WO2018173831A1

WO2018173831A1 - State monitoring device and state monitoring method

Info

Publication number: WO2018173831A1
Application number: PCT/JP2018/009510
Authority: WO
Inventors: 英之筒井
Original assignee: Ntn株式会社
Priority date: 2017-03-23
Filing date: 2018-03-12
Publication date: 2018-09-27

Abstract

This state monitoring device for detecting a bearing abnormality is provided with: a friction member (146) disposed in such a way as to face a circumferential surface of a rotating shaft (20) in such a way that a degree of contact changes when the rotating shaft (20), which is supported by a bearing, is displaced; and a state monitoring sensor (145) in contact with the friction member (146). The state monitoring sensor (145) is an AE sensor or an acceleration sensor. The friction member (146) is preferably disposed on the side, relative to the rotating shaft (20), on which a bearing load acting on the bearing acts. By means of such a configuration, the present invention provides a state monitoring device with which it is possible to monitor displacement of the rotating shaft with high precision, without being affected by the environment such as lubricating oil or water.

Description

Status monitoring device and status monitoring method

The present invention relates to a state monitoring device and a state monitoring method for detecting a bearing abnormality.

A state monitoring device that diagnoses abnormalities of rotating parts in an actual operating 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 is known (Patent Document 1: Japanese Patent Laid-Open No. 2006-2006). -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 incorporating the rotating component.

JP 2006-105956 A

∙ Bearing status monitoring devices often monitor the status 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 an abnormality 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. A monitoring device and a state monitoring method are provided.

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 state monitoring device includes a friction member disposed so as to face the peripheral surface of the rotation shaft so that the degree of contact changes when the rotation shaft supported by the bearing is displaced with respect to the housing, and the state monitoring contacting the friction member A sensor. The state monitoring sensor is an AE sensor or an acceleration sensor.

Preferably, the friction member is arranged on the side on which the bearing load acting on the bearing acts with respect to the rotating shaft.

Preferably, the state monitoring device further includes a stay for fixing the friction member and the state monitoring sensor to the housing of the bearing.

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

Preferably, during friction between the friction member and the rotary shaft, the wear amount of the friction member per rotation of the rotary shaft is larger than the wear amount of the bearing per rotation of the rotary shaft.

Preferably, the state monitoring device further includes an arithmetic processing unit that receives the output of the state monitoring sensor and determines whether or not an abnormality has occurred in the bearing. The arithmetic processing unit determines that an abnormality has occurred in the bearing when the feature amount obtained from the state monitoring sensor transitions from a state smaller than the first threshold value to a larger state.

Preferably, the state monitoring device further includes an arithmetic processing unit that receives the output of the state monitoring sensor and determines whether or not an abnormality has occurred in the bearing. The arithmetic processing unit determines (i) a first threshold value based on the feature value obtained from the state monitoring sensor in the first operation period, and (ii) transitions to a state where the feature value is smaller than the first threshold value. The second threshold value is determined based on the feature amount obtained from the state monitoring sensor in the second operation period after the first operation period, and (iii) obtained from the state monitoring sensor after the second operation period. It is determined that an abnormality has occurred in the bearing when the obtained feature value transitions from a state smaller than the second threshold value to a larger state.

Preferably, the friction member has a shape such that the contact area with the rotation shaft increases as the displacement amount of the rotation shaft increases.

Preferably, the contact area of the friction member with the rotating shaft increases stepwise as the amount of displacement of the rotating shaft increases.

Preferably, the friction member is disposed on a side on which the bearing load acting on the bearing acts with respect to the rotation shaft, and the cross-sectional area perpendicular to the direction of the bearing load on the friction member is increased as the distance from the rotation shaft increases. Increase.

Preferably, in the cross section of the friction member when it is cut by a plane including the axis of the rotation shaft and parallel to the bearing load direction, the surface of the friction member facing the rotation shaft is stepped.

More preferably, the state monitoring device further includes an arithmetic processing unit that receives the output of the state monitoring sensor and determines whether or not an abnormality has occurred in the bearing. The arithmetic processing unit determines that an abnormality has occurred in the bearing when the feature amount obtained from the state monitoring sensor transitions from a state smaller than the first threshold value to a larger state, and the feature amount and the first threshold value are determined. The amount of displacement of the rotating shaft is determined based on a comparison result with a larger second threshold value.

Alternatively, the arithmetic processing unit determines the first threshold value based on the feature amount obtained from the state monitoring sensor during the first operation period, and the first operation in which the feature amount transitions to a state smaller than the first threshold value. The second threshold value is determined based on the feature amount obtained from the state monitoring sensor in the second operation period after the period. The arithmetic processing unit determines that an abnormality has occurred in the bearing when the feature amount obtained from the state monitoring sensor after the second operation period transits from a state smaller than the second threshold value to a larger state. The arithmetic processing unit is larger than the second threshold value based on the feature value obtained from the state monitoring sensor in the third operation period after the feature value transits from a state smaller than the second threshold value to a larger state. A third threshold value is determined, and a predetermined amount of displacement corresponding to the third threshold value is stored. The arithmetic processing unit displaces the rotation axis by a predetermined displacement amount when the feature amount obtained from the state monitoring sensor after the third operation period transitions from a state smaller than the third threshold value to a larger state. It is determined that

The method according to another aspect of the present disclosure is a state monitoring method in which an abnormality of a bearing in which a fixed ring is fixed to a housing is detected by a state monitoring device. The state monitoring device includes a friction member disposed so as to face the peripheral surface of the rotation shaft so that the degree of contact changes when the rotation shaft supported by the bearing is displaced with respect to the housing, and the state monitoring contacting the friction member A sensor. The state monitoring sensor is an AE sensor or an acceleration sensor. The state monitoring method includes: (i) a step of determining a first threshold value based on a feature amount obtained from the state monitoring sensor during the first operation period; and (ii) a state in which the feature amount is smaller than the first threshold value. A step of determining a second threshold value based on a feature quantity obtained from the state monitoring sensor in a second operation period after the first operation period transitioned to (iii) a state after the second operation period And determining that an abnormality has occurred in the bearing when the feature amount obtained from the monitoring sensor transitions from a state smaller than the second threshold value to a larger state.

Preferably, the friction member has a shape such that the contact area with the rotation shaft increases as the displacement amount of the rotation shaft increases. The state monitoring method further includes a step of determining a displacement amount of the rotating shaft based on a comparison result between the feature amount and a third threshold value larger than the second threshold value.

The state monitoring device of the present invention enables highly accurate abnormality detection of a low-speed operation bearing without being affected by the 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 structure of the state monitoring apparatus of the modification 1 of Embodiment 1. FIG. It is a figure which shows the measurement data of the state monitoring apparatus of the modification 1 of Embodiment 1. FIG. It is a figure which shows the measurement data of the state monitoring apparatus of the modification 2 of Embodiment 1. FIG. 10 is a flowchart for explaining abnormality determination processing executed by the arithmetic processing device in Modification 2 of Embodiment 1; It is a figure which shows the measurement data of the state monitoring apparatus of the modification 3 of Embodiment 1. FIG. It is a figure which shows the structure of the state monitoring apparatus of Embodiment 2. FIG. It is a figure which shows one Example of a friction member. It is a figure which shows one Example of a friction member. It is a figure which shows one Example of a friction member. It is a figure which shows another Example of a friction member. It is a figure which shows another Example of a friction member. It is a figure which shows another Example of a friction member. It is a figure which shows another Example of a friction member. It is a figure which shows the measurement data of the state monitoring apparatus of Embodiment 2. FIG. 10 is a flowchart for explaining abnormality determination processing executed by the arithmetic processing device in the second embodiment. It is a figure which shows the structure of the state monitoring apparatus of the modification 1 of Embodiment 2. FIG. It is a figure which shows the measurement data of the state monitoring apparatus of the modification 1 of Embodiment 2. FIG. It is a figure which shows another Example of a friction member. It is a figure which shows the measurement data of the state monitoring apparatus of the modification 2 of Embodiment 2. FIG. 10 is a flowchart for explaining the first half of an abnormality determination process executed by an arithmetic processing device in a second modification of the second embodiment. 14 is a flowchart for explaining the second half of the abnormality determination process executed by the arithmetic processing device in the second modification of the second embodiment. It is a figure which shows the measurement data of the state monitoring apparatus of the modification 3 of Embodiment 2. FIG.

Hereinafter, embodiments of the present invention will be described 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 FIG. 1 and FIG. 2, a configuration of a wind turbine generator that is an example of a device to which the state monitoring device according to the present embodiment can be applied will be described. 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 is a diagram schematically showing 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 rotary shaft 20 is a main shaft of the wind turbine 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 supporting the main shaft. Referring to FIG. 2, bearing 60 includes a bearing 60 A installed on the hub 25 side and a bearing 60 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.

