A finite element analysis of air bearings applied in compact air bearing spindles

For micro machining high-speed aerostatic spindles are needed to achieve the required cutting speeds at high rotational accuracy. In this paper, a study of aerostatic bearings for the use in compact high-speed spindles for micro machining applications is introduced. The perturbation and the finite element method are used to determine the static and dynamic characteristics of the air bearings considering the translation and tilt motion of the rotor. These characteristics are then used to build a rotordynamic model of the entire spindle, provinding critical rotational speeds. With the help of the model a spindle was designed which could reach speeds up to 466,000 rpm at a high rotational accuracy. (C) 2017 The Authors. Published by Elsevier B.V.