engleski

Light rotor-stator partial rub characterization using Instantaneous Angular Speed measurement

Instantaneous angular speed (IAS) measurement is recently recognized as a promising technique for condition monitoring of various rotating machines and their subsystems. There are various approaches considering counting techniques and processing of signal. This paper considers application of analog signals from toothed wheel encoder or zebra tape encoder and acquisition at low to moderate sampling rates. Such a system can experience problems with non-uniformity of encoder segments geometry, thus correction of encoder segment non-uniformity was performed. The rubbing often occurs in rotating machinery at position with small clearances and can sometimes cause catastrophic breakdown of machine. So it is important to develop reliable tools for rub diagnosis. As the rubbing process is nonlinear this paper beside conventional Fourier transform also considered potential of sifting operation of Empirical mode decomposition (EMD) method. EMD was employed to produce intrinsic mode functions (IMFs) and to further improve the detection capabilities of Fourier transform. Developed procedure for IAS measurement was successfully tested on laboratory test rig for rotor to stator contact dynamics investigation at speed transition from no rub to light rotor to stator partial rub condition.

Rotor-stator partial rub; Rub characterization; Instantaneous Angular Speed; Analog encoder

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