JP2011185632A - Device and method for detecting faulure of bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a failure detection device for bearing and an failure detection method precisely detecting failure of a bearing (e.g., blade bearing) not performing continuous rotary motion. <P>SOLUTION: The failure detection device for a bearing rotatably supporting a body (e.g., blade) to be supported on a support (e.g., rotor head) includes: a vibration sensor 160; a frequency analysis part 164 analyzing a frequency of a vibration signal detected by the vibration sensor 160 to detect a natural frequency; a storage part 166 storing the natural frequency detected by the frequency analysis part 164; and an failure detection part 170 detecting the failure of a bearing on the basis of variation in the detected natural frequency. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a bearing abnormality detection device and an abnormality detection method, and more particularly to a bearing abnormality detection device and an abnormality detection method for rotatably supporting a supported body on a support.

  Various diagnosis methods have been studied for abnormality diagnosis during operation of the bearing. For example, Japanese Patent Laying-Open No. 2005-164314 (Patent Document 1) discloses an abnormality prediction method and an abnormality prediction device for a rolling device that detects a process leading to wear of a rolling contact surface in a rolling device and determines an abnormality. Disclosure.

  This abnormality prediction apparatus detects the friction sound in the ultrasonic region generated on the rolling contact surface of the rolling bearing with an ultrasonic microphone installed separately from the rolling bearing to be abnormally predicted. After the detected friction sound signal is amplified by an amplifier, a signal in the ultrasonic band is extracted by a filter. Next, the abnormality determination unit compares it with a predetermined abnormality determination reference value, and determines that the lubrication state of the rolling bearing is abnormal when the extracted frictional sound signal is large, and outputs an alarm signal.

JP 2005-164314 A

  Japanese Patent Application Laid-Open No. 2005-164314 described above determines an abnormality of a bearing used for a rotating shaft that rotates at a relatively high speed. However, the bearings are also used for applications where the rotational speed of the shaft is slow and for applications where only reciprocating rotational movement is performed to change the orientation of the supported body. Even in such applications, it is preferable to perform abnormality prediction and diagnosis in facilities that are installed for many years in places where people cannot frequently go for abnormality diagnosis. An example of such an application is a blade bearing of a wind power generator.

  In a large windmill, the blade swings (rotates) several degrees at a rotation angle while the main shaft rotates once. Also, during strong winds, the rotation of the windmill is stopped by setting the blade direction parallel to the wind direction in order to prevent damage to the generator or the like due to excessive rotation.

  The rotational speed of the blade is very slow, and even if it is attempted to detect a bearing abnormality by vibration acceleration, the magnitude of vibration acceleration is small and it is difficult to detect the abnormality.

  In addition, as with the detection of abnormalities for high-speed rotating shafts, even if the generation interval of vibrations due to bearings is used in signal processing, the movement of the bearing part is not a continuous rotational movement but a swinging movement. It cannot be applied. In addition, since blade vibration due to wind enters as a disturbance factor, it is difficult to detect vibration acceleration because of noise. Further, it is difficult to measure the frictional sound as disclosed in JP-A-2005-164314 due to the influence of wind noise.

  An object of the present invention is to provide a bearing abnormality detection device and an abnormality detection method for accurately detecting an abnormality of a bearing (for example, a blade bearing) that does not perform continuous rotational motion.

  In summary, the present invention provides a bearing abnormality detection device that rotatably supports a supported body on a support, and the vibration sensor and the frequency of the vibration signal detected by the vibration sensor are analyzed to analyze the natural frequency. A frequency analysis unit for detecting the natural frequency, a storage unit for storing the natural frequency detected by the frequency analysis unit, and an abnormality detection unit for detecting a bearing abnormality based on the detected change in the natural frequency.

  Preferably, the frequency analysis unit analyzes the frequency of the vibration signal in order to determine the natural frequency under a condition where a preferable force is applied to detect the natural frequency.

  Preferably, the supported body is a blade of a wind power generator. The bearing is a bearing for supporting the blade so that the angle of the blade can be changed.

  More preferably, the frequency analysis unit analyzes the frequency of the vibration signal to determine the natural frequency when the wind receiving surface of the blade is parallel to the wind direction.

