JPH01136032A - Apparatus for monitoring vibration of rotary machine - Google Patents

Abstract

PURPOSE:To accurately monitor abnormal vibration, by operating the vector of vibration synchronous to the number of rotations of a machine to monitor the difference from a reference vibration vector. CONSTITUTION:The output 2a of a vibration sensor 2 detecting the vibration of the rotary shaft 1a of a rotary machine 1 is amplified by an amplifier 3 and the reference position of the rotation of the rotary shaft 1a is detected by a rotary reference position detector 9. The vibration vectors Y1, Y2 of vibration synchronous to the rotary cycle of the machine 1 are operated on the basis of the vibration signal 3a from the amplifier 3 and the rotary reference position signal 9a from the detector 9 by vibration vector operators 101, 102 to be outputted as vibration vector signals 101a, 102a. A vector subtractor 11 operates the differences between the reference vibration vectors Y10, Y20 being the vectors of vibration generated when the machine 1 is normal and the vibration vectors Y1, Y2 to output the same as an abnormal vibration signal 11a which is, in turn, inputted to a comparator 12 and a recorder 13. When the signal exceeds a set value Vr, an alarm 12 emits an alarm signal 12a.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention is a device for monitoring the operating condition of a rotating machine based on the mode of vibration in the rotating machine. The present invention relates to a monitoring device with high reliability of busy monitoring results.

[Conventional technology]

BACKGROUND ART Conventionally, a method of monitoring the vibration state of a rotating machine has been widely adopted for preventive maintenance of the rotating machine. This is 1
This is because when an abnormality occurs in a rotating machine, a noticeable abnormality often appears first in the vibration state 11r+ of the machine, compared to physical quantities such as the temperature in the machine or the sonic sauce emitted by the machine.

Now, FIG. 4 is a block diagram of a conventional vibration monitoring device for a rotating machine. In the figure, 2 is a vibration sensor attached to the rotating machine IK, and this sensor 2 is the rotating shaft 1 of the rotating machine 1.
Displacement of vibration of the journal portion of m in a direction perpendicular to the axis of the shaft 1a (hereinafter, this vibration may be referred to as axial vibration of the rotating shaft 1a).

Alternatively, the vibration displacement of the bearing stand that supports the journal part via a bearing is detected, and an electric signal 2 corresponding to the result of this detection is detected.
It is configured to output a.

In Fig. 4, two sensors 2 are provided, but depending on the 10 types of machines that rotate, and the structure, there are one or three vibration sensors 2.
There may be more than one. 3 is two signals 2al
28 is input, and each of these input signals is amplified and output as vibration signals 3ae and 3b.The vibration signals 3as and 3b are respectively detected by a detector 4 and become DC signals 4a and 4b, and these DC signals 4@ , 4b are all input to the comparator 5 and the recorder 6.
There is. Then, the comparator 5 receives the input DC signal 4a.
, 4b and the set value v built in in advance in the comparator.
When the values of the signals 4a and 4b become equal to or higher than Vs by comparing the signals 4a and 4b with s, the system is configured to output a control signal @@5m. In this case, the set value v3 may be set to different values depending on the signals 4a and 4bVc. Reference numeral 7 denotes a vibration monitoring device consisting of the parts shown in the figure except for the rotating machine 1. Since each part of this device 7 is constructed as described above, a direct current signal 4a is generated.

Each instantaneous value of 4b is the amplitude X of the vibration displacement detected by sensor 2.
This means that it is compatible with K. Then, 1F alarm signal 5m
is output when the displacement amplitude X exceeds the amplitude corresponding to the set value VsVc.

[Problem that the invention seeks to solve]

The vibration monitoring device 7 monitors the vibrations of the one-rotation machine 14) as described above, but in this case there are problems as described below. Hereinafter, this problem will be explained with reference to FIGS. 4, 5, and 6.

FIG. 5 is a vector representation of a vibration spectrum having a frequency F equal to 10 rotations of a rotary machine, among the vibration spectra of various frequencies that constitute signal 3a, for example, among the signals 3a and 3b shown in FIG. Hereinafter, the vector representation of the vibration spectrum having this frequency F may be referred to as a rotation-synchronized vibration vector.

The state in which the phase angle θ is zero in FIG. 5 corresponds to the predetermined rotation angle position of the rotating shaft 1m in FIG.

