JP5293300B2 - Vibration monitoring device and vibration monitoring method for rotating machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device and a method of monitoring vibration precisely determining the number of revolutions of a rotating machine without installing a dedicated accessory instrument for measuring the number of revolutions of the rotating machine and allowing determination of a vibration condition in a constant rotational speed of the rotating machine on the basis of the number of revolutions. <P>SOLUTION: A vibration acceleration sensor 2 detects vibration of the rotating machine. An amplification part 3 amplifies an analog signal output from the vibration acceleration sensor 2 as a detection result of the vibration. An A/D conversion part 4 digital converts the analog signal amplified by the amplification part 3. A frequency analysis part 82 performs the frequency analysis of the digital signal converted by the A/D conversion part 4 by FFT processing and outputs frequency analysis data. A number-of-revolutions determination part 831 determines the number of revolutions of the rotating machine on the basis of the frequency analysis data. A condition determination part 832 determines the condition of the vibration of the rotating machine on the basis of the number of revolutions determined by the number-of-revolutions determination part 831. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a vibration monitoring apparatus and a vibration monitoring method for remotely monitoring the vibration state of a rotating machine in a plant or the like by wireless communication.

  Conventionally, in a plant where many rotating machines are installed, vibrations of main rotating machines are monitored in order to prevent operation stoppage due to equipment abnormality. As a monitoring cycle, a method of constantly monitoring a change in vibration of the rotating machine online or periodically monitoring offline is employed. As an analysis method, a data collection device such as a computer collects vibration waveform signals of a rotating machine, and analysis processing such as FFT (Fast Fourier Transform) is performed on the collected signals. (For example, refer to Patent Document 1).

In particular, in a large-scale system, there is an abnormality monitoring system in which a wireless tag is installed in a detection unit in order to avoid long-distance cable installation (see, for example, Patent Documents 2 and 3).
Here, the abnormal state determination of vibration is performed by calculating frequency analysis data indicating vibration speed, vibration displacement, and the like by FFT processing from the detected vibration waveform, and determining data detected in advance from changes in trends and frequency analysis data. This is performed by comparison with a set threshold value. Typical vibration frequencies used as the determination data include a rotation frequency component fn generated by imbalance of the rotating shaft, misalignment with a load machine, and the like, twice and three times the component, and twice the drive power supply frequency. It is an electromagnetic vibration that vibrates at a frequency of.

Japanese Patent Laid-Open No. 7-83972 JP-A-2005-24441 Japanese Patent Laid-Open No. 10-19655

  However, in order to detect the determination data from the frequency analysis data of the FFT-processed vibration, the rotational speed of the rotating machine and the drive power supply frequency need to be known in advance. For this reason, in a rotating machine operated at a variable speed, it has been necessary to obtain the number of rotations at the time of measurement from a control power supply, or to attach a tachometer to the rotating machine and take the output into a monitoring system. For this reason, there existed a problem that the installation cost cannot be increased or it cannot be attached to an existing rotating machine.

In addition, as a method of automatically detecting the rotation speed from the frequency spectrum of the measured vibration, the maximum peak frequency method for detecting the maximum value of the frequency spectrum as the rotation frequency, and the frequency interval of each order component of the peak frequency are obtained sequentially. There is a frequency interval method in which the most frequently occurring frequency interval is determined as the primary component of the rotation speed and the rotation frequency is determined.
However, the rotational frequency component does not necessarily become the maximum value. For example, the second harmonic component (twice the rotational frequency component) of the rotational frequency component is larger than the primary component, or the noise level due to disturbance components. May be the maximum peak, and may be misjudged.

In addition, in the rotational speed interval method, the level of either the primary component or the secondary component is small, and it may not be detected as a peak. Furthermore, there is a problem that the conditions for considering it as a peak are not clear, and when many disturbance noises are at a peak, accurate determination cannot be made.
The present invention has been made in view of the above, and accurately determines the rotation speed of a rotating machine without providing a dedicated incidental facility for measuring the rotation speed of the rotating machine, and rotates based on the rotation speed. An object of the present invention is to provide a vibration monitoring device and a vibration monitoring method that enable determination of a vibration state at a constant rotational speed of a machine.

