JPH04276555A - Method for detecting number of rotation of rotary machine - Google Patents

Abstract

PURPOSE:To make it possible to detect the number of rotation of a shaft by analyzing the frequency of a detected signal which represents the state of a rotary machine, comparing the spectrum value which is extracted in an arbitrarily set frequency region with a known spectrum value, and judging the result. CONSTITUTION:In a condition setting part 2, the number of rotation of an input shaft and a spectrum value are used as references (or centers) when the initial values of a rotary machine to be measured M are registered, and a frequency region for retrieving and a reference value for the number of rotation of the input shaft are set. A data sampling part 3 latch the vibration data from the vibration sensor of the machine M. In a data analyzing part 4, the frequencies of the data are analyzed. In a number-of-rotation detecting part 5, the spectrum value S1 at the initial registration is compared with the maximum value S2 in measurement in the preset 2 region. When the ratio S2/S1 is the specified value (e.g. 80%) or more, the frequency having the value S2 is determined as the number of rotation of the rotary shaft. In a database part 6, various data such as the spectrum value at the initial registration for each frequency of each rotary machine are stored.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] In equipment diagnosis of rotating machines using the vibration method, when measuring the shaft rotational speed of rotating machines such as fans, reducers, and separators, the system automatically analyzes vibration data by frequency analysis. The present invention relates to a method of detecting the shaft rotation speed of a rotating machine by detecting a vibration spectrum value having a peak near the frequency of the rotating shaft.

0002

[Prior Art] Conventionally, in equipment diagnosis of rotating machinery,
When determining the basic shaft rotation speed, the input shaft rotation speed is measured using a rotation speed measuring device, and the shaft rotation speed is determined based on the measurement result. Therefore, when diagnosing the equipment of rotating machinery, we first detect the basic shaft rotational speed using a rotational speed measuring device, and then use the obtained rotating shaft rotational frequency and equipment specifications of the rotating machinery to detect the basic shaft rotational speed. Equipment diagnosis of rotating machinery is performed using abnormality symptom data obtained from each specific spectral component value corresponding to each damage obtained.

0003

[Problems to be Solved by the Invention] However, in the conventional shaft rotation speed detection method for equipment diagnosis of rotating machines, a rotation speed measuring device is required, and due to the measurement accuracy of the rotation speed measuring device, The rotating shaft rotational frequency data cannot be used directly, and as a result, separate work and processing is required to correct the rotating shaft rotational frequency to a value that can be compared with the measured vibration spectrum data. However, there was a problem in that the effect could not be fully expected. In addition, in the online system, since a rotation speed measuring device is installed in each of a large number of rotating machines, there is also a problem that the installation cost becomes large. Therefore, an object of the present invention is to detect the shaft rotation speed of a rotating machine from vibration data indicating the state of the rotating machine without using a rotation speed measuring device.

0004

[Means for Solving the Problems] In order to achieve the above-mentioned object, the present invention analyzes the frequency of a detection signal representing the state of a rotating machine, and analyzes the frequency of a detected signal representing the state of a rotating machine to obtain the same result as a spectrum value extracted within an arbitrarily set frequency domain. This method detects the shaft rotation speed of a target rotating machine by comparing and determining a known spectrum value in the frequency domain. That is,
When detecting the rotation speed of a rotating machine using the vibration method, in advance,
A spectral value indicating the initial value of the rotational frequency of the rotating shaft to be sought is registered as a reference value, and then vibration data is collected from the target rotating machine and frequency analyzed to determine the frequency extracted within that frequency range. The extracted vibration spectrum value is compared with the known pre-registered spectrum value indicating the initial value of the rotating shaft rotation speed, and if the extracted vibration spectrum value is greater than or equal to the predetermined value of the spectrum value indicating the initial value, this vibration is detected. The frequency having the spectral value is determined as the rotation speed of the rotating shaft.

[0005]

[Operation] Therefore, in equipment diagnosis, the present invention can detect the rotational speed of the rotating shaft of the target rotating machine without using a dedicated rotational speed measuring device, so the rotational speed can be detected automatically at low cost. can do.

