Rubbing detection of sliding bearing in early stage by frequency modulation analysis

It is important for maintenance to detect the rubbing phenomenon of the sliding bearing in the early stage. The experiment of a slight rubbing condition conducted and the change of vibration was examined. Importantly, the fact newly found is that peaks in spectrum domain with rotational frequency period take place due to rubbing. As a result, the Cepstrum analysis was proved to be effective for the detection of rubbing in its early stage. A device, which can follow the level of quefrency, was developed based upon this idea, so that utilizing the device is highly efficient to monitor the sliding bearing condition.