Exploiting residual magnetization in bearing components to characterize bearing rotation

We investigate the possibility to exploit the residual magnetism of bearings to characterize their rotation. Several bearings with different characteristics and diameter have been studied. A magnetic field sensor and a search loop register the magnetic field variation due to the rotation. Data are processed by means of a Dynamic Signal Analyzer and frequency components characteristic of the bearing geometry appear to be easily identifiable, which makes this technique promising for applications in the transportation and, in particular, railway industry.