JP2017062196A - Bearing damage sing diagnosis device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bearing damage sign diagnosis device capable of early finding damage of a bearing resulting from deterioration or shortage of lubricant.SOLUTION: A bearing damage sign diagnosis device includes: a vibration sensor 10 provided in a bearing 80; a filtering processing unit 51 configured to subject detection output of the vibration sensor 10 to filtering processing; an FFT analysis processing unit 52 configured to subject output of the filtering processing unit 51 to FFT analyzing processing; an envelope processing unit 53 configured to subject output of the FFT analysis processing unit 52 to envelope processing; and a determination processing unit 54 configured to determine presence/absence of a damage sign of the bearing 80 on the basis of output of the envelope processing unit 53. The determination processing unit 54 regards change of an effective value of vibration, change of a peak value, a maximum region of FFT analysis, and a bearing characteristic frequency after enveloping processing as determination objects, and has determination reference for each determination object.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a bearing damage sign diagnostic apparatus for detecting an abnormality of a bearing used in industrial machines including railroad vehicles.

  Bearings used in industrial machines including railway vehicles may be damaged (for example, seizure, cage wear, track surface wear) due to deterioration or shortage of lubricant. The damage that occurs suddenly among the damages of the bearing is often seizure, cage pocket wear, and raceway surface wear caused by deterioration or shortage of the lubricant, and the damage progresses faster than damage such as peeling.

  FIG. 19 is a diagram showing a bearing damage process in the case where seizure, which is seizure, occurs in the bearing and in the case where cage pocket wear occurs. As shown in the figure, when tsubaki occurs, the gap between the bearings becomes large, and the whirling of the bearings becomes large. When the bearing swing increases, the rolling element (roller) collides with the cage pocket, and the cage is damaged. If the cage is damaged, the rolling elements are dropped from the cage and the bearing is damaged.

  On the other hand, when the cage pocket wear occurs, the swing of the cage increases, the collision of the rolling elements with the cage pocket increases, and the cage is damaged. If the cage is damaged, the rolling element is dropped from the cage in the same manner as described above, resulting in bearing damage.

  Conventional methods for detecting axle damage due to lubricant deterioration include methods for measuring the optical characteristics and electrical conductivity of wear particles and moisture contained in the lubricant, as well as various methods in mechanical devices (for example, railway vehicles). There is a method (for example, Patent Document 1) in which a temperature / vibration in a bearing is compared with a temperature / vibration in another bearing.

JP 2006-341659 A

  However, as a method of detecting an abnormality of the bearing due to deterioration or shortage of the lubricant, in the method of measuring the optical characteristics and electrical conductivity of the abrasion powder and moisture contained in the lubricant, the bearing is rotated from the inside while it is rotating. Since the abrasion powder of the lubricant cannot be extracted, there is a problem that the abnormality of the bearing cannot be detected at an early stage. In particular, when the lubricant is grease, it is difficult to detect it when it is present inside the bearing and contributes to lubrication during rotation of the bearing.

  On the other hand, in the method of relatively comparing the temperature and vibration of all the bearings in the mechanical device, there is a problem that an abnormality cannot be detected when all the bearings in the mechanical device are damaged. In other words, it is possible to detect an abnormality if at least one normal bearing remains, but if all bearings become abnormal, there is no reference bearing for relative comparison. Cannot be detected.

  The present invention has been made in view of the above-described circumstances, and an object of the present invention is to provide a bearing damage sign diagnostic apparatus capable of early detecting damage to a bearing caused by deterioration or shortage of a lubricant. is there.

The above object of the present invention can be achieved by the following constitution.
(1) a vibration sensor provided on the bearing;
A filtering processing unit that performs a filtering process on the detection output of the vibration sensor;
An FFT analysis processing unit that performs an FFT analysis process on the output of the filtering processing unit;
An envelope processing unit that performs envelope processing on the output of the FFT analysis processing unit;
A bearing damage sign diagnostic apparatus comprising: a determination processing unit that determines presence / absence of a damage sign of the bearing based on an output of the envelope processing unit.

(2) In the above (1), the determination processing unit has a determination criterion for a change in effective value of vibration, a change in peak value, a maximum region of FFT analysis, and a bearing characteristic frequency after envelope processing, and has respective determination criteria. The bearing damage predictive diagnosis device described.