  In order to achieve the above object, a vibration monitoring device of the present invention outputs a vibration acceleration sensor that individually detects vibrations in two orthogonal directions of a rotating machine, and a vibration detection result output from the vibration acceleration sensor. An amplifier for amplifying an analog signal, an A / D converter for digitally converting the analog signal amplified by the amplifier, a frequency analysis of the digital signal converted by the A / D converter, and the frequency analysis As a result, a frequency analysis unit that outputs the frequency analysis data of the vibration, a rotation speed determination unit that determines the rotation speed of the rotating machine based on the frequency analysis data output from the frequency analysis unit, and the rotation speed determination unit And a state determination unit that determines a state of vibration of the rotating machine based on the rotation number determined by the rotation number, wherein the rotation number determination unit includes frequency analysis data of the vibration. Based on a plurality of frequencies that are less than or equal to an integer multiple of 2 or more of the maximum rotation frequency of the rotating machine, and that the order of magnitude of peak amplitude is included in a predetermined order The rotational speed of the rotating machine is determined.

According to the present invention, even when there is a peak amplitude due to noise, the rotational frequency component is included in any of the first to nth (n is an integer) large peak amplitudes, so that the rotational speed of the rotating machine is measured. Therefore, it is possible to accurately determine the rotational speed of the rotating machine based on the frequency analysis data, and to determine the vibration state of the rotating machine based on the rotational speed. Compared with the rotation speed detected by an external signal such as a rotation control signal or a rotation detector, it is possible to detect the rotation speed without a time difference, and to accurately monitor the vibration state of the rotating machine operated at variable speed. Can contribute to cost reduction.
In the above configuration, the rotation speed determination unit may determine the rotation speed of the rotating machine based on the frequency analysis data output from the frequency analysis unit twice or more continuously. .

According to the present invention, since the rotational speed can be compared and determined based on the determination result based on a plurality of frequency analysis data, it is possible to determine when the rotation is stopped or during the rotation speed change.
Further, in the above configuration, the peak amplitude of the rotation frequency detected from the vibration frequency analysis data by the rotation number determination unit is an amplitude between a predetermined frequency before and after the first predetermined frequency at the peak amplitude frequency. The ratio of the square sum square root of the amplitude between the second predetermined frequency before and after the second predetermined frequency that is narrower than the first predetermined frequency before and after the square sum square root is equal to or more than a predetermined value. It is characterized by being.

According to the present invention, erroneous determination due to noise can be prevented.
In the above configuration, the rotation speed determination unit detects a peak amplitude at a frequency that is 1/2 and 2 times the frequency indicating the peak amplitude, and the lowest frequency among the detected peak amplitude frequencies. Is calculated as the rotational frequency of the rotating machine.
According to the present invention, even when the maximum peak value is not the primary component of the rotational speed component but the secondary component, the primary component can be determined as the rotational frequency.

Further, in the above configuration, the state determination unit may calculate a coefficient obtained by dividing the maximum rotation number of the rotating machine by the rotation number determined by the rotation number determination unit and then squared, and the vibration of the determined rotation number. A value obtained by multiplying the value is calculated as a vibration value of the maximum rotational speed.
According to the present invention, before operating at the maximum number of rotations, it is possible to grasp the vibration state when the rotating machine is operated at the maximum number of rotations, and to prevent troubles.
Further, in the above configuration, the state determination unit calculates a vibration value of a component twice the driving power supply frequency obtained from a relationship between a rotation frequency and the number of poles of the rotating machine as a vibration value of the electromagnetic vibration component. It is characterized by.