C1 In general, when a rotating machine 1 is operating normally, the shaft vibration of the rotating shaft 1a that occurs in the rotating machine is 1 rotating shaft 1.
Most of the vibrations are based on the residual unbalance with respect to a, so among the many vibration spectra representing the vibration spectra of various frequencies that make up the signal 3m, the one-rotation period vibration vector is usually the dominant vector. It is self-evident (hereinafter, this vector may be referred to as the normal rotation synchronous vibration vector). If an abnormality occurs in the one-rotation machine 1 and abnormal vibration occurs during shaft vibration of the shaft 1a, the occurrence of such abnormal vibration is due to loosening of fasteners in the rotating body including the one-rotation shaft 1m. creation of new imbalances,
Occurrence of defect in the front rotor The one-rotation part and the stationary part come into abnormal contact. Occurrence of the so-called rubbing phenomenon, 1! tI
Based on changes in the position of the support part of the rotating body (new misalignment, thermal bending in the rotating body, etc. are the common causes) It is clear that among the many vibration vectors with different frequencies in vibration, the rotation synchronous vibration vector is predominant (hereinafter, this vibration vector may be referred to as the abnormal rotation synchronous image motion vector).

In FIG. 5, vector A is an example of a normal rotation synchronous S motion vector when rotating machine I is operating normally.
The vector B1 causes an abnormality in the rotating machine 1, causing the rotation axis 11&
This is an abnormal rotation synchronous vibration vector that appears as signal 3aK when abnormal vibration is added to the signal 3aK. Therefore, in this case, the signal 38 has a vibration waveform having the sum vector AI of vectors 80 and B as a rotational periodic vibration vector, and this vector 81 corresponds to the signal 3a? ：This is the dominant vector among the many vibration vectors with different frequencies, so in the end, in the vibration monitoring system &7&C, the signal 4 is influenced by the magnitude IA, 1K of the vector A.
The magnitude of a is monitored by the comparator 5 in degrees Celsius. In FIG. 5, the vibration vector B1 has a small magnitude at the beginning of the abnormality in the rotating machine 1, but as the abnormality in the rotating machine I progresses, the vibration vector B1 becomes larger than the vector. Suppose a large vector B changes.

At this time, the sum vector of B and 80 becomes the vector person shown in the diagram. However, at this time, the signal 4, which depends on the size of the monitoring device 7 or vector person, depending on the magnitude IA, I
This means that the magnitude of a is monitored, and in the end, the signal 3a
When the vibration vector shown in FIG. 5 appears, the recording result of the signal 4a by the recorder 6 will exhibit a change over time as shown at 100 in FIG. However, in the case of FIG. 6, the magnitude of the signal 4a before and after the time T when the abnormality occurs in the rotating machine IK is a vibration vector B.

B, is a vector with a considerable size, but no significant change appears in spite of the sum; in this case, rather, the signal 4
The magnitude of a tends to decrease after time T1. Therefore, it is clear that in such a case, the % transmission monitoring device 7 cannot detect abnormalities occurring in the rotating machine IK.

That is, in the vibration monitoring device 7 shown in FIG.

Since the magnitude of the signals 3a and 3b in which the rotational synchronous vibration vector is predominant is monitored, even if an abnormality occurs in the rotating machine 1, the magnitude K of the rotational synchronous vibration vector may not change. However, there is a problem that vibration monitoring cannot be performed accurately. In other words, there is a problem in that the reliability of S motion monitoring is low.

The purpose of the present invention is not to monitor the magnitude of the signals 3m and 3b corresponding to the shaft fitting displacement of the one-rotation machine l, but to monitor the magnitude of the abnormal rotation synchronous vibration vector at °C.
It is an object of the present invention to enable accurate vibration monitoring of a rotating machine 1 without causing a change in the magnitude of the sum vector of the vibration vector and a normal rotation synchronous vibration vector.

[Means for solving problems]

In order to solve the above problems, according to the present invention, vibration at at least one vibration detection location of a rotating machine is detected, and a vibration signal corresponding to the detection result is outputted to each of the vibration detection locations. at least one rotational reference position detector that detects a rotational reference position of the rotating machine and outputs a rotational reference position signal according to the detection result; The rotation reference position signal is input, and predetermined signal processing is performed on these two human force signals to calculate a vibration vector of vibration having a frequency equal to the rotational speed of the rotating machine in the vibration signal. a vibration vector calculator corresponding to the vibration detector that outputs a vibration vector signal, and calculates a difference between the vibration vector represented by the vibration vector signal and a built-in reference vibration vector corresponding to the vibration vector signal; and at least one vector subtracter that outputs an abnormal vibration signal according to the magnitude of the difference vector of the calculation result, and monitors the vibration of the rotating machine based on the abnormal vibration signal.

The reference position for rotation of the rotary machine is provided corresponding to the rotation reference position detector, thereby constituting a vibration monitoring device for a rotary machine.

[Effect]

With the above configuration, instead of monitoring the magnitude of the vibration signal as in conventional monitoring devices, the abnormal rotation synchronous vibration vector is obtained as a difference vector obtained by the dynamic hector calculator and the vector subtractor. Since monitoring is performed via an abnormal vibration signal with a magnitude of Even without this, vibrations of the rotating machine shelf can be accurately monitored.

