Salient pole rotor with partially covered shrouds for the windage loss reduction of bearingless switched reluctance motors

Abstract

As a high efficient mechatronic system, the bearingless switched reluctance motors (BSRMs) have been proposed in recent decades. In this paper, the windage loss of the salient pole rotor of a high-speed BSRM is investigated. Several conventional methods for reducing the windage loss of salient pole rotors, including optimizing the profile of the rotor and covering shrouds for the rotor, are analyzed in detail based on computational fluid dynamics (CFD). Simulation results show that the windage loss cannot be reduced by only optimizing the profile of the salient pole rotor. However, the windage loss of the rotor with covered shrouds is decreased significantly. At last, a salient pole rotor with partially covered shrouds is presented. CFD results reveal that it not only alleviates the windage loss caused by the salient poles, but also guarantees the effective convection of air flow between the rotor slot and the cavity of shell to cool the rotor.