3, the outer ring 12 is installed by being fitted to the inner diameter surface of the bearing housing 15, and the inner ring 11 is fitted to the outer periphery of the main shaft 3 to support the main shaft 3. The bearing housing 15 has side wall portions 15 a that cover both ends of the bearing 5, and a seal 16 such as a labyrinth seal is formed between each side wall portion 15 a and the main shaft 3. Since the sealing performance is obtained by the bearing housing 15, the bearing 5 is used without a seal. The bearing 5 is a wind power generator bearing according to an embodiment of the present invention.

  As shown in FIG. 4, the bearing 5 has a current-carrying member that can be switched between contact and non-contact in such a way that the outer ring 12 serving as one of the race rings and the inner ring 11 serving as the other race ring can be energized. 17 is provided. The energizing member 17 is made of a conductive elastic body. Specifically, the energizing member 17 includes a plate spring-like conductive metal member 17a and a conductive brush 17b attached to the distal end of the conductive metal member 17a. The conductive metal member 17a is the base end of the outer ring 12. It is fixed to the end face. In the natural state, the energizing member 17 is not in contact with the end surface of the inner ring 11 as shown in FIG. 5A, and is electrically conductive on the end surface of the inner ring 11 by forcibly elastically deforming as shown in FIG. The brush 17b can contact. Forcible pressing of the energizing member 16, that is, switching to the contact state is performed by the switching drive means 19. The switching drive means 19 is composed of, for example, an electromagnetic solenoid, and the main body is installed in the bearing housing 15 and presses the energizing member 17 with the plunger portion.

  FIG. 4B shows a view of the energizing member 17 and the switching drive means 19 as seen from the direction of arrow B in FIG. The energizing member 17 has a grease removing spatula 18 on both sides or one side of the conductive brush 17b in the circumferential direction of the inner ring. The grease removing spatula 18 prevents the grease that has been supplied into the bearing 5 and that has flowed out to the inner ring width surface from adhering to the conductive brush 17b serving as a contact point, thereby improving the contact reliability.

  The operation of the switching drive means 19 is performed by the switching control means 21 separated from the nacelle 4 as shown in FIG. The switching control means 21 is provided, for example, in a part of the monitoring panel 24 in the monitoring room 23 that monitors the entire wind power generator 1. The switching control means 21 is provided with an operation portion 21a for manual operation by the operator 25. Note that the switching control means 21 may perform automatic control. In that case, the switching control means 21 switches the switching drive means 19 on according to the setting conditions in accordance with the thundercloud electric field detection signal from the thundercloud electric field detection device 26, and switches the switching drive means 19 off when the setting conditions are no longer met. It is supposed to be.

  A detection result display means 27 of the thundercloud electric field detection device 26 is provided in the room of the monitoring room 23 provided with the operation unit 21a. The detection result display means 27 may be a device that displays a screen such as a liquid crystal display device or a CRT, or may display a detection result by sound or a lighting state of a lamp.

  The thundercloud electric field detection device 26 is a device that detects a thundercloud electric field in a predetermined area where the wind power generator 1 is provided. The thundercloud electric field detection device 26 detects, for example, an electric field change measuring device that measures a change in electromagnetic waves emitted by a precursor discharge of the thundercloud 28, detects a thundercloud that is equal to or greater than a set value from the measurement signal of this measuring device, and outputs a detection signal. A detection unit (both not shown). The thundercloud electric field detector 26 measures the electric field strength at a plurality of locations in the space, and detects the position of the thundercloud by performing arithmetic processing on the measured electric field strength value. Various types of thundercloud electric field detectors 26 have been developed, and any type may be used.

According to this configuration, when lightning approaches the wind power generator 1, the situation is captured by the thundercloud electric field detection device 26, and the energization member 17 is brought into contact with the switching drive means 19 provided in the wind power generator 1. be able to. The energization member 17 is not in contact with the inner ring 11 of the bearing 5 in a state in which the wind power generator 1 is operating normally, and is not energized between the inner and outer rings 11 and 12, but is operated by the proximity of lightning. The switching drive means 19 made of a solenoid or the like can be driven by manual operation of the portion 21 a to bring the energization member 17 into contact with the inner ring 11.
That is, when the possibility of a lightning strike occurs, an energization path for protecting the bearing 5 is made by contacting the current-carrying member 17, so that even if a lightning strike occurs, the rolling element 13 in the bearing 5 is passed through. Energization can be prevented. Therefore, damage to the raceway surfaces 11a and 12a of the inner and outer rings 11 and 12 and the rolling elements 13 is prevented. In addition, since the current-carrying member 17 is not normally contacted and is contacted only when necessary, the generation of wear powder of the current-carrying member 17 and the member that the current-carrying member 17 contacts can be reduced as much as possible. Is prevented. Further, since the current-carrying member 17 is less worn, reliable contact of the current-carrying member 17 can be ensured even when used for many years, and the reliability of current-carrying is increased.

  6 and 7 show another embodiment of the bearing for a wind power generator according to the present invention. The bearing 5A is provided in place of the main shaft support bearing 5 in the embodiment shown in FIGS. This bearing 5A is the same as the bearing 5 according to the first embodiment with respect to the configuration as a double row spherical roller bearing, that is, the inner and outer rings 11, 12, the rolling elements 13, and the cage 14. In the bearing 5 </ b> A of this embodiment, the energization member 17 </ b> A is attached to the outer ring 12 and can be switched between contact and non-contact with the main shaft 3. The energizing member 17A is made of a conductive elastic body, for example, a conductive metal member, and is formed in a linear shape or a ribbon shape, and is provided at positions where both ends are chords with respect to a part of the arc of the outer ring 12, and both ends are on the outer ring. It is fixed. The switching drive means 19 (FIG. 7A) in which the plunger advances and retreats in the radial direction of the main shaft 3 is arranged with respect to the energizing member 17A, and is installed in the bearing housing 15 (FIG. 3).

