Dynamic behaviour of active magnetic bearings spindle in high-speed domain

High speed machining (HSM) is a new technology used to product parts in different sectors. This technology permits time and processing cost reduction. One of the principal components of the HSM is the spindle. It is generally supported by active magnetic bearings (AMBs), in order to guarantee the greatest speed without affecting the dynamic characteristics of the machine. In this paper, a spindle supported by two AMBs is modelled using the finite element method. It is discretised with Timoshenko beam finite element with different circular sections. Both flexible and rigid movements are taken into account. The non-linear electromagnetic loads exerted by bearings are computed in terms of the nominal air gap between bearings and spindle, the control current and the degrees of freedom of each node. A parametric study is performed to determine the influence of some parameters on the magnetic forces and subsequently the dynamic behaviour of the spindle. Copyright © 2013 Inderscience Enterprises Ltd.