〔Example〕

FIG. 1 is a block diagram of an embodiment of the present invention. In FIG. 1, 8 is a vibration detector consisting of a vibration sensor 2 and an amplifier 3 for amplifying the output signal 2a of the sensor. In this case, two detectors 8 are provided corresponding to the sensors 2. . Reference numeral 9 denotes a rotation reference position detector that detects the rotation reference position of the rotation shaft 1a and outputs a pulse signal 9a as a rotation reference position signal according to the detection result, and the signal 9a is output every time the rotation shaft 1a rotates once. This is a signal in which one pulse is output. i
ol and 102 are the vibration signal 3a and the pulse signal 9.
a is input, these sub-input signals are subjected to power-off signal processing and sent! 3a, the rotational synchronous vibration vectors Y, , Y, of vibrations having the same frequency as the sum of the rotation speeds of the rotating machine l are calculated, and the vibration vector Y1* is calculated.
A vibration vector calculator that outputs vibration vector signals 101a and 102a according to Y and K. In FIG. 1, vector calculators lot and 102 are provided corresponding to each vibration detector 8. . Here, the vibration vector Y.

Y! For example, is a vector as shown in Figure 2.

FIG. 2 is a vector diagram using the phase of the pulse signal 9a in FIG. 1 as a phase reference. 11, vibration vector signals tota and 102a are input.

The vibration vectors Y,,Y that these vector signals represent.

and a reference vibration vector Y, which is built in in advance so as to correspond to each of the signals 101a and 102a,
The difference between o@Y and o is computed, and both signals corresponding to the magnitude of the difference vector (Y1Y+e) - (Yt Yte) of the computed results are alternately repeated to generate the abnormal low motion signal tta. The vector subtracter outputs the reference vibration vector Y11Y. is a normal rotation synchronous vibration vector that appears in the impression signal 38 corresponding to each of the vector computing units tot, 102 when the rotating machine l is operating normally.

Now, assuming that the vector Yl11 is as shown in FIG. 2, the output signal ttaVc of the vector subtractor 11 is the difference vector Z, −
Yl-Y,. If the signal value corresponding to the magnitude lz, + is included.

In FIG. 1, 12 and 13 are both comparators and recorders to which the signal 11a is input. In this case, the comparator 12 outputs an alarm signal 12a when the magnitude of the signal tta is greater than or equal to the built-in set value Vr. The recorder 13 is configured to output the difference vector I'''Zt - Yt which includes the signal ttaVc.
Y+e to WM hect 7L/Z! =Y, -Y@.

It is configured to perform recording for each section corresponding to each section. Reference numeral 14 denotes a vibration monitoring device consisting of each part shown in the figure except for the rotating machine 1. In the monitoring device @14, the set value Vr in the comparator 12 is the difference vector 21.2. are set up corresponding to each of them.

21.2 thus provided. The setting f corresponding to
lijVrt, Vrxt, zl included in signal tta
.

2, so that comparisons can be made with each part corresponding to each of
The comparator 12 may be constructed in a temperature range as low as 0°C.

Since the vibration monitoring device 14 is configured as described above, the above-mentioned difference vector 2.
, 2. It is clear that is the above-mentioned abnormal rotation synchronous vibration vector, and therefore, in this monitoring device 14, the magnitude of this abnormal rotation synchronous vibration vector is monitored by the comparator 12 and the recorder 13. Therefore, according to such a viewing device 14, there is no large change in the amplitude of the vibration signal 3a, which is influenced by the magnitude of the sum vector of the abnormal rotation synchronous vibration vector and the normal rotation synchronous vibration vector, and the degree of temperature changes. , abnormality monitoring of the °C rotating machine 1 can be performed with high reliability.

FIG. 3 shows an example of the results recorded by the recorder 13.

15 in FIG. 3 is a recording line corresponding to the difference vector z1. When an abnormal state occurs in the rotating machine 1, the magnitude of the normal difference vector Z is small at the beginning of the abnormal state, but gradually becomes larger.

The recorder 15 forms a curve that increases over time as shown. However, the recording line recorded in °C by the recorder 6 of the vibration monitoring device 7 mentioned in 111I is! Since the recording line 100 shown in the above-mentioned pattern shows a temporal pattern, the vibration monitoring device 14
, the rotating machine 16 is activated before the alarm signal 12a is output.
Another advantage is that it is possible to detect the occurrence of an abnormal condition at c.

In the above embodiment - CG? In the present invention, C is assumed to be output from the vector subtractor 11 as a time-series signal.

