Application of a Tubular Linear Actuator as an Axial Magnetic Bearing

Magnetic bearing systems have been the subject of intense research for many years. In many applications, they have matured to state-of-the-art machine components. In this paper, the improvement and application of a previously introduced axial magnetic bearing is described. This bearing, a tubular linear actuator (TLA), does not only avoid some constructional problems, but also it combines positive axial stiffness with the possibility to actively influence axial bearing properties. Functionality and design of the TLA are described. The applicability as an axial bearing in a magnetic bearing system is shown, and force-displacement measurements are performed. The results are discussed, and the performance of the TLA as an axial magnetic bearing is evaluated.