JP2909134B2 - Abnormality detector for rotating parts of rotating machinery - Google Patents

Description

Description: Object of the Invention (Field of Industrial Application) The present invention relates to an apparatus for detecting an abnormality in a rotating part of a rotating machine, and in particular, to a shaft of a rotating shaft rotatably supported by a plurality of bearings. The present invention relates to a rotating part abnormality detecting device for a rotating machine that detects run-out.

(Prior Art) In recent years, the scale of plants in general industry has been reduced to a large size, and accordingly, rotary machines used in the plants have also become large. Since high reliability is required for these rotating machines, maintenance and inspection are strictly performed to prevent accidents and the like.

An outline of this type of rotary unit abnormality detecting device for a rotary machine of a large plant will be described with reference to FIGS. 5, 6, 7, and 8. FIG. That is, FIG. 6 shows a rotating machine 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.
10 is shown. The rotating shafts 12, 14 are provided with an upper guide bearing 15, a lower guy bearing 16, a thrust bearing 17, a water turbine guide bearing 18, and the like, and these rotating shafts 12, 14 are rotatably supported.

As shown in FIG. 7, an appropriate distance g is provided in the radial direction around the rotating shafts 12 and 14 close to the guide bearings 15, 16 and the thrust bearing 17 and a 90 ° interval in the circumferential direction. And shaft runout detectors 19a and 19b such as gap sensors.

The shaft runout of each detector detected by these detectors 19a and 19b is as shown in FIGS. 8 (a), 8 (b) and 8 (c), and this shaft runout signal f1 is shown in FIG. The signal f2 of the absolute value and the amplitude values A1, A2, A3 is sent to the arithmetic circuit 20 of the rotating part abnormality detecting device A of the rotary machine, and is calculated. The absolute signal and the amplitude signal f2 are sent to the comparator 21, and the rotation axes 12, 14
Are compared with preset values a1, a2, and a3.

In this comparison, the absolute signal and the amplitude signal f2 are equal to the set value a1,
Above a2 and a3, an abnormal signal fo is output and this output signal
fo is sent to the alarm circuit 22. In the alarm circuit 22, the output signal fo is processed, and the processed signal foo is sent to the abnormality display device 23 and the alarm device 24 to perform an abnormality display or an alarm.

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 drop signal fd, the active power signal fp, and the like are sent to the determination value calculation circuit 25, and the set values a1, a2, and a3 of the respective detection positions are calculated as parameters based on these signals. The setting signal fs of the setting values a1, a2, a3 is relatively
The setting signal fs is compared with the absolute signal and the amplitude signal f2.

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

(Problem to be Solved by the Invention) Detector of Rotary Part Abnormality Detecting Apparatus A for Such a Rotating Machine
19a, 19b are provided on the outer peripheral portion close to the rotating shafts 12, 14,
Vibrations of the rotating shafts 12, 14 close to the upper guide bearing 15, the lower guide bearing 16, the thrust bearing 17, the turbine guide bearing 18, and the like are constantly detected, and the presence or absence of an abnormal state is detected.

Such detection is performed separately on the rotating shafts 12 and 14 close to the upper guide bearing 15, the lower guide bearing 16, the water turbine guide bearing 18 and the like, and their vibrations (see FIGS. 8 (a), (b) and (c)).
The presence / absence of an abnormal state is detected based on the magnitude of the error. Although this detection is simple, there is a problem that it is not possible to quickly and accurately grasp the state of exertion on the entire rotating shaft system because the magnitude of the shaft runout is performed only by each detecting unit.

SUMMARY OF THE INVENTION The present invention is to provide a rotating unit abnormality detecting device for a rotating machine developed to solve the above-mentioned problem.

[Configuration of the invention]

(Means for Solving the Problems) The present invention provides a plurality of bearings provided at intervals in the axial direction of a rotating shaft, and detects shaft runout in the circumferential direction of the rotating shaft close to these bearings. Attach a shake detector, form a shaft shake Lissajous vector of each detection unit from the detection values detected by these shaft shake detectors, calculate the absolute maximum vector, and calculate a difference vector between the detection units. And a comparator for comparing the difference vector calculated by the vector calculator with the normal state vector and calculating the absolute value and the phase shift angle with the normal state vector.

(Operation) In the rotating part abnormality detecting device of the rotating machine of the present invention, shaft contact supported by a square bearing is detected by a detector, and a detection signal of the detector is vector-operated to extract a Lissajous vector of shaft runout. A difference vector between the angle detectors is calculated from the absolute maximum vector, and the difference vector is the absolute value of the normal state vector and the phase angle of the phase angle. Is calculated and the Abnormal vibration of the entire rotating shaft is detected based on the magnitude of.

(Embodiment) An embodiment of the apparatus for detecting abnormality of a rotating section of 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 unit abnormality detecting device B of a rotating machine according to the present invention. The rotating machine abnormality detecting device B of the rotating machine is basically the same as the rotating machine abnormality detecting device A of the rotating machine shown in FIG. 5 except that the arithmetic circuit 20 is replaced by a vector arithmetic circuit 30.

Rotary part abnormality detecting device B for a rotary machine configured as described above
In the upper guide bearing 15, the lower guide bearing 16,
Shafts of the rotating shafts 12, 14 close to the water turbine guide bearings 18 and the like are arranged at appropriate distances in the radial direction and 90 ° in the circumferential direction, such as gap sensors, as shown in FIG. It is detected by the shake detectors 19a and 19b.