As described above, the bearing may have different directions in which the bearing load acts depending on the place of use. 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 embodiment, 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 more likely to be worn than the rotating shaft is disposed on the bearing load acting side (load region side) with respect to the bearing, and the rotation of the bearing is based on AE or vibration generated in the friction member. Detect shaft displacement.

[Embodiment 1]
FIG. 3 is a diagram illustrating a configuration of the state monitoring apparatus according to the first embodiment. Referring to FIG. 3, state monitoring apparatus 100 according to the first embodiment monitors a state such as wear of bearing 160, and includes a friction member 146 and a state monitoring sensor 145 in contact with friction member 146. Prepare.

The bearing 160 is surrounded by the rotary 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. In the bearing 160, an outer ring 132 that is a fixed ring is fixed to the housing 120. The friction member 146 is disposed so as to face the peripheral surface of the rotary shaft 20 so that the degree of contact changes when the rotary shaft 20 supported by the bearing 160 is displaced in the bearing load direction with respect to the housing 120. The state monitoring sensor 145 is an AE sensor or an acceleration sensor. The bearing 160 corresponds to the bearing 60A in FIG.

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

The friction member 146 is preferably made of a material that easily wears and generates AE and vibration acceleration. The friction member 146 is more preferably made of a material that does not easily damage the mating member (rotating shaft 20). Further, in order to detect the wear of the bearing 160, the friction member 146 is configured so that the amount of wear of the friction member 146 per rotation of the rotary shaft 20 is equal to that of the rotary shaft 20 when the friction member 146 and the rotary shaft 20 are frictioned. A bearing that is larger than the wear amount of the bearing 160 (inner ring, outer ring, rolling element) per rotation is selected. For example, as the friction member 146, a carbon material, a resin, a resin in which various reinforcing materials are combined, a copper alloy, an aluminum alloy, a titanium alloy, a metal sintered body, a metal powder compression molding, and a resin powder compression molding are used. be able to.

The state monitoring device 100 further includes a stay 141, a vibration isolator 143, a vibration isolator cover 142, and an arithmetic processing unit 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 feature amount obtained from the state monitoring sensor 145 has transitioned from a state smaller than the threshold A to a larger state (FIGS. 4, 5, and 5). (See FIG. 7). 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 placed in contact with or close to the rotating 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.

When 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 rotary shaft 20 is displaced, the friction member 146 is worn to generate AE and vibration acceleration, and the state monitoring sensor 145 directly adhered to the friction member 146 can detect that the rotary shaft 20 is displaced 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.

Further, the state monitoring device 100 includes a vibration isolating material 143 for isolating vibration between the state monitoring sensor 145 and the stay 141, and a vibration isolating material cover 142. The anti-vibration material 143 can block AE and vibration acceleration transmitted to the state monitoring sensor 145 via the stay 141. 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 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 Embodiment 1, the friction member 146 was not brought into contact with the rotating shaft 20 at the start of operation, and the relative distance was set to 0.06 mm. 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. In FIG. 4, the displacement X1, the effective value E1, and the variation coefficient C1 are shown. The displacement X1 indicates a displacement in which the bearing load direction of the rotating shaft 20 is positive. The effective value E1 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 C1 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 E1 and the coefficient of variation C1 is a plot of values calculated at a data length of 15 seconds at 10-minute intervals, and the displacement X1 of the rotating shaft 20 is in the vicinity of the friction member 146. It is an instantaneous value measured using a displacement meter.

The wear of the bearing 160 proceeds from about 2 hours of operation time, and the displacement X1 of the rotary shaft 20 gradually increases. In the first embodiment, the threshold value A is determined based on the effective value E1 obtained in the initial period when the friction member 146 at the beginning of operation is not in contact with the rotating shaft 20. For example, the threshold value A can be determined in consideration of the average value and standard deviation of the initial period.

When the friction member 146 is brought close to the rotating shaft 20 without being brought into contact, the distance between the friction member 146 and the rotating shaft 20 can be accurately grasped during installation so that it can be regarded as abnormal if the friction member 146 and the rotating shaft 20 come into contact with each other. The distance is adjusted to the amount of change between the inner ring and the outer ring gap of the bearing which is detected as abnormal. The friction member 146 immediately after the start of operation is not in contact with the rotating shaft and is not worn. This period without wear is suitable as a period for generating a threshold value for detecting an abnormality because there is no abnormality in the bearing and the level of AE and vibration acceleration and its fluctuation are small.

FIG. 5 is a flowchart for explaining the abnormality determination process executed by the arithmetic processing unit in the first embodiment. 3 to 5, first, in step S1, the arithmetic processing unit 81 samples the output signal of the state monitoring sensor 145 in the initial operation period to obtain initial value data. In step S2, the arithmetic processing unit 81 calculates an average value, standard deviation σ, and the like of the initial value data obtained in the initial period, and determines the threshold A based on these. For example, the average value + 3σ 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 wear of the bearing, and can be determined experimentally as appropriate.

In step S3, 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 A. If E> A, the process of step S3 is executed again. If E> A, the process proceeds to step S4. In step S4, the arithmetic processing unit 81 determines that an abnormality has occurred in the bearing 160, performs recording or notification as necessary, and ends the process in step S5.

By setting the threshold value A in this way, it is possible to avoid erroneously detecting the occurrence of a bearing abnormality due to background noise. In the first embodiment, the displacement of the bearing rotating shaft 20 from the start of operation (the amount of change in the gap between the inner ring and the outer ring due to wear of the bearing) has increased to an initial gap of 0.06 mm or more accurately. Can be detected.

[Variation 1 of Embodiment 1]
In the first modification of the first embodiment, an example will be described in which the same detection process is performed on a sliding bearing instead of a rolling bearing.

FIG. 6 is a diagram illustrating a configuration of the state monitoring apparatus according to the first modification of the first embodiment. Referring to FIG. 6, state monitoring apparatus 101 includes a friction member 146 and a state monitoring sensor 145 in contact with friction member 146. The friction member 146 is disposed so as to face the circumferential surface of the rotary shaft 20 so that the degree of contact changes when the rotary shaft 20 supported by the bearing 160A, which is a plain bearing, is displaced. The state monitoring sensor 145 is an AE sensor or an acceleration sensor.

The bearing 160 A is surrounded by the rotary shaft 20, the housing 220, and the bearing retainer 221. The bearing 160A has a back metal integrated structure, a sliding member is disposed on the inner side of the back metal, and the rotary shaft 20 penetrates further on the inner side. The bearing 160A is fitted with the housing 220 on the outside. For the sliding member disposed inside the back metal, for example, a resin material such as polytetrafluoroethylene (PTFE) can be used. Moreover, you may use the porous sintered compact which has a metal powder as a main component as a sliding member. It is. Since the pores of the sliding member are impregnated with oil, the oil circulates inside the bearing and plays a role of lubrication during operation.

The friction member 146 is disposed on the rotating shaft 20 on the side on which the bearing load FA acting on the bearing 160A acts (the load region side of the back metal). Since friction member 146, vibration isolator 143, vibration isolator cover 142, and stay 141 are the same as those in the first embodiment, description thereof will not be repeated.

FIG. 7 is a diagram illustrating measurement data of the state monitoring device according to the first modification of the first embodiment. The data in FIG. 7 is obtained under the following measurement conditions.
<Measurement conditions>
Device configuration: Configuration shown in FIG. 6 Friction member material: Carbon material state detection sensor: AE (Envelope-processed time waveform is voltage output)
Bearing material: PTFE composite material (inner diameter 100mm, width 50mm)
Load: 50kN
Rotation speed: 20 rotations / minute (one rotation time 3 seconds)
Sampling rate: 100 kHz
Data length: 15 seconds Measurement interval: 15 hours (hour)
FIG. 7 shows the displacement X2, the effective value E2, and the variation coefficient C2. The displacement X2 indicates a displacement in which the direction of the bearing load of the rotating shaft 20 is positive. The effective value E2 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 C2 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 E2 and the coefficient of variation C2 is obtained by plotting values calculated for a data length of 15 seconds at 15-hour intervals, and the displacement X2 of the rotating shaft 20 is in the vicinity of the friction member 146 for comparison. These are instantaneous values measured using other displacement meters. In order to reproduce the state in which the bearing in the normal state starts to increase the displacement between the inner and outer rings during the operation, the load is gradually increased during the constant rotation speed operation.