It is clear that the two signals corresponding to each of the difference vectors Zl + Z accents from the vector subtractor 11 may be summed so that they are output in parallel; in this case, the comparator! Of course, the recorder 2 and the recorder 13 are formed to correspond to such a signal output mode.

In addition, in FIG. 1, two vibration detectors 8 are provided, but in the present invention, one or three or more vibration detectors 8 may be provided. In addition, a plurality of rotation reference position detectors 9 are provided, and the rotation reference positions of the rotating machine detected by each of these detectors are provided in the same number as the number of rotation reference position detectors so as to correspond to each of these detectors. Temperatures as low as ℃ are acceptable. Further, although in FIG. 1, one vector subtractor 11 is provided to calculate the temperature in degrees Celsius, it is obvious that a plurality of such vector subtractors may be provided in the present invention.

〔Effect of the invention〕

As described above, the present invention includes a vibration detector corresponding to each of the vibration detection locations that detects vibrations at at least one vibration detection location of a rotating machine and outputs a vibration signal according to the detection result. One rotation reference position detector that detects the rotation reference position of a rotating machine and outputs a rotation reference position signal according to the detection result (one rotation reference position detector, one vibration signal, and one rotation reference position signal) Performing predetermined signal processing on these input human force signals.C. Calculating a vibration vector of vibration having a frequency equal to the rotational speed of the rotating machine in the vibration signal and outputting a vibration vector location corresponding to the vibration vector. A vibration vector calculator corresponding to the vibration detector calculates the difference between the vibration vector represented by the vibration vector signal and the built-in reference vibration vector corresponding to the vibration vector signal, and the magnitude of the difference vector of this calculation result depends on the and at least one vector subtractor that outputs an abnormal vibration signal, and the vibration of the rotating machine is monitored based on the abnormal vibration signal, and the rotation reference position of the rotating machine at 1 °C corresponds to the rotation reference position detector. A vibration monitoring device for a one-rotation machine was constructed in such a manner as to be provided as follows.

Therefore, with the above configuration, instead of monitoring the magnitude of vibration signals as in conventional monitoring devices, abnormal rotation synchronization is performed as a difference vector obtained by the action of a vibration vector calculator and a vector subtracter. Since the magnitude of the vibration vector will be monitored via the normal vibration signal, the present invention requires the magnitude of the sum vector of the abnormal rotation periodic vibration vector and the normal rotation synchronous vibration vector.
This has the effect of accurately monitoring the vibration of a rotating machine even if there is no large change in the amplitude of the affected vibration signal. Furthermore, in the present invention, since the abnormal rotation synchronization vector is monitored,
It also has the effect of allowing early detection of abnormalities in rotating machinery.

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram of a vibration monitoring device according to an embodiment of the present invention, Fig. 2 is an explanatory diagram of the operating principle of the embodiment shown in Fig. 1, and Fig. 3 is an explanatory diagram of the operation of the main parts in Fig. 1. , FIG. 4 is a block diagram of a conventional vibration monitoring device, FIG. 5 is a diagram illustrating problems in the monitoring device shown in FIG. 4, and FIG. 6 is a diagram illustrating the operation of main parts in FIG. 4. 1...Rotating machine, 1m...Rotating shaft, 3
a, 3b... Vibration signal, 7.14...
Vibration monitoring device, 8 vibration detectors. 9...Rotation reference position detector, 9m...
・Rotation reference position signal, 11...Vector subtractor, eye a---Abnormal vibration signal, tot, 102
... Vibration vector calculator, tota. 102 a --- Vibration vector signal, A6 + A
th AHm 131 mB, , Y, , Y,
...Rotation synchronous vibration vector, Yl, ...Reference vibration vector, Z, ...Difference vector. Notebook 2 Mouth □ Time (T) 1 3 Closed note 4 Diagram

Claims (1)

[Claims] a vibration detector corresponding to each of the vibration detection locations that detects vibrations at at least one vibration detection location of the rotating machine and outputs a vibration signal according to the detection result; at least one rotational reference position detector that detects and outputs a rotational reference position signal according to the detection result; one vibration signal and one rotational reference position signal are input; A vibration vector calculation corresponding to the vibration detector that performs signal processing to calculate a vibration vector of vibration having a frequency equal to the rotational speed of the rotating machine in the vibration signal, and outputs a vibration vector signal corresponding to the vibration vector. calculates the difference between the vibration vector represented by the vibration vector signal and a built-in reference vibration vector corresponding to the vibration vector signal, and outputs an abnormal vibration signal according to the magnitude of the difference vector as a result of this calculation. at least one vector subtractor, the vibration of the rotating machine is monitored based on the abnormal vibration signal, and the reference position of rotation of the rotating machine is provided corresponding to the rotation reference position detector. A vibration monitoring device for rotating machinery, characterized in that: