This paper presents a new type of magnetic bearing with active control only
in the axial direction. The bearing uses two pairs of permanent magnets wo
rking in attraction mode to restrict the radial motion and a control system
composed of two electromagnets, a gap sensor, and a controller to keep the
axis in a fixed axial position. The principle, the dynamic model for axial
motion, and the control system for this bearing are presented. Finally, by
experiments conducted on a prototype, the effectiveness of the concept her
e presented is shown.