The wear of the bearing 160A rapidly increases from about 270 hours (hour) in operation time, and the displacement X2 of the rotary shaft 20 gradually increases. In the first modification of the first embodiment, the threshold value A is determined based on the effective value E2 obtained in the initial period when the friction member 146 at the beginning of operation is not in contact with the rotating shaft 20. For example, the threshold value A can be determined in consideration of the average value and standard deviation of the initial period.

Note that the threshold A calculation process and the abnormality determination process are the same as those in the flowchart of FIG.

In this way, a similar state monitoring device can be realized for the sliding bearing.
[Modification 2 of Embodiment 1]
In the first embodiment, the friction member 146 immediately after the start of operation is not worn because it is not in contact with the rotating shaft 20. However, if there is too much space between the rotary shaft 20 and the friction member 146, the friction member 146 will not contact the rotary shaft 20 until a while after the rotary shaft 20 starts to be displaced. There is a possibility. Therefore, it is difficult to set the gap between the rotating shaft 20 and the friction member 146.

In the second modification of the first embodiment, a state monitoring method is used in which the friction member 146 is brought into contact with the rotary shaft 20 immediately after the start of operation. The configuration of the apparatus is the same as that described in FIG.

FIG. 8 is a diagram illustrating measurement data of the state monitoring device according to the second modification of the first embodiment. The data in FIG. 8 is obtained under the same measurement conditions as in FIG. However, the second modification of the first embodiment is different from the first embodiment in that the friction member 146 is brought into contact with the rotating shaft 20 from the beginning of the operation.

As shown in FIG. 8, 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.

When the friction member 146 is brought into contact with the rotary shaft 20 at the beginning of operation, the contact force is determined by the rigidity of the parts supporting the friction member 146 such as the stay 141. Therefore, in the preliminary operation period T1, the friction member 146 is greatly worn immediately after the start of operation, but the contact force decreases with the wear, so that the progress of wear of the friction member 146 is shifted to the threshold generation period T2. To do. 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.

In FIG. 8, 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 second modification of the first 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. A step (S15, S16) of calculating a threshold value A2 for detecting a bearing abnormality in the value generation period T2 and a step (S17, S18) of detecting a bearing abnormality based on the threshold value A2. It is a feature. Hereinafter, the abnormality determination process executed by the state monitoring method will be described.

FIG. 9 is a flowchart for explaining an abnormality determination process executed by the arithmetic processing device in the second modification of the first embodiment. 3, 8, and 9, first, in step S 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 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 threshold value A can be set to an average value −3σ or 1/10 of the average value. 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. 8 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 satisfied in step S13 (YES in S13), the arithmetic processing unit 81 determines whether or not the change ΔE in the feature amount is smaller than the determination value B1 in step S14. In FIG. 8, it is preferable that the threshold value A2 is generated after the value of E3 has settled down.

While ΔE <B1 is not satisfied (NO in S14), the process is returned 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 to obtain 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 larger 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 device 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. 8 to 10).

According to the state monitoring device of the second modification of the first embodiment, since the friction member 146 is worn to the limit unless it contacts the rotating shaft 20 during the preliminary operation period, the elapsed time from the start of operation. The phenomenon of rapid increase in wear around 2 hours (hour) can be captured immediately with little time delay.

[Modification 3 of Embodiment 1]
In the third modification of the first embodiment, an example will be described in which the same process as the detection process of the second modification of the first embodiment is performed on the slide bearing instead of the rolling bearing. Since the configuration of the slide bearing and the state monitoring device is shown in FIG. 6, description thereof will not be repeated here.

FIG. 10 is a diagram illustrating measurement data of the state monitoring device according to the third modification of the first embodiment. The data in FIG. 10 is obtained under the same measurement conditions as the data in FIG.

FIG. 10 shows a displacement X4, an effective value E4, and a variation coefficient C4. The displacement X4 indicates a displacement in which the bearing load direction of the rotating shaft 20 is positive. The effective value E4 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 C4 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 E4 and the variation coefficient C4 is obtained by plotting values calculated for a data length of 15 seconds at 15-hour intervals, and the displacement X4 of the rotating shaft 20 is near the friction member 146 for comparison. These are instantaneous values measured using other displacement meters.

The wear of the bearing 160A rapidly increases from about 270 hours (hours) of operation, and the displacement X4 of the rotary shaft 20 gradually increases. In the third modification of the first embodiment, in the preliminary operation period T1, 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 wear is about 270 hours (hours) in operation time. Rapid increase in phenomena can be detected immediately with little time delay.

It should be noted that threshold value A2 calculation processing and abnormality determination processing are the same as the processing in the flowchart of FIG.

In this way, a similar state monitoring device can be realized for the sliding bearing.
Although the embodiment of the present invention has been described above, the above-described embodiment can be variously modified.

For example, 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.

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

In addition, although the example of the effective value of AE is shown as the feature quantity of the measurement data, other physical quantities may be used as the feature quantity. 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.

[Embodiment 2]
FIG. 11 is a diagram illustrating a configuration of the state monitoring apparatus according to the second embodiment. Referring to FIG. 11, state monitoring apparatus 300 according to the second embodiment monitors a state such as wear of bearing 160, and includes friction member 346 and state monitoring sensor 145 in contact with friction member 346. Prepare. The friction member 346 is disposed so as to face the peripheral surface of the rotary shaft 20 so that the degree of contact changes when the rotary shaft 20 supported by the bearing 160 is displaced in the bearing load direction. The shape of the friction member 346 will be described later. The state monitoring sensor 145 is an AE sensor or an acceleration sensor. The bearing 160 corresponds to the bearing 60A in FIG.

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. In the bearing 160, an outer ring 132 that is a fixed ring is fixed to the housing 120. The friction member 346 is disposed so as to face the circumferential surface of the rotary shaft 20 so that the degree of contact changes when the rotary shaft 20 supported by the bearing 160 is displaced in the bearing load direction with respect to the housing 120. The state monitoring sensor 145 is an AE sensor or an acceleration sensor. The bearing 160 corresponds to the bearing 60A in FIG.

The friction member 346 is arranged on the side on which the bearing load FA acting on the bearing 160 acts (the load region side of the outer ring) with respect to the rotary shaft 20.

The friction member 346 is preferably made of a material that easily wears and that easily generates AE and vibration acceleration. The friction member 346 is more preferably made of a material that does not easily damage the mating member (rotating shaft 20). Further, in order to detect the wear of the bearing 160, the friction member 346 is configured so that the amount of wear of the friction member 346 per rotation of the rotary shaft 20 is equal to that of the rotary shaft 20 when the friction member 346 and the rotary shaft 20 are in friction. A bearing that is larger than the wear amount of the bearing 160 (inner ring, outer ring, rolling element) per rotation is selected. For example, as the friction member 346, a carbon material, a resin, a resin in which various reinforcing materials are combined, a copper alloy, an aluminum alloy, a titanium alloy, a metal sintered body, a metal powder compression molding, and a resin powder compression molding are used. be able to.

The state monitoring device 300 further includes a stay 141, a vibration isolator 143, a vibration isolator cover 142, and an arithmetic processing unit 81. The stay 141 fixes the friction member 346 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 feature amount obtained from the state monitoring sensor 145 has transitioned from a state smaller than the threshold value A11 to a larger state (FIGS. 15 and 16). (See FIG. 18). 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 300 is a device that detects the displacement of the rotating shaft 20. For this reason, the friction member 346 is installed in contact with or close to the rotating shaft 20. A state monitoring sensor 145 that is an AE sensor or an acceleration sensor is bonded to the friction member 346. The stay 141 fixes the state monitoring sensor 145 to the housing 120 or the bearing retainer 121. The friction member 346 is installed at a position where wear proceeds with the displacement of the rotary shaft 20.

When 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 these wears occur, 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 rotary shaft 20 is displaced, the friction member 346 is worn to generate AE and vibration acceleration, and the state monitoring sensor 145 directly adhered to the friction member 346 can detect that the rotary shaft 20 is displaced 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.

Further, the state monitoring device 300 includes a vibration isolating material 143 for isolating vibration between the state monitoring sensor 145 and the stay 141, and a vibration isolating material cover 142. The anti-vibration material 143 can block AE and vibration acceleration transmitted to the state monitoring sensor 145 via the stay 141. 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 346 can be measured with higher sensitivity.

FIGS. 12A to 12C are diagrams showing an example (friction member 346a) of the friction member 346. FIG. FIG. 12A shows a plan view of the friction member 346a. FIG. 12B shows a side view of the friction member 346a when viewed from a direction perpendicular to the axis 21 of the rotating shaft 20 and the bearing load direction. FIG. 12C shows a side view of the friction member 346a when viewed from the direction of the axis 21 of the rotating shaft 20.

