JP3876976B2 - Evaluation apparatus and evaluation method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention converts an electrical signal based on sound or vibration generated by a rotating body into frequency spectrum data by predetermined waveform processing, and stores in advance a specific frequency component value resulting from an abnormality of the rotating body as a reference value. In this regard, the present invention relates to an evaluation apparatus and an evaluation method for diagnosing the presence / absence of an abnormality with respect to a specific part of a rotating body based on whether or not a peak appears at a position corresponding to a reference value on the frequency spectrum data described above.
[0002]
[Prior art]
Up to now, for example, in bearings used in large rotating devices (hereinafter also simply referred to as devices) such as steel rolling mills and railway car main motors, the occurrence of inconvenience due to wear and breakage of bearing parts is prevented. Therefore, periodic visual inspections are carried out. In this visual disassembly inspection, the bearings are removed from the equipment after being used for a certain period of time and disassembled, and each bearing component is visually inspected by a trained professional inspector. If abnormalities such as unevenness and wear that are not found in a new bearing are detected, assembly is performed again after replacement with a new bearing.
[0003]
[Problems to be solved by the invention]
However, the above-described overhaul inspection has a problem that a great deal of labor is required for the disassembly work for removing the bearing from the apparatus and the assembling work for reincorporating the inspected bearing into the apparatus, resulting in a significant increase in the maintenance cost of the apparatus. there were.
In addition, there is a risk that the inspection itself may increase parts replacement by making a dent in the bearing parts or the like by mistake during disassembling work or assembling work at the time of inspection.
Furthermore, depending on the level of proficiency of the person in charge of inspection, there is a risk that defects may be overlooked or inadequate, such as implementation of unnecessary parts replacement.
[0004]
Therefore, recently, an evaluation device that is widely used in abnormality diagnosis of small bearings, etc., is applied to the presence or absence of abnormality due to wear or breakage of the bearing used in such a large device, without using the above-described disassembled visual inspection. It was examined.
This evaluation device detects a sound or vibration generated from a bearing and converts an electrical signal output into frequency spectrum data by a predetermined waveform processing, and a specific frequency component value caused by the abnormality of the bearing in advance as a reference value. Is stored, and whether or not there is an abnormality in a specific part of the rotating body is diagnosed based on whether or not a peak appears at a position corresponding to the reference value on the frequency spectrum data.
[0005]
In this type of conventional evaluation device, the frequency spectrum data to be diagnosed is generated regardless of the actual normal rotation speed of the bearing, focusing on the resonance band in the state of being incorporated in the device using the bearing. A vibration signal only in the resonance band is extracted from the vibration signal, and the extracted signal is finished into frequency spectrum data by envelope analysis or the like.
[0006]
If an abnormality diagnosis of a large-sized bearing can be performed with such an evaluation device, the work of disassembling and assembling the bearing becomes unnecessary, and further, it is possible to avoid the inconvenience of accidentally damaging the bearing during the operation of the inspection work. In addition, the reliability of the inspection is not affected by the skill level of the person in charge of inspection, and it is possible to reduce the maintenance cost of the apparatus by eliminating unnecessary parts replacement.
[0007]
However, when the above-described conventional evaluation apparatus is used to diagnose whether there is an abnormality due to wear or breakage on a bearing used in a large apparatus such as the steel rolling mill described above or the main motor of a railway vehicle, FIG. As shown in Fig. 3, the frequency component due to bearing damage does not appear remarkably, and even if there is an abnormality due to defects such as wear or breakage, it may not be regarded as abnormal and may be overlooked. Is thin and lacks practicality.
[0008]
In addition, in the case of a bearing for an axle of a railway vehicle, for example, a wheel shaft test may be periodically inspected while being driven in a low-speed rotation range. However, in the case of a bearing for an axle of a railway vehicle, the rigidity of the housing in which the bearing is incorporated is high. For example, even if the bearing raceway surface is damaged, the rolling element passes over the damage. In the evaluation device for diagnosing the presence or absence of abnormality using the frequency spectrum data in the resonance band described above, the damage to the bearing is overlooked. There was a risk of it.