  More preferably, the abnormality detection unit determines whether the blade is damaged in addition to the abnormality of the bearing.

  More preferably, the abnormality detection unit includes a data processing unit that is provided at a place away from the support and the support and receives a rate of change from the initial state of the natural frequency detected by the frequency analysis unit.

  More preferably, the abnormality detection unit includes a change rate calculation unit that calculates a change rate of the natural frequency detected by the frequency analysis unit with respect to the initial natural frequency stored in the storage unit, and a data processing unit from the change rate calculation unit. And a transmission unit that transmits the rate of change using radio.

Preferably, the vibration sensor includes an acceleration sensor.
Preferably, the frequency analysis unit detects the natural frequency based on the phase inversion of the phase difference spectrum of the vibration signal.

  In another aspect, the present invention relates to a bearing abnormality detection method for rotatably supporting a supported body on a support, and detects a natural frequency by analyzing a frequency of a vibration signal detected by a vibration sensor. And a step of storing the detected natural frequency, and a step of detecting a bearing abnormality based on the detected change in the natural frequency.

  Preferably, in the step of detecting the natural frequency, the frequency of the vibration signal is analyzed in order to determine the natural frequency under a condition in which a preferable force is applied to detect the natural frequency.

  Preferably, the supported body is a blade of a wind power generator. The bearing is a bearing for supporting the blade so that the angle of the blade can be changed.

  More preferably, in the step of detecting the natural frequency, the frequency of the vibration signal is analyzed to determine the natural frequency when the wind receiving surface of the blade is parallel to the wind direction.

  More preferably, in the step of detecting an abnormality, in addition to the abnormality of the bearing, the blade damage is also determined.

  More preferably, the step of detecting an abnormality includes a step of receiving a rate of change from the initial state of the detected natural frequency at a place away from the support and the support.

  More preferably, the step of detecting abnormality includes a step of calculating a change rate of the detected natural frequency with respect to the stored initial natural frequency, and a transmission from the step of calculating the change rate to the step of receiving the change rate. And transmitting the rate of change by radio on the route.

Preferably, the vibration sensor includes an acceleration sensor.
Preferably, the step of detecting the natural frequency detects the natural frequency based on the phase inversion of the phase difference spectrum of the vibration signal.

  According to the present invention, it is possible to accurately detect an abnormality of a bearing (for example, a blade bearing) that does not perform continuous rotational motion.

It is a figure for demonstrating the wind power generator which is an example in which the abnormality detection apparatus of the bearing of this Embodiment is used. It is the figure which expanded and showed the nacelle part of the wind power generator. It is the figure which expanded and showed the bearing 120 for blades of FIG. It is a figure for demonstrating the abnormality detection method of the bearing in this Embodiment. It is a fragmentary sectional view which shows the state which attached the bearing 120 for blades to the braid | blade and the rotor head. It is a functional block diagram which shows the structure of the data processor 80 shown in FIG. 1 functionally. FIG. 10 is a diagram for explaining processing of a frequency analysis unit 164. It is a figure which shows the result of having numerically analyzed the influence of the blade support rigidity on the natural frequency of a blade. It is a figure which shows the "inclination of the blade | wing of a blade surface perpendicular | vertical direction" deformation mode. It is a figure which shows the "inclination of the blade | wing of a blade surface tangent direction" deformation | transformation mode. It is a figure which shows the "bending primary direction bending primary" deformation | transformation mode. It is a figure which shows a bending primary tangential direction deformation mode. It is a figure which shows the "bending secondary direction bending secondary" deformation | transformation mode. It is a figure which shows an "extension / contraction" deformation | transformation mode. It is the figure which showed schematically the whole structure of the abnormality diagnosis system by Embodiment 2. FIG.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

[Embodiment 1]
FIG. 1 is a diagram for explaining a wind turbine generator that is an example in which the bearing abnormality detection device of the present embodiment is used.

  With reference to FIG. 1, a nacelle 90 and a rotor head 20 are provided at an upper end portion of a tower 100 of the wind turbine generator 10. The rotor head 20 is connected to a tip portion of a main shaft (not shown) of the wind turbine generator 10. The main shaft is supported inside the nacelle 90 and connected to a generator (not shown) via the tower 100. A plurality of blades 30 are attached to the rotor head 20.

