SU480292A1 - Method of spectral analysis of gas turbine engine vibrations - Google Patents

Description

(54) METHOD FOR SPECTRAL ANYLISE OF GAS TURBINE VIBRATION ENGINE

A return value 16 is included in the X input circuit of a two-coordinate recording potentiometer 14. The return value converter 16 is an automatically set-potentiometric measurement circuit for a voltage with a reference voltage and a measured signal reversed between them.

The work on the proposed method, as a result of which the amplitude-frequency characteristic of the oscillation of the machine is obtained according to the frequency of turns and its harmonics, proceeds as follows.

Machine vibrations propagating through the housing and transformed by sensor 1 into electrical signals are amplified by a vibrometer 2 and recorded by the first channel of the tape recorder 3 on a tape moving at a speed proportional to the frequency of turns of the machine under investigation.

Signals of a constant frequency from a generator 7 of a constant marking frequency are recorded on another channel of the tape recorder 3. Then continue processing the recordings by reproducing the magnetic recordings on the two tracks of the magnetic tape ,. For this, the electric motor 6 of the tape recorder 3 is switched on by the switch 9 onto the contacts 8 of the three-phase network. In this case, the magnetic tape of the tape recorder switched to playback will move at a constant speed.

The vibration signals recorded during the previous operation on the first track of the tape, multiples {integer or fractional) of the revolutions of the machine under investigation, are reproduced by constant frequencies with the corresponding multiplicity. These frequencies are filtered by filters 11 of the analyzer 10.

After that, the signals of the first channel through the amplitude detector 12 is fed to the input of the X coordinate recording potentiometer 14.

From the output of the second channel of the tape recorder 3, at a constant speed of movement of the tape, the signals of the marks are removed at a frequency inversely proportional to the frequency of revolutions of the examined machine. These signals are fed through the frequency detector 15 to the input X of a two-coordinate recording potentiometer 14, which at the same time converts the reverse frequency values by analog division. For this, in the converter 16 of the two-coordinate self-recording potentiometer 14, the measured voltage and the reference voltage are interchanged. As a result, the above described operations on a paper tape of a two-coordinate self-recording potentiometer l4j receive an amplitude-frequency characteristic in terms of the frequency of revolutions of the machine or multiple frequencies,

Claims (1)

Invention Formula A method for spectral analysis of vibrations of a gas turbine engine by processing oscillation signals using frequency filters with fixed passbands, characterized in that, in order to shorten the construction time of amplitude-frequency characteristics, oscillation waves are recorded in one channel of a tape recorder on a tape moving at a speed proportional to frequency engine revolutions, the signals of the marking frequency are recorded in another channel, and during reproduction of the recording by moving the tape at a constant speed The oscillation signals are filtered by harmonics and frequencies, multiple to the frequency of turns, amplitude detected and recorded on one of the axes of the two-coordinate recording recorder, and the signals of the marking frequency are often detected. convert to the reciprocal, about. proportional to the frequency of turns, and register on another axis. "