Method of Extracting Torsional Vibration Signal Based on Lateral Vibration Signal in Rotating Machinery

Lateral and torsional vibrations are coupled with each other in a rotor system，and the information of torsional vibration is modulated in lateral vibration signals. In view of this，a method of extracting weak torsional vibration signal from lateral vibration signals is proposed in this paper. Specifically，the Hilbert vibration decomposing is firstly applied on the lateral vibration signal to obtain a single-component signal，which is used to extract the phase angle with Hilbert transformation，and then the phase angle is decomposed to extract the torsional vibration signal. After that，the amplitude and frequency of the original torsional vibration signal are obtained. Numerical simulation and experimental results indicate that the method can accurately detect torsional vibration signals，with a high frequency resolution，and the error of extracted torsional frequency in the experiment is merely 0.38%. An industrial scale of centrifugal compressor experimental platform is employed to validate its feasible application in engineering as well. This method can enable an additional monitoring of torsional vibrations for the machines without dedicated torsional vibration testers，providing a convenient way to measure torsional vibrations in engineering. © 2023 Nanjing University of Aeronautics an Astronautics. All rights reserved.