(3) The bearing damage sign diagnostic apparatus according to (1) or (2), further including a statistical processing unit that performs statistical processing on a determination result of the determination processing unit.

  ADVANTAGE OF THE INVENTION According to this invention, the damage of the bearing which generate | occur | produces by deterioration or lack of a lubricant can be discovered at an early stage.

1 is a block diagram showing a schematic configuration of a bearing damage sign diagnostic apparatus according to an embodiment of the present invention. It is a block diagram which shows the function of CPU main unit of the bearing damage sign diagnostic apparatus which concerns on this embodiment. It is a figure which shows the attachment state to the bearing of the temperature sensor and vibration sensor of the bearing damage sign diagnostic apparatus which concerns on this embodiment. The effective value change, peak value change, maximum area of FFT analysis, and bearing characteristic frequency after envelope processing obtained by testing a tapered roller type bearing using the bearing damage sign diagnostic apparatus according to the present embodiment are shown. FIG. It is a figure which shows the conditions of the 1st test using the bearing damage sign diagnostic apparatus which concerns on this embodiment. It is a figure which shows the temperature and vibration state during a test in the 1st test using the bearing damage sign diagnostic apparatus which concerns on this embodiment. It is a figure which shows the waveform of the detection output of the vibration sensor in the 1st test using the bearing damage sign diagnostic apparatus which concerns on this embodiment. It is a figure which shows PEAK value / 5 and effective value of the detection output of a vibration sensor in the 1st test using the bearing damage sign diagnostic apparatus which concerns on this embodiment. It is a figure which shows the FFT analysis result in the 1st test using the bearing damage sign diagnostic apparatus which concerns on this embodiment. It is a figure which shows the FFT analysis result after the envelope process in the 1st test using the bearing damage sign diagnostic apparatus which concerns on this embodiment. It is a figure which shows the relationship between the defect of each member of a bearing, and the abnormal vibration frequency which generate | occur | produces in each member. It is a figure which shows the structure of a cylindrical roller type bearing. The effective value change, peak value change, maximum FFT analysis region, and bearing characteristic frequency after envelope processing obtained by testing a cylindrical roller type bearing using the bearing damage sign diagnostic apparatus according to the present embodiment are shown. FIG. It is a figure which shows the conditions of the 2nd test using the bearing damage sign diagnostic apparatus which concerns on this embodiment. It is a figure which shows the temperature and vibration state during a test in the 2nd test using the bearing damage sign diagnostic apparatus which concerns on this embodiment. It is a figure which shows the effective value of the detection output of a vibration sensor in the 2nd test using the bearing damage sign diagnostic apparatus which concerns on this embodiment. It is a figure which shows the FFT analysis result in the 2nd test using the bearing damage sign diagnostic apparatus which concerns on this embodiment. It is a figure which shows the FFT analysis result after the envelope process in the 2nd test using the bearing damage sign diagnostic apparatus which concerns on this embodiment. It is a figure which shows the damage process of a bearing in case the brim which is seizure in a bearing, and the case where cage pocket wear arises.

  Hereinafter, a bearing damage sign diagnostic apparatus according to an embodiment of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a block diagram showing a schematic configuration of a bearing damage sign diagnostic apparatus 1 according to an embodiment of the present invention. FIG. 2 is a block diagram showing functions of the CPU main unit 5 of the bearing damage sign diagnostic apparatus 1 according to the present embodiment. FIG. 3 is a view showing a state in which the temperature sensors 8 and 9 and the vibration sensor 10 of the bearing damage sign diagnostic apparatus 1 according to the present embodiment are attached to the bearing 80.

  First, the structure of the bearing 80 will be described with reference to FIG. In the figure, a bearing 80 is a rotating component provided on an axle 100 of a railway vehicle, for example. The bearing 80 is a tapered roller type bearing using a conical rolling element, and includes an inner ring 81 that is externally fitted to the rotating shaft 101, an outer ring 82 that is internally fitted to the housing 102, and an inner ring 81 and an outer ring 82. A plurality of rolling elements 83 (which do not appear to be plural in FIG. 3 but actually exist) in FIG. 3 and a holder 84 that holds each of the plurality of rolling elements 83 in a freely rollable manner. And comprising. A lubricant (not shown) is injected into the bearing 80. When there are four axles 100 for one vehicle, a total of eight bearings 80 are provided.

