Free-Form Rotor Optimization for Synchronous Reluctance Machines used in X-ray Tubes

This paper presents a proof-of-concept for a rotor design based on a previously introduced free-form shape optimization which is applied to a two-pole synchronous reluctance machine specifically designed to drive the anode in an X-ray tube. The rotor is optimized by means of 2D-finite element analysis with the goal of increasing the maximum torque per ampere. An unsymmetrical rotor shape proves to be most beneficial. 3D-Effects introduced by the large air gap together with the protruding rotor are subsequently analyzed by means of 3D-finite element analysis. Prior to manufacturing, certain mechanical and geometrical constraints are considered. After experimentally validating the optimized rotor, the chosen rotor design proves to be a viable alternative to the more common induction machine employed in X-ray tube applications.