According to the present invention, it is possible to monitor the state of electromagnetic vibration of a rotating machine that is operated at a variable speed.
The vibration monitoring method of the present invention is a vibration monitoring method for a rotating machine performed by a vibration monitoring apparatus, and digital signals indicating vibrations in two orthogonal directions of the rotating machine individually detected by a vibration acceleration sensor, Frequency analysis step of performing frequency analysis by fast Fourier transform processing and outputting frequency analysis data of the vibration as a result of the frequency analysis, and the number of rotations of the rotating machine based on the frequency analysis data output in the frequency analysis step determines a rotational speed determining step, based on the rotational speed is determined in the rotational speed determination step of, and a state determining step of performing a state determination of the vibration of the rotating machine, the rotational speed determining step, the vibration Among the frequencies detected from the frequency analysis data, the frequency is an integer multiple that is 2 or more of the maximum rotational frequency of the rotating machine. The number of rotations of the rotating machine is determined based on a plurality of frequencies included in the order of the magnitude of the peak amplitude up to a predetermined order .

  According to the vibration monitoring apparatus of the present invention, the frequency analysis of the vibration of the rotating machine is performed by the fast Fourier transform process, and the maximum of the rotating machine is detected among the frequencies detected from the frequency analysis data of the vibration as a result of the frequency analysis. The number of rotations of the rotating machine is determined based on a frequency that is equal to or less than twice the rotation frequency and that exhibits the first to nth (n is an integer) peak amplitude, and based on the determined number of rotations In order to determine the state of vibration of the rotating machine, the rotational speed of the rotating machine is accurately determined without providing a dedicated accessory for measuring the rotational speed of the rotating machine, and the vibration of the rotating machine is determined based on the rotational speed. The state can be determined. Compared with the rotation speed detected by an external signal such as a rotation control signal or a rotation detector, it is possible to detect the rotation speed without a time difference, and to accurately monitor the vibration state of the rotating machine operated at variable speed. Can contribute to cost reduction.

It is a block diagram which shows the function structure of the vibration monitoring apparatus comprised by the RFID tag and vibration monitoring part which concern on embodiment of this invention. It is a whole flowchart which shows the procedure of the vibration monitoring process which the vibration monitoring apparatus which concerns on the same embodiment performs. It is a flowchart which shows the procedure of the rotation frequency determination process which concerns on the same embodiment. It is a flowchart which shows the procedure of the rotation frequency determination process which concerns on the embodiment in detail. It is a figure which shows the frequency spectrum for demonstrating the peak occupation frequency which concerns on the same embodiment. It is a frequency distribution figure which shows the peak occupation rate of the peak amplitude which concerns on the same embodiment. It is a figure which shows the rotational frequency determination method which concerns on the same embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(Configuration of vibration monitoring device)
FIG. 1 is a block diagram showing a configuration of a vibration monitoring apparatus according to an embodiment of the present invention. The vibration monitoring apparatus includes an RFID tag 1 and a vibration monitoring unit 8.
In the figure, an RFID tag 1 includes a vibration acceleration sensor 2 configured to detect vibrations of a rotating machine (not shown) formed of a piezoelectric element, an amplification unit 3 that amplifies an analog signal output from the vibration acceleration sensor 2, An A / D conversion unit 4 for converting the analog signal output from the amplification unit 3 into a digital signal, a data storage unit 5 for temporarily storing the converted digital signal, and data storage based on a command from the outside A wireless transmission / reception unit 6 for wirelessly transmitting a digital signal stored in the unit 5 and a power supply unit 7 formed of a battery are provided. Here, the vibration acceleration sensor 2 is provided in two directions in which at least two piezoelectric elements are orthogonal to each other, and can individually detect vibrations in two directions orthogonal to the rotating machine. Note that the vibration acceleration sensor 2 may be configured such that three piezoelectric elements are provided in three directions orthogonal to each other, and vibrations in the three directions orthogonal to each other of the rotating machine can be individually detected.

