Monitoring of the Damage in Rolling Element Bearings

Envelope Analysis of vibration signal is the most used and simplest method for the diagnostics of rolling element bearings. This method is based on the identification of bearing damage frequency components in the so-called Envelope Spectrum. If the recognition of the damage type is quite a simple task, the monitoring and the evaluation of the trend of a suitable damage index are complex tasks to be performed in an automatic way. The damage index must be robust against variations of system operating conditions and external vibration sources to avoid misleading results. In the paper, the case of a rolling element bearing in which the defect develops until a permanent failure is described as well as the algorithm implemented for alarm signaling.