Concept, Design, Realization and Measurement of a 3 Airgap Slotless Brushless Motor

This paper presents the development of a novel multi-face slotless motor. The core idea of this motor is to collect the magnetic flux linkage on three faces of an IPM rotor. Thus it enables to improve the torque production of the slotless motor with controlling the acoustic noise. A prototype has been measured with 75% efficiency at 40W/32krpm with only 30dB of noise.