  The temperature sensor 8 is attached to the inner ring 81 of the bearing 80 and detects the temperature of the inner ring collar. The temperature sensor 9 is attached to the outer ring 82 of the bearing 80 and detects the outer ring temperature. Similar to the temperature sensor 9, the vibration sensor 10 is attached to the outer ring 82 of the bearing 80 and detects vibration of the bearing 80. The temperature sensors 8 and 9 and the vibration sensor 10 are attached to each axle.

  For the temperature sensors 8 and 9, for example, a thermocouple, thermistor, infrared sensor or the like is used. As the vibration sensor 10, for example, an acceleration sensor, an AE (Acoustic Emission) sensor, an ultrasonic sensor, a shock pulse sensor, or the like is used. In addition, a device that can detect vibration, equivalently, and convert it into an electrical signal by detecting acceleration, speed, strain, stress, displacement, and the like can be used as appropriate. When the vibration sensor 10 is attached to the axle 100 that is expected to have a lot of ambient noise, it is preferable to use an insulation type because the influence of ambient noise can be suppressed. Further, when a vibration detecting element such as a piezoelectric element is used for the vibration sensor 10, water resistance and impact resistance can be imparted by adopting a structure in which this element is integrally molded with resin.

  In FIG. 3, an arrow written as Fa = 60 kN is one of the test conditions described later, and indicates the axial load that the bearing 80 receives. An arrow written as Fr = 80 kN is also one of the test conditions described later, and indicates the radial load that the bearing 80 receives.

  Next, the bearing damage sign diagnostic apparatus 1 according to the present embodiment will be described. In FIG. 1, a bearing damage sign diagnostic apparatus 1 according to the present embodiment is an apparatus having a function of predicting damage due to deterioration or shortage of lubricant in a bearing 80 provided on an axle 100. The bearing damage sign diagnostic apparatus 1 includes a power supply unit 2, sensor input units 3A to 3C, a power supply unit 4, a CPU main unit 5, a memory 6, and I / F boards 7A and 7B. The power supply unit 2 supplies power for operation to the sensor input units 3A to 3C. Detection outputs of the temperature sensors 8 and 9 and the vibration sensor 10 described above are input to the sensor input units 3A to 3C. A temperature sensor 8 is connected to the sensor input unit 3A, and a detection output of the temperature sensor 8 is input. A temperature sensor 9 is connected to the sensor input unit 3B, and a detection output of the temperature sensor 9 is input. A vibration sensor 10 is connected to the sensor input unit 3C, and a detection output of the vibration sensor 10 is input. The sensor input unit 3A and the temperature sensor 8, the sensor input unit 3B and the temperature sensor 9, and the sensor input unit 3C and the vibration sensor 10 are connected by lead wires 11, respectively.

  The sensor input unit 3 </ b> A amplifies the input detection output of the temperature sensor 8 and outputs the amplified detection output to the CPU main unit 5. The sensor input unit 3 </ b> B amplifies the detection output of the input temperature sensor 9 and outputs it to the CPU main unit 5. The sensor input unit 3 </ b> C amplifies the detected detection output of the vibration sensor 10 and outputs the amplified detection output to the CPU main unit 5. The power supply unit 4 supplies power for operation to the CPU main unit 5, the memory 6, and the I / F boards 7A and 7B.

  The CPU main unit 5 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), an A / D (Analog / Digital) converter, an amplifier, a DSP (Digital Signal Processor), etc. Consists of. The ROM retains a diagnostic program for predicting damage due to deterioration or shortage of the lubricant in the bearing 80. The functional block diagram of the CPU main unit 5 is as shown in FIG. 2 and is composed of a filtering processing unit 51, an FFT (Fast Fourier Transform) analysis processing unit 52, an envelope processing unit 53, a determination processing unit 54, and a statistical processing unit 55. Is done.