[0009]
The present invention has been made in view of the above circumstances, and there is no need for disassembling the apparatus and the like with high reliability, whether or not there is an abnormality such as wear or breakage of a rotating body such as a large bearing used at low speed rotation. An object is to provide an evaluation apparatus and an evaluation method capable of making a diagnosis.
[0010]
The object of the present invention is achieved by the following constitution.
(1) detection means for detecting sound or vibration generated by a rotating body incorporated in the rotating device in a state of being incorporated in the rotating device and outputting it as an electrical signal;
Waveform processing means for converting an electrical signal into frequency spectrum data by envelope analysis, and a rotational speed detection means for detecting and outputting the rotational speed of the rotating body,
Is predetermined by the specification output result of the rotating body of the rotation speed detection means, a specific frequency component value caused by abnormal of the rotating body is stored as a reference value, the reference on the frequency spectrum data In an evaluation apparatus comprising comparison determination means for diagnosing the presence or absence of abnormality of the rotating body by whether or not a peak appears at a corresponding position of the value,
The rotating device is a steel rolling mill or railway vehicle having a resonance band greater than 1 kHz; and
Filter processing means for performing a filter process for cutting a frequency component of 1 kHz or more on the electric signal output from the detection means and limiting the electric signal input to the waveform processing means to only a frequency component of 1 kHz or less. An evaluation apparatus provided at a preceding stage of the waveform processing means.
(2) The rotating body is a rolling bearing,
The evaluation device according to (1), wherein the specific frequency component value is a frequency component value corresponding to any of an inner ring, an outer ring, a rolling element, and a cage of the rolling bearing.
( 3 ) a detection process in which sound or vibration generated by a rotating body incorporated in the rotating device is detected as an electrical signal in a state of being incorporated in the rotating device;
Waveform processing process to convert electrical signal into frequency spectrum data by envelope analysis,
A rotational speed detection process for detecting the rotational speed of the rotating body;
Is predetermined by the specifications of the detection result and the rotating body in the rotation speed detection step, wherein the specific frequency component value abnormally due rotating body is stored as a reference value, said on the frequency spectrum data In an evaluation method comprising a comparison determination process for diagnosing the presence or absence of abnormality of the rotating body by whether or not a peak appears at a corresponding position of a reference value,
The rotating device is a steel rolling mill or railway vehicle having a resonance band greater than 1 kHz; and
A filtering process for performing a filter process for cutting a frequency component of 1 kHz or more on the electric signal detected in the detection process, and limiting an electric signal converted in the waveform processing process to a frequency component of 1 kHz or less. Is performed before the waveform processing step.
(4) The rotating body is a rolling bearing,
The evaluation method according to (3), wherein the specific frequency component value is a frequency component value corresponding to any of an inner ring, an outer ring, a rolling element, and a cage of the rolling bearing.
[0011]
According to the above configuration, when used for detecting an abnormality in a rotating body such as a large bearing used at low speed rotation, for example, the frequency spectrum data by the envelope analysis created by the waveform processing means is the normal rotation range of the rotating body. If there is an abnormality such as wear or breakage in a specific part of the rotating body with the data that matches the above, the frequency spectrum data output by the waveform processing means so that the specific frequency component resulting from the abnormality takes a good peak value Expressed above. Therefore, when the comparison determination means diagnoses, the frequency component value stored in advance as a determination criterion for the presence or absence of abnormality is identified by whether or not the peak portion of the actually measured frequency spectrum data extracted by the waveform processing means overlaps. The presence or absence of an abnormality at the site can be reliably diagnosed.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of an evaluation apparatus according to the invention will be described in detail with reference to the accompanying drawings.
1 to 3 show an embodiment of an evaluation apparatus according to the present invention, FIG. 1 is a block diagram showing a schematic configuration of the evaluation apparatus according to an embodiment of the present invention, and FIG. FIG. 3 is a waveform diagram showing a frequency spectrum obtained by extracting only a frequency component of 1 kHz or less from a vibration signal generated by a rotating body and performing an envelope analysis on the extracted signal. .