The amplifying unit 3 includes a charge amplifier 31 that converts the charge output of the vibration acceleration sensor 2 into a voltage, a low-pass filter 32 that uses the output signal of the charge amplifier 31 as a cutoff frequency near the upper limit of the vibration monitoring frequency range, and its output voltage. And a voltage amplifier 33 for amplifying the signal.
The vibration monitoring unit 8 includes a transmission / reception unit 81 for transmitting a digital signal stored in the data storage unit 5 of the RFID tag 1 via the wireless transmission / reception unit 6, a CPU, and a program. The frequency analysis unit 82 that performs frequency analysis of the digital signal received via 81 by FFT processing, a CPU and a program, and shows the vibration displacement, vibration speed, vibration acceleration, etc. output as a result of the frequency analysis A calculation unit 83 that calculates the rotation speed of the rotating machine from the frequency analysis data indicating the frequency spectrum of vibration and determines the vibration state of the rotating machine, and a display unit that displays a calculation result, a determination result, a level trend graph, and the like 84. The calculation unit 83 includes a rotation number determination unit 831 that determines the rotation number of the rotating machine and a state determination unit 832 that determines a vibration state of the rotating machine.

(Vibration monitoring process)
An overall procedure of vibration monitoring processing of the rotating machine performed by the vibration monitoring apparatus having the above configuration will be described with reference to FIG.
The digital signal transmitted from the FRID tag 1 to the vibration monitoring unit 8 is subjected to frequency analysis by FFT in the frequency analysis unit 82 (step S101), and frequency analysis data is output.
Thereafter, in step S <b> 102, the rotation speed determination unit 831 of the calculation unit 83 determines the rotation speed of the rotating machine based on the frequency analysis data output from the frequency analysis unit 82. A detailed procedure for determining the rotation speed in step S102 will be described later.
In step S103, it is determined based on the determination result whether the rotating machine is rotating at a constant speed. When it is determined that the motor is rotating at a constant speed, the process proceeds to the next step.

  In step S104, the state determination unit 832 of the calculation unit 83 estimates the vibration amplitude (vibration value) at the maximum number of rotations preset as the performance of the rotating machine. In the case of a rotating machine composed of a rigid shaft whose natural frequency of the rotating shaft is equal to or higher than the maximum rotating frequency, the vibration of the rotating frequency component is approximately proportional to the square of the rotating frequency, so the state determining unit 832 determines the rotating speed. The square of the value obtained by dividing the maximum rotational speed by the rotational speed determined by the output unit 831 is obtained, and the vibration amplitude at the maximum rotational speed is estimated by multiplying it by the vibration amplitude of the calculated rotational frequency. Thereby, before driving | running by a maximum rotation speed, the vibration state at the time of driving | running a rotary machine at the maximum rotation speed can be grasped | ascertained, and a trouble can be prevented beforehand.

  In step S105, the state determination unit 832 calculates the electromagnetic vibration amplitude (vibration value of the electromagnetic vibration component). When the rotating machine is an AC motor, there is a relationship of N = (120 · f) / P between the rotational speed N, the number P of the rotating machine, and the drive power supply frequency f. By using this, the state determination unit 832 obtains the driving power source frequency f from the rotational speed, so that the electromagnetic vibration amplitude excited at a frequency twice the driving power source frequency f can be obtained even in a variable speed rotating machine. Can be sought. Thereby, the state of the electromagnetic vibration of the rotating machine that is operated at a variable speed can also be monitored.

In step S106, the state determination unit 832 detects the vibration displacement at 2fn and 3fn of the rotation frequency component fn of the rotating machine, and is set in advance as a vibration speed effective value (specified in ISO 10816-1, JIS B 0906). The determination reference value (threshold value) is compared. As a result of the comparison, the state of vibration of the rotating machine such as unbalance and misalignment of the rotating machine is determined.
In step S107, the result of the state determination performed in step 106 is displayed on display unit 84 (step S107).
In step S108, the display unit 84 stores the calculated effective value and vibration displacement in the memory, and in step S109, displays the numerical graph on a trend screen (not shown).
Thus, by obtaining the rotational speed of the rotating machine from the measured frequency analysis data of a plurality of vibrations, the vibration of the rotational frequency component at a constant speed of the rotating machine operating at a variable speed that changes stepwise is obtained. It is possible to determine the state of vibration of the rotating machine.

