JP6897064B2 - Bearing abnormality diagnosis method and diagnosis system - Google Patents

Description

The present invention relates to a bearing abnormality diagnosis method and a diagnostic system, and more particularly to a bearing abnormality diagnosis method and a diagnostic system capable of diagnosing the presence or absence of an abnormality without disassembling the mechanical equipment.

Conventionally, as seen in, for example, Patent Document 1, in order to determine the presence or absence of an abnormality in a rolling bearing, at least a detection device that detects vibration accompanying the rotation of the rolling bearing and a signal representing the vibration detected by the detection device are used. It branches into two signals, and based on one of the signals, the presence or absence of damage to the rolling bearing and the damaged member are determined, and based on the other signal, the amount of foreign matter mixed in the lubricant is determined. , At least based on the results of both of these determinations, an abnormality determination device or determination method for rolling bearings including an arithmetic processor for determining the presence or absence of an abnormality in the rolling bearing is known.

JP-A-2009-109267

However, in the rolling bearing abnormality determination device or determination method described in Patent Document 1, the signal representing the vibration detected by the detection device is branched into at least two signals, and the presence or absence of an abnormality is determined based on the two determination results. Therefore, the determination method is complicated.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a bearing abnormality diagnosis method and a diagnostic system capable of diagnosing a bearing abnormality by a simple determination method.

The above object of the present invention is achieved by the following configuration.
(1) A vibration acceleration sensor that detects the vibration acceleration of the bearing housing is attached to the bearing housing that supports the bearing, and the presence or absence of an abnormality in the bearing is diagnosed based on the vibration acceleration signal from the vibration acceleration sensor. In the case of, the site of the abnormality is specified, and when it is diagnosed that there is an abnormality, it is based on whether or not the predetermined vibration pattern indicated by the vibration acceleration signal at the time of diagnosing the abnormality appears continuously. , Determine the type of abnormality in the specified site ,
The bearing is a radial roller bearing.
A method for diagnosing a bearing abnormality, characterized in that the occurrence of scratches in the radial direction or the occurrence of scratches in the axial direction is determined as the type of the abnormality.
(2) A vibration acceleration sensor that is attached to the bearing housing that supports the bearing and detects the vibration acceleration of the bearing housing.
A diagnostic unit that diagnoses the presence or absence of an abnormality in the bearing based on the vibration acceleration signal from the vibration acceleration sensor and identifies the abnormal portion when there is an abnormality.
When the diagnosis unit diagnoses that there is an abnormality, the diagnosis unit determines whether or not a predetermined vibration pattern indicated by the vibration acceleration signal at the time of the diagnosis of the abnormality appears continuously. An abnormality discriminating unit that discriminates the type of abnormality in the specified site,
Equipped with a,
The bearing is a radial roller bearing.
The bearing abnormality diagnosis system is characterized in that the abnormality determination unit determines, as a type of abnormality, the occurrence of scratches in the radial direction or the occurrence of scratches in the axial direction.

According to the present invention, the presence or absence of an abnormality in the bearing is diagnosed based on the vibration acceleration signal of the vibration acceleration sensor that detects the vibration acceleration of the bearing housing that supports the bearing. Since the type of abnormality is determined by checking the frequency of occurrence, it is possible to diagnose the presence or absence and type of abnormality based on the same signal. That is, it becomes possible to easily perform a plurality of different diagnoses based on the same signal.
Further, since a plurality of types of diagnoses can be performed with one vibration acceleration signal, the effects of reducing the number of sensors, the input Ch, the current consumption due to the reduction of the signal input circuit, the compactness of the device, and the cost reduction can be obtained.

It is a block diagram which shows the schematic structure of the bearing abnormality diagnosis system which concerns on one Embodiment of this invention. It is a block diagram which shows the functional structure of the diagnostic apparatus which concerns on this embodiment. It is a flowchart for demonstrating the operation procedure of the bearing abnormality diagnosis system which concerns on this embodiment. It is a table which shows the relationship between the scratched part of the rolling bearing which concerns on this embodiment, and the vibration frequency generated by the scratch. (A) is a diagram showing an example of a vibration acceleration signal from a vibration acceleration sensor, (b) and (c) are diagrams showing an example of spectral data, and (d), (e) and (f) are diagrams explaining an abnormality occurrence frequency. , (G) and (h) are diagrams showing an example of a vibration acceleration signal from the vibration acceleration sensor.

Hereinafter, an embodiment of the bearing abnormality diagnosis method and the diagnosis system according to the present invention will be described in detail with reference to the drawings.

