Determination of unbalance, misalignment and bent shaft problems of a machine through condition monitoring

The rotating machinery running at good condition may suffer some serious problems with the passage of time. The most common problems are unbalance, misalignment, looseness, bent shaft, and eccentric rotor etc. Some time it is doubtful that the excessive vibration is caused by unbalance, misalignment or bent shaft. Experiments are performed to differentiate between unbalance, misalignment and bent shaft conditions. The vibration spectra and phase analysis are presented to distinguish between various problems. As a result of experiment the condition of bent shaft is confirmed. It provides a firm base for diagnosing the bent shaft condition in a shaft and its distinction from the unbalance and misalignment condition. (author)