TO DIAGNOSTICS OF THE INTERSHAFT BEARING STATE USING VIBRATION SIGNAL

O.N. Bylinkina, B.B. Korovin, E.V. Brycheva

The problem of diagnostic sign for the intershaft bearing state using is discussed. This sign is detected for a bearing that had an insertion defects while technological afterburning turbofan bend working. It was shown that during flight operation of standard engine transitory appearance of above mentioned diagnostic sign is possible for the bearing without defects. It is took notice of possibility the rotors combination vibration component appearance with the frequency near or equal of diagnostic one. This phenomenon of rotors combination vibration subharmonic appearance proceeded on maximal engine mode. That is why the bearing diagnostic procedure have being recommended for low engine modes.

Key words: intershaft bearing, diagnostic sign, spectrum component, bearing cage, harmonic, ssubharmonic.