Analysis of hob vibration frequency components distribution mechanism of different faults states

Abstract

The correct understanding of the effective frequency components distribution in different states is essential for high precision hob fault diagnosis and wear identification. To explore the unclear vibration frequencies, a hob dynamic differential equation is established. The frequency components of gear hobbing under healthy states, steady faults, impact faults, and composite faults are summarized theoretically, especially the higher harmonics and the corresponding modulation sidebands, which are mainly the results of the convolution, overlapping, and the nonlinear feedback of the hobbing frequency and its harmonics, meshing frequency and its harmonics, rotating frequency and its harmonics. Moreover, the influence of the hob second response function on the amplitudes of the vibration components are analyzed, which has a relatively negative effect on the amplitudes of the lower frequency vibration components but markedly increases the vibration components near the natural frequency. The above theoretical analysis is verified by the acquired hob vibration signal.