New Approaches for Axial Magnetic Bearings

This paper describes the design, construction and tests of two new axial bearing concepts for rotating machines. They are mainly developed to reduce the total rotor length or the moment of inertia of the axial bearing segment. This leads to a stiffer rotor, and consequently a controller without considering the bending modes may be used although a higher speed of rotation is allowed. In the first approach the axial thrust disk is integrated into one single bearing element including control windings for three directions. Hence an extra axial bearing segment is not necessary here. In the second approach a tubular linear actuator is developed to serve as an active axial bearing. Instead of a thrust-disk, a rotor with a teeth contour is used here to provide axial force.