  The filtering processing unit 51 performs filtering processing on the detection output (hereinafter referred to as “vibration measurement signal”) of the vibration sensor 10 input by the sensor input unit 3C. That is, the filtering processing unit 51 realizes the function of a bandpass filter by a DSP, and from the digital vibration measurement signal obtained by A / D converting and amplifying the vibration measurement signal, the bearing characteristic frequency band corresponding to the natural frequency of the bearing 80. To extract. The natural frequency of the bearing 80 is easily obtained by vibrating the object to be measured by an impact method using an impal hammer or the like, and analyzing the frequency of the vibration detector attached to the object to be measured or the sound generated by the impact. be able to.

The FFT analysis processing unit 52 performs an FFT analysis process on the output of the filtering processing unit 51. That is, the FFT analysis processing unit 52 performs FFT analysis on the frequency of the waveform of the filtered vibration measurement signal and obtains a frequency spectrum of vibration generated in the bearing 80. The envelope processing unit 53 performs envelope processing on the output (that is, the frequency spectrum of vibration) of the FFT analysis processing unit 52. The determination processing unit 54 determines whether there is a sign of damage to the bearing 80 based on the output of the envelope processing unit 53. The determination processing unit 54 uses the vibration effective value change, the peak value change, the FFT analysis maximum region, and the bearing characteristic frequency after the envelope processing as determination targets, and has respective determination criteria. The determination processing unit 54 compares the determination targets of the effective value change of the vibration, the change of the peak value, the maximum region of the FFT analysis and the bearing characteristic frequency after the envelope processing with the respective determination criteria, thereby damaging the bearing 80. Predictive diagnosis. Note that the determination target is not necessarily limited to all of the effective value change of the vibration, the change of the peak value, the maximum region of the FFT analysis, and the bearing characteristic frequency after the envelope processing, and may be any one. However, it goes without saying that the accuracy of predictive diagnosis can be improved as the number of determination targets increases.
The statistical processing unit 55 performs statistical processing on the determination result of the determination processing unit 54.

  In the bearing damage sign diagnostic apparatus 1 according to the present embodiment, the criteria for determining the effective value change of vibration, change in peak value, maximum region of FFT analysis, and bearing characteristic frequency after envelope processing are normal products of the bearing 80. It is obtained by comparison with. That is, by performing a damage test of the bearing 80 in advance and comparing the effective value change with the normal product, the peak value change, the maximum region change of the FFT analysis, and the change in the bearing characteristic frequency after the envelope processing, Judgment criteria are set. The determination processing unit 54 sets determination criteria for each determination target of vibration effective value change, peak value change, maximum region of FFT analysis, and bearing characteristic frequency after envelope processing. The statistical processing unit 55 records the number of determinations and the determination contents of the determination processing unit 54.

  In addition, if the determination processing unit 54 is configured to determine the determination criterion based on the occurrence frequency and occurrence probability of the damage of the bearing 80 based on the number of determinations and the determination content recorded by the statistical processing unit 55, the reliability can be further improved. It is possible to determine a sign with a high sign. Further, when the rotational speeds of the bearings are different from each other, such as in a railway vehicle, it is possible to make a highly reliable judgment by recording the occurrence frequency at the same rotational speed and taking statistics.

  In FIG. 1, a memory 6 is a non-volatile storage medium such as a flash memory. The effective value change of vibration, the change in peak value, the maximum area of FFT analysis, the bearing characteristic frequency after envelope processing, and the determination criteria thereof Stores statistical processing results. In addition to the non-volatile storage medium such as a flash memory, a storage device such as a hard disk can be used as the memory 6. The I / F boards 7 </ b> A and 7 </ b> B are interfaces for outputting a determination result of the presence or absence of a sign of damage of the bearing 80 by the determination processing unit 54 to the outside. The output destination is, for example, an information device such as a computer (not shown) or a PDA (Personal Digital Assistant).

Next, the test result of the bearing damage sign diagnostic apparatus 1 according to the present embodiment will be described.
In the test, two types of bearings 80, “conical roller type” and “cylindrical roller type”, were used. A test using the tapered roller type bearing 80 is referred to as a “first test”, and a test using the cylindrical roller type bearing 80 is referred to as a “second test”.

