This work presents the most common errors in the production of electronically commutated blowers. Elementary sources of noise and vibration are described as a more complex source of a blower’s noise. The main focus is on mechanical sources of noise and their identification as a consecuence of structural vibrations of the bearings. To identify bearing error, Hilbert transform of sound pressure and acceleration signal is used, which results in an envelope of a signal. The principle of envelope analysis is first verified by a synthetic experiment of simulated bearing failure. By envelope analysis, we successfully identified typical frequencies of damaged bearings based on both accelerations and sound pressure.
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