Bauzer Medeiros E., Torre e Silva L.

Vibration monitoring of rotating machinery has become a well established practice for a variety of systems. However, as it happens with any other technique, vibration monitoring sometimes does not provide sufficient information for the required purpose. At other times, it presents practical difficulties which cannot be easily avoided. For this reason, other complementary or substitute techniques have been developed in order to produce more effective results. The present work discusses a development of simple acoustic monitoring techniques used in combination of conventional vibration monitoring of rotating systems. A testing rig having a rotating shaft, and a varying number of rotors and bearings has been developed to observe the resulting effects of normal and typical faulty operation, the latter being introduced by either system unbalance and/or bearing damage. The signal of both microphone and accelerometer sensors is compared and analysed in order to establish a typical comparison and associate a pattern between acceleration and sound generation for a few typical conditions. The results are then analysed according to their potential use as identification tools for a given system condition.