A method for tachometer-free and resampling-free bearing fault diagnostics under time-varying speed conditions

Bearings often operate under time-varying rotational speed conditions. Processing the signal in the time-frequency domain and extracting the Instantaneous Fault Characteristic Frequency (IFCF) and the Instantaneous Shaft Rotational Frequency (ISRF) are important approaches for bearing fault diagnosis under time-varying speed conditions without signal resampling and without using a tachometer. However, there are two problems: (1) the collected...