JP2018159623A - Condition monitoring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a condition monitoring device capable of highly accurately monitoring a displacement of a rotation shaft without influences of environments such as lubricant and water.SOLUTION: The present disclosure relates to a condition monitoring device for detecting abnormality of a bearing. A condition monitoring device 100 for monitoring conditions such as wear of a bearing 160 comprises an annular member 201, a friction member 146, and a condition monitoring sensor 145 coming into contact with the friction member 146. The annular member 201 is disposed on a circumferential surface of a rotation shaft 20 and rotated with the rotation shaft. The friction member 146 is disposed in such a position facing the circumferential surface of the rotation shaft 20 that displacement of the rotation shaft 20 relative to a housing 120 causes a degree of contact with the annular member 201 to be varied. The condition monitoring sensor 145 is an AE sensor or an acceleration sensor.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a state monitoring device that detects a bearing abnormality.

  There is known a state monitoring apparatus that diagnoses abnormalities of rotating parts in an actual operation state in order to detect and maintain abnormalities of rotating parts such as railway vehicles and wind turbines for power generation at an early stage (Patent Document 1: Japanese Patent Laid-Open No. 2003-26883). 2006-105956). With such a state monitoring device, it is possible to diagnose an abnormality from a remote location without having to manually disassemble and check the device in which the rotating component is incorporated.

JP 2006-105956 A

  Bearing state monitoring devices often monitor the state by installing sensors that measure acceleration, speed, displacement, sound, and AE (Acoustic Emission) on fixed parts such as housings and cases.

  However, in the case of low speed rotation where the dn value (inner diameter × rotational speed) is 20000 or less, it is difficult to detect with the conventional state monitoring device. For example, when detecting acceleration, speed, and sound, it is difficult to detect abnormality because the response is small. Further, when detecting AE, a signal from a part other than the damaged part, for example, a signal due to creep, contact between the cage and the raceway, contact between the rolling element and the cage, etc. is disturbed and it is difficult to detect the abnormality. Therefore, it is conceivable to use a displacement sensor, but even with a displacement sensor, the eddy current type has a large temperature drift, making it difficult to detect abnormalities with high accuracy. There is a problem in monitoring the condition of the bearing because of the great influence of the environment such as water.

  The present invention has been made to solve the above-described problems, and the object thereof is a state in which the displacement of the rotating shaft can be monitored with high accuracy without being affected by the environment such as lubricating oil and water. It is to provide a monitoring device.

  The present disclosure relates to a state monitoring device that detects an abnormality of a bearing in which a fixed ring is fixed to a housing. The bearing monitoring device is arranged on the peripheral surface of the rotating shaft supported by the bearing, and rotates so that the degree of contact between the first member rotating with the rotating shaft and the first member changes when the rotating shaft is displaced with respect to the housing. A second member disposed to face the peripheral surface of the shaft; and a state monitoring sensor in contact with the second member. The state monitoring sensor is an AE sensor or an acceleration sensor.

  Preferably, the state monitoring device further includes a vibration isolating material that is disposed between the first member and the rotating shaft and blocks vibration.

More preferably, the vibration isolator is made of rubber.
Preferably, a 2nd member is arrange | positioned with respect to the rotating shaft at the side where the bearing load which acts on a bearing acts.

Preferably, the first member has higher hardness than the second member.
Preferably, the state monitoring device further includes a stay for fixing the second member and the state monitoring sensor to the housing.

  More preferably, the state monitoring device further includes a vibration isolating material that is disposed between the state monitoring sensor and the stay and blocks vibration.

  With the state monitoring device of the present invention, it is possible to detect anomalies with high accuracy in a low-speed operation bearing without being affected by an environment such as lubricating oil or water.

It is the figure which showed schematically the structure of the wind power generator to which the state monitoring apparatus according to embodiment of this invention is applied. It is a schematic diagram for demonstrating the direction of the bearing load concerning the bearing which supports a main axis | shaft. 1 is a diagram illustrating a configuration of a state monitoring device according to a first embodiment. It is a figure which shows the measurement data of the state monitoring apparatus of Embodiment 1. FIG. 4 is a flowchart for explaining abnormality determination processing executed by the arithmetic processing device in the first embodiment. It is a figure which shows the principal part of a structure of 100 A of state monitoring apparatuses of Embodiment 2. FIG. It is a figure which shows the principal part of a structure of the state monitoring apparatus 100B of the modification of Embodiment 2. FIG. It is a figure which shows the principal part of a structure of the state monitoring apparatus 100C of Embodiment 3. FIG.

