JPH03287021A - Rotary part abnormallity detecting device for rotary machine - Google Patents

Abstract

PURPOSE:To detect abnormality of a rotary part by providing shaft vibration detectors at an interval in the axial direction of a rotary shaft, generating a shaft vibration Lissajous vector, and providing a vector arithmetic circuit and a comparator. CONSTITUTION:Detectors 19a and 19b detects the vibrations of rotary shafts 12 and 14 nearby bearings 15, 16, and 18. The vector arithmetic circuit 30 puts the shaft vibrations together to find the composite Lissajous vector. The absolute value maximum vector of the shaft vibrations is calculated. Then the relative difference (difference in absolute value) vector between the shaft vibrations is calculated. Each signal v1 of this relative difference vector is sent to a comparator 21. The set vector of the normal operation characteristic of the rotary machine 10 is calculated by a decision value calculating circuit 25 from a fall fp, active electric power fd, etc., and a set vector signal vs is sent to the comparator 21. When the comparison value exceeds a specific value, an output vo is sent to an alarm circuit 22 to display the abnormal place on a display unit 23 and generate an alarm by a warning device 24.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to an abnormality detection device for a rotating part of a rotating machine, and particularly relates to a rotating shaft that is rotatably supported by a plurality of bearings. The present invention relates to a rotating part abnormality detection device for a rotating machine that detects runout.

(Prior Art) In recent years, the scale of plants in general industries has become larger and larger, and the rotating machines used in the plants have also become larger accordingly. Since these rotating machines are required to have high reliability, maintenance and inspections are strictly performed to prevent accidents and the like.

An outline of this type of apparatus for detecting an abnormality in a rotating part of a rotating machine in a large plant will be explained with reference to FIGS. 5, 6, 7, and 8. That is, FIG. 6 shows a rotating machine 10 in which a rotating shaft 14 of a vertical water turbine 13 is directly connected to a rotating shaft 12 of a vertical rotating electric machine 11 in a hydroelectric power plant or the like.

The rotating shaft 12.14 is provided with an upper guide bearing 15, a lower guide bearing 16, a thrust bearing 17, a water wheel guide bearing 18, etc., and these rotating shafts 13.14 are rotatably supported.

As shown in FIG. 7, an appropriate distance Mg is placed around each rotating shaft 12.14 close to the guide bearing 15.16, thrust bearing 17, etc. in the radial direction, and 90° in the circumferential direction.
shaft runout detectors 19a such as gap sensors spaced apart;
19b is provided.

The shaft runout of each detection section detected by these detectors 19a and 19b is as shown in FIGS. 8(a), (b), and (C), and this shaft runout signal f1 is as shown in FIG. The signal is sent to the arithmetic circuit 20 of the rotating part abnormality detection device A of the rotating machine, and the absolute value and signal f2 of the amplitude values A1, A2, and A3 are calculated. This absolute signal and amplitude signal f2 are sent to a comparator 21 and compared with set values a1, a2, and a3 predetermined by each rotating shaft 12.14.

In this comparison, the absolute signal and amplitude signal f2 are set at the set value a1.
, a2, a3, an abnormality signal f.

is output and this output signal fo is sent to the alarm circuit 22. In the alarm circuit 22, this output signal fO is processed, and the processed signal foo is sent to an abnormality display device 23 and an alarm device 24 for abnormality display or warning.

The set value a to be compared by the comparator 21 in such abnormality detection
1, a2, and a3 differ depending on the head, active power, etc. in the case of a hydroelectric power plant. Therefore, the head signal fd, the active power signal fp, etc. are sent to the determination value calculation circuit 25, and set values a1, a2, a3 of each detection position, etc. are calculated as parameters based on these signals. This setting value a1, a2, a
The setting signal fs of No. 3 is sent to a comparator 21, and this setting signal fs is compared with the bus pair signal and the amplitude signal f2.

The shaft runout signal f1, absolute value and amplitude value signal f2, abnormal signal fo, output signal foo, head signal fd, and active power signal fp are each sent to the recording device 26 and recorded for rechecking.

