• A novel proximity probe-based bearing spall size estimation approach was proposed. • Relative displacement between inner and outer races is used to estimate spall size. • The method was proven effective on two configurations with floating and rigid housing. • This approach is accurate and requires little signal pre-processing. Bearing fault severity assessment is a key obstacle which lies between bearing diagnostics and prognostics. Most developed methods up to date are based on vibration, acoustic emission (AE), and instantaneous angular speed (IAS) signals, however, a recent study suggested that the relative displacement between bearing inner and outer race could better reveal the naturally extended spall size than the traditionally used signals. To validate this finding, a proximity probe-based approach is proposed in this paper, and it is tested on two different facilities: a small bearing rig, and a large multi-stage gearbox rig. This approach has the advantages of low signal processing requirement and intuitiveness, and it has been proven effective on both cases.
Zhang et al. (Wed,) studied this question.