(First test)
FIG. 4 shows the effective value change, peak value change, maximum area of FFT analysis, and after envelope processing, obtained by testing the tapered roller type bearing 80 using the bearing damage sign diagnostic apparatus 1 according to the present embodiment. It is a figure which shows the bearing characteristic frequency. As shown in the figure, the effective value change (RMS ratio) of vibration is “3 to 5 or more”, the peak value is “about 5”, the maximum area of FFT analysis is “0 to 6 kHz, 12 to 14 kHz”, envelope processing The later bearing characteristic frequency is “fc, Zfc, Zfi”. FIG. 5 is a diagram showing the conditions of the first test using the bearing damage sign diagnostic apparatus 1 according to the present embodiment. As shown in the figure, the bearing 80 used in this test is “QT9B (single row tapered roller bearing)”, the radial load is “80 kN”, the axial load is “60 kN”, and the rotational speed is “0 to 6000 rpm”. is there.

FIG. 6 is a diagram showing the temperature and vibration state during the test in the first test using the bearing damage sign diagnostic apparatus 1 according to the present embodiment. In the figure, the horizontal axis represents time (minutes), and the vertical axis represents temperature (° C.) and vibration (m / s ² ). The temperature is the temperature at the inner ring collar of the bearing 80. FIG. 7 is a diagram showing a detection output (vibration raw waveform) of the vibration sensor 10 in the first test using the bearing damage sign diagnostic apparatus 1 according to the present embodiment. In the figure, the horizontal axis represents time (seconds), and the vertical axis represents vibration (m / s ² ). FIG. 8 is a diagram showing the PEAK value / 5 and the effective value of the detection output of the vibration sensor 10 in the first test using the bearing damage sign diagnostic apparatus 1 according to the present embodiment. In the figure, the horizontal axis represents time (seconds), and the vertical axis represents vibration (m / s ² ). FIG. 9 is a diagram showing the FFT analysis result in the first test using the bearing damage sign diagnostic apparatus 1 according to the present embodiment. In the figure, the horizontal axis represents frequency and the vertical axis represents dB. As shown in the figure, the maximum region of the FFT analysis is “0 to 6 kHz, 12 to 14 kHz”. FIG. 10 is a diagram showing the FFT analysis result after the envelope processing in the first test using the bearing damage sign diagnostic apparatus 1 according to the present embodiment. In the figure, the horizontal axis represents frequency and the vertical axis represents dB. fc, Zfc, and Zfi are characteristic frequency components, respectively.

  In the first test, a test for diagnosis of seizure signs was performed. In this test, normal bearing 80 is installed and oiling is cut off to reproduce seizure, and the effective value change before and after seizure, peak value change, maximum area of FFT analysis, and bearing characteristic frequency after envelope processing are grasped. did. From the result of this test, it was found that the retainer 84 of the bearing 80 was also worn. It is considered that wear has occurred between the cage 84 and the rolling element 83, and a characteristic frequency component (fc, see FIG. 10) of the swing of the cage 84 due to the collision between the cage 84 and the rolling element 83 has occurred. It is done. In addition, although Zfc (refer FIG. 10) has generate | occur | produced as a characteristic frequency component, the collar surface and the rolling element 83 are damaged by seizing, an inner ring | wheel (collar surface) rotates, and the rolling element 83 goes to a load zone. This is probably because the rolling element passing pulse component at the time of rushing was detected more significantly than usual.

  In addition, after carrying out this test, the seizure-damaged bearing 80 was continuously operated to analyze the characteristic frequency component. It is considered that a part of the inner ring collar surface was worn greatly, and the Zfi component, which is a frequency generated in the case of an inner ring flaw, was detected. The characteristic frequency components are publicly known (see FIG. 11 described later), and these characteristic frequency components are recorded in the bearing damage sign diagnostic apparatus 1 according to the present embodiment and compared with the bearing 80 in actual use. It is possible to identify 80 damage points and events. For example, the vibration of scratches such as peeling is known to have a crest value of 5 or more and 10 or less, and the crest value due to seizure as a result of this test is about “5”. Since there is not so much change, it is possible to distinguish between peeling and scratching. FIG. 11 is a diagram illustrating a relationship between a defect in each member of the bearing and an abnormal vibration frequency generated in each member.

