JP3014201B2 - Bearing abnormality prediction device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus having a plurality of bearings, and for predicting abnormality and remaining life of the bearings by measuring the rotation noise of each bearing.

[0002]

2. Description of the Related Art 2-59
Japanese Patent Publication No. 420 (JP-A-59-81531) discloses a method for predicting the failure of a plurality of bearings. In this method, a piezoelectric element type vibration acceleration sensor is attached to each bearing, and the signal output from these many sensors is time-divided by a scanning device and sent to a single frequency analyzer, and each vibration acceleration intensity is measured. Frequency analysis of the high-frequency band (20
The vibration acceleration magnification is calculated from the ratio of the vibration acceleration intensity of about 75 KHz) to the initial vibration acceleration intensity that was normal in the band, and when this vibration acceleration magnification exceeds a preset threshold value, each bearing is calculated. The failure prediction signal is issued, and the bearing failure prediction display of each rotating device is performed based on this signal. In addition, the vibration acceleration intensity in the low frequency band (1 Hz to 1 KHz) and the normal value in this band were obtained. The vibration acceleration magnification can be calculated from the ratio with the initial vibration acceleration intensity, and when the vibration acceleration magnification exceeds a preset threshold value, an abnormality notification signal derived from a machine other than the bearing can be issued.

A method of estimating the remaining life of a bearing, which further improves the method of predicting the failure, is disclosed in Japanese Patent Application Laid-Open No. HEI 3-12533 by the same inventor as the present invention. According to this, the time-dependent change of the vibration acceleration magnification is a so-called “respiratory range” in which the magnification temporarily decreases before the fracture occurs.
The remaining life of the bearing is estimated by taking into account the existence of the respiratory range and taking this respiratory range into consideration.

[0004]

According to the method described in Japanese Patent Publication No. 2-59420 and Japanese Patent Laid-Open Publication No. 3-12533,
It is possible to estimate the remaining life of the bearing by using the vibration acceleration magnification with respect to the initial normal state of up to 75 KHz as an index, and to predict abnormalities, but using a piezoelectric element type vibration acceleration sensor to detect vibration speed and vibration acceleration Therefore, it is necessary to directly contact or fix the sensor to the bearing.

However, some of them bearing portion is concealed by the device, the mounting of the sensor is difficult in this case. Further, in a device having a large number of bearings, it is necessary to install sensors as many as the number of the bearings, and the number of sensors is increased, which may complicate wiring and may cause difficulty in mounting. The present invention is directed to solving this problem.

[0006]

According to the means for solving the problems] The present invention, a microphone that measures the sound positionable so installed and ultrasonic region positioned at a predetermined distance against the only plurality of bearings, in the microphone A monitoring station that records and analyzes the measured sound from each bearing and outputs an abnormality prediction signal for each bearing. At the monitoring station, the measured sound corresponding to each bearing from the microphone is processed by an envelope processing device. After performing the envelope processing , the frequency component intensity is analyzed by the frequency analyzer , and the management personal computer calculates the magnification of the component intensity of the monitoring frequency measured this time with respect to the component intensity of the registered monitoring frequency at the time of initial normal operation of the bearing. The present invention provides a bearing abnormality prediction device that calculates and estimates the abnormality and the remaining life of the bearing from the magnification.

[0007]

FIG. 1 shows the equipment configuration of the apparatus of the present invention. 1 is an ultrasonic microphone, that is, 10Hz to 50KHz
It can measure the sound up to. The microphone 1 is one type of a condenser microphone, and has a nozzle 3 attached for recording the sound of a sound source (rotating bearing) 2 with directivity. It is desirable that the microphone 1 be as close as possible to the bearing. The sound collected by the microphone 1 is amplified by the amplifier 4 and transmitted to the monitoring station 5.

The monitoring station 5 includes a sound level meter 6, an envelope processing device 7, a frequency analyzer 8, a management personal computer 9, a CR
It consists of T10 and printer 11. After the measurement signal of the microphone 1 is amplified by the amplifier 4, it enters the sound level meter 6. The sound level meter 6 assigns a physical unit to the signal and outputs a sound up to 5 KHz to remove background noise. Cut with the built-in filter.

[0009] Next, an envelope processing device 7 is entered.
A signal obtained by modulating the sound from KHz to 50KHz to the low frequency range,
Divide into raw (non-modulated) signals that are not envelope processed. These two signals enter a frequency analyzer 8 where both signals are analyzed for the component strength of each frequency from 1 Hz to 50 KHz. Then, the all-pass values of the two signals are measured and transmitted to the management personal computer 9. In some devices, the frequency analyzer itself has a built-in envelope processing device.

The management personal computer 9 performs the function processing of the sound level meter 6, the envelope processing device 7, and the frequency analyzer 8, and also measures the component intensity of the registered monitoring frequency at the time of initial normal operation of the bearing. The magnification of the component intensity of the monitored frequency is calculated, the abnormality of the bearing is diagnosed and the remaining life is estimated by using the magnification as an evaluation criterion.
A signal for turning on the alarm lamp 13 is transmitted to the annunciator 12 in some cases.