  In the case of the bearing 5A having this configuration, normally, the energizing member 17A is not in contact with the main shaft 3 as shown in FIG. 7A, and the energizing member 17A is pressed against the main shaft 3 by the switching drive means 19, whereby the outer ring 12 And the main shaft 3 are energized. Therefore, as in the first embodiment, the bearing 15 can be protected by energization, and since it contacts only when necessary, generation of wear powder is suppressed, early failure is prevented, and energization reliability is improved. .

  In each of the above-described embodiments, energization is performed between the outer ring 12 and the inner ring 11 or the main shaft 3 by the energization members 17 and 17A. And an energizing member that can be switched between contact and non-contact in such a way that it can be energized over the other set of members on which the bearing ring is installed and the other set of members and the set of members supported by the other race ring. What is provided is sufficient. The current-carrying members 17 and 17A are not limited to those attached to the raceway such as the outer ring 12, but are normally not in contact with both raceways or their member sets. It is good also as what contacts a member set. Further, the wind turbine generator bearing having the energizing member of the present invention is not limited to the main shaft support bearing, but may be any one used for the wind turbine generator 1. For example, the present invention can also be applied to a bearing that supports each gear or a gear support shaft constituting the speed increaser 6 (FIG. 2), and a swivel bearing 20 that supports the nacelle 4 (FIG. 1).

It is explanatory drawing which shows the conceptual structure of the lightning strike protection apparatus of the bearing for wind power generators concerning 1st Embodiment of this invention. It is a notch perspective view of the wind power generator. It is sectional drawing which shows the installation part to the bearing housing of the spindle support bearing in the same wind power generator. (A) is the fragmentary sectional view of the bearing for the wind power generators, (B) is the partial arrow line view which looked at the figure (A) from the arrow B direction. It is a fragmentary sectional view which shows the energization member contact state of the bearing for wind power generators. It is sectional drawing of the bearing for wind power generators concerning other embodiment of this invention. (A) is a side view of the bearing for the wind power generator, and (B) is a partial side view showing a contact state of the current-carrying member.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Wind power generator 2 ... Blade | wing 3 ... Main shaft 4 ... Nacelle 5, 5A ... Bearing 6 ... Speed up gear 7 ... Generator 11 ... Inner ring (track ring)
12 ... Outer ring (Raceway)
DESCRIPTION OF SYMBOLS 15 ... Bearing housing 17 ... Current supply member 19 ... Switching drive means 21 ... Switching control means 21a ... Operation part 26 ... Thunder cloud electric field detection apparatus

Claims (10)

A device for protecting a rolling bearing having a plurality of rolling elements interposed between a pair of raceways and both raceways from a lightning strike provided in a wind power generator,
Switching between contact and non-contact is possible for one raceway and the set of members installed with this raceway and the other raceway and the set of members supported by the other raceway. Lightning protection for a wind power generator bearing, comprising: a current-carrying member; a switching drive unit that switches the current-carrying member between a contact state and a non-contact state; and a switching control unit that gives a switching command to the switching drive unit apparatus.   The detection result display means according to claim 1, further comprising a thundercloud electric field detection device that detects a thundercloud electric field in a predetermined area where the wind power generator is provided, wherein the switching control means displays a detection result of the thundercloud electric field detection device. A lightning protection device for a wind power generator bearing having an operation unit for switching between contact and non-contact by an operator in the vicinity of the installation position.   In Claim 1, the thundercloud electric field detection apparatus which detects the thundercloud electric field electric field in the predetermined area in which the said wind power generator was provided is provided, and the said switching control means is the operation state in which the current supply member is always non-contacting the said switching drive means And a lightning strike protection device for a wind turbine generator bearing, wherein the switching drive means is brought into contact with the switching drive means in response to a detection signal of the thundercloud electric field detection device.   4. The lightning strike protection device for a wind power generator bearing according to claim 1, wherein the rolling bearing is a main shaft support bearing that supports a main shaft to which blades of the wind power generator are attached. A rolling bearing used in a wind power generator and having a plurality of rolling elements interposed between a pair of race rings and both race rings,
It is possible to switch between contact and non-contact in such a way that energization is possible between one race ring and a set of members on which this race ring is installed, and the other race ring and a set of members supported by the other race ring. A bearing for a wind power generator having an energization member.   The wind turbine generator bearing according to claim 5, further comprising switching drive means for switching the energization member between a contact state and a non-contact state.   In Claim 5 or Claim 6, the energizing member is a conductive elastic body attached to one of the race rings, and the conductive elastic body is not in contact with the other race ring in a natural state, A wind power generator bearing that is capable of contacting the other race ring in a state of being forced to elastically deform.   The conductive member according to claim 5 or 6, wherein the current-carrying member is a conductive elastic body attached to one of the race rings, and the conductive elastic body is in a natural state with respect to a member supported by the other race ring. A bearing for a wind power generator that is non-contact and can be brought into contact with a member supported by the other race ring in a state where it is forcibly elastically deformed.   The wind turbine generator bearing according to any one of claims 5 to 8, wherein the energizing member comprises a conductive metal member and a conductive brush. 10. The wind power generator bearing according to claim 5, wherein the wind power generator is a main shaft support bearing that supports the main shaft to which the blades of the wind power generator are attached.

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