Localization of double spalling on the outer rings of paired ball bearings by time-delay sound analysis

Abstract

Rolling bearings are widely used in spindle systems, and are usually arranged in pairs for higher running accuracy. Spalling often occurs on the outer ring of rolling bearings, and the impact of double spalling located on a single bearing is quite different from that of spalling on both bearings. This paper proposes a method for localizing double spalling based on radiated sound signals. A model of the sound radiation produced by spalling is established, and the sound signals are analyzed in the time and frequency domains. The numerical simulation and experimental results show that double spalling can be detected through the appearance of corresponding frequency components, and the relative spalling positions can be distinguished through the time–delay ratio (TDR) between the impacts in the time-domain signal. When spalling takes place on the same bearing, the distances to the sources of the impact sounds are different, compared to spalling on different bearings, leading to significant differences in the TDRs of the time domain signal. Impacts from different spalling locations can be distinguished from the time domain signal, and the double spalling localization can be realized through TDR matching. The method provides a new approach for accurate fault localization, which is helpful for the operation and maintenance of spindle systems.