  Embodiments of the present invention will be described below with reference to the drawings. In the following drawings, the same or corresponding parts are denoted by the same reference numerals, and description thereof will not be repeated.

[Configuration of the entire wind power generator]
With reference to FIGS. 1-2, the structure of the wind power generator which is an example of the apparatus which can apply the state monitoring apparatus which concerns on this embodiment is demonstrated. The wind power generator is an example, and the state monitoring device according to the present embodiment can be applied to a bearing such as a railway vehicle or a spindle.

  FIG. 1 schematically shows a configuration of a wind turbine generator to which a state monitoring device according to an embodiment of the present invention is applied. Referring to FIG. 1, the wind power generator 10 includes a rotating shaft 20, a hub 25, a blade 30, a speed increaser 40, a generator 50, a control panel 52, and a power transmission line 54. The wind power generator 10 further includes a main shaft bearing (hereinafter simply referred to as a “bearing”) 60 and a data processing device 80. The step-up gear 40, the generator 50, the control panel 52, the bearing 60, and the data processing device 80 are stored in a nacelle 90, and the nacelle 90 is supported by a tower 92.

  The rotating shaft 20 is a main shaft of the wind power generator, is rotatably supported by a bearing 60, and is connected to the input shaft of the speed increaser 40 in the nacelle 90. The rotating shaft 20 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 attached to the hub 25 at the tip of the rotating shaft 20, and converts wind force into rotating torque and transmits the rotating torque to the rotating shaft 20.

  The bearing 60 is fixed in the nacelle 90 and supports the rotary shaft 20 in a freely rotatable manner. The bearing 60 is configured by a rolling bearing. For example, self-aligning roller bearings can be used as shown in FIG. 2 and FIG. 3, but they may be constituted by tapered roller bearings, cylindrical roller bearings, ball bearings or the like. These bearings may be single row or double row.

  The speed increaser 40 is provided between the rotary shaft 20 and the generator 50, and increases the rotational speed of the rotary shaft 20 to output to the generator 50. 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 control panel 52 includes an inverter (not shown) and the like. The inverter converts the electric power generated by the generator 50 into a system voltage and frequency and outputs it to the power transmission line 54 connected to the system.

  A signal from the state monitoring sensor is transmitted to the data processing device 80 from the bearing 60 that supports the rotating shaft 20. Although the signal from the bearing 60 is representatively shown here, a signal from a state monitoring sensor also provided from another bearing is transmitted to the data processing device 80.

  FIG. 2 is a schematic diagram for explaining the direction of the bearing load applied to the bearing that supports the main shaft. Referring to FIG. 2, bearing 60 includes a bearing 60 </ b> A installed on the hub 25 side and a bearing 60 </ b> B provided on the speed increaser 40 side in FIG. 1.

  The gravity G acting on the blade 30 and the hub 25 acts on the tip of the rotating shaft 20. For this reason, the bearing load FA acts on the bearing 60 in the same direction as gravity. On the other hand, since the bearing 60A serves as a fulcrum, when the gravity G acts, the bearing load FB acts on the bearing 60B in the opposite direction to the gravity.

  Thus, the direction in which the bearing load acts on the bearing may vary depending on the place where it is used. However, since the direction in which the bearing load acts is almost determined once the place where the bearing is used is determined, the direction in which the bearing load acts is known in advance when assembling the equipment using the bearing.

  A load region is generated in the outer ring of the bearing with respect to the direction in which the bearing load acts. Since the inner ring and rolling elements of the bearing are rotating, it is expected to wear evenly. However, since the outer ring of the bearing is fixed, the wear proceeds more in the load region. As a result, it can be considered that the rotating shaft is displaced in the direction of the bearing load.

  In the following embodiments, a state monitoring device capable of detecting the displacement of the rotating shaft will be described in detail. In this state monitoring device, a friction member that is easily worn is disposed on the bearing load side (load region side) with respect to the bearing, and the displacement of the rotation shaft of the bearing is determined based on AE or vibration generated in the friction member. To detect.