  The wind power generator 10 obtains an appropriate rotation by changing the angle of the blade 30 with respect to the wind direction (hereinafter referred to as pitch) in accordance with the strength of the wind power. Similarly, when starting and stopping the windmill, the blade pitch is controlled. Further, each blade 30 is controlled to swing several degrees even during one rotation of the main shaft. In this way, the amount of energy that can be obtained from the wind can be adjusted. In a strong wind or the like, the wind receiving surface (also referred to as a blade surface or a blade surface) of the blade is made parallel to the wind direction in order to suppress the rotation of the windmill.

FIG. 2 is an enlarged view of the nacelle portion of the wind turbine generator.
Referring to FIG. 2, the wind power generator 10 includes a main shaft 22, a blade 30, a speed increaser 40, a generator 50, a main shaft bearing 60, and a data processing device 80. The speed increaser 40, the generator 50, the main shaft bearing 60, and the data processing device 80 are stored in the nacelle 90, and the nacelle 90 is supported by the tower 100.

  The main shaft 22 enters the nacelle 90, is connected to the input shaft of the speed increaser 40, and is rotatably supported by the main shaft bearing 60. The main shaft 22 transmits the rotational torque generated by the blade 30 receiving wind force to the input shaft of the speed increaser 40. The blade 30 is provided at the tip of the main shaft 22, converts wind force into rotational torque, and transmits it to the main shaft 22.

  The main shaft bearing 60 is fixed in the nacelle 90 and rotatably supports the main shaft 22. The main shaft bearing 60 is constituted by a rolling bearing, for example, a self-aligning roller bearing, a tapered roller bearing, a cylindrical roller bearing, a ball bearing or the like. These bearings may be single row or double row.

  The speed increaser 40 is provided between the main shaft 22 and the generator 50, and increases the rotational speed of the main shaft 22 to output to the generator 50. As an example, the speed increaser 40 is configured by a gear speed increasing mechanism including a planetary gear, an intermediate shaft, a high speed shaft, and the like. Although not specifically illustrated, a plurality of bearings that rotatably support a plurality of shafts are also provided in the speed increaser 40. The generator 50 is connected to the output shaft of the speed increaser 40, and generates power by the rotational torque received from the speed increaser 40. The generator 50 is constituted by, for example, an induction generator. A bearing that rotatably supports the rotor is also provided in the generator 50.

  The blade pitch variable mechanism includes a blade pitch changing motor 24 attached to the rotor head side, and a ring gear 26 rotated by a pinion gear fitted to the rotating shaft of the motor 24. The ring gear 26 is fixedly attached to the blade 30.

  The blade pitch variable mechanism swings (rotates) the plurality of blades 30 to change (adjust) the pitch of the blades 30. Here, blade bearings 120 are provided at the base end portions of the plurality of blades 30, and the blades 30 are respectively supported by the blade bearings 120 and rotate around the rotation shaft of the blade bearings 120.

  When a load is applied to the generator 50, the pitch of the blade 30 is set so that the angle formed by the wind direction and the wind receiving surface of the blade 30 is an angle θ (≠ 0). Then, the wind receiving surface of the blade 30 receives energy from the wind. The plurality of blades 30 rotate about the main shaft 22 connected to the rotor head 20 with respect to the tower 100 together with the rotor head 20. The rotation of the rotating shaft is transmitted to the generator, and power generation is performed.

  When the wind is strong, the pitch of the blade 30 is changed so that the wind direction and the wind receiving surface of the blade 30 are parallel to each other. Thus, in a state where the direction of the wind and the pitch of the blade 30 are parallel (feathering), the wind receiving surface of the blade 30 receives almost no energy from the wind. By doing in this way, damage to the wind power generator 10 due to an abnormal increase in the rotational speed of the blade 30 and the rotor head 20 can be prevented.

FIG. 3 is an enlarged view of the blade bearing 120 of FIG.
Referring to FIG. 3, the blade bearing 120 includes an outer ring 122, an inner ring 124, a rolling element 126 sandwiched between the rolling surface of the inner ring and the rolling surface of the outer ring, and a cage 128. And sealing members 130 and 132 for sealing a lubricant such as grease.

