An evaluation system of the eccentric orbit of shaft with aerostatic bearing in the microscale

Abstract

In order to improve the machining precision of the aerostatic bearing, an eccentric rotor orbit model considering the microscale effects is established. A flow factor Q embodying the effects in the microscale is introduced into the fluid control equation, the dynamic stiffness, and damping coefficients of bearing are calculated considering the microscale effects. According to the actual working condition of the shaft, the modal analysis in both cases (with and without the microscale effects) is performed. And with the modal information, the dynamic orbit in both states (with and without the microscale effects) is described by the deduced orbit model of the shaft system. Finally, experiments of the frequency by LMS vibration test system and shaft orbit by displacement sensor are measured, and the results indicate that the simulated results considering the microscale effects are more similar with the actual experimental one, which provides a guideline and evaluation standard for further optimization design and precision control of the shaft system.