(Rotation speed judgment process)
Here, with reference to the flowchart shown in FIG. 3, the rotation speed determination process executed by the rotation speed determination unit 831 of the calculation unit 83 in step S102 of FIG. 2 will be described.
Here, the vibration acceleration sensor 2 measures vertical and horizontal vibrations of the rotating machine twice each. Thereby, the transmission / reception unit 81 of the vibration monitoring unit 8 continuously receives the digital signal transmitted from the RFID 1 by the first measurement and the second measurement twice. The frequency analyzing unit 82 analyzes the digital signal received twice each time by FFT to generate frequency analysis data indicating frequency spectrum data of vertical and horizontal vibrations (step S201). Here, the vertical direction and the horizontal direction of the rotating machine include two patterns of a vertical direction and a horizontal direction on a plane orthogonal to the rotating shaft of the rotating machine, and a radial direction and an axial direction of the rotating shaft of the rotating machine. .

The rotation speed determination unit 831 of the calculation unit 83 determines the rotation speed of the rotating machine based on the frequency analysis data output from the frequency analysis unit 82 twice in succession.
First, the rotational speed determination unit 831 detects the maximum peak value and the second peak value of the vibration amplitude from the frequency spectrum of the vibration, respectively (step S202). In the present embodiment, the peak value up to the second is used, but it is also possible to detect up to a predetermined third peak value.
The rotation speed determination unit 831 determines noise from the detected peak value by performing level determination (step S203) and spectrum pattern determination (step S204).

Thereafter, in the rotation order determination in step S205, the rotation basic component (primary component) and its double component (secondary component) are discriminated, and the primary component is detected as the rotation frequency.
There are four processes in the above-described steps S202 to S205 for each of the vertical direction and the horizontal direction twice (V1: vertical first time, V2: vertical second time, H1: horizontal first time, H2: horizontal second time). This is done for the frequency spectrum of vibration.
When the processing has been completed for all the amplitude spectra (step S206: Yes), in the rotation speed determination of step S207, the four rotation frequencies obtained in step S205 (fV1: vertical first rotation frequency, fV2: vertical second time). For example, as shown in FIG. 7, the rotation frequency is determined, and the number of rotations is determined.

The determination as shown in FIG. 7 has the following advantages.
(1) Since the rotation frequency is determined based on the detection results of the rotation frequency a plurality of times, it is possible to determine when the rotation has stopped or when the rotation speed is changing.
(2) When the maximum peak amplitude is the rotation secondary component and the second peak amplitude is the noise component, or vice versa, the rotation frequency is determined as the rotation secondary component (or noise component) in the rotation order determination. If one or two of the results are different, it is re-detected whether the rotation frequency has a peak amplitude, so that erroneous determination can be avoided.
In FIG. 7, the range in which a plurality of detection results are considered coincident is ± 1.875 Hz, but can be set as appropriate according to the purpose of measurement and the operation of the target rotating machine.

(Details of rotation speed judgment process)
Next, the details of the processing from steps S202 to S206 in FIG. 3 will be described with reference to the flowchart shown in FIG.
First, a minimum rotation frequency and a maximum rotation frequency are set in advance as information relating to the performance of the rotating machine. In step S301, the maximum peak amplitude between the minimum rotation frequency and a frequency twice the maximum rotation frequency is set. Amax and its frequency Fmax, and the second peak amplitude Amax2 and its frequency Fmax2 are detected. Here, the amplitude is expressed as a displacement amplitude (μm), but may be an acceleration amplitude. When there are a plurality of detected maximum peak amplitudes, the peak amplitudes with the lowest frequency are Amax and Fmax, and the second peak is a peak at least ± 1.875 Hz away from Fmax. Here, the detection of the maximum peak amplitude and the second peak amplitude is based on the premise that even if there is a peak value due to noise, one of them contains a rotation frequency component. Of course, the third and fourth peak amplitudes may be detected within a non-congested range, but in a normal rotating machine, there is no problem because the rotation frequency component and its harmonic component indicate the peak amplitude.