The procedure of the arithmetic processing in the management personal computer 9 is as follows. (1) Determine the bearing to be measured and confirm the address. (2) Determine the measurement range according to the sound intensity and change the measurement range. (3) Switching the envelope processing and managing the signal flow. (4) 1 at normal time (start of operation) for each bearing
The strength of each frequency component of the sound from Hz to 50 KHz is registered. (5) Calculate the monitoring frequency. As shown in Fig. 2, there is a certain correlation between the frequency of the backlash of the gantry, the imbalance of the bearing, the misalignment of the bearing, the bending of the shaft, the loss of the gear, etc., which cause the bearing to be abnormal. The monitoring frequency for each cause factor is calculated based on the equation in FIG. These correlations are not substantially different from those described in Japanese Patent Publication No. 2-59420. (6) For each bearing, register the intensity at the monitoring frequency of the envelope-processed sound in the normal state (start of operation).

(7) Calculate the magnification of how many times the all-pass value of each bearing transmitted from the frequency analyzer is higher than the registered all-pass value in the normal state. (8) Calculate the magnification of the component intensity at the monitoring frequency of the measured and envelope-processed sound with respect to the component intensity registered for each monitoring frequency. (9) Measured sound, for example, 5KHz to less than 20KHz, 20KH
For each frequency band from z to less than 35KHz and from 35KHz to less than 50KHz, calculate the average value of each intensity. (10) For the average intensity of each frequency band of normal sound, (9)
Calculate the magnification of the average intensity of each frequency band measured in the above. (11) Diagnosis of bearing abnormality is performed based on the magnification of the component intensity at the monitoring frequency obtained as described above, the magnification of the average intensity of each frequency band, and the relative evaluation standard of the all-pass value.
FIG. 3 shows an example of the relationship between these magnifications and the abnormal region. (12) The remaining life time of each bearing is estimated from the magnification. This is obtained from the approximate curve of the magnification. FIG. 4 shows the change over time of the average intensity magnification in a certain frequency band.
This shows that there is consistency between the approximate curve of the magnification and the actually measured value of the magnification. FIG. 5 shows the relationship between the predicted remaining life and the actual remaining life. The estimated remaining life time is transmitted to the CRT 10 or the printer 11 together with the measurement time, the name or number of the bearing unit, the result of the diagnosis, the measured value, and the like.
When an abnormality is determined, a signal for turning on the alarm lamp 13 of the annunciator 12 is transmitted.

The CRT 10 and the printer 11 are the management personal computer 9
In particular, the printer performs arbitrary printing when an error occurs and prints a daily report at a predetermined time.

The microphone 1 for measuring the rotation sound is provided with a single monitoring station 5 for the sound generated from a large number of bearings.
The two-dimensional traverser or three-dimensional traverser is positioned at a predetermined distance from the bearing part to be measured in order to measure the sound of many bearings with one microphone. Supported. The management personal computer moves and stops the traverser and manages the measurement cycle time.

FIG. 6 and FIG. 7 are flow charts showing the measurement and management procedures at the monitoring station.

[0016]

As described above, according to the present invention, the use of one microphone makes it possible to measure a device having many bearings at a position away from the bearings. Therefore, even in a device having a concealed bearing or a device having a large number of bearings, it is possible to know the bearing abnormality and the remaining life without contact. The range of use can be further expanded as compared with the case of using the vibrometer described in Japanese Patent Application Laid-Open Publication No. H10-260, 1993.

[Brief description of the drawings]

FIG. 1 is a device layout of the apparatus of the present invention.

FIG. 2 is a diagram illustrating a calculation example of a monitoring frequency used in the present invention.

FIG. 3 is a diagram showing the relationship between the magnification of a monitoring frequency with respect to a normal state and the destruction of a bearing.

FIG. 4 is a diagram showing a change over time of a magnification of an average intensity in a frequency band.

FIG. 5 is a diagram showing a relationship between a remaining life time of a bearing estimated by the device of the present invention and an actual remaining life time.

FIG. 6 is a flowchart of a measurement and management procedure of a monitoring station.

FIG. 7 is a flowchart of a measurement and management procedure of a monitoring station related to FIG. 6;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ultrasonic microphone 2 Sound source (bearing to be measured) 3 Sound collecting nozzle 4 Amplifier 5 Monitoring station 6 Sound level meter 7 Envelope processing device 8 Frequency analyzer 9 Management personal computer 10 CRT 11 Printer 12 Annunciator 13 Alarm lamp

Continuation of the front page (56) References JP-A-3-160326 (JP, A) JP-A-59-81531 (JP, A) JP-A-57-45428 (JP, A) (58) Fields investigated (Int) .Cl. ⁷ , DB name) G01H 17/00 G01M 13/04

Claims (3)

(57) [Claims] And 1. A microphone that measures the sound positionable so installed and ultrasonic region to a position a predetermined distance away against the only plurality of bearings, recorded sound from the bearing is measured by the microphone・ Consists of a monitoring station that analyzes and outputs an abnormality prediction signal for each bearing,
At the monitoring station, the measured sound corresponding to each bearing from the microphone is envelope-processed by an envelope processing device, and the frequency component intensity is analyzed by a frequency analyzer.
The management personal computer calculates the magnification of the component intensity of the monitoring frequency measured this time with respect to the component intensity of the registered monitoring frequency at the time of initial normal operation of the bearing, and from this magnification the abnormality of the bearing and the estimation of the remaining life of the bearing. Forecasting device. 2. The bearing abnormality prediction device according to claim 1, wherein the monitoring station comprises a sound level meter, an envelope processing device, a frequency analyzer, a management personal computer, and a printer. 3. A microphone, by the two-dimensional or three-dimensional traverser, a position away from a plurality of bearing by a predetermined distance, bearing Anomaly device according to claim 1 or 2 is positioned in each respective bearing .