Bearing defect frequencies

Characteristic vibration frequencies generated by defects in each bearing component, calculated from bearing geometry and rotational speed. BPFO = ball pass frequency outer race, BPFI = ball pass frequency inner race, BSF = ball spin frequency, FTF = fundamental train (cage) frequency. Expressed in multiples of shaft rotation speed (Hz). Foundation of predictive maintenance via spectral vibration analysis. ISO 15242 standard.