Referring to FIGS. 12A to 12C, the friction member 346a has a substantially conical shape, and its side surface is stepped. In other words, the friction member 346a gradually decreases in height from the bottom surface as it goes from the top to the end of the cone. The friction member 346 a having a substantially conical shape is arranged such that its axial direction coincides with the direction of the bearing load and the top faces the rotating shaft 20.

13A to 13C are diagrams showing another example of the friction member 346 (friction member 346b). FIG. 13A shows a plan view of the friction member 346b. FIG. 13B shows a side view of the friction member 346b when viewed from a direction perpendicular to the axis 21 of the rotating shaft 20 and the bearing load direction. FIG. 13C shows a side view of the friction member 346b when viewed from the direction of the axis 21 of the rotating shaft 20.

Referring to FIGS. 13A to 13C, the friction member 346b has a rectangular shape in plan view, and is formed in a descending step shape from the central portion toward the short side so that the central portion in the longitudinal direction is the top. . In other words, the friction member 346b has a rectangular bottom surface, and the height from the bottom surface decreases stepwise from the central portion in the longitudinal direction toward the short side. The friction member 346b is arranged so that the direction perpendicular to the bottom surface coincides with the direction of the bearing load and the top faces the rotating shaft 20.

A surface of the

friction members

346a and 346b facing the rotation shaft 20 in a cross-section (see FIG. 11) of the

friction members

346a and 346b when cut along a plane that includes the axis 21 of the rotation shaft 20 and is parallel to the bearing load direction. Is stepped. The surface facing the rotating shaft 20 in each stage is orthogonal to the direction of the bearing load.

When viewed from the direction of the axis 21 of the rotary shaft 20, the friction member 346a shown in FIGS. 12A to 12C is stepped, whereas the friction member 346b shown in FIGS. 13A to 13C is rectangular. Therefore, the friction member 346b shown in FIGS. 13A to 13C can save space compared to the friction member 346a shown in FIGS. 12A to 12C.

Here, the step including the tops of the

friction members

346a and 346b is the first step, the lower step is the second step, the lower step is the third step, and so on. A peripheral surface of a portion of the rotating shaft 20 facing the

friction members

346 a and 346 b is parallel to the axis 21 of the rotating shaft 20. Therefore, when the first stage of the friction member 346a is scraped due to wear on the rotating shaft 20, and the rotating shaft 20 starts to contact the second stage of the friction member 346a, the contact area between the friction member 346a and the rotating shaft 20 is not sufficient. Increase continuously. When the second stage of the friction member 346a is scraped and the rotating shaft 20 starts to contact the third stage of the friction member 346a, the contact area between the friction member 346a and the rotating shaft 20 increases discontinuously. The same applies to the friction member 346b. As described above, the

friction members

346a and 346b have such shapes that the contact area with the rotating shaft 20 increases stepwise as the displacement amount of the rotating shaft 20 increases.

The contact area between the

friction members

346a and 346b and the rotating shaft 20 correlates with a feature amount (AE wave or vibration acceleration amplitude or the like) obtained from the state monitoring sensor 145. Therefore, when the contact area between the

friction members

346a and 346b and the rotating shaft 20 increases stepwise, the feature amount (AE wave or vibration acceleration amplitude, etc.) obtained from the state monitoring sensor 145 also increases stepwise. That is, the timing at which the feature value obtained from the state monitoring sensor 145 increases stepwise matches the timing at which one of the

friction members

346a and 346b is scraped off due to wear and the wear of the next step is started. To do.

When the characteristic amount obtained from the state monitoring sensor 145 transits from a state smaller than the threshold value A11, B11 (or A13, B13, B14) to a larger state, the arithmetic processing unit 81 causes the

friction members

346a, 346b to It is determined that it is the timing at which the wear of the step corresponding to the threshold is started (see FIGS. 15, 16, and 18). The arithmetic processing unit 81 stores in advance the displacement amount M of the rotating shaft 20 corresponding to each threshold value, and compares the feature amount obtained from the state monitoring sensor 145 with the threshold value, thereby rotating the rotating shaft 20. The amount of displacement is determined. The displacement amount M stored in the arithmetic processing unit 81 is determined in advance based on the initial value of the distance between the

friction members

346a and 346b and the rotary shaft 20 and the height of each step in the

friction members

346a and 346b. Here, when the surface corresponding to the rotating shaft 20 in each step is the upper surface of the step, the height of each step of the friction member 346 is the height of the upper surface of the step relative to the upper surface of the step below the step. means.

FIG. 14 is a view showing still another example of the friction member 346 (friction member 346c). Referring to FIG. 14, the friction member 346c is substantially conical like the friction member 346a shown in FIGS. 12A to 12C, and its side surface is stepped (two steps). In the friction member 346c, the height t1 of the first step is 0.04 mm, and the total value t2 of the heights of the first and second steps is 0.08 mm.

FIG. 15 is a diagram illustrating measurement data of the state monitoring device according to the second embodiment. The data in FIG. 15 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. 11 Friction member shape: Shape shown in FIG. 14 Friction member material: Carbon material state detection sensor: AE (Envelope-processed time waveform is output as voltage)
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 the second embodiment, the friction member 346c is not brought into contact with the rotary shaft 20 at the start of operation, and the relative distance (the initial value of the distance between the friction member 346c and the rotary shaft 20). ) Was set to 0.06 mm. 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. FIG. 15 shows a displacement X11, an effective value E11, and a variation coefficient C11. A displacement X11 indicates a displacement in which the bearing load direction of the rotating shaft 20 is positive. The effective value E11 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 C11 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 E11 and the variation coefficient C11 is a plot of values calculated for a data length of 15 seconds at 10-minute intervals. The displacement X11 of the rotating shaft 20 is in the vicinity of the friction member 346c, and other values are compared for comparison. It is an instantaneous value measured using a displacement meter.

The wear of the bearing 160 proceeds from about 2 hours of operation time, and the displacement X11 of the rotary shaft 20 gradually increases. When the friction member 346c is brought close to the rotating shaft 20 without being brought into contact, the distance between the friction member 346c and the rotating shaft 20 can be accurately grasped at the time of installation so that it can be regarded as abnormal if the friction member 346c contacts the rotating shaft 20. The distance is adjusted to the amount of change between the inner ring and the outer ring gap of the bearing which is detected as abnormal. Here, the distance is set to 0.06 mm.

When the displacement X11 of the rotating shaft 20 reaches 0.06 mm, the first stage of the friction member 346c and the rotating shaft 20 come into contact with each other, and the effective value E11 increases. The effective value E11 at this time is a value corresponding to the size of the contact area between the friction member 346c and the rotating shaft 20. The contact area is substantially equal to the cross-sectional area perpendicular to the bearing load direction in the first stage of the friction member 346c.

In the second embodiment, the threshold value A11 is based on the effective value E11 obtained in the initial period (first threshold value generation period T1) in which the friction member 346c at the start of operation is not in contact with the rotating shaft 20. Is determined. The threshold value A11 is a value that is compared with the effective value E11 in order to detect an increase in the effective value E11 due to the start of contact between the first stage of the friction member 346c and the rotating shaft 20. For example, the threshold value A11 can be determined in consideration of the average value and standard deviation of the initial period (first threshold value generation period T1). The friction member 346c immediately after the start of operation does not wear because it is not in contact with the rotating shaft. This period without wear is suitable as a period for generating the threshold value A11 for detecting an abnormality because there is no abnormality in the bearing and the level of AE and vibration acceleration and its fluctuation are small.

Until the displacement X11 of the rotating shaft 20 changes from 0.06 mm to 0.1 mm, the rotating shaft 20 continues to be displaced while contacting only the first stage of the friction member 346c. During this time, there is no change in the contact area between the friction member 346c and the rotary shaft 20. Therefore, the effective value E11 is stabilized at a value corresponding to the contact area.

When the displacement X11 of the rotary shaft 20 reaches 1.00 mm, the rotary shaft 20 starts to contact the second stage of the friction member 346c, and the effective value E11 increases. The effective value E11 at this time is a value corresponding to the size of the contact area between the second stage of the friction member 346c and the rotary shaft 20. The contact area is substantially equal to the cross-sectional area perpendicular to the direction of the second stage bearing load in the friction member 346c.

In the present embodiment, the effective value E11 obtained in the period during which the effective value E11 until the displacement X11 of the rotating shaft 20 changes from 0.06 mm to 0.1 mm is stable (second threshold value generation period T2) is obtained. Based on this, the threshold value B11 is determined. The threshold value B11 is a value that is compared with the effective value E11 in order to detect an increase in the effective value E11 due to the start of contact between the second stage of the friction member 346c and the rotating shaft 20.

