Novel Integrated Bearingless Hollow-Shaft Drive

This paper describes a novel and compact design concept for contactless levitation and rotation of a wide annular rotor through the walls of a process chamber. In the proposed set-up, a homopolar magnetic bearing biased by permanent magnets is combined with a high-pole-number segment motor. The paper describes the functional principle of the motor focusing on the design and the behavior of the drive. An experimental system is presented along with a comprehensive set of measurement results verifying the theoretical considerations