  The outer ring 122 is provided with a bolt through hole 142 for attaching a blade, and the inner ring 124 is provided with a bolt through hole 140 for attaching a rotor head.

  In the case of a large wind power generator, for example, the outer diameter of the blade bearing 120 is about 2.6 m, and the weight is about 2200 kg.

FIG. 4 is a diagram for explaining a bearing abnormality detection method in the present embodiment.
Referring to FIG. 4, since the blade bearing 120 that swings and rotates, the damage mode is expected to be due to wear. Therefore, it is required to detect the magnitude of wear.

  FIG. 5 is a partial cross-sectional view showing a state in which the blade bearing 120 is attached to the blade and the rotor head.

  Referring to FIG. 5, blade 30 is fixed to outer ring 122 by bolt 150 and nut 152. The rotor head 20 is fixed to the inner ring 124 by bolts 154 and nuts 156. Then, the vibration sensor 160 is attached inside the inner ring 124. The vibration sensor 160 may be installed in the rotor head side housing of the blade bearing 120.

  Referring to FIGS. 4 and 5, the blade bearing 120 generally has a structure using a plurality of four-point contact ball bearings. The blade bearing 120 is used with a slight preload. The progress of wear of the blade bearing leads to a decrease in the preload. When the preload of the bearing is lowered, the rigidity with which the blade bearing 120 supports the blade 30 is lowered. That is, wear causes a reduction in the rigidity of the support portion of the blade 30. As a result, the natural frequency f0 related to the bearing rigidity such as the bending and translational displacement of the blade 30 is lowered.

  Therefore, in the present embodiment, the natural frequency of the blade 30 is detected by the vibration sensor 160, and the progress of wear of the blade bearing 120 is detected by the change of the natural frequency. When there are a plurality of natural vibration modes, all of the changes are recorded, and the change of the natural frequency is detected. As a result, the wear of the blade bearing 120 can be detected, and the occurrence of cracks in the blade 30 itself can also be detected.

  The vibration sensor 160 is fixed to the blade bearing 120. The vibration sensor 160 detects the vibration of the blade 30 and outputs the detected value to the data processing device in the nacelle. The vibration sensor 160 is constituted by, for example, an acceleration sensor using a piezoelectric element.

  FIG. 6 is a functional block diagram functionally showing the configuration of the data processing device 80 shown in FIG. The data processing device 80 in FIG. 1 is provided in the nacelle 90 and receives a vibration detection value of the blade 30 described later from the vibration sensor 160. Then, the data processing device 80 performs processing for detecting an abnormality in the main shaft bearing 60 using the vibration waveform of the main shaft bearing 60.

  Referring to FIG. 6, data processing device 80 includes high-pass filter (hereinafter referred to as “HPF (High Pass Filter)”) 162, frequency analysis unit 164, storage unit 166, and abnormality detection unit 170. A change rate calculation unit 172 and a transmission unit 174. The abnormality detection unit 170 further includes a data processing unit 300 that receives data wirelessly from the transmission unit 174.

  The frequency analysis unit 164 performs frequency analysis on the output of the vibration sensor 160 that has passed through the HPF 162.

FIG. 7 is a diagram for explaining the processing of the frequency analysis unit 164.
With reference to FIGS. 6 and 7, the frequency analysis unit 164 obtains a Fourier spectrum by fast Fourier transform after the noise component of the signal detected by the vibration sensor 160 is removed by the HPF 162. In the Fourier spectrum, the natural frequency is indicated by a peak value. At that time, the phase of the spectrum is inverted at the natural frequency, so that the phase difference spectrum crosses zero. Preferably, the frequency analysis unit 164 detects the natural frequency based on this phase inversion. For example, the frequency analysis unit 164 records the natural frequency in the storage unit 166 in a state where the bearing at the time of completion is not yet worn. This value is used as the initial value of the natural frequency. The change rate calculation unit 172 reads the initial value of the natural frequency from the storage unit, compares it with the natural frequency newly detected by the frequency analysis unit 164, and changes the rate of change from the initial value of the natural frequency (for example, in%). Displayed). This rate of change is transmitted from the transmission unit 174 to the data processing unit 300 together with the natural frequency by a method such as wireless.