  From the result of this test, by incorporating the discrimination criterion into the diagnostic program, it is possible to perform a predictive diagnosis of seizure of the bearing 80 and cage wear.

  Although this test was performed on the single-row tapered roller bearing 80, the same test can also be performed on the double-row tapered roller bearing, and the double-row tapered roller bearing is actually used. Although tests were conducted, it was confirmed that the change in effective value of vibration, change in peak value, and bearing characteristic frequency after envelope processing were equivalent.

  Further, the actual diagnosis is during railroad travel in the railroad industry, but if the noise or the like is grasped by running with a normal bearing 80, it is known that interference with the frequency generated when the bearing 80 is damaged is known. Therefore, it is possible to avoid interference by filtering.

(Second test)
Before describing the second test, the cylindrical roller type bearing 80A used in the second test will be described. FIG. 12 is a view showing the structure of a cylindrical roller type bearing 80A. In the figure, a bearing 80A includes a plurality of rolling wheels arranged so as to be able to roll between an inner ring 81A fitted on the rotation shaft 101A, an outer ring 82A fitted on the housing 102A, and the inner ring 81A and the outer ring 82A. A moving body 83A (only two are visible in FIG. 12, but there are actually more), and a holder 84A that holds each of the plurality of rolling bodies 83A in a freely rollable manner. A lubricant (not shown) is injected into the bearing 80A. When there are four axles 100A for one vehicle, eight bearings 80A are provided in total. A temperature sensor 9 and a vibration sensor 10 are attached to the outer ring 82A of the bearing 80A. A second test was performed using the bearing 80A having such a structure.

  FIG. 13 shows the effective value change, peak value change, maximum region of FFT analysis, and after envelope processing, obtained by testing the cylindrical roller type bearing 80A using the bearing damage sign diagnostic apparatus 1 according to the present embodiment. It is a figure which shows the bearing characteristic frequency. As shown in the figure, the effective value change (RMS ratio) of vibration is “2 to 3 or more”, the peak value is “about 5”, the maximum area of FFT analysis is “1.5 to 4 kHz”, and after the envelope processing The bearing characteristic frequency is “fc, Zfc”. FIG. 14 is a diagram showing conditions of the second test using the bearing damage sign diagnostic apparatus 1 according to the present embodiment. As shown in the figure, the bearing 80A used in this test is “NU324 (single-row cylindrical roller bearing)”, the radial load is “30 kN”, the axial load is “0 kN”, and the rotational speed is “0 to 3000 rpm”. is there.

FIG. 15 is a diagram showing the temperature and vibration state during the test in the second test using the bearing damage sign diagnostic apparatus 1 according to the present embodiment. In the figure, the horizontal axis represents time (minutes), and the vertical axis represents temperature (° C.) and vibration (m / s ² ). The temperature is a temperature at the outer ring 82A of the bearing 80A. FIG. 16 is a diagram illustrating the effective value of the detection output of the vibration sensor 10 in the second test using the bearing damage sign diagnostic apparatus 1 according to the present embodiment. In the figure, the horizontal axis represents the rotational speed (rpm), and the vertical axis represents the vibration (m / s ² ). Further, the vibration waveform indicated by a solid line in the figure is a vibration waveform when the bearing 80A is normal, and the vibration waveform indicated by a chain line in the figure is a vibration waveform when the retainer 84A of the bearing 80A is worn. FIG. 17 is a diagram showing an FFT analysis result in the second test using the bearing damage sign diagnostic apparatus 1 according to the present embodiment. In the figure, the horizontal axis represents frequency (Hz) and the vertical axis represents dB. Further, the waveform shown by the solid line in the figure is a waveform when the bearing 80A is normal, and the waveform shown by the chain line in the figure is a waveform when the cage 84A of the bearing 80A is worn. FIG. 18 is a diagram showing the FFT analysis result after the envelope processing in the second test using the bearing damage sign diagnostic apparatus 1 according to the present embodiment. In the figure, the horizontal axis represents frequency (Hz) and the vertical axis represents dB. Further, the waveform shown by the solid line in the figure is a waveform when the bearing 80A is normal, and the waveform shown by the chain line in the figure is a waveform when the cage 84A of the bearing 80A is worn. As can be seen from FIGS. 16 to 18, the normal state and the abnormal state of the bearing 80 </ b> A can be clearly distinguished.