The bearing abnormality diagnosis system of the present embodiment shown in FIG. 1 diagnoses an abnormality of the rolling bearing 11, which is a rotating component supported by the bearing housing 10, and detects the vibration acceleration generated from the rolling bearing 11. The acceleration sensor 12, the rotation sensor (not shown) that detects the rotation speed of the rolling bearing 11, and the signal detected by the vibration acceleration sensor 12 and the rotation sensor are received via the data transmission means (transmission means) 13. The diagnostic unit 21 that performs signal processing to diagnose the presence or absence of an abnormality in the rolling bearing 11, and when the diagnostic unit 21 diagnoses that there is an abnormality, the type of abnormality is determined by checking the frequency of occurrence of the abnormality. It is provided with an abnormality determination unit 22 and an output device 30 including a monitor, an alarm, and the like.
The diagnostic unit 21 and the abnormality determination unit 22 constitute a diagnostic device 20.

The rolling bearing 11 has a plurality of rolls rotatably arranged between the inner ring 111 fitted on the rotating shaft 101 of the mechanical equipment, the outer ring 112 fitted on the bearing housing 10, and the inner ring 111 and the outer ring 112. It has a moving body 113 and a cage (not shown) that holds the rolling body 113 so that it can roll freely.

The vibration acceleration sensor 12 is fixed to the bearing housing 10 that supports the bearing 11. Methods for fixing the vibration acceleration sensor 12 include bolt fixing, adhesion, combined use of bolt fixing and adhesion, and embedding with a resin material.
In the case of bolt fixing, a detent function may be provided. Further, by molding the vibration acceleration sensor 12 with a resin material, it is possible to prevent the ingress of moisture, and further, the vibration isolation property against external vibration is improved, so that the reliability of the sensor itself is dramatically improved. can do.

FIG. 2 is a block diagram showing a main functional configuration of the diagnostic apparatus 20 according to the present embodiment.
As shown in FIG. 2, the diagnostic apparatus 20 includes a data collection / distribution unit 211, a rotation analysis unit 212, a filter processing unit 213, a vibration analysis unit 214, a comparison determination unit 215, an internal memory 216, and an abnormality determination unit 23. It is composed of. The data collection / distribution unit 211, the rotation analysis unit 212, the filter processing unit 213, the vibration analysis unit 214, the comparison determination unit 215, and the internal memory 216 mainly constitute the diagnosis unit 21.
The diagnostic device 20 is composed of a microcomputer, that is, when a program recorded and held in the microcomputer is executed, each processing unit such as the data collection / distribution unit 211 is as follows. Each process will be executed.

The data collection / distribution unit 211 converts the signal Sig1 sent from the vibration acceleration sensor 12 into a digital signal by the A / D converter, and at the same time, simultaneously collects and temporarily stores the signal related to the rotation speed to determine the type of signal. Depending on the situation, the data is distributed to either the rotation analysis unit 212 or the filter processing unit 213.
The A / D converter may be integrated with the vibration acceleration sensor 12 and receive a digital signal via the data transmission means 13 described above.

The rotation analysis unit 212 uses the predetermined relational expression shown in FIG. 4 based on the design specification data of the rolling bearing 11 and the rotation speed signal from the rotation sensor 14, and causes damage to each part of the rolling bearing 11. Calculate the bearing damage frequency.
For the calculation of the theoretical bearing damage frequency, if the same diagnosis has been performed before, the past data stored in the internal memory 216 may be used.
Further, when the rotation speed detecting means (not shown) for detecting the rotation speed of the rolling bearing 11 is composed of an encoder attached to the inner ring 111 and a magnet or magnetic detection element attached to the outer ring 112. , The output signal becomes a pulse signal according to the shape and rotation speed of the encoder. Therefore, the rotation analysis unit 212 has a predetermined conversion function or conversion table according to the shape of the encoder, and calculates the rotation speed of the inner ring 111 from the pulse signal.

The filter processing unit 213 has a function of a bandpass filter (BPF), extracts a damaged filter frequency band from the vibration acceleration signal Sig1 of the vibration acceleration sensor 12, and removes other unnecessary frequency bands. The damage filter frequency band is set according to the natural frequency band in each bearing device. This natural frequency can be easily obtained by vibrating the object to be measured by a striking method using an impulse hammer or the like, and using a vibration detector attached to the object to be measured or frequency analysis of the sound generated by the striking. it can.
When the object to be measured is a rolling bearing 11, a natural frequency caused by any of the inner ring 111, the outer ring 112, the rolling element 113, the bearing housing 10, and the like is given. Generally, there are a plurality of natural frequencies of machine parts, and the amplitude level at the natural frequencies is high, so that the measurement sensitivity is good.

