Running Performance of a Squeeze Film Air Bearing with Flexure Pivot Tilting Pad

Abstract

A novel flexure pivot tilting pad squeeze film air bearing (FPTP-SFAB) based on near-field acoustic levitation (NFAL) for a rotor is proposed in this article. The most important advantage of this structure is the suitability of the bearing for high-speed and light load conditions because the FPTP can adapt well to squeeze action during operation. The rotating orbit of the rotor can be adjusted according to the machining conditions. A theoretical model is employed to analyze the running characteristics of the rotor by using the coupled NFAL and FPTP model. Experiments were conducted to investigate the running performance of the rotor–bearing system. Moreover, the effects of input voltage, rotational speed, eccentricity ratio, radial clearance, vibration amplitude, and installation method on bearing performance were analyzed. Numerical and experimental results show that a rotor supported by the FPTP-SFAB with a reasonable input excitation magnitude can effectively adjust the rotating orbit of the rotor and inhibit the divergence of the rotor vibration amplitude, thus improving the stability of the rotor–bearing system under complicated and alternating machining conditions.