The threshold value B11 is an effective value E11 when the rotary shaft 20 is in contact with the first stage of the friction member 346c, and an effective value E11 when the rotary shaft 20 is in contact with the second stage of the friction member 346c. It is preferable that the value is determined between. Sa is the contact area between the rotary shaft 20 and the friction member 346c when the rotary shaft 20 is in contact with the first stage of the friction member 346c, and the rotary shaft 20 is in contact with the second stage of the friction member 346c. The contact area between the rotary shaft 20 and the friction member 346c is Sb. At this time, the ratio between the effective value E11 when the rotary shaft 20 is in contact with the first stage of the friction member 346c and the effective value E11 when the rotary shaft 20 is in contact with the second stage of the friction member 346c. Is approximately equal to the ratio of Sa to Sb. Therefore, based on the effective value E11 when the rotating shaft 20 is in contact with the first stage of the friction member 346c, the effective value E11 is estimated when the rotating shaft 20 is in contact with the second stage of the friction member 346c. The threshold value B11 can be determined in consideration of the estimated value. Therefore, the period in which the rotary shaft 20 contacts the first stage of the friction member 346c and the effective value E11 is stably output is suitable as the period for generating the threshold value B11. The threshold value B11 is determined based on, for example, the average value of the effective values E11 in the period and the ratio between Sa and Sb. The ratio of Sa and Sb is, for example, the ratio of the cross-sectional area perpendicular to the bearing load direction at the first stage of the friction member 346c and the cross-sectional area perpendicular to the bearing load direction at the second stage of the friction member 346c. It is almost the same.

FIG. 16 is a flowchart for explaining abnormality determination processing executed by the arithmetic processing unit in the second embodiment. FIG. 16 shows a flowchart when the friction member 346c shown in FIG. 14 is used.

Referring to FIGS. 11 and 14 to 16, first, in step S31, arithmetic processing unit 81 samples the output signal of state monitoring sensor 145 in the initial operation period (first threshold value generation period T1). To obtain initial value data. In step S32, the arithmetic processing unit 81 calculates an average value, standard deviation σ, and the like of the initial value data obtained in the initial period, and determines the threshold value A11 based on these values. For example, the average value + 3σ can be set as the threshold value A11. This initial period is usually a period in which no displacement occurs in the rotating shaft due to wear of the bearing, and can be determined experimentally as appropriate. The arithmetic processing unit 81 stores an initial value (for example, 0.06 mm) of the distance between the friction member 346 and the rotating shaft 20 as the displacement amount M1 of the rotating shaft 20 corresponding to the threshold value A11.

In step S33, the arithmetic processing unit 81 monitors the subsequent effective value E and determines whether or not the effective value E is larger than the threshold value A11. If E> A11 is not satisfied (NO in S33), the process of step S33 is executed again. On the other hand, if E> A11 (YES in S33), the process proceeds to step S34. In step S34, the arithmetic processing unit 81 determines that an abnormality has occurred in the bearing 160, and the rotary shaft 20 has been displaced by the displacement amount M1 (the initial value of the distance between the friction member 346 and the rotary shaft 20), and if necessary. Record and notify.

By thus setting the threshold value A11, it is possible to avoid erroneously detecting the occurrence of a bearing abnormality due to background noise. Further, in the second embodiment, it is accurately detected that the amount of displacement of the rotating shaft 20 from the start of operation (the amount of change in the gap between the inner ring and the outer ring due to bearing wear) has reached M1 (for example, 0.06 mm). it can.

Next, in step S35, the arithmetic processing unit 81 determines whether or not the feature amount change ΔE is smaller than the determination value K1. In FIG. 15, it is preferable to generate the threshold value B11 after the value of E11 has settled after exceeding the threshold value A11.

While ΔE <K1 is not satisfied (NO in S35), the process is returned to step S35 again. On the other hand, if ΔE <K1 is satisfied (YES in S35), the process proceeds to step S36.

In step S36, the arithmetic processing unit 81 samples the output signal from the state monitoring sensor 145 in the second threshold value generation period T2, and obtains data for generating the threshold value B11. In step S37, the arithmetic processing unit 81 calculates the average value of the data obtained in the second threshold value generation period T2, and determines the threshold value B11 based on the calculated average value. For example, when the sectional area perpendicular to the bearing load direction at the first stage of the friction member 346c is Sc and the sectional area perpendicular to the bearing load direction at the second stage of the friction member 346c is Sd, 0.5 × (1 + Sd / Sc) × average value can be set as the threshold value B11. The second threshold value generation period T2 starts after ΔE <K1 is established, and the end point can be determined experimentally as appropriate. The arithmetic processing unit 81 uses the displacement amount M1 of the rotating shaft 20 corresponding to the threshold value A11 and the first stage height t1 of the friction member 346c as the displacement amount M2 of the rotating shaft 20 corresponding to the threshold value B11 (FIG. 14) = 0.04 mm (for example, 0.10 mm) is stored.

In step S38, the arithmetic processing unit 81 monitors the subsequent effective value E and determines whether or not the effective value E is larger than the threshold value B11. If E> B11 is not satisfied (NO in S38), the process of step S38 is executed again. On the other hand, if E> B11 (YES in S38), the process proceeds to step S39. In step S39, the arithmetic processing unit 81 determines that the rotary shaft 20 has been displaced by a displacement amount M2 corresponding to the threshold value B11, performs recording and notification as necessary, and ends the process in step S40.

As described above, the state monitoring device 300 includes the friction member 346 disposed so as to face the circumferential surface of the rotary shaft 20 so that the degree of contact changes when the rotary shaft 20 supported by the bearing 160 is displaced. A state monitoring sensor 145 in contact with the friction member 346. The friction member 346 has a shape such that the contact area with the rotating shaft 20 increases as the displacement amount of the rotating shaft 20 increases. The feature amount output from the state monitoring sensor 145 varies according to the contact area between the friction member 346 and the rotating shaft 20. Therefore, according to the above configuration, the displacement amount of the rotating shaft 20 can be determined by monitoring the feature amount output from the state monitoring sensor 145.

The arithmetic processing unit 81 determines that an abnormality has occurred in the bearing 160 when (i) the feature amount obtained from the state monitoring sensor 145 has transitioned from a state smaller than the threshold value A11 to a larger state, and (ii) The amount of displacement of the rotating shaft 20 is determined based on the comparison result between the feature amount and the threshold value B11 larger than the threshold value A11. Specifically, the arithmetic processing unit 81 stores a predetermined displacement amount M2 corresponding to the threshold value B11, and rotates when the feature amount changes from a state smaller than the threshold value B11 to a larger state. It is determined that the shaft 20 has been displaced by the displacement amount M2. Thereby, the amount of displacement of the rotating shaft 20 from the start of operation (the amount of change in the gap between the inner ring and the outer ring due to bearing wear) can be accurately detected.

[Modification 1 of Embodiment 2]
In the first modification of the second embodiment, an example will be described in which a similar detection process is performed on a sliding bearing instead of a rolling bearing.

FIG. 17 is a diagram illustrating a configuration of the state monitoring apparatus according to the first modification of the second embodiment. Referring to FIG. 17, the state monitoring device 301 includes a friction member 346 and a state monitoring sensor 145 that contacts the friction member 346. The friction member 346 is disposed so as to face the circumferential surface of the rotary shaft 20 so that the degree of contact changes when the rotary shaft 20 supported by the bearing 160A that is a sliding bearing is displaced. The state monitoring sensor 145 is an AE sensor or an acceleration sensor.

The friction member 346 is arranged on the side on which the bearing load FA acting on the bearing 160A acts (the load region side of the back metal) with respect to the rotary shaft 20. Since friction member 346, vibration isolator 143, vibration isolator cover 142, and stay 141 are the same as those in the second embodiment, description thereof will not be repeated.