The vibration analysis unit 214 performs frequency analysis of the vibration acceleration signal generated from the rolling bearing 11 based on the output signal from the vibration acceleration sensor 12 from which the damage filter frequency band is extracted. The vibration analysis unit 214 is an FFT calculation unit that calculates the frequency spectrum of the vibration acceleration signal, and calculates the frequency spectrum of the vibration acceleration signal based on the FFT algorithm and the envelope analysis. The calculated frequency spectrum is output to the comparison determination unit 215 as spectrum data as shown in FIG. 5B or FIG. 5C, for example.
The vibration analysis unit 214 may perform an absolute value processing or an envelope processing as a preprocessing for performing the FFT, and convert only the frequency components necessary for diagnosing the abnormality. Further, if necessary, the spectrum data (envelope frequency spectrum) after the envelope processing is also output to the comparison determination unit 215.
In FIG. 5, f is the frequency (Hz) and G is the acceleration (m / s ² ).

The comparison determination unit 215 and the abnormality determination unit 22 diagnose the abnormality of the bearing 11 as follows, for example, based on the spectrum data obtained by the vibration analysis unit 214.

When the comparison determination unit 215 detects, for example, the rolling element passing vibration SD1 as seen in FIG. 5B in the spectrum data obtained by the vibration analysis unit 214, the comparison determination unit 215 determines that the bearing 11 has some abnormality. At the same time as diagnosing, the abnormal portion is identified based on the bearing damage frequency calculated by the rotation analysis unit 212, and the spectrum data thereof is transmitted to the abnormality determination unit 22 in the subsequent stage.
On the other hand, if the spectral data obtained by the vibration analysis unit 214 does not detect the rolling element passing vibration as shown in FIG. 5 (c), for example, it is diagnosed that there is no abnormality in the bearing 11. To do.

Regarding the abnormality diagnosis, the vibration frequency generated by the rotation of the bearing, such as the rolling element passing vibration frequency, the rolling element revolution frequency, and the rolling element rotation frequency, can be used as a diagnostic index to detect and diagnose the behavior at the time of abnormality occurrence.

The abnormality determination unit 22 determines the type of abnormality by confirming the occurrence frequency of the abnormality (frequency of inputting spectrum data from the comparison determination unit 215).
For example, when the bearing 11 is a radial roller bearing, it is determined as follows.
For example, when the rolling element passing vibration as seen in FIG. 5D appears continuously, it is determined that the scratch is generated in the radial direction (for example, the outer ring raceway surface is peeled off). The output signal (actual measurement data) from the vibration acceleration sensor 12 in this case is shown in FIG. 5 (g), for example.
On the other hand, as seen in FIGS. 5 (e) and 5 (f), for example, the rolling element passing vibration does not appear continuously, and the rolling element passing vibration appears, for example, when an axial load is applied, that is, FIG. When the state shown in (e) and the state shown in (f) appear alternately, scratches are generated in the axial direction (for example, scratches are generated on the roller head surface and the brim surface). To determine. The output signal (actual measurement data) from the vibration acceleration sensor 12 in this case is shown in FIG. 5 (h), for example.

The diagnosis result of the rolling bearing 11 determined as described above is stored in the internal memory 216 and sent to the output device 30 by the data transmission means 31 using wireless or wireless in consideration of the network.

The internal memory 216 is composed of, for example, a memory or an HDD, and various data necessary for determination and determination by the comparison determination unit 215 and the abnormality determination unit 22, for example, design specification data of each rotating component used for calculating the abnormality frequency, etc. And, each data regarding the diagnosis of the presence or absence of abnormality of the rolling bearing 11 and the type of abnormality determined by the comparison determination unit 215 and the abnormality determination unit 22 is stored.

The output device 30 displays the diagnosis result of the rolling bearing 11 on a monitor or the like in real time. Further, when an abnormality is detected, an alarm such as a light or a buzzer may be used to alert the user to the abnormality.
Further, the signal data transmission means 13 and 31 may be wired or wireless in consideration of the network, as long as they can accurately transmit and receive signals.

Next, the operation of the bearing abnormality diagnosis system configured in this way will be described. FIG. 3 is a flowchart for explaining the operation procedure of the bearing abnormality diagnosis system.

First, in step S1, the vibration acceleration generated from the rolling bearing 11 by the vibration acceleration sensor 12 and the rotation speed of the rolling bearing 11 are detected by the rotation sensor, and the detected vibration acceleration signal and rotation speed signal are used as the data transmission means 13. Is input to the data collection / distribution unit 211 of the diagnosis unit 21 via.

The data acquisition / distribution unit 211 amplifies the input analog vibration signal as necessary, and converts it into a digital signal by the A / D converter.

