Vaggeeram Hariharan and PSS.Srinivasan

pp. 61 - 68

Abstract

Misalignment is the most common cause of machine vibration. In this paper, experimental studies were performed on
a rotor dynamic test apparatus to predict the vibration spectrum for shaft misalignment. A self-designed simplified 3–pin type
flexible coupling was used in the experiments. Vibration accelerations were measured using dual channel vibration analyzer
for baseline and the misalignment condition. The experimental and numerical frequency spectra were obtained. The experimental predictions are in good agreement with the numerical results. Both the vibration spectra show that misalignment can
be characterized primarily by 2X shaft running speed. However, misalignment is not close enough to one of the system
natural frequency to excite the system appreciably. Therefore, in some case the misalignment response is hidden and does
not show up in the vibration spectrum. The misalignment effect can be amplified, and a high acceleration level at 2X shafts
running speed is pronounced in the frequency spectrum.