FIG. 18 is a diagram illustrating measurement data of the state monitoring device according to the first modification of the second embodiment. The data in FIG. 18 is obtained under the following measurement conditions.
<Measurement conditions>
Device configuration: Configuration shown in FIG. 17 Friction member shape: Shape shown in FIG. 14 Friction member material: Carbon material state detection sensor: AE (Envelope-processed time waveform is output as voltage)
Bearing material: PTFE composite material (inner diameter 100mm, width 50mm)
Load: 50kN
Rotation speed: 20 rotations / minute (one rotation time 3 seconds)
Sampling rate: 100 kHz
Data length: 15 seconds Measurement interval: 15 hours (hour)
In FIG. 18, a displacement X12, an effective value E12, and a variation coefficient C12 are shown. The displacement X12 indicates a displacement in which the bearing load direction of the rotating shaft 20 is positive. The effective value E12 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 C12 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 E12 and the coefficient of variation C12 is obtained by plotting values calculated for a data length of 15 seconds at 15-hour intervals, and the displacement X12 of the rotating shaft 20 is near the friction member 346 for comparison. These are instantaneous values measured using other displacement meters. In order to reproduce the state in which the bearing in the normal state starts to increase the displacement between the inner and outer rings during the operation, the load is gradually increased during the constant rotation speed operation.

The wear of the bearing 160A rapidly increases from about 270 hours (hours), and the displacement X12 of the rotary shaft 20 gradually increases. In the first modification of the second embodiment, based on the effective value E12 obtained in the initial period (first threshold value generation period T1) in a state where the friction member 346 at the beginning of operation is not in contact with the rotating shaft 20, The threshold value A11 is determined. For example, the threshold value A11 can be determined in consideration of the average value and standard deviation of the initial period (first threshold value generation period T1).

Further, the threshold value B11 is determined based on the effective value E12 obtained in a period during which the effective value E12 exceeds the threshold value A11 and is stable (second threshold value generation period T2). For example, based on the average value of this period (second threshold value generation period T2), the first-stage cross-sectional area Sc of the friction member 346c, and the second-stage cross-sectional area Sd of the friction member 346c, the threshold value B11 can be determined.

It should be noted that threshold value A11, B11 calculation processing and abnormality determination processing are the same as the processing of the flowchart of FIG.

In this way, a similar state monitoring device can be realized for the sliding bearing.
[Modification 2 of Embodiment 2]
In the second embodiment, the friction member 346 immediately after the start of operation is not worn because it is not in contact with the rotating shaft 20. However, if there is too much space between the rotary shaft 20 and the friction member 346, the friction member 346 will not come into contact with the rotary shaft 20 until a while after the rotary shaft 20 starts to be displaced. There is a possibility. Therefore, it is difficult to set the gap between the rotating shaft 20 and the friction member 346.

In the second modification of the second embodiment, a state monitoring method is used in which the friction member 346 is brought into contact with the rotary shaft 20 immediately after the start of operation. The configuration of the apparatus is the same as that described in FIG.

FIG. 19 is a view showing still another embodiment of the friction member 346 (friction member 346d). Referring to FIG. 19, the friction member 346d has a substantially conical shape like the friction member 346a shown in FIGS. 12A to 12C, and its side surface has a step shape (three steps). The first stage height t3 of the friction member 346d is 0.06 mm, and the total height t4 of the first stage and the second stage of the friction member 346c is 0.10 mm.

FIG. 20 is a diagram illustrating measurement data of the state monitoring device according to the second modification of the second embodiment. The data in FIG. 20 is obtained under the same measurement conditions as in FIG. 15 except that the friction member 346d having the shape shown in FIG. 20 is used. Furthermore, the second modification of the second embodiment is different from the second embodiment in that the friction member 346d is brought into contact with the rotating shaft 20 from the beginning of operation. FIG. 20 shows a displacement X13, an effective value E13, and a variation coefficient C13. The displacement X13 indicates a displacement in which the bearing load direction of the rotary shaft 20 is positive. The effective value E13 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 C13 is obtained by dividing the standard deviation of the sampling value by the arithmetic average, and represents a relative variation.

As shown in FIG. 20, the operation period includes a preliminary operation period T0 at the beginning of operation, a first threshold value generation period T1, and a second threshold value generation period T2.

When the friction member 346d is brought into contact with the rotary shaft 20 at the beginning of the operation, this contact force is determined by the rigidity of the parts supporting the friction member 346d such as the stay 141. Therefore, in the preliminary operation period T0, the friction member 346d is greatly worn immediately after the start of the operation, but the progress of wear of the friction member 346d is stagnated due to a decrease in contact force accompanying the wear. Migrate to In order to determine the transition to the first threshold value generation period T1, the threshold value Z is determined based on the sampled feature amount data such as AE and vibration acceleration in the initial stage of the preliminary operation period T0. Then, based on the fact that the feature amount has dropped below the threshold value Z, it is determined that the preliminary operation period T0 has shifted to the first threshold value generation period T1.

The period until this stagnation (preliminary operation period T0) is several hundred to several tens of thousands of rotations from the start of operation, and there is no abnormality in the bearings. However, as the friction member 346 wears, the level of AE and vibration acceleration And the variation is great.

On the other hand, during the period in which the wear is stagnant (first threshold value generation period T1), since there is no abnormality in the bearing and the level and fluctuation of AE and vibration acceleration are small, the threshold value A13 for detecting abnormality is generated. Suitable as a period.

In FIG. 20, the displacement X13 of the rotating shaft 20 gradually increases from an operation time of 2 hours (hour). The timing at which the clearance between the inner ring and the outer ring of the bearing begins to increase by generating a threshold value A13 for detecting anomaly at a stable operating time of 1.5 hours (hour) where the effective value and coefficient of variation are low. Can be detected accurately.

Until the displacement X13 of the rotating shaft 20 reaches 0.06 mm, the rotating shaft 20 continues to be displaced while contacting only the first stage of the friction member 346d. During this time, there is no change in the contact area between the friction member 346d and the rotary shaft 20. Therefore, the effective value E13 is stabilized at a value corresponding to the contact area.

When the displacement X13 of the rotating shaft 20 reaches 0.06 mm, the rotating shaft 20 starts to contact the second stage of the friction member 346d, and the effective value E13 further increases. The effective value E13 at this time is a value corresponding to the size of the contact area between the second stage of the friction member 346d and the rotary shaft 20. The contact area is substantially equal to the cross-sectional area perpendicular to the bearing load direction in the second stage of the friction member 346d.

When the rotary shaft 20 is further displaced and the displacement X13 of the rotary shaft 20 reaches 0.10 mm, the rotary shaft 20 starts to contact the third stage of the friction member 346d, and the effective value E13 further increases. The effective value E13 at this time is a value corresponding to the size of the contact area between the third stage of the friction member 346d and the rotary shaft 20. The contact area is substantially equal to the cross-sectional area perpendicular to the bearing load direction at the third stage of the friction member 346c.

In the present embodiment, the threshold value is based on the effective value E13 obtained in the period (second threshold value generation period T2) until the displacement X13 becomes 0.06 mm after the rotation shaft 20 starts to be displaced. B13 and B14 are determined. The threshold value B13 is a value that is compared with the effective value E13 in order to detect an increase in the effective value E13 due to the start of contact between the second stage of the friction member 346d and the rotary shaft 20. The threshold value B14 is a value that is compared with the effective value E13 in order to detect an increase in the effective value E13 due to the start of contact between the third stage of the friction member 346d and the rotating shaft 20.

The threshold value B13 is, for example, the average value of the effective value E11 of the second threshold value generation period T2, the first level and the second level of the friction member 346d, similarly to the threshold value B11 of the second embodiment. It is determined based on the ratio of the cross-sectional areas.

The threshold value B14 is an effective value E13 when the rotary shaft 20 is in contact with the second stage of the friction member 346d, and an effective value E13 when the rotary shaft 20 is in contact with the third stage of the friction member 346d. It is preferable that the value is determined between. Let Se be the contact area between the rotary shaft 20 and the friction member 346d when the rotary shaft 20 is in contact with the first stage of the friction member 346d. Let Sf be the contact area between the rotating shaft 20 and the friction member 346d when the rotating shaft 20 is in contact with the second stage of the friction member 346d. Let Sg be the contact area between the rotary shaft 20 and the friction member 346d when the rotary shaft 20 is in contact with the third stage of the friction member 346d. At this time, the ratio between the effective value E13 when the rotary shaft 20 is in contact with the first stage of the friction member 346d and the effective value E13 when the rotary shaft 20 is in contact with the second stage of the friction member 346c. Is approximately equal to the ratio of Se and Sf. Further, the ratio between the effective value E13 when the rotary shaft 20 is in contact with the first stage of the friction member 346d and the effective value E13 when the rotary shaft 20 is in contact with the third stage of the friction member 346d is , Approximately equal to the ratio of Se and Sg. Therefore, based on the effective value E13 when the rotating shaft 20 is in contact with the first stage of the friction member 346d, the effective value E13 when the rotating shaft 20 is in contact with the second stage of the friction member 346d and the rotation The effective value E13 can be estimated when the shaft 20 is in contact with the third stage of the friction member 346d. Then, the threshold value B14 can be determined in consideration of the estimated value. Therefore, a period during which the effective value E11 is stably output when the rotating shaft 20 is in contact with the first stage of the friction member 346d is suitable as a period for generating the threshold value B14. The threshold value B14 is determined based on, for example, the average value of the effective values E11 in the period and the ratio of Se, Sf, and Sg. The ratio of Se, Sf, and Sg is substantially the same as the ratio of the cross-sectional area perpendicular to the bearing load direction in each of the first to third stages of the friction member 346d.