In the peak level determination in step S302, Amax is compared with a threshold value of the maximum peak amplitude set in advance, and if it is equal to or less than the threshold value, the rotation frequency fn is set to 0 and the process is terminated (step S317). Thereby, it is determined whether the vehicle is rotating or stopped. This threshold value is equal to or higher than the amplitude resolution of the frequency spectrum, and here the displacement amplitude is 1 μm.
When Amax is equal to or larger than the threshold value (step S302: Yes), in peak pattern determination, a square sum square Poa1 between Fmax ± 1.875 Hz is obtained (step S303), and the square sum between Fmax ± 0.625 Hz is obtained. The square root Poa2 is obtained (step S304). When the peak occupancy rate Poa2 / Poa1 is a value of 80% or more, the peak amplitude is determined, and the process proceeds to step S306. Otherwise, it is determined as noise, and peak value determination is similarly performed for the second peak amplitude (steps S314, S316, S302,...).

Here, Poa, for example, in the case of a frequency spectrum based on data having a sampling frequency of 2560 Hz and sampling points of 4096, the frequency resolution is 0.625 Hz, and as shown in FIG. 5, as Poa1 and Poa2, ± 3 points from Fmax, respectively. The square sum of squares of amplitudes between ± 1 points is obtained and the peak pattern is determined.
This is effective when a vibration level is detected by the vibration acceleration sensor 2 and the noise level of a low frequency component of 20 Hz or less becomes a maximum peak value by performing displacement conversion.

According to the experimental investigation, as shown in the frequency distribution shown in FIG. 6, the peak occupancy (Poa2 / Poa1) has a rotational frequency component distributed over 80%, and can be separated from the peak occupancy due to noise. Thereby, it is possible to prevent erroneous determination due to low-frequency noise.
The peak occupancy can be set as appropriate according to the purpose of measurement and the operation of the target rotating machine. The bandwidths of Poa1 and Poa2 vary depending on the frequency resolution, but when Poa2 is set to several Hz, disturbance noise other than the rotational frequency component may be introduced, and it may be ± 1 Hz or less, and Poa1 may be about twice that. .

When the maximum peak value is not determined as the peak amplitude (step S305: No), the second peak value is determined (step S314: No, step S316, step S302,...), And the peak amplitude is also determined there. When it is not determined (step S305: No), the process ends with fn = 0 (step S314: Yes, step S315).
On the other hand, if the peak amplitude is determined (step S305: Yes), the process proceeds to step S306, and the rotation order is determined.

  In steps S306 to S313, the peak amplitude is similarly determined for frequencies that are twice and ½ of the determined peak amplitude Fmax, and Fmax at Amax having the lowest frequency determined as the peak amplitude is rotated. Detect as frequency fn and amplitude fa. Thereby, even when the maximum peak value is not the primary component of the rotational speed component but the secondary component, the primary component can be determined as the rotational frequency and the rotational speed can be determined.

The above rotation speed detection is performed with vibration data measured at least twice successively.
In the detailed description of the rotation speed determination process, the maximum peak amplitude Amax and its frequency Fmax and the second peak amplitude Amax2 and its frequency Fmax2 are detected between frequencies twice the maximum rotation frequency. Alternatively, detection may be performed with the Mth (M2 or greater) peak amplitude AmaxM and its frequency FmaxMm between N times the maximum rotation frequency (N is an integer of 2 or greater). Here, N and M are determined in advance.

  As described above, since the vibration monitoring device is adapted to determine the rotational speed from the vibration frequency component after the FFT processing, without providing a dedicated incidental facility for measuring the rotational speed of the rotating machine, The rotational speed of the rotating machine can be calculated based on the frequency analysis data, and the vibration state of the rotating machine can be determined based on the rotational speed. Compared with the rotation speed detected by an external signal such as a rotation control signal or a rotation detector, it is possible to detect the rotation speed without a time difference, and to accurately monitor the vibration state of the rotating machine operated at variable speed. Can contribute to cost reduction. Further, since the vibration value at the maximum rotation speed is estimated from the vibration value at the low speed rotation and the state is determined, it is possible to determine the state regardless of the rotation speed. Further, since the drive power supply frequency is calculated from the rotation speed and the electromagnetic vibration component is detected, it is possible to constantly monitor.

