SU1193468A2 - Arrangement for vibration-acoustic diagnosis of rotary machines - Google Patents

Abstract

DEVICE FOR VIBROACUS. CHECK OF DIAGNOSTICS OF ROTARY MACHINES on auth.St. No. 1057790, characterized in that, in order to increase the sensitivity, it is equipped with a tunable filter and a frequency-voltage converter connected in series between the input of the first mixer and the output of the second mixer, and the second input of the tunable filter is connected to the output of the matching device.

Description

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SAE 4 0)

00 1. The invention relates to a measurement technique and can be used for in-place monitoring of the technical condition of rotary machines. . The purpose of the invention is to increase sensitivity. In the drawing, shows a block diagram of the device. The device contains a vibration transducer 1, installed on the body of the object being diagnosed, matching device 2, first mix 3, quartz filter 4 with intermediate frequency, measuring device 5, phase detector 6, tunable, 7 and supporting 8 generators, second mixer 9 with the unit 10 comparison-frequency., the frequency divider 11 and the block 12 of the display. The measuring channel is made in the form of a series-connected vibration transducer 1, a matching device 2, a first mixer 3, an intermediate frequency filter 4 and a measuring device 5. The control channel is made in the form of a series-connected reference frequency generator 8, phase generator 6 and generator 7 of the tunable frequency, while the second input of the phase detector 6 is connected to the output of the intermediate frequency filter 4, and the output of the tunable generator 7 is connected to the first mixer 3. Measuring frequency channel The rotor rods are made in the form of a parallel-connected frequency divider 11 and a second mixer 9, the common input of which is connected to the output of the reference frequency generator 8, the phase detector 6 and the tunable frequency generator 7, the second input of the phase detector 6 is connected to the output of the filter 4 is intermediate frequency, and the output of the tunable generator 7 is connected to the first mixer 3. The measuring channel. The rotation frequency of the rotor is made in the form of a parallel connected frequency divider 11 and the second mixer 9, the common input of which The second input of the second mixer 9 is connected to the output of the generator 8 of the reference frequency, and the output of the tunable generator 7, and its output to the comparison unit 10, often 682 and the frequency display unit 12 connected in series with the tunable filter 13 and converter 14, the frequency-voltage is connected between the input of the first mixer 3 and the output of the second mixer 9, and the second input of the tunable filter 13 is connected to the output of the matching device 2. The device operates as follows. The signal from the vibration sensor 1 is fed through a matching device 2 and automatically tunable filter 13 to one of the inputs of the mixer 3, to the second input of which a control signal is output from the output of the tunable generator 7. On mixer 3, the signals are summed and the resulting signal is filtered by an intermediate frequency quartz filter 4. From the output of the filter 4, the filtered signal of the intermediate frequency is fed to the measuring device 5, where it is detected, averaged and measured, and to the first input of the phase detector 6, the second input of which receives the reference signal of the crystal oscillator 8. The generator 8 outputs a reference frequency equal to the resonance frequency of the quartz filter 4. When the frequency of the spectral component is fluctuating, the vibration component vibrates. Ratio-signal or instability of the clock. Photons of tunable generator 7. The signals from filter 4 and reference generator 8 receive a mutual shift in phase. As a result, at the output of phase detector 6, a control voltage appears that affects the frequency of the tunable generator. 7, ensures that the intermediate frequency component of the spectrum, I-, remains constant. The signals of the tunable 7 and reference 8 generators are fed to the inputs of the second mixer 9, from the output of which the difference signal with a frequency equal to the frequency of the spectral component to be applied is fed to one of the inputs of the comparison unit 10. The second input of the block 10 through the frequency divider 11 receives a stable frequency signal from the output of the reference oscillator, and the choice of the division factor of the divider 11 to

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its output can be successively obtained a series of frequencies set with high accuracy, corresponding to the operation of the diagnosed rotary machines at a given (fixed) rotation frequency. Frequency comparison unit 10 generates a signal depending on the magnitude and sign of the deviation monitored and set by frequency divider 11, which is indicated in frequency indication unit 12.

The automatic reorganization of the filter 13 is carried out as follows.

From the output of the mixer 9, a voltage with a frequency equal to the tuning frequency of the measuring channel is fed to the input of the transducer 14, a static voltage, where a constant voltage is formed, the value of which depends on the frequency of the input voltage. This voltage is applied to y93468.

the equal input of the filter 13. The frequency of the settings of the filter 13 depends on the voltage at the control input. The characteristics of the converter 14 and

5 of the filter 13 are selected in such a way that the resonant frequency of the filter 13 is always equal to the tuning frequency. Consequently, the input of the first

10 signal determined by the passband of the filter 13.

In the study of spectral components with a low level, it is necessary to spin the coefficient of amplification of a matching (input) device. In this case, an overload of the subsequent path of the instrument with components of the spectrum with a high level may occur. The presence before the first mixer 1 tunable filter 14 eliminates the possibility of such an overload.

Claims (1)

, DEVICE FOR VIBROACOUSTIC DIAGNOSTICS OF ROTARY MACHINES by ed. No. 1057790, characterized in that, in order to increase sensitivity, it is equipped with a tunable filter and a frequency-voltage converter connected in series between the input of the first mixer and the output of the second mixer, and the second input of the tunable filter is connected to the output of the matching device.