  In the data processing unit 300, when the change rate of the natural frequency in the limit bearing wear state obtained separately is set as a threshold value, the change rate with respect to the initial value of each natural frequency exceeds the previous threshold value, which is abnormal. Is detected. Such an abnormality detection device can be realized only by an acceleration sensor and signal processing, is inexpensive and has high durability of the detection device.

  At the time of Fourier transform, the Hanning window function is multiplied to the waveform that has passed through the anti-aliasing filter and reflected in the spectrum, as in the case of commercially available FFT analyzers.

HPF is not essential.
Each functional block shown in FIG. 6 can also be realized by software using digital signal processing.

  FIG. 8 is a diagram showing the result of numerical analysis of the influence of blade support rigidity on the natural frequency of the blade. The results shown in FIG. 8 are obtained by restraining one blade (blade) at a position where the rolling element of the blade bearing contacts and calculating the eigenvalue at that time.

  FIG. 8 shows the result of eigenvalue analysis in the case of restraining at 6 places × 2 rows and the case of restraining at 3 places × 2 rows. In FIG. 8, when restrained at 6 locations × 2 rows, it is shown as an eigenvalue (Hz) with strong restraint, and when restrained at 3 locations × 2 rows, it is shown as an eigenvalue (Hz) with weak constraints.

  Strictly speaking, these results are different from the constraints due to the increase in the clearance due to the wear of the blade bearings, but since the change in the support rigidity of the part supporting the blade can be reproduced, the change tendency of the eigenvalue of the entire blade is Be the same.

Hereinafter, the image of the deformation mode will be described with reference to the drawings.
FIG. 9 is a diagram showing the “blade inclination in the direction perpendicular to the blade surface” deformation mode.

  Referring to FIGS. 8 and 9, in the case of the blade tilt deformation mode in the direction perpendicular to the wing surface, the eigenvalue (natural frequency) with strong constraint is 2.7 Hz, and the eigenvalue with weak constraint is 2.36 Hz. The eigenvalue change rate was 13%.

FIG. 10 is a diagram showing the “blade inclination in the blade tangent direction” deformation mode.
Referring to FIGS. 8 and 10, in the blade deformation mode in the blade tangential direction, the eigenvalue (natural frequency) with strong constraint is 3.22 Hz, and the eigenvalue with weak constraint is 2.66 Hz. The eigenvalue change rate was 17%.

FIG. 11 is a diagram showing a “first bending direction perpendicular to the blade surface” deformation mode.
Referring to FIGS. 8 and 11, in the case of the bending primary deformation mode in the direction perpendicular to the wing surface, the natural value (natural frequency) with strong constraint is 9.50 Hz, and the natural value with weak constraint is 8.44 Hz. The eigenvalue change rate was 7.0%.

FIG. 12 is a diagram showing the “first bending direction in the tangential direction of the blade surface” deformation mode.
With reference to FIGS. 8 and 12, in the case of the bending primary deformation mode in the wing surface tangential direction, the natural value (natural frequency) in the strong constraint is 16.2 Hz, and the natural value in the weak constraint is 15.1 Hz. The eigenvalue change rate was 6.8%.

FIG. 13 is a diagram showing a “second bending direction perpendicular to the blade surface” deformation mode.
8 and 13, in the case of the bending secondary deformation mode in the direction perpendicular to the wing surface, the eigenvalue (natural frequency) with a strong constraint is 21.4 Hz, and the eigenvalue with a weak constraint is 20.4 Hz. The eigenvalue change rate was 4.7%.

FIG. 14 is a diagram illustrating the “stretching” deformation mode.
Referring to FIGS. 8 and 14, in the case of the expansion / contraction deformation mode, the eigenvalue (natural frequency) with strong constraint is 33.7 Hz, the eigenvalue with weak constraint is 24.0 Hz, and the eigenvalue change rate is 29%. Met.

  9 to 14, the arrow indicates the direction in which the blade vibrates, the broken line indicates the shape before deformation, and the solid line indicates the shape at a certain moment during vibration.