[0013]
The evaluation apparatus 1 according to the embodiment includes a detection unit 5 that detects a sound or vibration generated by the rotating body 3 and outputs an electric signal corresponding to the detected sound or vibration, and an electric signal output from the detection unit 5 Amplifying means 7 for amplifying the signal, and a filter processing means for performing a filter process for cutting a frequency component of 1 kHz or more on the electric signal amplified by the amplifying means 7 and outputting an electric signal having only a frequency component of 1 kHz or less 9, waveform processing means 11 for converting the electrical signal output from the filter processing means 9 into frequency spectrum data by predetermined waveform processing (envelope analysis), and the number of revolutions detected and output from the actual number of revolutions of the rotating body 3 The detection unit 13 and a specific frequency component value caused by the abnormality of the rotating body 3 are stored in advance as a reference value, and the corresponding position of the reference value on the frequency spectrum data described above is recorded. The comparison / determination means 15 for diagnosing the presence / absence of an abnormality with respect to a specific part of the rotator 3 by comparison / verification processing of whether or not an error occurs is displayed, and detection data, processing status, diagnosis result, prestored data, and the like are displayed. For example, a display unit 17 such as a CRT, and a printer 19 that outputs processing contents, data, and diagnosis results as a hard copy.
[0014]
In the case of this Embodiment, the rotary body 3 is a rolling bearing for low speed rotation used for large apparatuses, such as a rolling mill for steel, and the main motor of a railway vehicle.
Detection of sound or vibration generated when the rotating body 3 rotates is performed by rotationally driving the rotating body 3 in a state where it is incorporated in the apparatus in a normal use state.
As in the actual use, the rotating body 3 is detected, for example, in the state where it is rotated at a rotational speed of 150 revolutions per minute.
[0015]
As the detection means 5, various known contact-type and non-contact-type detectors that convert vibrations into electrical signals can be used. As a vibration detection format, an appropriate format such as an acceleration method, a velocity method, a displacement method, or the like can be adopted. The detecting means 5 can be directly attached to the rotating body 3 itself, or attached to a housing or the like to which a bearing is attached. However, when using in an environment with a lot of electrical noise, an insulating type is used. However, it is preferable in terms of preventing the influence of noise.
The signal processing in the filter processing unit 9, the waveform processing unit 11, the comparison determination unit 15 and the like can be configured by incorporating an appropriate program for predetermined arithmetic processing into the computer by input data arithmetic processing.
[0016]
When the amplified signal output from the amplifying means 7 is subjected to waveform processing (frequency analysis) by the waveform processing means 11 in a state before being subjected to the filter processing by the filter processing means 9, a frequency spectrum as shown in FIG. Indicates. In FIG. 2, region A is a frequency component region of 1 kHz or less, and region B is a resonance band.
[0017]
The filter processing unit 9 extracts only the frequency component in the region A in FIG. 2 from the amplified electrical signal output from the amplification unit 7 and passes it to the waveform processing unit 11.
The waveform processing unit 11 performs predetermined waveform processing such as envelope analysis on the received signal, thereby obtaining frequency spectrum data shown in FIG. 3 showing the vibration state of the rotating body 3.
FIG. 4 is frequency spectrum data shown for comparison, and is frequency spectrum data obtained by similarly performing predetermined waveform processing such as envelope analysis on the signal in the resonance band B shown in FIG.
[0018]
Although not shown, the comparison / determination means 15 is input with a circuit for inputting design data of the rotating body 3 and various data (for example, rotation speed information) used for diagnosis of abnormality. A circuit for storing the data is connected.
As shown in FIG. 5, a bearing that is a rotating body has a frequency component value that is determined when a specific part is abnormal depending on design specifications and use conditions.
