A clear trend towards smaller systems saving material cost and weight can be observed in many modern drives. By increasing the speed, equal output power can be provided by a much smaller system. Mechanical bearings often limit the maximum speed and the achievable life time of such drives.
A disk rotor topology with a slotless stator and a toroidally wound, 5-phase winding system has been constructed in order to demonstrate the high-speed suitability of bearingless drives. A special feature of the winding system is that it creates both bearing forces and motor torque with the same set of windings. This allows further integration of the drive and, together with the bearingless disk topology, results in a highly compact drive unit.
The prototype has been operated to a high-speed of 115.000rpm.
Hubert Mitterhofer, Johannes Kepler University Linz
Research conducted at Linz Center of Mechatronics GmbH (LCM)