  As can be seen from FIG. 8, the change in eigenvalue due to the change in rigidity of the support portion in the eigenvalue mode of wing bending is small. This is because the characteristics of the wing itself are strongly influenced. On the other hand, the change rate of the eigenvalue is large in the wing inclination and expansion / contraction deformation patterns. This is because the influence of the rigidity of the support portion is strong in these deformation modes.

  Therefore, it is preferable to observe the change in eigenvalues of the wing inclination deformation and the expansion / contraction deformation pattern because it is easy to detect the rigidity change of the support portion. Especially, the rate of change is greater in the tilt deformation in the wing surface tangential direction than in the tilt deformation in the wing surface vertical direction. Such natural frequency can be detected because wind force and centrifugal force act as excitation force even during normal windmill operation. However, in order to increase the amplitude of vibration, it is easier to observe the moment when some larger excitation force is applied. A condition in which the tilt deformation in the tangential direction of the wing surface is likely to occur is a state where the wing surface is parallel to the wind direction. Such a state is seen when the operation of the windmill is stopped during a strong wind. Exciting force is large during strong winds. Therefore, for example, when the wind speed exceeds a threshold value, the blade is rotated so that the wind direction and the wing surface are parallel, and the natural frequency is observed. It is preferable to detect the deterioration of wear of the blade bearing if it continues to observe the change with time of the natural frequency.

  Further, when the eigenvalue of the wing inclination deformation does not change much, but the eigenvalue of the wing bending deformation greatly changes, it can be determined that the blade itself is damaged such as a crack.

  As described above, according to the present embodiment, it is possible to detect an abnormality due to the progress of wear of the rocking bearing. Also, abnormalities such as cracks in the blade itself can be detected.

  Note that the present embodiment has been described by taking the detection of an abnormality in a blade bearing of a wind turbine generator as an example. However, the present invention can be applied to various types of bearings as long as they support a rod-shaped object and rotate the direction of the shape object about a rod-shaped shaft.

[Embodiment 2]
Since the nacelle 90 (FIG. 1) is installed at a high place, it is desirable that the above-described abnormality diagnosis apparatus is originally installed in a place away from the nacelle 90 in consideration of the maintainability of the apparatus itself. However, transferring the vibration waveform of the blade bearing 120 measured using the vibration sensor 160 to a remote place requires a transmission means having a high transfer speed, resulting in an increase in cost. Considering that the nacelle 90 is installed at a high place as described above, it is desirable to use wireless communication as a communication means from the nacelle 90 to the outside.

  Therefore, in the second embodiment, the natural frequency obtained by the frequency analysis process is calculated by a data processing device provided in the nacelle 90, and the calculated natural frequency and each change rate data are wirelessly transmitted. It is transmitted from the nacelle 90 to the outside. The data wirelessly transmitted from the nacelle 90 is received by a communication server connected to the Internet, and transmitted to the diagnosis server via the Internet, so that an abnormality diagnosis of the blade bearing 120 is performed.

  FIG. 15 is a diagram schematically showing the overall configuration of the abnormality diagnosis system according to the second embodiment.

  Referring to FIG. 15, the abnormality diagnosis system includes a wind power generator 10, a communication server 310, the Internet 320, and a bearing state diagnosis server 330.

  The configuration of the wind turbine generator 10 is as described with reference to FIGS. Note that the communication server 310, the Internet 320, and the bearing state diagnosis server 330 in FIG. 15 correspond to the data processing unit 300 in FIG.

  The transmission unit 174 in FIG. 6 outputs the calculated natural frequency and the rate of change thereof to the communication server 310 wirelessly.

  Communication server 310 is connected to the Internet 320. Then, the communication server 310 receives the data transmitted wirelessly from the wind power generator 10 and outputs the received data to the bearing state diagnosis server 330 via the Internet 320. The bearing state diagnosis server 330 is connected to the Internet 320. Then, the bearing state diagnosis server 330 receives data from the communication server 310 via the Internet 320, and the blade provided in the wind power generator 10 based on the natural frequency calculated in the wind power generator 10 and the rate of change thereof. An abnormality diagnosis of the bearing 120 (FIG. 2) is performed.

