Abstract
Vortex levitation can achieve non-contact handling by blowing air into a vortex cup through a tangential nozzle to generate a swirling air flow. In this paper, its dynamical characteristics are investigated by means of pressure frequency response to note that inside the cup pressure response relative to movement of a work piece is very rapid. Furthermore, an obvious pressure hysteresis is observed while the work piece repeats sinusoidal movement under the cup, which results from squeeze film effect of thin air layer entrapped between the work piece and the skirt of the cup. According to those experimental observations, we proposed a spring-damper model by modelling the lifting force caused by swirling air flow and the resistive force related to squeeze film air damping separately. Finally, the validity of the proposed model is confirmed through an experiment of loading process.