The comparison / determination unit 15 stores the frequency component value generated when the specific part shown in FIG. 5 is abnormal as a reference value, and a peak is present at a location corresponding to the reference value on the frequency spectrum data obtained by the waveform processing unit 11. The presence / absence of abnormality of the specific part of the rotating body 3 is diagnosed by the comparison / verification process of whether or not to express.
3 and 4, the frequency component value (frequency value) at the position indicated by the broken line is a specific part when the inner ring is rotated at 150 revolutions per minute with the outer ring fixed in the rolling bearing as the rotating body 3. This is a frequency component value generated due to damage of the outer ring.
[0019]
As shown in FIG. 3, in the frequency spectrum data of the data processed by the filter processing means 9, the waveform peak is satisfactorily overlapped with the frequency component value generated due to the damage of the outer ring, and the abnormality due to the damage of the outer ring is detected. Suggest clearly.
Therefore, the abnormality of the outer ring can be easily diagnosed.
However, in the frequency spectrum data obtained by extracting the signal of the resonance band, as shown in FIG. 4, the peak of the frequency component generated due to the damage of the outer ring is not remarkable. For this reason, in this case, even if there is an abnormality in the outer ring, it is diagnosed that there is no abnormality.
The peak of the waveform is considered to be due to an abnormality in another specific part.
[0020]
As described above, in the evaluation apparatus 1 of the present embodiment, when used for detecting an abnormality in the rotating body 3 such as a large bearing used at low speed rotation, for example, by the envelope analysis created by the waveform processing means 11 The frequency spectrum data is data that matches the normal rotation range of the rotator 3, and if there is an abnormality such as wear or damage in the rotator 3, the waveform is such that a specific frequency component resulting from the abnormality takes a peak value. It is expressed on the frequency spectrum data output from the processing means 11.
[0021]
Therefore, it is determined whether or not the peak portion of the actually measured frequency spectrum data extracted by the waveform processing unit 11 overlaps the frequency component value stored in advance as a determination criterion for the presence or absence of abnormality when the comparison determination unit 15 diagnoses. Thus, it is possible to reliably diagnose the presence or absence of an abnormality with respect to a specific part, and to ensure high reliability of the diagnosis result. Further, since it is possible to diagnose the presence or absence of abnormalities such as wear and breakage of the rotating body 3 such as a large bearing used at low speed rotation by frequency analysis from vibration including sound generated by the rotating body 3, No disassembly or the like is required, and it is possible to reduce labor and cost required for abnormality diagnosis.
[0022]
Note that the rotating body diagnosed by the apparatus of the present invention is not limited to the rolling bearing used at low speed. Needless to say, other than rolling bearings, it can be used for abnormality diagnosis of various rotating bodies used at low speed.
In the above-described embodiment, the waveform processing by the envelope analysis is performed on the electrical signal obtained by the rotation of the rotating body to diagnose the presence or absence of bearing damage. An absolute value detection process performed using a means such as detection can also be applied.
[0023]
【The invention's effect】
According to the evaluation apparatus of the present invention, in a state where the rotating body is incorporated in the rotating apparatus, for example, the rigidity of the housing is high, and the vibration caused by the damage to the rotating body is hardly transmitted to the resonance band. The sound or vibration generated by the rotating body is detected in a state where it is incorporated in the rotating device and output as an electric signal. The electric signal is subjected to filter processing for cutting a frequency component of 1 kHz or more, and the waveform processing means. Since the input electric signal is limited to only frequency components of 1 kHz or less , when used for detecting abnormalities in a rotating body such as a large bearing used at low speed rotation, for example, a frequency spectrum by envelope analysis created by waveform processing means The data is data that matches the normal rotation range of the rotating body, and if there is an abnormality such as wear or damage at a specific part of the rotating body, the specific frequency caused by the abnormality Min to take good peak value will be exposed on the frequency spectrum data output by the waveform processing means.
[0024]
Therefore, when the comparison determination means diagnoses, the frequency component value stored in advance as a determination criterion for the presence or absence of abnormality is identified by whether or not the peak portion of the actually measured frequency spectrum data extracted by the waveform processing means overlaps. It is possible to reliably diagnose the presence or absence of an abnormality at the site, and to ensure high reliability of the diagnosis result.