(Problem to be solved by the invention) Detector 1 of such a rotating part abnormality detection device A of a rotating machine
9a and 19b are provided on the outer periphery close to the rotating shaft] 2.14, and are provided with an upper guide bearing 15 and a lower guide bearing 16.
, the vibration of the rotating shaft 12.14 near the thrust bearing 17, the water wheel guide bearing 18, etc. is constantly detected to detect the presence or absence of an abnormal state.

Such detection is performed when the rotating shaft 12.1 is close to the upper guide bearing 15, the lower guide bearing 16, the water turbine guide bearing 18, etc.
4 and its vibration (Fig. 8(a)(b)(c)
) The presence or absence of an abnormal state is detected based on the magnitude of (see ). Although this detection is simple, there is a problem in that since the magnitude of shaft runout is determined only by each detection section, it is not possible to quickly and accurately grasp the effect on the entire rotating shaft system.

The present invention provides a rotating part abnormality detection device for a rotating machine developed to solve the above problem.

[Structure of the invention]

(Means for Solving the Problems) The present invention provides a rotating part abnormality detection device for a rotating machine in which a rotating shaft is rotatably supported by a plurality of bearings.
A plurality of shaft runout detectors are installed at intervals in the axial direction of the rotating shaft, and the shaft runout Lissajous vector of each detection part is formed from the detection values of these detectors, and its absolute maximum vector is determined. A vector calculation circuit is provided to calculate a difference vector between the two, and a comparator is provided to compare this difference vector with the normal state vector and calculate the absolute value and phase angle with respect to the normal state vector.

(Function) The shaft runout of the rotating shaft supported by each bearing is detected by a detector, and the absolute maximum vector of the shaft runout surge vector is extracted from the f≦ signal detected by this detector. A difference vector between each detection unit is calculated from this absolute maximum vector, and the difference vector is compared with the normal state vector signal. By this comparison, the absolute value with the normal state vector,
Abnormal oscillations in the overall phase angle are detected.

(Embodiment) An embodiment of the rotating part abnormality detection device for a rotating machine according to the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a block diagram showing an outline of a rotating part abnormality detection device B for a rotating machine according to the present invention. This rotating machine abnormality detection device B is basically the same as the rotating machine abnormality detection device A shown in FIG. 5, except that the arithmetic circuit 20 is replaced with a vector calculation circuit 30.

In the rotating part abnormality detection device B of a rotating machine configured as described above, an upper guide bearing 15 and a lower guide bearing 16 are provided.
, a rotating shaft 12.14 adjacent to the water wheel guide bearing 18, etc.
The shaft runout is detected by the detector 19a.

19b.

The shaft runout detected by these detectors 19a and 19b is combined by a vector calculation circuit 30 to obtain a behavioral composite Lissajous vector for each shaft runout (see FIG. 3).

Rotation axis 12.14 from this behavior composite Lissajous vector
The maximum absolute value vector Vl, (AI, β1), V2 (A2. B
2), V3 (A3.B3) are extracted by calculation.

Next, the maximum absolute value vectors Vl (AI, β1), V2 (A2.
B2), V3 (A3.B3), the relative difference vector between each shaft runout, that is, A1(Aln, β1n
)-V3-Vl is calculated by the vector calculation circuit 30 (see FIG. 4).

This relative difference vector Δ1(Aln, θin), A
2 (A2n, β2n), A3 (A3n, β
Each signal vl of 3n) is sent to a comparator 21 and compared with the set vector Δ1 o sΔ20, A30.

By the way, the normal operating characteristics of the rotating machine 10 exhibit different values depending on the head fp, active power fd, etc. Therefore, the head fp,
Setting vectors Δ1o (Bl, β1), Δ2o of the normal operation characteristics of the rotating machine 10 determined from the value of the active power fd, etc.
(B2.B2) and Δ3o (B3.B3) are calculated by the judgment value calculation circuit 25, and each setting vector signal vs is sent to the comparator 21.