  In this test, a test for predicting the wear of the cage in the bearing 80A was performed, and the change in the effective value before and after the wear of the cage, the change in the peak value, the maximum area of the FFT analysis, and the bearing characteristic frequency after the envelope processing were obtained. Also from the result of this test, the characteristic frequency component (fc) of the cage swing due to the collision between the cage 84A and the rolling element 83A is generated, which is consistent with the result of the first test. Although Zfc is also generated as a characteristic frequency component, it is considered that a large collision between the cage 84A and the rolling element 83A occurred at the entrance of the load zone, and a rolling element passing pulse component was generated. In addition, since the slight seizure occurred on the inner ring raceway surface in the result of this test, it is considered that the same characteristic frequency component as the result of the first test was generated.

  From the result of this test, by incorporating the discrimination criterion into the diagnostic program, it is possible to perform a predictive diagnosis of the cage wear of the bearing 80A.

  Although the Zfc component is also detected in the first and second test results, it is possible to distinguish the Zfc from damage due to scratches such as peeling by comparing the peak values. In general, in the case of a flaw, there is a case where the vibration when passing through the rolling element is large and the peak value becomes “10 or more”.

  As described above, the bearing damage sign diagnostic apparatus 1 according to the present embodiment sequentially performs the filtering process, the FFT analysis process, and the envelope process on the detection output of the vibration sensor 10 provided in the bearing 80 (80A), so that the envelope Since it is determined whether or not there is a sign of damage to the bearing 80 (80A) based on the result after processing, it is possible to detect damage to the bearing 80 (80A) caused by deterioration or shortage of the lubricant at an early stage.

  In particular, in determining whether or not there is a sign of damage to the bearing 80 (80A), the effective value change of vibration, the change in peak value, the maximum area of FFT analysis, and the bearing characteristic frequency after the envelope processing are determined as determination targets. By performing based on the above, it is possible to effectively diagnose the signs of bearing 80 (80A) seizure, cage wear, and raceway surface wear.

  Moreover, since the bearing damage sign diagnostic apparatus 1 according to the present embodiment performs statistical processing on the determination result, it is possible to set a determination criterion based on the occurrence frequency and occurrence probability of damage, thereby enabling more accurate diagnosis. Become.

  Note that a display such as a liquid crystal monitor may be added to the bearing damage sign diagnostic apparatus 1 according to this embodiment so that the diagnosis result of the damage sign can be visually displayed.

  The present invention is not limited to the above-described embodiments, and can be applied without departing from the gist of the present invention. For example, the present invention can be applied to other uses such as industrial machine uses.

DESCRIPTION OF SYMBOLS 1 Bearing damage prediction diagnostic device 2 Power supply part 3A-3C Sensor input part 4 Power supply unit 5 CPU main unit 6 Memory 7A, 7B I / F board 8, 9 Temperature sensor 10 Vibration sensor 11 Lead wire 51 Filtering process part 52 FFT analysis process 53 53 Envelope processing unit 54 Judgment processing unit 55 Statistical processing unit 80, 80A Bearing 81, 81A Inner ring 82, 82A Outer ring 83, 83A Rolling element 84, 84A Cage 100, 100A Axle 101, 101A Rotating shaft 102, 102A Housing

Claims (3)

A vibration sensor provided in the bearing;
A filtering processing unit that performs a filtering process on the detection output of the vibration sensor;
An FFT analysis processing unit that performs an FFT analysis process on the output of the filtering processing unit;
An envelope processing unit that performs envelope processing on the output of the FFT analysis processing unit;
A determination processing unit that determines the presence or absence of a sign of damage to the bearing based on the output of the envelope processing unit,
Bearing damage diagnosis device. The bearing damage sign diagnostic apparatus according to claim 1,
The determination processing unit has a determination criterion for an effective value change of vibration, a peak value change, a maximum region of FFT analysis, and a bearing characteristic frequency after envelope processing, and has respective determination criteria.
Bearing damage diagnosis device. The bearing damage predictive diagnosis device according to claim 1 or 2,
A statistical processing unit that performs statistical processing on the determination result of the determination processing unit;
Bearing damage diagnosis device.

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