And since it is possible to diagnose the presence or absence of abnormalities such as wear and breakage of a rotating body such as a large bearing used at low speed rotation by frequency analysis from vibration including sound generated by the rotating body, for example, a rolling mill for steel In trouble diagnosis and periodic inspection of bearings used in large-sized devices such as a main motor of a railway vehicle, it is not necessary to disassemble the troublesome device, and it is possible to reduce labor and cost required for trouble diagnosis.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a schematic configuration of an embodiment of an evaluation apparatus according to the present invention.
FIG. 2 is a waveform diagram showing a frequency spectrum of a vibration signal generated by a rotating body.
FIG. 3 is a waveform diagram showing a frequency spectrum obtained by extracting only a frequency component of 1 kHz or less from a vibration signal generated by a rotating body and performing envelope analysis on the extracted signal.
FIG. 4 is a waveform diagram showing a frequency spectrum obtained by extracting a vibration signal only in a resonance band from a vibration signal generated by a rotating body and performing envelope analysis on the extracted signal.
FIG. 5 is a diagram showing a relationship between a flawed portion in a rolling bearing and a frequency after envelope processing that causes a peak value on a frequency spectrum due to the flaw.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Evaluation apparatus 3 Rotating body 5 Detection means 7 Amplification means 9 Filter processing means 11 Waveform processing means 13 Rotation speed detection means 15 Comparison determination means

Claims (4)

Detecting means for detecting sound or vibration generated by a rotating body incorporated in the rotating device in a state of being incorporated in the rotating device and outputting as an electric signal;
Waveform processing means for converting an electrical signal into frequency spectrum data by envelope analysis;
A rotational speed detection means for detecting and outputting the rotational speed of the rotating body;
Is predetermined by the specification output result of the rotating body of the rotation speed detection means, a specific frequency component value caused by abnormal of the rotating body is stored as a reference value, the reference on the frequency spectrum data in the evaluation device comprising a comparison and determination means depending on whether a peak in the corresponding position values are exposed to diagnose the presence or absence of abnormality of the rotating body, and
The rotating device is a steel rolling mill or railway vehicle having a resonance band greater than 1 kHz; and
A filter that cuts a frequency component of 1 kHz or more with respect to the electrical signal output from the detection means, and that restricts the electrical signal input to the waveform processing means to only a frequency component of 1 kHz or less and outputs it. An evaluation apparatus characterized in that a processing means is provided in a stage preceding said waveform processing means. The rotating body is a rolling bearing;
  The evaluation device according to claim 1, wherein the specific frequency component value is a frequency component value corresponding to any of an inner ring, an outer ring, a rolling element, and a cage of the rolling bearing. A detection process for detecting sound or vibration generated by a rotating body incorporated in the rotating device as an electrical signal in a state incorporated in the rotating device;
Waveform processing process to convert electrical signal into frequency spectrum data by envelope analysis,
A rotational speed detection process for detecting the rotational speed of the rotating body;
Is predetermined by the specifications of the detection result and the rotating body in the rotation speed detection step, wherein the specific frequency component value abnormally due rotating body is stored as a reference value, said on the frequency spectrum data In an evaluation method comprising a comparison determination process for diagnosing the presence or absence of abnormality of the rotating body by whether or not a peak appears at a corresponding position of a reference value,
The rotating device is a steel rolling mill or railway vehicle having a resonance band greater than 1 kHz; and
A filtering process for performing a filter process for cutting a frequency component of 1 kHz or more on the electric signal detected in the detection process, and limiting an electric signal converted in the waveform processing process to a frequency component of 1 kHz or less. Is performed before the waveform processing step. The rotating body is a rolling bearing;
  The evaluation method according to claim 3, wherein the specific frequency component value is a frequency component value corresponding to any of an inner ring, an outer ring, a rolling element, and a cage of the rolling bearing.

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