[0006]

Embodiments Hereinafter, embodiments of the present invention will be explained in detail with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of a device to which the method for detecting the rotation speed of a rotating machine according to the present invention is applied. In the figure, 1 is a starting point terminal section, 2 is a condition setting section, 3 is a data collection section, 4 is a data analysis section, 5 is a rotation speed detection section, 6 is a database section, and 7 is an end point terminal section.

Next, the operation of the above device will be explained based on the flowchart shown in FIG. In the condition setting section 2, in order to detect the input shaft rotation speed of the target rotating machine, first,
At the time of initial registration of the rotating machine, a frequency range to be searched and a reference value for the input shaft rotation speed are set using the frequency and spectrum value of the input shaft rotation speed as a reference (or center) (step 10). The data acquisition section 3 acquires vibration data from a vibration sensor attached to the target rotating machine (step 11), and the data analysis section 4 analyzes the frequency of the vibration data acquired by the data acquisition section 3 (step 11). 12). Then, the rotation speed detection section 5
Now, the spectrum value S1 at the time of initial registration and the condition setting section 2
In the region set by (l1 ≦frequency ≦l2), it is determined whether the rotating machine The input shaft rotation speed is detected (step 13). Note that the database unit 6 stores various information such as spectrum values at the time of initial registration at each frequency of each rotating machine.

Next, in FIG. 3, a method for determining the rotational speed of the input shaft of a rotating machine will be illustrated. Note that (a) in the same figure is a detection signal waveform diagram near the input shaft rotation speed at the time of initial registration, and (b) is a detection signal waveform diagram when the input shaft rotation speed is detected during measurement. (c) shows a detection signal waveform diagram when the input shaft rotation speed is not detected during measurement. As described above, in the region (l1≦frequency≦l2) set by the condition setting unit 2, first, the maximum value S2 or S3 of the spectrum value at the time of measurement is searched. Next, the ratio S2 to the spectrum value S1 at the time of initial registration
/S1 or S3 What percentage is /S1 (e.g. 80%
, here it is assumed to be N) or more. In this case, S2 /S1 or S3 /S1 is N
If it is above, the frequency of S2 or S3 is adopted as the input shaft rotation frequency, but if it is less than N, the frequency is not adopted as the input shaft rotation speed. By the method described above, it becomes possible to systematically and simply detect the shaft rotation speed of a rotating machine without using a rotation measuring device.

[0009]

Effects of the Invention As explained above, when detecting the rotational speed of the rotating shaft, which is the basis for equipment diagnosis of rotating machinery, the present invention uses the data analysis result of the detection signal and the initially registered known rotating shaft rotational speed. Since the rotation speed of the rotating shaft can be detected by comparing the spectral value of , the rotation speed can be accurately detected without using a rotation measuring device.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a device to which a rotation speed detection method for a rotating machine according to the present invention is applied.

FIG. 2 is a flowchart explaining the operation of this device.

FIG. 3 is a detection signal waveform diagram illustrating determination of the rotation speed of a rotating machine.

[Explanation of symbols]

1 Starting point terminal section 2 Condition setting section 3 Data collection section 4 Data analysis section 5 Rotation speed detection section 6 Database 7 End point terminal section f1 Input rotation speed at initial registration f2 Input rotation speed at measurement f3 Within the set frequency range at measurement Frequency S1 of maximum spectral value at spectral value S2 of input rotation speed at initial registration
Spectrum value S3 of the input rotation speed during measurement Maximum spectrum value l1 within the set frequency range during measurement Lower limit value of the frequency to be set l2 Upper limit value of the frequency to be set

Claims (1)

[Claims] Claim 1: In a method for measuring the shaft rotation speed of a rotating machine, a detection signal representing the state of the rotating machine is frequency-analyzed, and a spectral value extracted within an arbitrarily set frequency range and a spectrum value within the same frequency range are analyzed. A rotation speed detection method for a rotating machine, characterized in that the shaft rotation speed of a target rotating machine is detected by comparing and determining a known spectrum value.