[Embodiment 1]
FIG. 3 is a diagram illustrating a configuration of the state monitoring apparatus according to the first embodiment. Referring to FIG. 3, the state monitoring device 100 according to the first embodiment monitors a state such as wear of the bearing 160, and includes an annular member 201 (first member) and a friction member 146 (second member). ) And a state monitoring sensor 145 that contacts the friction member 146.

  The bearing 160 is surrounded by the rotating shaft 20, the housing 120, and the bearing retainer 121. Although not shown, the housing 120 is fixed to a nacelle or the like. Bearing 160 includes an inner ring 131, an outer ring 132, and a plurality of rolling elements 133 (for example, barrel-shaped rollers). The inner ring 131 has a rolling surface in contact with the plurality of rolling elements 133 on its outer peripheral surface, and the outer ring 132 has a rolling surface in contact with the plurality of rolling elements 133 on its inner peripheral surface. ing.

  The inner ring 131 is fitted with the rotary shaft 20 on the inner side of the rolling surface, and the outer ring 132 is fitted with the housing 120 on the outer side of the rolling surface. The inner ring 131 and the rotating shaft 20 are rotatably provided as a unit.

  The rotating shaft 20 is supported by a bearing 160 in which a fixed ring (outer ring 132) is fixed to the housing 120. The annular member 201 (first member) is disposed on the peripheral surface of the rotating shaft 20 and rotates together with the rotating shaft. The friction member 146 (second member) is arranged to face the peripheral surface of the rotary shaft 20 so that the degree of contact with the annular member 201 (first member) changes when the rotary shaft 20 is displaced with respect to the housing 120. Is done. The annular member 201 is provided to face the end surface of the friction member 146 on the rotating shaft side, and is fixed to the rotating shaft. The state monitoring sensor 145 is an AE sensor or an acceleration sensor. The bearing 160 corresponds to the bearing 60A in FIG.

  As described above, the annular member 201 is disposed around the rotating shaft 20, and the friction member 146 does not directly contact the rotating shaft 20, so that the rotating shaft 20 is protected.

  A vibration isolator 202 is disposed between the rotary shaft 20 and the annular member 201. Preferably, the vibration isolator 202 is made of rubber.

  The anti-vibration material 202 blocks transmission of AE and vibration acceleration generated elsewhere from the rotary shaft 20 via the annular member 201 and the friction member 146 to the state monitoring sensor 145. For this reason, it becomes difficult for the state monitoring sensor 145 to detect AE and vibration that are noise components generated in the bearing 160 and other parts. For this reason, AE and vibration acceleration generated from the friction member 146 can be measured with higher sensitivity.

  The friction member 146 is disposed on the rotating shaft 20 on the side on which the bearing load FA acting on the bearing 160 acts (the load region side of the outer ring).

  If there is a sufficient difference in hardness between the friction member 146 and the annular member 201, one is selectively worn and does not seize. For this reason, it is possible to detect AE normally regardless of whether the hardness is high. However, when the rotating shaft 20 is displaced due to wear of the bearing 160 and wear between the friction member 146 and the annular member 201 proceeds, the wear volume of the friction member 146 is smaller and the amount of wear powder discharged is also smaller. Therefore, it is desirable to use the friction member 146 as a soft material and the annular member 201 as a hard material. That is, preferably, the annular member 201 (first member) has higher hardness than the friction member 146 (second member). Specifically, the friction terminal can be exemplified by graphite and the annular member can be exemplified by steel. If the vibration isolator 202 has sufficient wear resistance in sliding with the friction member 146, the surface of the vibration isolator 202 on the rotating shaft 20 side and the friction member 146 may slide, or the vibration isolator A coating with high wear resistance may be formed on the surface of 202.

  The state monitoring apparatus 100 further includes a stay 141, a vibration isolation material 143, a vibration isolation material cover 142, and an arithmetic processing device 81. The stay 141 fixes the friction member 146 and the state monitoring sensor 145 to the housing 120 and the bearing retainer 121 of the bearing 60. The vibration isolator 143 is disposed between the state monitoring sensor 145 and the stay 141, and blocks or attenuates AE and vibration transmitted from the stay 141 to the sensor. The arithmetic processing unit 81 receives the output of the state monitoring sensor 145 and determines whether or not an abnormality has occurred in the bearing. The arithmetic processing unit 81 determines that an abnormality has occurred in the bearing 160 when the characteristic amount obtained from the state monitoring sensor 145 has transitioned from a state smaller than the threshold value A2 to a larger state (see FIGS. 4 and 5). ). The arithmetic processing device 81 can be installed, for example, inside the data processing device 80 of FIG. A computer that receives data from the data processing device 80 at a remote location may be used as the arithmetic processing device 81.

  As described above, the state monitoring device 100 is a device that detects the displacement of the rotating shaft 20. For this reason, the friction member 146 is installed in contact with or close to the annular member 201 disposed around the rotation shaft 20. A state monitoring sensor 145 that is an AE sensor or an acceleration sensor is bonded to the friction member 146. The stay 141 fixes the state monitoring sensor 145 to the housing 120 or the bearing retainer 121. The friction member 146 is installed at a position where wear proceeds with the displacement of the rotating shaft 20. That is, the friction member 146 is provided in a phase where it is estimated that the bearing 160 is worn under normal use conditions. In the present embodiment, a friction member 146 is provided at the lowermost end where the bearing load acts.

  As the operating time of the bearing 160 becomes longer, the rolling element 133, the inner ring 131, and the outer ring 132 are worn. When such wear occurs, the rotary shaft 20 is displaced in the direction in which the bearing load acts due to the bearing load. That is, the displacement of the rotating shaft 20 occurs as the distance between the inner ring 131 and the outer ring 132 of the bearing 160 changes.

  When the rotating shaft 20 is displaced, the friction member 146 is worn and AE and vibration acceleration are generated, and the state monitoring sensor 145 directly adhered to the friction member 146 can detect the displacement of the rotating shaft 20 with high sensitivity. By detecting this displacement, it is possible to detect with high sensitivity that the bearing 160 has been damaged due to wear or the like.

  In addition, the state monitoring device 100 includes a vibration isolation material 202 between the annular member 201 and the rotating shaft 20, and includes a vibration isolation material 143 between the state monitoring sensor 145 and the stay 141. The vibration isolators 143 and 202 can block AE and vibration acceleration transmitted to the state monitoring sensor 145 via the stay 141 and the rotating shaft 20. For this reason, it is difficult for the state monitoring sensor 145 to detect AE and vibration occurring in the bearing 160 and other parts. For this reason, AE and vibration acceleration generated from the friction member 146 can be measured with higher sensitivity.

FIG. 4 is a diagram illustrating schematic measurement data of the state monitoring apparatus according to the first embodiment. The data in FIG. 4 simulates the case where the direction of the bearing load is vertically downward like the bearing 60A in FIG. 2, and is obtained under the following measurement conditions.
<Measurement conditions>
Apparatus configuration: Configuration shown in FIG. 3 Friction member material: Carbon material state detection sensor: AE (envelope processed time waveform voltage output)
Bearing: Spherical roller bearing (inner diameter 560mm, outer diameter 820mm, width 195mm)
Displacement of rotating shaft: Up to 0.1 mm, observed with another displacement meter for comparison Rotating speed: 20 rev / min (Time of one rotation 3 seconds)
Sampling rate: 100 kHz
Data length: 15 seconds Measurement interval: 10 minutes In this embodiment, a state monitoring method is used in which the friction member 146 is brought into contact with the rotating shaft 20 immediately after the start of operation. The configuration of the apparatus is the same as that described in FIG. In FIG. 4, a displacement X3, an effective value E3, and a variation coefficient C3 are shown. The displacement X3 indicates a displacement in which the bearing load direction of the rotating shaft 20 is positive. In order to reproduce the state in which the bearing 160 in the normal state starts to increase the displacement of the rotating shaft 20 during the operation, the load is gradually increased during the constant rotation speed operation.

  The effective value E3 is a square root of an average value of values obtained by squaring each sampling value of the output of the state monitoring sensor 145 included in the data length of 15 seconds. The variation coefficient C3 is obtained by dividing the standard deviation of the sampling value by the arithmetic average and represents a relative variation.

  The plot of the effective value E3 and the coefficient of variation C3 is obtained by plotting values calculated for a data length of 15 seconds at 10-minute intervals, and the displacement X3 of the rotating shaft 20 is in the vicinity of the friction member 146. It is an instantaneous value measured using a displacement meter.

  As shown in FIG. 4, the operation period includes a preliminary operation period T1 at the beginning of operation, a subsequent threshold generation period T2, and a determination period T3.

  Preload is applied between the friction member 146 and the annular member 201 at the beginning of operation. This preload is determined by the rigidity of the parts supporting the friction member 146 such as the stay 141. When the rotating shaft 20 starts rotating, the friction member 146 is worn by sliding with the annular member 201, and AE is continuously generated. Accordingly, in the preliminary operation period T1, the friction member 146 is greatly worn immediately after the start of the operation, but the transition to the threshold value generation period T2 in which the wear progress of the friction member 146 is stagnated due to the decrease in the contact force accompanying the wear. To do. In the threshold generation period T2, wear stops and AE does not occur. In order to determine the transition to the threshold generation period T2, the threshold A1 is determined based on the sampled feature amount data such as AE and vibration acceleration in the initial stage of the preliminary operation period T1. Then, based on the fact that the feature amount has decreased below the threshold value A1, it is determined that the preliminary operation period T1 has shifted to the threshold value generation period T2.

  The period until this stagnation (preliminary operation period T1) is several hundred to several tens of thousands of rotations from the start of operation, and there is no abnormality in the bearing. However, as the friction member 146 wears, the level of AE and vibration acceleration is increased. And the variation is great.

  On the other hand, the period in which the wear is stagnant (threshold generation period T2) is a period for generating the threshold A2 for detecting an abnormality because there is no abnormality in the bearing and the level and fluctuation of AE and vibration acceleration are small. Is suitable.

  However, when the rotation is at a low rotation speed, an oil film having a sufficient thickness cannot be expected on the bearing portion, and wear of the bearing 160 occurs when the operation is continued. When the rotary shaft 20 is displaced due to wear of the bearing 160, the contact force between the friction member 146 and the annular member 201 increases, and the friction member 146 is worn and AE occurs.

  In FIG. 4, the displacement of the rotating shaft gradually increases from the operation time of 2 hours (hour). The time when the clearance between the inner ring and the outer ring of the bearing begins to increase by generating a threshold value A2 for detecting anomalies at around 1.5 hours (hours) when the effective value and coefficient of variation are low and stable. Can be detected accurately.

  The state monitoring method used in the present embodiment includes a step (S11 to S14) of determining a threshold generation period T2 based on a characteristic amount (E3) of measurement data at the beginning of operation, and a threshold generation period T2. And calculating a threshold value A2 for detecting a bearing abnormality (S15, S16), and detecting a bearing abnormality based on the threshold value A2 (S17, S18). It is. Hereinafter, the abnormality determination process executed by the state monitoring method will be described.

  FIG. 5 is a flowchart for explaining an abnormality determination process executed by the arithmetic processing unit in the first embodiment. 3, 4, and 5, first, in step S <b> 11, the arithmetic processing unit 81 samples the output signal of the state monitoring sensor 145 in the initial operation period (initial stage of the preliminary operation period T <b> 1), Get value data. In step S12, the arithmetic processing unit 81 calculates an average value, standard deviation σ, and the like from the initial value data obtained in the initial period, and determines the threshold value A1 based on these values. For example, the average value −3σ or 1/10 of the average value can be set as the threshold value A. This initial period is usually a period in which no displacement occurs in the rotating shaft due to bearing wear, and is a period in which the friction member 146 is in contact with the rotating shaft 20 and AE occurs in the friction member 146.

  In step S13, the arithmetic processing unit 81 determines whether or not the feature amount E obtained from the state monitoring sensor 145 is smaller than the threshold value A1. As long as E <A1 is not satisfied (NO in S13), the preliminary operation period T1 in FIG. 4 has not ended, and the threshold value generation period T2 for determining the threshold value A2 has not transitioned. The process of S13 is executed again.

  If E <A1 is established in step S13 (YES in S13), the arithmetic processing unit 81 determines whether or not the feature value change ΔE is smaller than the determination value B1 in step S14. This is because it is preferable to generate the threshold value A2 after the value of E3 has settled in FIG.

  While ΔE <B1 is not satisfied (NO in S14), the process returns to step S13 again. On the other hand, if ΔE <B1 is satisfied (YES in S14), the process proceeds to step S15.

  In step S15, the arithmetic processing unit 81 samples the output signal of the state monitoring sensor 145 in the threshold generation period T2 and obtains data for generating the threshold A2. In step S16, the arithmetic processing unit 81 calculates an average value, standard deviation σ, and the like of the data obtained during the threshold generation period T2, and determines the threshold A2 based on these. For example, the average value + 3σ can be set as the threshold value A2. The threshold generation period T2 starts after E <A1 and ΔE <B1 are satisfied, and the end point can be determined experimentally as appropriate.

  In step S17, the arithmetic processing unit 81 monitors the subsequent effective value E and determines whether or not the effective value E is greater than the threshold value A2. If E> A2, the process of step S17 is executed again. If E> A2, the process proceeds to step S18. In step S18, the arithmetic processing unit 81 determines that an abnormality has occurred in the bearing 160, performs recording and notification as necessary, and ends the process in step S19.

  As described above, the state monitoring apparatus 100 includes the arithmetic processing unit 81 that receives the output of the state monitoring sensor 145 and determines whether or not an abnormality has occurred in the bearing. The arithmetic processing unit 81 determines (i) the first threshold value A1 based on the feature value obtained from the state monitoring sensor 145 at the initial stage of the preliminary operation period T1 (first operation period), and (ii) the feature value. Is based on the characteristic amount obtained from the state monitoring sensor 145 in the initial stage of the threshold generation period T2 (second operation period) after the preliminary operation period T1 in which the state transitions to a state smaller than the first threshold value A1. A second threshold value A2 is determined, and (iii) after the threshold value generation period T2, the feature quantity obtained from the state monitoring sensor 145 changes from a state smaller than the second threshold value A2 to a larger state. It is determined that an abnormality has occurred in the bearing 160 (FIGS. 4 and 5).

  According to the state monitoring apparatus of the first embodiment, in the preliminary operation period, the friction member 146 is worn to the limit as long as it does not come into contact with the rotating shaft 20, so that the elapsed time from the start of operation is 2 hours (hour ) The phenomenon of rapid increase in front and rear wear can be detected immediately with little time delay.

  Moreover, in this Embodiment, the sensitivity of a measurement improves with the vibration isolator 143,202. That is, the friction member 146 generates AE or vibration by being worn during sliding contact with the annular member 201. The state monitoring sensor 145 detects this AE or vibration. However, the bearing 160, the gear, the shaft coupling, and the like provided directly on the rotating shaft 20 or through other members may also generate AE and vibration, which causes noise. In some cases, this noise cannot be separated from AE and vibration generated by the friction member 146. The anti-vibration materials 143 and 202 can attenuate AE and vibration that are noise transmitted to the state monitoring sensor 145 via the stay 141 and the rotating shaft 20, so that the AE and vibration generated from the friction member 146 can be made more sensitive. It can be measured.

[Embodiment 2]
FIG. 6 is a diagram illustrating a main part of the configuration of the state monitoring apparatus 100A according to the second embodiment. FIG. 7 is a diagram showing a main part of the configuration of a state monitoring apparatus 100B according to a modification of the second embodiment.

  The friction member 146A may have a shape in which the contact area increases as it wears as shown in FIG. As the contact area increases, the strength of AE generated at the time of wear also increases, so the amount of wear of the bearing can be grasped quantitatively, and if a threshold value is set in advance, it is easy to issue a bearing replacement warning. Become. When the hardness of the annular member 201A is made lower than the hardness of the friction member 146 and the annular member 201A is worn, the contact surface increases as the annular member 201A wears as shown in FIG. You can also.

[Embodiment 3]
FIG. 8 is a diagram illustrating a main part of the configuration of the state monitoring apparatus 100C according to the third embodiment. The state monitoring device 100C of the third embodiment includes a member 201C and a vibration isolating material 202C instead of the annular member 201 and the vibration isolating material 202 in the configuration of the state monitoring device 100 of the first embodiment. Since other parts are the same as those in the first embodiment, description thereof will not be repeated.

  In the case of a rolling bearing, the inner ring may be worn or peeled off. Since the peeling position of the inner ring cannot be specified in advance, as shown in FIG. 3, the annular member 201 that is in sliding contact with the friction member 146 needs to be annular.

  On the other hand, in the case of a sliding bearing, since the bearing is usually more easily worn than the rotating shaft, if the shaft swing can be ignored, it is sufficient to detect the displacement once per rotation. Need not be circular. Therefore, the configuration as shown in FIG.

  Although the embodiment of the present invention has been described above, the above-described embodiment can be variously modified.

  In FIGS. 4 and 5, the preload is applied at the initial stage of installation, but the preload is not applied at the initial stage of installation, and it may be installed with a predetermined gap between the friction terminal and the annular member. If a clearance corresponding to the wear amount of the bearing's service life limit or the wear amount that should give a warning for replacement is provided, a warning can be given to the user upon receipt of the AE signal.

  In FIG. 1 and the like, an example in which the present invention is applied to a bearing of a wind power generator is shown, but the state monitoring apparatus of the present embodiment can also be applied to a bearing such as a railway vehicle or a spindle. In particular, the slide bearing is suitably used for a small machine.

  In addition, when there is a possibility that the direction in which the bearing load acts may change or when the bearing load is indefinite, monitoring may be performed by providing a plurality of friction members at different positions.

  Moreover, although the example of the effective value of AE was shown as a feature-value of measurement data, you may use another physical quantity as a feature-value. For example, typical effective values such as AE and vibration acceleration, maximum value, minimum value, kurtosis, skewness, coefficient of variation (standard deviation / average value), standard deviation, variance, peak-to-peak A value etc. can be used.

  Note that the feature amount of the measurement data can be calculated with a data length of at least one rotation of the rotating shaft in order to avoid adverse effects due to rotational runout and surface roughness distribution on the contact surface of the rotating shaft 20 with the friction member 146. preferable. Further, the feature amount may be calculated after the band pass filter processing or may be calculated after being converted into the frequency domain by FFT processing.

  Furthermore, the threshold value for detecting a bearing abnormality is determined based on the feature value calculated over the entire threshold value generation period, or the threshold value generation period is first divided into a plurality of feature values. May be calculated again, and the feature value may be calculated again over the entire period, and determined based on the feature value.

  In the case of a bearing used in a harsh environment such as ultra-high temperature, ultra-low temperature, liquid, or vacuum atmosphere, in order to protect the sensor, a long friction member 146 is used, or AE or vibration is generated between the friction member 146 and the sensor. The distance between the bearing or the friction member 146 and the sensor may be greatly separated by connecting with a long component made of a material that easily transmits acceleration.

  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.

  DESCRIPTION OF SYMBOLS 10 Wind power generator, 20 Rotating shaft, 25 Hub, 30 Blade, 40 Speed up gear, 50 Generator, 52 Control panel, 54 Power transmission line, 60, 60A, 60B, 160 Bearing, 80 Data processing device, 81 Arithmetic processing device , 90 nacelle, 92 tower, 100, 100A, 100B, 100C condition monitoring device, 120 housing, 121 bearing retainer, 131 inner ring, 132 outer ring, 133 rolling element, 141 stay, 142 anti-vibration material cover, 143, 202, 202C Vibration material, 145 state monitoring sensor, 146, 146A friction member, 201, 201A annular member.

Claims (7)

A state monitoring device for detecting an abnormality of a bearing in which a fixed ring is fixed to a housing,
A first member disposed on a peripheral surface of a rotating shaft supported by the bearing and rotating together with the rotating shaft;
A second member arranged to face the peripheral surface of the rotating shaft so that the degree of contact with the first member changes when the rotating shaft is displaced relative to the housing;
A state monitoring sensor in contact with the second member,
The state monitoring sensor is a state monitoring device which is an AE sensor or an acceleration sensor.   The state monitoring device according to claim 1, further comprising a vibration isolating material that is disposed between the first member and the rotating shaft and blocks vibration.   The state monitoring device according to claim 2, wherein the vibration isolator is made of rubber.   The state monitoring device according to claim 1, wherein the second member is disposed on a side on which a bearing load acting on the bearing acts, with respect to the rotating shaft.   The state monitoring device according to claim 1, wherein the first member has higher hardness than the second member.   The state monitoring apparatus according to claim 1, further comprising a stay that fixes the second member and the state monitoring sensor to the housing.   The state monitoring device according to claim 6, further comprising a vibration isolating material that is disposed between the state monitoring sensor and the stay and blocks vibration.

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