The shaft runouts detected by the detectors 19a and 19b are combined by the vector calculation circuit 30 to obtain a behavioral combined Lissajous vector of each shaft runout (see FIG. 3). From this behavioral synthesis Lissajous vector, the rotation axes 12, 14
Absolute value maximum vector in which the axis runout changes most greatly ▲
▼ (A1, θ1) 、 ▲ ▼ (A2, θ2) 、 ▲ ▼ (A
3, θ3) is obtained by calculation.

Next, the absolute value maximum vectors ▲ ▼ (A1, θ1), ▲ ▼ (A2, θ2), ▲ ▼
From (A3, θ3), the relative difference vector between each axis runout, ie, ▲ ▼ (A1n, θ1n) = ▲ ▼-▲ ▼, ▲
▼ (A2n, θ2n) = ▲ ▼-▲ ▼, ▲ ▼ (A3
(n, θ3n) = ▲ -− is calculated by the vector calculation circuit 30 (see FIG. 4).

This relative difference vector ▲ ▼ (A1n, θ1n), ▲
Each signal v1 of ▼ (A2n, θ2n) and ▲ ▼ (A3n, θ3n) is sent to the comparator 21, and the setting vectors ▲ ▼, ▲
Compared with ▼, ▲ ▼.

Incidentally, the normal operation characteristics of the rotating machine 10 show different values depending on the head fp, the active power fd, and the like. Therefore, the setting vectors ▲ ▼ (B1, β1), ▲ ▼, (B2, β
2) and ▲ ▼ (B3, β3) are calculated by the judgment value calculation circuit 25, and the respective set vector signals vs are sent to the comparator 21.

At 21, the relative difference vectors ▲ ▼, ▲ ▼, ▲
▼ and setting vector ▲ ▼, ▲ ▼, ▲
Are compared, and when the comparison value exceeds a predetermined value, an output signal vo is generated.

These relative difference vectors ▲ ▼, ▲ ▼, ▲ ▼
When abnormal vibration occurs in a certain portion of the rotating shafts 12, 14, for example, the rotating shaft 12 of the upper guide bearing 15 portion, the change of the upper rotating shaft 12 in which the abnormal vibration occurs is large. Of course, the entire axis meter can be greatly changed.
This overall change in the axis system is calculated using the relative difference vectors ▲ ▼, ▲
By detecting as ▼ and ▲ ▼, the behavior state of the entire rotating shafts 12 and 14 can be detected early and accurately.

The output signal vo of these relative difference vectors is output from the alarm circuit 22.
The alarm is displayed 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 the rotating machine is extracted as a Lissajous vector, the relative difference vector of the absolute value is obtained, and the vibration of the rotary shaft is detected from the value. Can be accurately detected.

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

In addition, although a vertical rotation axis is assumed as the rotation axis, a horizontal rotation axis can be detected by a substantially similar method.

〔The invention's effect〕

According to the present invention, a plurality of bearings are provided at intervals in the axial direction of the rotary shaft, and a plurality of shaft runout detectors for detecting shaft runout in a circumferential direction of the rotary shaft close to these bearings are attached. A vector calculator for forming an axial runout Lissajous vector of each detector from the detection value detected by the shake detector, obtaining an absolute maximum vector thereof, and calculating a difference vector between the detectors is provided. A comparator is provided to compare the difference vector with the normal state vector and calculate the absolute value and the phase shift angle with the normal state vector, so that abnormal vibrations of the rotating shaft can be detected as a whole and abnormal parts can be detected accurately. Can be detected.

[Brief description of the drawings]

FIG. 1 is an electric block diagram showing a main part of a rotating part abnormality detecting device for a rotary machine of the present invention, FIG. 2 is an explanatory diagram showing a main configuration of a rotary machine to be detected, and FIG. FIG. 4 is a Lissajous vector diagram of the rotating shaft calculated by the rotating unit abnormality detecting device of the rotary machine in FIG. 1, FIG. 4 is an absolute difference vector diagram of the Lissajous vector calculated in FIG. 3, and FIG.
FIG. 6 is an electric block diagram showing a main part of a conventional rotary machine abnormality detecting device for a rotary machine, FIG. 6 is an explanatory diagram showing a main configuration of a rotary machine to be detected, and FIG. FIG. 8 is an explanatory diagram for explaining an arrangement relationship of detectors to be detected, and FIG. 8 is a vibration waveform diagram detected by the detector of FIG. 10 ... rotating machine, 11 ... rotating electric machine, 12, 14 ... rotating shaft,
13 ... water turbine, 15, 16, 18 ... bearing, 17 ... thrust bearing, 19a, 19b ... detector, 20 ... arithmetic circuit, 21 ... comparator, 22 ... alarm circuit, 23 ... abnormal Display circuit, 24 ... Alarm, 24 ... Judgment value calculation circuit, 26 ... Recording circuit, 30 ...
Vector operation circuit.

Claims (1)

(57) [Claims] A plurality of bearings are provided at intervals in the axial direction of a rotating shaft, and a plurality of shaft runout detectors are mounted to detect shaft runout in a circumferential direction of the rotating shaft adjacent to these bearings. A vector calculator for forming a shaft runout Lissajous vector of each detection unit from the detection value detected by the shaft runout detector, obtaining an absolute maximum vector thereof, and calculating a difference vector between the detection units is provided. A rotating unit abnormality detecting device for a rotating machine, comprising: a comparator that compares the calculated difference vector with a normal state vector and calculates an absolute value and a phase shift angle with the normal state vector.