Next, in step S2, the filter processing unit 213 and the vibration analysis unit 214 generate spectral data to be used for subsequent diagnosis based on the data stored in the data collection / distribution unit 211 and the internal memory 216. The data is output to the comparison determination unit 215.

Next, in step S3, the comparison determination unit 215 diagnoses the presence or absence of an abnormality in the bearing 11 from the spectrum data obtained by the vibration analysis unit 214, and if there is an abnormality, the rotation analysis unit 212 calculates. The damaged bearing frequency is compared with the peak frequency of the spectral data to identify the abnormal portion, and the spectral data is sent to the abnormality determining unit 22 in the subsequent stage.
If there is no abnormality, the process returns to step S1. As a result, the state of the bearing 11 can be constantly monitored.

Next, in step 4, the abnormality determination unit 22 confirms the occurrence frequency of the abnormality (frequency of inputting spectrum data from the comparison determination unit 215), and determines the type of abnormality.

The result of the diagnosis carried out in this way is sent to the output device 30 by the data transmission means 31 using a wire or a wireless network in consideration of the network.

According to the bearing abnormality diagnosis method or diagnosis system as described above, the following effects can be obtained.
(A) The presence or absence of an abnormality in the bearing 11 is diagnosed based on the vibration acceleration signal of the vibration acceleration sensor 12 that detects the vibration acceleration of the bearing housing 10 that supports the bearing 11, and if it is diagnosed as having an abnormality, the abnormality is found. Since the type of abnormality is determined by checking the frequency of occurrence, it is possible to diagnose the presence or absence and type of abnormality based on the same signal. That is, it becomes possible to easily perform a plurality of different diagnoses based on the same signal.
(B) Since a plurality of types of diagnoses can be performed with one vibration acceleration signal, the effects of reducing the number of sensors, the input Ch, the current consumption due to the reduction of the signal input circuit, the compactness of the device, and the cost reduction can be obtained.

The present invention is not limited to those exemplified in the above embodiments, and can be appropriately modified without departing from the gist of the present invention.
For example, the band setting value, the diagnostic index, and the number of corresponding failures are not limited to the above-described embodiment, and can be optimally set each time according to the target bearing, the failure or diagnostic condition to be detected, the required specifications, and the like.
Further, the bearing abnormality diagnosis method or diagnosis system of the present invention can be applied to mechanical equipment such as automobiles, railroad vehicles, machine tools, wind power generators, and elevator devices.
Further, in the present embodiment, the case of diagnosing the abnormality of the rolling bearing in the case of the inner ring rotation has been mainly described, but the bearing abnormality diagnosis method or the diagnostic system of the present invention is intended to monitor the state of the rolling bearing of the outer ring rotation. Is also applicable.

10 Bearing housing 11 Rolling bearing (bearing)
12 Vibration acceleration sensor 20 Diagnostic device 21 Diagnostic unit 22 Abnormality discrimination unit

Claims (3)

A vibration acceleration sensor that detects the vibration acceleration of the bearing housing is attached to the bearing housing that supports the bearing, and the presence or absence of an abnormality in the bearing is diagnosed based on the vibration acceleration signal from the vibration acceleration sensor. When the site of the abnormality is specified and it is diagnosed that there is an abnormality, the specification is based on whether or not the predetermined vibration pattern indicated by the vibration acceleration signal at the time of diagnosing the abnormality appears continuously. determine the type of abnormality in the site,
The bearing is a radial roller bearing.
A method for diagnosing a bearing abnormality, characterized in that the occurrence of scratches in the radial direction or the occurrence of scratches in the axial direction is determined as the type of the abnormality. The predetermined vibration pattern is characterized by being based on any of a rolling element passing vibration frequency, a rolling element revolution frequency, or a rolling element rotation frequency, which is defined based on at least one of the bearing configuration and operating conditions. The bearing abnormality diagnosis method according to claim 1. A vibration acceleration sensor that is attached to the bearing housing that supports the bearing and detects the vibration acceleration of the bearing housing.
A diagnostic unit that diagnoses the presence or absence of an abnormality in the bearing based on the vibration acceleration signal from the vibration acceleration sensor and identifies the abnormal portion when there is an abnormality.
When the diagnosis unit diagnoses that there is an abnormality, the diagnosis unit determines whether or not a predetermined vibration pattern indicated by the vibration acceleration signal at the time of the diagnosis of the abnormality appears continuously. An abnormality discriminating unit that discriminates the type of abnormality in the specified site,
Equipped with a,
The bearing is a radial roller bearing.
The bearing abnormality diagnosis system is characterized in that the abnormality determination unit determines, as a type of abnormality, the occurrence of scratches in the radial direction or the occurrence of scratches in the axial direction.

Images