JPS60108728A - Vibration-characteristics testing apparatus of rotary machine - Google Patents

Abstract

PURPOSE:To ensure the actual measurement of the vibration characterictics of a rotary machine in operation safely, by providing a vibration-characteristics testing apparatus, which is provided with a vibration applying device, a vibration- applying force detector, vibration response detectors, and a vibration analyzing means. CONSTITUTION:In a rotary machine, a rotary shaft 12, to which a rotor under test 11 is fixed, is rotatably supported by bearings 13 and 14. An inertial-type hydraulic-vibration applying device 15 and a vibration-applying force detector 16 are attached on one bearing 13. Vibration response detectors 17 and 18 are attached in the vicinity of the supporting parts of the bearings 13 and 14 for the rotary shaft 12. A vibration analyzing device 20 analyzes the vibration characteristics based on a sine wave reference signal (a) generated by a control circuit 19, a vibration-applying-force signal (b) from the vibration-applying force detector 16, and vibratin response signals c1 from the vibration response detectors 17a and 18. The desired vibration characteristics of the rotary machine in operation can be actually measured safely and positively.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vibration characteristic testing device for a rotating machine that analyzes vibration characteristics during operation of the rotating machine.

As is well known, rotating machinery such as steam turbines, gas turbines, generators, and compressors suffer from vibration problems (2), such as abnormal vibrations caused by large vibrations during machine operation.
'', he says, is an important issue that must be resolved. To solve this vibration problem, the following two measures are required, and in recent years there has been a great demand for the establishment of these techniques.

(1) Estimating the vibration characteristics of a rotary machine at the crotch stage 1 by calculation.

(2) Measure the vibration IJ of the finished product.
) has been rapidly progressing in recent years through the use of combitas. Regarding (2), it has also been put into practical use in stationary structures because it is easy to conduct experiments. However, since the vibration characteristics of a rotating machine differ between when it is stationary and when it is in operation, it is not possible to accurately estimate vibrations during operation using only the actual iron in a stationary state as described above. For example, the characteristics of an oil film bearing and the gyro moment of a rotating disk are related to its rotational speed, so it is extremely difficult to measure them. There is a strong desire for the emergence of a test device fU that can perform actual measurements.

Conventionally, as the above-mentioned vibration characteristic testing device, a known unbalance device is added to the rotating shaft, and the response of the unbalance device to the rotation speed of the rotating shaft is continuously recorded. There is a device that allows you to understand the vibration characteristics of components that are synchronized with the number of rotations, but this device can only clarify conditions that are synchronized with the number of rotations, and it is difficult to understand the characteristics of the bearing oil film, which is practically important in rotating machinery. It is not possible to elucidate vibrations caused by vibrations or load-dependent vibrations.

Therefore, there is a need for a safe and effective testing device that can actually measure the vibration characteristics during operation of rotating machines such as those described above.This invention was developed in consideration of the above circumstances. An object of the present invention is to provide an extremely good vibration characteristic testing device for a rotating machine that can safely and reliably measure the desired vibration characteristics during operation of the rotating machine.

That is, a vibration characteristic testing device for rotating machinery according to the present invention.
;-I-ij: , a vibration response detector that detects motion in a rotating machine based on a reference @ number and outputs a vibration response signal; The present invention is characterized by comprising vibration analysis means for analyzing vibration characteristics during operation of the rotary machine with respect to the vibration of the vibrator from the response signal.

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings. Figure 1 shows its configuration, and this vibration characteristic testing device for rotating machinery has a test rotor 1 fixed. Rotating axis 1
2 is rotatably supported by bearings 13 and 14, an inertial hydraulic vibrator 15 and an excitation force detector 16 are mounted on one of the bearings 13, and the rotating shaft 12 of the bearing 13 and 14 is mounted on one of the bearings 13. A vibration response detector 17.
18 is attached.

That is, the vibrator 15 applies an excitation force toward the center of the rotating shaft 12 via the bearing 13 based on the sine wave reference signal a supplied from the control circuit 19. The excitation force detector 16 detects the excitation force of the vibrator 15, converts it into an electrical signal (excitation force signal b), and outputs it. The vibration response detectors 17.18 detect the vibrations generated in the bearings 13.14 and convert them into electrical signals (vibration response signals cl, c
2) and outputs it. Further, the reference signal a1, the excitation force signal S, and the vibration response signals cl, e2 are both supplied to each input terminal of the vibration analysis device 20. This vibration analysis device 2o includes the reference signal a, the excitation force signal S, and the vibration response signal cl.

The component corresponding to the excitation force is extracted from c2, and the transfer function, natural frequency, damping ratio, etc. are analyzed from these data.

In the test apparatus configured as described above, the operation and test method in an unstable vibration test based on the oil film characteristics of the flat bearing will be described below with reference to the flowchart shown in FIG.

First, in step 21 "T:" test conditions A (~D) of the unstable vibration test based on the oil film characteristics of the Vessel bearing are set, and in step 22 the rotating machine is operated steadily and the The test rotor 11 is rotated. Then, in step 23, the frequency of the sine wave reference signal a is changed, and the excitation frequency of the inertial hydraulic vibrator 15 is gradually changed, so that the excitation force signal of the sine wave reference signal a1 at this time is and the vibration response signals cl, c2 are sent to the vibration analysis device 2o.
The vibration analyzer 2o records each change in the excitation force and vibration response. In addition, Stetsuno 2
4, the test conditions set in step 21 above are conditions A~
If all D is not completed (No), step 21
If the program is finished (YES), Stellar f2s is executed.

