Modal and response analysis of vertical guideway of vertical lathe considering hydrostatic bearing

Forced vibration of vertical guideway of vertical lathe can decreases machining accuracy of vertical lathe. Hydrostatic bearing can improve stability of bearing system, and has been applied to vertical guideway of vertical lathe in recent years. However, variation law of modal parameters of hydrostatic vertical guideway under different working conditions and influence mechanism of hydrostatic bearing on its modal parameters are unclear. To this end, we conduct the modal and harmonic response analysis of vertical guideway with hydrostatic bearing and without hydrostatic bearing based on finite element method (FEM). The results show that hydrostatic bearing can improve the low-order natural frequencies and low-order resonance frequencies of vertical guideway under certain working conditions, and can reduce amplitude of vertical guideway. Additionally, the accuracy of finite element simulation is validated by experimental modal analysis (EMA). This investigation provides theoretical basis for identifying weak links, determining optimal working condition, and improving stability of hydrostatic vertical guideway.