Study on the basic characteristics of a vortex bearing element

Abstract

A new air bearing element called as vortex bearing is introduced and investigated in this study. In comparison to the conventional orifice bearing, the new bearing is characterized by blowing air through tangential nozzles to form a vortex flow. The study focuses on one vortex-bearing element to investigate its basic characteristics (flow rate characteristics, pressure and velocity distributions, load capacity, and static stiffness). We show that the vortex bearing uses vortex flow to form a sunken negative pressure distribution at the central area, so that it can narrow the gap clearance between the workpiece and the bearing and thereby improve the flotation stiffness. Moreover, blowing air tangentially instead of emitting onto the workpiece directly can avoid the formation of intense pressure distribution on the workpiece’s surface, which would reduce the partial stress concentration acting on the workpiece. For these reasons, the new vortex bearing is applicable in air conveyors that float and transport workpieces such as glass substrates and silicon wafers.