  In the above description, it is assumed that wireless communication is performed between the nacelle 90 and the communication server 310, but the nacelle 90 and the communication server 310 may be connected by wire. In this case, although wiring is required, it is not necessary to separately provide a wireless communication device, and generally, wired information can be transmitted more, so that processing is performed on the main board in the nacelle 90. Can be aggregated.

  Moreover, it is desirable that the above-described abnormality diagnosis system is configured independently of the existing power generation monitoring system. By comprising in this way, the introduction cost of an abnormality diagnosis system can be suppressed, without adding a change to the existing system.

As described above, according to the second embodiment, the bearing abnormality diagnosis server 330 provided in the remote place performs the bearing abnormality diagnosis provided in the wind turbine generator 10, thereby reducing the maintenance load and cost. Can do.

  Further, since the nacelle 90 is installed at a high place, the working environment is inferior. However, since the signal output from the nacelle 90 is made wireless by providing the wireless communication unit 280 and the communication server 310, the wiring work in the nacelle 90 is performed. Wiring work in the tower 100 that supports the nacelle 90 can be minimized.

  Finally, referring to each figure again, the embodiments of the present application will be summarized. Referring to FIGS. 1 and 6, the abnormality detection device of the present embodiment is a bearing abnormality detection device that rotatably supports a supported body (for example, blade 30) on a support (for example, rotor head 20). The vibration sensor 160, the frequency analysis unit 164 that analyzes the frequency of the vibration signal detected by the vibration sensor 160 and detects the natural frequency, and the memory that stores the natural frequency detected by the frequency analysis unit 164. 166 and an abnormality detection unit 170 that detects an abnormality of the bearing based on the detected change in natural frequency.

  Preferably, the frequency analysis unit 164 determines the natural frequency under a condition in which a preferable force is applied for the supported body to detect the natural frequency (for example, when the windmill is rotating or when the rotation is stopped in a strong wind). Therefore, the frequency of the vibration signal is analyzed.

  As shown in FIGS. 1 and 2, the supported body is preferably a blade 30 of the wind power generator 10. The bearing is a blade bearing 120 for supporting the blade so that the angle of the blade 30 can be changed.

  The change rate of the eigenvalue described with reference to FIG. 8 is more preferable because the change rate of the eigenvalue of the wing surface tangential inclination deformation mode is large. More preferably, the frequency analysis unit 164 has the wind receiving surface of the blade 30 parallel to the wind direction. In order to determine the natural frequency, the frequency of the vibration signal is analyzed.

  In addition, when there is a change in the eigenvalue in the primary and secondary bending other than the tangential inclination deformation of the blade surface, it is considered that the blade has been damaged. More preferably, the abnormality detection unit 170 is used for the blade. In addition to the abnormality of the bearing 120, the blade 30 is also damaged.

  As shown in FIGS. 6 and 15, more preferably, the abnormality detection unit 170 is provided in a place away from the support and the support, and the change from the initial state of the natural frequency detected by the frequency analysis unit. A data processing unit 300 for receiving the rate is included.

  As shown in FIG. 6, more preferably, the abnormality detection unit 170 calculates a change rate of the natural frequency detected by the frequency analysis unit with respect to the initial natural frequency stored in the storage unit 166. And a transmission unit 174 that is provided on a transmission path from the change rate calculation unit 172 to the data processing unit 300 and transmits the change rate by radio.

Preferably, the vibration sensor includes an acceleration sensor.
As shown in FIG. 7, preferably, the frequency analysis unit detects the natural frequency based on the phase inversion of the phase difference spectrum of the vibration signal.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiments but by the scope of claims for patent, and is intended to include meanings equivalent to the scope of claims for patent and all modifications within the scope.

  10 wind power generator, 20 rotor head, 22 spindle, 24 blade pitch changing motor, 26 ring gear, 30 blade, 40 gearbox, 50 generator, 60 spindle bearing, 80 data processor, 90 nacelle, 100 tower, 120 Blade bearing, 122 Outer ring, 124 Inner ring, 126 Rolling element, 128 Cage, 130, 132 Seal member, 140, 142 Bolt through hole, 150, 154 Bolt, 152, 156 Nut, 160 Vibration sensor, 164 Frequency analysis unit 166 storage unit, 170 abnormality detection unit, 172 change rate calculation unit, 174 transmission unit, 280 wireless communication unit, 300 data processing unit, 310 communication server, 320 Internet, 330 bearing state diagnosis server.

