Teeth matching frequency in vibration diagnostics of technical condition of aviation gas turbine engine gearboxes

The performance of an aviation gas turbine engine with gearbox is largely determined by the technical condition of this unit. Vibroacoustic diagnostics is the most effective method for identifying defects in rotary machines. It is generally recognized that the most informative diagnostic signs of gearing defects are the intensity of tooth harmonic and its multiples. However, in this case it is necessary to carry out vibration measurements in a wide frequency range. On the example of defects of the NK-12 engine gearbox we have shown that the use of the parameters of teeth matching frequency can reduce the frequency range under study by more than two orders of magnitude and improve efficiency of diagnostics of such defects as teeth wear and backlash.