On numerical analysis and experiment verification of characteristic frequency of angular contact ball-bearing in high speed spindle system

The purpose of this research is to analyze the characteristics frequencies of angular-contact ball-bearing used in high-speed spindle system under the running conditions of different preloads and rotating speeds. A number of dynamic states are investigated, consisting of the equilibrium among the centrifugal force, gyroscopic moment and ball-race contact forces, and the geometric relationship of contact deformation. By solving the equations of the dynamic states, the contact angles between the rolling ball and the inner/outer race are estimated under the running conditions of different preloads and rotating speeds. Using the estimated contact angles, the characteristic frequencies of bearing can be determined. The numerical results of the characteristic frequencies are compared with the analysis results of vibration measurements in the experiment. The spectral features of different bearing defects are extracted by means of the empirical mode decomposition method as well as the fast-Fourier transform (FFT) algorithm.