FIG. 21 is a flowchart for explaining the first half of the abnormality determination process executed by the arithmetic processing unit in the second modification of the second embodiment. FIG. 22 is a flowchart for explaining the second half of the abnormality determination process executed by the arithmetic processing device in the second modification of the second embodiment. 21 and 22 show a flowchart when the friction member 346d shown in FIG. 19 is used.

Referring to FIG. 11, FIG. 19 to FIG. 21, and FIG. 22, first, in step S51, arithmetic processing unit 81 samples the output signal of state monitoring sensor 145 in the initial operation period (initial stage of preliminary operation period T0). To obtain initial value data. In step S52, 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 Z based on these values. For example, the average value −3σ or 1/10 of the average value can be set as the threshold value Z. This initial period is usually a period in which no displacement occurs in the rotating shaft 20 due to wear of the bearing, and a period in which the friction member 346d is in contact with the rotating shaft 20 and AE occurs in the friction member 346d.

In step S53, the arithmetic processing unit 81 determines whether or not the effective value E of the feature amount obtained from the state monitoring sensor 145 is smaller than the threshold value Z. While E <Z is not satisfied (NO in S53), the preliminary operation period T0 in FIG. 20 has not ended, and the transition is made to the first threshold value generation period T1 for determining the threshold value A13. Since there is not, the process of S53 is performed again.

In step S53, if E <Z is satisfied (YES in S53), the arithmetic processing unit 81 determines whether or not the feature amount change ΔE is smaller than the determination value K0 in step S54. This is because, in FIG. 20, it is preferable to generate the threshold value A13 after the value of E13 has settled down.

While ΔE <K0 is not satisfied (NO in S54), the process is returned to step S53 again. On the other hand, if ΔE <K0 is satisfied (YES in S54), the process proceeds to step S55.

In step S55, the arithmetic processing unit 81 samples the output signal of the state monitoring sensor 145 in the first threshold value generation period T1, and obtains data for generating the threshold value A13. In step S56, the arithmetic processing unit 81 calculates the average value, standard deviation σ, and the like of the data obtained during the first threshold value generation period T1, and determines the threshold value A13 based on these values. For example, the average value + 3σ can be set as the threshold value A13. The first threshold value generation period T1 starts after E <Z and ΔE <K0 is satisfied, and the end point can be determined experimentally as appropriate.

In step S57, the arithmetic processing unit 81 monitors the subsequent effective value E and determines whether or not the effective value E is larger than the threshold value A13. If E> A13, the process of step S57 is executed again. If E> A13, the process proceeds to step S58. In step S58, the arithmetic processing unit 81 determines that an abnormality has occurred in the bearing 160, and performs recording and notification as necessary.

Next, in step S59, the arithmetic processing unit 81 determines whether or not the feature amount change ΔE is smaller than the determination value K1. In FIG. 20, it is preferable to generate the threshold values B13 and B14 after the value of E13 has settled after exceeding the threshold value A13.

While ΔE <K1 is not satisfied (NO in S59), the process returns to step S59 again. On the other hand, if ΔE <K1 is satisfied (YES in S59), the process proceeds to step S60.

In step S60, the arithmetic processing unit 81 samples the output signal from the state monitoring sensor 145 in the second threshold value generation period T2, and obtains data for generating the threshold values B13 and B14. In step S61, the arithmetic processing unit 81 calculates the average value of the data obtained in the second threshold value generation period T2, and determines the threshold values B13 and B14 based on the calculated average value. For example, when the cross-sectional area perpendicular to the bearing load direction in the first stage of the friction member 346d is Sh and the cross-sectional area perpendicular to the bearing load direction in the second stage of the friction member 346d is Si, 0.5 × (1 + Si / Sh) × average value can be the threshold value B13. Furthermore, when the cross-sectional area perpendicular to the bearing load direction at the third stage of the friction member 346d is Sj, the threshold value B14 can be 0.5 × {(Si + Sj) / Sh} × average value. The second threshold value generation period T2 starts after ΔE <K1 is established, and the end point can be determined experimentally as appropriate.

The arithmetic processing unit 81 stores the first height t3 (see FIG. 19) = 0.06 mm of the friction member 346d as the displacement amount M3 of the rotating shaft 20 corresponding to the threshold value B13. Further, the arithmetic processing unit 81 uses the total amount t4 (see FIG. 19) of the first and second heights of the friction member 346d as the displacement amount M4 of the rotating shaft 20 corresponding to the threshold value B14 = 0. 10 mm is stored in advance.

In step S62, the arithmetic processing unit 81 monitors the subsequent effective value E and determines whether or not the effective value E is larger than the threshold value B13. If E> B13 is not satisfied, the process of step S62 is executed again. On the other hand, if E> B13, the process proceeds to step S63. In step S63, the arithmetic processing unit 81 determines that the rotary shaft 20 has been displaced by the displacement amount M3 corresponding to the threshold value B13, and performs recording and notification as necessary.

Next, in step S64, the arithmetic processing unit 81 monitors the subsequent effective value E and determines whether or not the effective value E is larger than the threshold value B14. If E> B14 is not satisfied, the process of step S64 is executed again. On the other hand, if E> B14, the process proceeds to step S65. In step S65, the arithmetic processing unit 81 determines that the rotary shaft 20 has been displaced by the displacement amount M4 corresponding to the threshold value B14, performs recording and notification as necessary, and ends the process in step S66.

As described above, the state monitoring apparatus 300 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 (i) determines the threshold value Z (first threshold value) based on the feature quantity obtained from the state monitoring sensor 145 at the initial stage of the preliminary operation period T0 (first operation period). , (Ii) obtained from the state monitoring sensor 145 at the initial stage of the first threshold generation period T1 (second operation period) after the preliminary operation period T0 in which the feature amount is changed to a state smaller than the threshold value Z. Based on the feature value, a threshold value A13 (second threshold value) is determined. (Iii) The feature value obtained from the state monitoring sensor 145 after the first threshold value generation period T1 is greater than the threshold value A13. When the transition from the small state to the large state is made, it is determined that an abnormality has occurred in the bearing 160, and (iv) the second threshold value generation period T2 (the first threshold value) after the feature value has transitioned to a state greater than the threshold value A13. In the early stage Threshold values B13 and B14 (third threshold values) are determined based on the feature values obtained from the state monitoring sensor 145, and (v) predetermined displacement amounts corresponding to the threshold values B13 and B14, respectively. M3 and M4 are stored, and (vi) rotation is performed when the feature quantity obtained from the state monitoring sensor 145 changes from a state smaller than the threshold values B13 and B14 to a larger state after the second threshold value generation period T2. It is determined that the shaft 20 is displaced by M3 and M4, respectively (FIGS. 20 to 22).

By determining the threshold values B13 and B14 in this way, the amount of displacement of the rotary shaft 20 from the start of operation (the amount of change in the gap between the inner ring and the outer ring due to bearing wear) has reached M3 (for example, 0.60 mm). Or that M4 (for example, 0.10 mm) has been reached.

In the preliminary operation period T0, the friction member 346 is worn to the limit as long as it does not come into contact with the rotary shaft 20, so that the phenomenon of a sudden increase in wear about 2 hours (hours) after the start of operation occurs. It can be caught immediately with little time delay.

[Modification 3 of Embodiment 2]
In the third modification of the second embodiment, an example will be described in which the same process as the detection process of the second modification of the second embodiment is performed on the slide bearing instead of the rolling bearing. Since the configuration of the slide bearing and the state monitoring device is shown in FIG. 17, the description thereof will not be repeated here.

FIG. 23 is a diagram illustrating measurement data of the state monitoring device according to the third modification of the second embodiment. The data in FIG. 23 is obtained under the same measurement conditions as the data in FIG.

FIG. 23 shows a displacement X14, an effective value E14, and a variation coefficient C14. The displacement X14 indicates a displacement in which the bearing load direction of the rotating shaft 20 is positive. The effective value E14 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. Further, the variation coefficient C14 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 E14 and the coefficient of variation C14 is a plot of values calculated for a data length of 15 seconds at 15 hour intervals, and the displacement X14 of the rotating shaft 20 is near the friction member 346 for comparison. These are instantaneous values measured using other displacement meters.