DESCRIPTION OF SYMBOLS 1 RFID tag 2 Vibration acceleration sensor 3 Amplifying part 31 Charge amplifier 32 Low pass filter 33 Voltage amplifier 4 A / D conversion part 5 Data storage part 6 Wireless transmission / reception part 7 Power supply part 8 Vibration monitoring part 81 Transmission / reception part 82 Frequency analysis part 83 Calculation Unit 84 display unit 831 rotation speed determination unit 832 state determination unit

Claims (7)

A vibration acceleration sensor that individually detects vibrations in two orthogonal directions of the rotating machine;
An amplifying unit for amplifying an analog signal output as a detection result of the vibration from the vibration acceleration sensor;
An A / D converter for digitally converting the analog signal amplified by the amplifier;
A frequency analysis unit that frequency-analyzes the digital signal converted by the A / D conversion unit and outputs the frequency analysis data of the vibration as a result of the frequency analysis;
A rotational speed determination unit that determines the rotational speed of the rotating machine based on the frequency analysis data output from the frequency analysis unit;
A state determination unit that determines a state of vibration of the rotating machine based on the rotation number determined by the rotation number determination unit;
The rotation speed determination unit
Of the frequencies detected from the frequency analysis data of the vibration, the frequency is equal to or less than an integer multiple of 2 or more of the maximum rotation frequency of the rotating machine, and the order of magnitude of the peak amplitude is included by a predetermined order. A vibration monitoring device that determines the number of rotations of the rotating machine based on a plurality of frequencies. The vibration monitoring apparatus according to claim 1,
The vibration monitoring device, wherein the rotational speed determination unit determines the rotational speed of the rotating machine based on the frequency analysis data output from the frequency analysis unit twice or more continuously. In the vibration monitoring apparatus according to claim 1 or 2,
The peak amplitude detected from the vibration frequency analysis data by the rotational speed determination unit is equal to the square sum of squares of amplitudes between predetermined first and second predetermined frequencies in the frequency of the peak amplitude. A vibration monitoring apparatus characterized in that a ratio occupied by a square sum of squares of amplitude between a predetermined second predetermined frequency before and after the predetermined frequency before and after 1 is not less than a predetermined value. . In the vibration monitoring device according to any one of claims 1 to 3,
The rotation speed determination unit detects a peak amplitude at a frequency that is 1/2 and 2 times the frequency indicating the peak amplitude, and sets the lowest frequency among the detected peak amplitude frequencies to rotate the rotating machine. A vibration monitoring apparatus that calculates the frequency. The vibration monitoring apparatus according to any one of claims 1 to 4,
The state determination unit is a value obtained by multiplying the vibration value of the determined rotation number by a coefficient obtained by squaring after dividing the maximum rotation number of the rotating machine by the rotation number determined by the rotation number determination unit, A vibration monitoring apparatus that calculates the vibration value of the maximum rotation speed. In the vibration monitoring device according to any one of claims 1 to 5,
The state determination unit calculates a vibration value of a double component of a driving power supply frequency obtained from a relationship between a rotation frequency and the number of poles of the rotating machine as a vibration value of an electromagnetic vibration component. . A vibration monitoring method for a rotating machine performed by a vibration monitoring device,
A frequency analysis step of performing frequency analysis on a digital signal indicating vibrations in two orthogonal directions of a rotating machine individually detected by a vibration acceleration sensor, and outputting frequency analysis data of the vibration as a result of the frequency analysis;
A rotational speed determination step for determining the rotational speed of the rotating machine based on the frequency analysis data output in the frequency analysis step;
A state determination step for determining a state of vibration of the rotating machine based on the rotation number determined in the rotation number determination step ;
The rotational speed determination step includes
Of the frequencies detected from the frequency analysis data of the vibration, the frequency is equal to or less than an integral multiple of 2 or more of the maximum rotation frequency of the rotating machine, and the order of magnitude of peak amplitude is included by a predetermined order. A vibration monitoring method , comprising: determining a rotational speed of the rotating machine based on a plurality of frequencies .

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