In the comparator 21, the relative difference vectors Δ1, A2, A3
and the set vector Δ10%Δ2 o sΔ3o are compared, and if the comparison value exceeds a predetermined value, an output signal vo is generated.

When abnormal vibration occurs in a certain part of the rotating shaft 12.14, for example, in the rotating shaft 12 of the upper guide bearing 15, each signal vl of the relative difference vectors Δ1, A2, and A3 is Of course, the change in the rotating shaft 12 is large, but the entire shaft system is also changed greatly. This overall change in the axis system is represented by relative difference vectors Δ1, A2, A
3, and the behavioral state of the entire rotating shaft 12, 14 can be detected early and accurately.

The output signal vo of these relative difference vectors is sent to the alarm circuit 2.
2, the location is displayed as abnormal on the abnormality display 23, and an alarm is issued by the alarm 24.

In this way, the axial runout of the rotating shaft of a rotating machine is extracted as a Lissajous vector, and the relative difference vector of its absolute value is determined, and the vibration of the rotating shaft is detected from that value. Axial runout can be detected accurately overall.

In the above embodiment, the rotary shaft is supported by three bearings, but the number of bearings may be two, or the vibration of three or more bearings may be measured.

Further, although a vertical rotation axis is assumed as the rotation axis, a horizontal rotation axis can also be detected using substantially the same method.

〔Effect of the invention〕

The rotating part abnormality detection device for a rotating machine of the present invention rotatably supports a rotating shaft by a plurality of bearings, and a detector for detecting shaft runout is attached close to each bearing of the rotating shaft. Connect a vector calculation circuit that calculates the shaft runout surge vector and difference vector from the signal, compare the difference vector calculated by this vector calculation circuit with the normal state vector, and calculate the absolute value of the shaft runout of the rotating shaft from the comparison value. Since the phase angle is calculated, it is possible to comprehensively detect abnormal vibrations of the rotating shaft, and also to accurately detect abnormal portions.

[Brief explanation of drawings]

FIG. 1 is an electrical block diagram showing the main parts of the rotating part abnormality detection device for a rotating machine of the present invention, FIG. 2 is an explanatory diagram showing the main structure of the rotating machine to be detected, and FIG. Fig. 1 is a diagram of the rotation axis surge vector calculated by the rotating part abnormality detection device of a rotating machine, Fig. 4 is an absolute difference vector diagram of the surge vector calculated by Fig. 3, and Fig. 5 is a diagram of the absolute difference vector of the surge vector calculated by Fig. 3.
An electrical block diagram showing the main parts of a conventional rotary machine rotating part abnormality detection device, Fig. 6 is an explanatory diagram showing the main configuration of the rotating machine to be detected, and Fig. 7 is an electrical block diagram showing the main components of the rotating machine to be detected. FIG. 8, an explanatory diagram illustrating the arrangement of the detectors for detection, is a vibration waveform diagram detected by the detector of FIG. 7. 10... Rotating machine, 11... Rotating electric machine, 12.14
...Rotating shaft, 13...Water wheel, 15.16.18...
・Bearing, 17... Thrust bearing, 19a, 19b
...Detector, 20...Arithmetic circuit, 21...Comparator, 22...Alarm circuit, 23...Abnormality display circuit, 24
...Alarm device, 24...Judgment value calculation circuit, 26...
Recording circuit, 3o...vector calculation circuit.

Claims (1)

[Claims] In a rotating part abnormality detection device for a rotating machine in which a rotating shaft is rotatably supported by a plurality of bearings, a plurality of shaft runout detectors are installed at intervals in the axial direction of the rotating shaft,
A vector calculation circuit is provided to form the shaft runout Lissajous vector of each detection part from the detection values of these detectors, find its absolute maximum vector, and calculate the difference vector between each detection part, and convert this difference vector into a normal state vector. 1. An abnormality detection device for a rotating part of a rotating machine, comprising a comparator that calculates an absolute value and a phase angle with respect to a normal state vector.