The wear of the bearing 160A increases rapidly from around 270 hours (hours) of operation, and the displacement X14 of the rotary shaft 20 gradually increases. In the third modification of the second embodiment, in the preliminary operation period T0, the friction member 346 is worn to the limit as long as it does not come into contact with the rotary shaft 20, so that the wear is about 270 hours (hours). Rapid increase in phenomena can be detected immediately with little time delay.

Note that calculation processing and abnormality determination processing of threshold values Z, A13, B13, and B14 are the same as the processing of the flowcharts of FIGS. 21 and 22, and therefore description thereof will not be repeated.

It should be noted 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 346. 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.

The contact area of the friction member 346 with the rotating shaft 20 may continuously increase as the displacement amount of the rotating shaft 20 increases. In this case, information indicating the correlation between the amount of displacement of the rotating shaft 20 and the feature amount output from the state monitoring sensor 145 is acquired in advance through experiments or the like, and the arithmetic processing device 81 uses the information to obtain a feature. What is necessary is just to determine the displacement amount of the rotating shaft 20 according to quantity.

Furthermore, the contact area of the friction member 346 with the rotating shaft 20 may increase continuously as the displacement amount of the rotating shaft 20 increases. In this case, information indicating the correlation between the amount of displacement of the rotating shaft 20 and the feature amount output from the state monitoring sensor 145 is acquired in advance through experiments or the like, and the arithmetic processing device 81 uses the information to obtain a feature. What is necessary is just to determine the displacement amount of the rotating shaft 20 according to quantity.

Further, the threshold values Z, A11, A13, B11, B13, and B14 for detecting a bearing abnormality are determined based on the feature amount calculated over the entire threshold generation period, or first the threshold generation period. The feature amount may be calculated in a plurality of small periods, the value may be calculated again in the entire period, and the value may be determined based on the feature amount. The threshold values Z, A11, A13, B11, B13, and B14 may be determined in advance through experiments or the like. In this case, steps S31, S32, S36, and S37 in FIG. 16 and steps S51, S52, S55, S56, S60, and S61 in FIGS. 21 and 22 can be omitted.

Further, in the case of a bearing used in a harsh environment such as ultra-high temperature, ultra-low temperature, liquid, and vacuum atmosphere, in order to protect the state monitoring sensor 145, a long friction member 346 is used, or the friction member 346 and the state monitoring sensor 145 are used. The distance between the bearing and the friction member 346 and the state monitoring sensor 145 may be greatly separated by connecting them with long parts made of a material that easily transmits AE or vibration 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, and is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

10 wind power generators, 20 rotary shafts, 25 hubs, 30 blades, 40 speed increasers, 50 generators, 52 control panels, 54 power transmission lines, 60, 60A, 60B, 160, 160A bearings, 80 data processing devices, 81 operations Processing device, 90 nacelle, 92 tower, 100, 101 condition monitoring device, 120, 220 housing, 121, 221 bearing holder, 131 inner ring, 132 outer ring, 133 rolling element, 141 stay, 142 vibration isolator cover, 143 vibration isolator 145 state monitoring sensor, 146 friction member.

Claims

A state monitoring device for detecting an abnormality of a bearing in which a fixed ring is fixed to a housing,
A friction member arranged to face the peripheral surface of the rotating shaft so that the degree of contact changes when the rotating shaft supported by the bearing is displaced with respect to the housing;
A state monitoring sensor in contact with the friction 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, wherein the friction member is arranged on a side on which a bearing load acting on the bearing acts, with respect to the rotating shaft.
The condition monitoring device according to claim 1 or 2, further comprising a stay for fixing the friction member and the condition monitoring sensor to the housing.
The state monitoring apparatus according to claim 3, further comprising a vibration isolating material that blocks vibrations disposed between the state monitoring sensor and the stay.
The amount of wear of the friction member per rotation of the rotating shaft during friction between the friction member and the rotating shaft is larger than the amount of wear of the bearing per rotation of the rotating shaft. State monitoring device.
An arithmetic processing unit that receives an output of the state monitoring sensor and determines whether or not an abnormality has occurred in the bearing is further provided, wherein the arithmetic processing unit has a feature value obtained from the state monitoring sensor as a first threshold value. The state monitoring device according to any one of claims 1 to 5, wherein it is determined that an abnormality has occurred in the bearing when a transition is made from a smaller state to a larger state.
An arithmetic processing unit that receives the output of the state monitoring sensor and determines whether or not an abnormality has occurred in the bearing;
The arithmetic processing unit includes:
The first threshold value is determined based on the feature amount obtained from the state monitoring sensor in the first operation period, and the feature amount is changed to a state smaller than the first threshold value than the first operation period. Based on the feature amount obtained from the state monitoring sensor in the subsequent second operation period, the second threshold value is determined,
2. It is determined that an abnormality has occurred in the bearing when the characteristic amount obtained from the state monitoring sensor transitions from a state smaller than the second threshold value to a larger state after the second operation period. The state monitoring apparatus according to any one of 1 to 5.
2. The state monitoring device according to claim 1, wherein the friction member has a shape such that a contact area with the rotation shaft increases in accordance with an increase in a displacement amount of the rotation shaft.
The state monitoring device according to claim 8, wherein a contact area of the friction member with the rotating shaft increases stepwise as the displacement amount of the rotating shaft increases.
The friction member is arranged on a side where a bearing load acting on the bearing acts on the rotating shaft,
The state monitoring device according to claim 8, wherein a cross-sectional area of the friction member perpendicular to the direction of the bearing load increases stepwise as the distance from the rotation shaft increases.
The surface of the friction member facing the rotation shaft in a cross-section of the friction member when cut along a plane including the axis of the rotation shaft and parallel to the direction of the bearing load is stepped. The state monitoring device described in 1.
An arithmetic processing unit that receives the output of the state monitoring sensor and determines whether or not an abnormality has occurred in the bearing;
The arithmetic processing unit includes:
When the characteristic amount obtained from the state monitoring sensor transitions from a state smaller than a first threshold value to a larger state, it is determined that an abnormality has occurred in the bearing,
The state monitoring device according to claim 9, wherein a displacement amount of the rotating shaft is determined based on a comparison result between the feature amount and a second threshold value that is larger than the first threshold value.
An arithmetic processing unit that receives the output of the state monitoring sensor and determines whether or not an abnormality has occurred in the bearing;
The arithmetic processing unit includes:
The first threshold value is determined based on the feature amount obtained from the state monitoring sensor in the first operation period, and the feature amount is changed to a state smaller than the first threshold value than the first operation period. Based on the feature amount obtained from the state monitoring sensor in the subsequent second operation period, the second threshold value is determined,
When the characteristic amount obtained from the state monitoring sensor after the second operation period has changed from a state smaller than the second threshold value to a larger state, it is determined that an abnormality has occurred in the bearing,
Based on the feature amount obtained from the state monitoring sensor in the third operation period after the feature amount has transitioned from a state smaller than the second threshold value to a larger state, the feature amount is larger than the second threshold value. 3 Determine the threshold,
Storing a predetermined amount of displacement corresponding to the third threshold value;
When the characteristic amount obtained from the state monitoring sensor after the third operation period transits from a state smaller than the third threshold value to a larger state, the rotation shaft is displaced by the predetermined displacement amount. The state monitoring apparatus according to claim 9, wherein it is determined that a failure has occurred.
A state monitoring method for detecting an abnormality of a bearing in which a fixed ring is fixed to a housing by a state monitoring device,
The state monitoring device
A friction member arranged to face the peripheral surface of the rotating shaft so that the degree of contact changes when the rotating shaft supported by the bearing is displaced with respect to the housing;
A state monitoring sensor in contact with the friction member,
The state monitoring sensor is an AE sensor or an acceleration sensor,
The state monitoring method includes:
Determining a first threshold value based on a feature amount obtained from the state monitoring sensor in a first operation period;
Based on the feature value obtained from the state monitoring sensor in the second operation period after the first operation period in which the feature value has transitioned to a state smaller than the first threshold value, the second threshold value is set. A step to determine;
Determining that an abnormality has occurred in the bearing when the characteristic amount obtained from the state monitoring sensor transitions from a state smaller than the second threshold value to a larger state after the second operation period. , Status monitoring method.
The friction member has a shape such that a contact area with the rotation shaft increases in accordance with an increase in a displacement amount of the rotation shaft,
The state monitoring method includes:
The state monitoring method according to claim 14, further comprising a step of determining a displacement amount of the rotating shaft based on a comparison result between the feature amount and a third threshold value larger than the second threshold value.