Claims (18)

A bearing abnormality detection device that rotatably supports a supported body on a support,
A vibration sensor;
A frequency analyzer that detects the natural frequency by analyzing the frequency of the vibration signal detected by the vibration sensor;
A storage unit for storing the natural frequency detected by the frequency analysis unit;
An abnormality detection device for a bearing, comprising: an abnormality detection unit that detects an abnormality of the bearing based on the detected change in natural frequency.   The frequency analysis unit analyzes the frequency of the vibration signal in order to determine the natural frequency under a condition where a preferable force is applied to the supported body to detect the natural frequency. An abnormality detection device for a bearing as described in 1. The supported body is a blade of a wind power generator,
The bearing abnormality detection device according to claim 1, wherein the bearing is a bearing for supporting the blade so that an angle of the blade can be changed.   The bearing according to claim 3, wherein the frequency analysis unit analyzes the frequency of the vibration signal to determine the natural frequency when the wind receiving surface of the blade is parallel to the wind direction. Anomaly detection device.   5. The bearing abnormality detection device according to claim 3, wherein the abnormality detection unit determines whether or not the blade is damaged in addition to the abnormality of the bearing. The abnormality detection unit
6. The data processing unit according to claim 3, further comprising a data processing unit that is provided at a location apart from the supported body and the support body and receives a rate of change from an initial state of the natural frequency detected by the frequency analysis unit. The bearing abnormality detecting device according to claim 1. The abnormality detection unit
A change rate calculation unit that calculates a change rate of the natural frequency detected by the frequency analysis unit with respect to the initial natural frequency stored in the storage unit;
The bearing abnormality detection device according to claim 6, further comprising: a transmission unit that is provided on a transmission path from the change rate calculation unit to the data processing unit and transmits the change rate by radio.   The bearing abnormality detection device according to claim 1, wherein the vibration sensor includes an acceleration sensor.   The bearing abnormality detection device according to claim 1, wherein the frequency analysis unit detects the natural frequency based on a phase inversion of a phase difference spectrum of the vibration signal. An abnormality detection method for a bearing that rotatably supports a supported body on a support,
Analyzing the frequency of the vibration signal detected by the vibration sensor to detect the natural frequency;
Storing the detected natural frequency;
Detecting an abnormality of the bearing based on the detected change in natural frequency.   The step of detecting the natural frequency includes analyzing the frequency of the vibration signal in order to determine the natural frequency under a condition in which a preferable force is applied to the supported body to detect the natural frequency. The method for detecting an abnormality of a bearing according to claim 10. The supported body is a blade of a wind power generator,
The bearing abnormality detection method according to claim 10 or 11, wherein the bearing is a bearing for supporting the blade so that an angle of the blade can be changed.   The step of detecting the natural frequency comprises analyzing the frequency of the vibration signal to determine the natural frequency when the wind receiving surface of the blade is parallel to the wind direction. An abnormality detection method for a bearing as described in 1.   The bearing abnormality detection method according to claim 12 or 13, wherein the abnormality detection step determines whether or not the blade is damaged in addition to the bearing abnormality. The step of detecting the abnormality includes
The bearing according to any one of claims 12 to 14, further comprising a step of receiving a rate of change from an initial state of the detected natural frequency at a place away from the supported body and the support body. Anomaly detection method. The step of detecting the abnormality includes
Calculating a rate of change of the detected natural frequency relative to a stored initial natural frequency;
The bearing abnormality detection method according to claim 15, further comprising: transmitting the change rate wirelessly on a transmission path from the step of calculating the change rate to the step of receiving the change rate.   The bearing vibration detection method according to claim 10, wherein the vibration sensor includes an acceleration sensor.   The abnormality of the bearing according to any one of claims 10 to 17, wherein the detecting the natural frequency detects the natural frequency based on a phase inversion of a phase difference spectrum of the vibration signal. Detection method.

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