In this step 25, the vibration analysis device 2o extracts only the component corresponding to the excitation force exerted by the vibrator 15,
Determine the vibration transfer function j=ma/v (X is the vibration response vector, F is the excitation force vector). And the above test conditions A-D
For each case, determine the resonance characteristics of the frequency with respect to the frequency of the reference signal a as shown in Figure 3(a) (in this case, under condition A), and then determine the frequency ω and damping ratio to be focused on based on this diagram and numerical calculations. Enter ζ. Incidentally, the above-mentioned damping ratio ζ is given by:

Furthermore, in step 26, the results of the frequency ω and damping ratio obtained for each test case A to D are plotted as shown in FIG. .

Evaluation Criteria Table If such an evaluation is not made, all operations are terminated at Stella F27. Here, an example of the test results using the test equipment gi is shown in Fig. 4. This section explains unstable vibration testing based on oil film characteristics.

That is, it is assumed that the damping ratio ζ of the rotating machine decreases with the rotational speed, and at the rotational speed Nl, the damping ratio ζ becomes O and the rotation becomes unstable. The maximum rotation speed Nmax of this rotating machine
When the above rotation speed N is lowered to the ground (NL<N1Tla
X), The rotation became unstable while the rotation speed was increasing and the rotation stopped.
You won't be able to score two. In this case, the above rotation speed NL
Although it is possible to actually measure the maximum rotation speed? 'Jmax
is slightly below the rotational speed N, the instability limit N'L
Despite the closeness of the vehicle, it is not possible to obtain information such as PJ regarding stability due to operation. In this way, if the rotation speed NL and the maximum rotation speed N are close to each other, it is necessary to check the rotation speed N in advance because such vibrations may occur at any time due to errors in the operating conditions. There is.

For this reason, when the damping ratio is actually measured by setting ♀゛ and 1 for each rotation speed using the method described above and displaying it as shown in Figure 4, it is as follows:
The above rotation speed NiL can be estimated without rotating to the rotation speed Nl, and the damping ratio ζ at the maximum rotation speed NmAK, which is important in knowing the stability margin at the maximum rotation speed NmaK, can be determined. Become.

Therefore, by using the rotating machine vibration characteristics testing device configured as described above, vibration characteristics such as the natural frequency and damping ratio during operation, which could only be estimated by calculation, can be measured safely and reliably. You can color it. This makes it possible to accurately understand the characteristics of the target rotating machine, making it possible to formulate countermeasures in the event of vibration troubles and to consider design margins for subsequent newly designed machines.

In the above embodiment, the sine wave reference signal a is continuously varied to cause the exciter 15 to vibrate continuously. By discontinuing the vibration after shaking or by applying intermittent vibration in pulses, it becomes possible to obtain variously modified vibration characteristics. In other words, the vibration excitation method includes, in addition to the above-mentioned sine wave excitation and resonance response measurement, sudden stop during resonance and free damping vibration measurement, shock excitation, random excitation, and the like. In the example described above, a sine sweep excitation test was performed using an inertial type vibrator, but a non-contact electromagnet excitation test using multiple vibrators It is also possible to use a vibrator such as a vibrator or an unbalanced motor.

As described above, according to the present invention, a vibration characteristic testing device for a rotating machine includes a vibrator that vibrates the rotary machine based on a reference signal, and an excitation force detector that detects the excitation force of the vibrator. a vibration response detector that detects vibrations of the rotating machine and outputs a vibration response signal; and a vibration response detector that detects vibrations of the rotating machine and outputs a vibration response signal; An extremely good rotating machine that can safely and reliably measure the desired vibration divergence during operation of the rotating machine by being equipped with a vibration analysis means for analyzing the vibration characteristics of the rotating machine during operation. It is possible to provide a vibration characteristic testing device Hl.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram showing an embodiment of a vibration characteristic testing device for rotating machines according to the present invention, FIG. 2 is a flowchart for explaining the operation of the above embodiment, and FIGS. 3 and 4 are respectively the same as those described above. It is a characteristic diagram for explaining the test method of the example. 1... Test rotor, 12... Rotating shaft, 13°14
...Bearing, 15...Inertia hydraulic exciter, 16...
Excitation force detector, 17.18... Vibration response detector, 19
...Control circuit, 20...Vibration analysis device, a...Reference signal, b...Excitation force (I number, cl, e2...Vibration response signal, ζ...Damping ratio, calm ...Rotation speed, Nmax
...Maximum rotation speed. Applicant's sub-agent Patent attorney Takehiko Suzue Figure 1 Figure 2 Figure 3 (a) Shoulder 1 (b) Line order nI dongyang Figure 4

Claims (1)

[Claims] a vibration force detector; a vibration response detector that detects the vibration of the rotating machine and outputs a vibration response signal; and a vibration response detector that detects the vibration of the rotating machine and outputs a vibration response signal; 1. A vibration characteristic testing device for a rotating machine, comprising a vibration analysis means for analyzing vibration characteristics during operation of the rotating machine in response to excitation of a rotating machine.