A novel axial-flux electric machine for in-wheel gearless drive in plug-in hybrid electric vehicles

A novel low-speed axial-flux-modulated motor (AFMM) is presented. The proposed motor breaks the traditional design rule which stipulates that the pole-pair numbers of the stator and the rotor must be the same. It can be fit into the limited space such as the wheel rim of electric vehicles. Compared with those of radial-flux-modulated motor (RFMM), its manufacturing and assembling process are simple and easy. Its performance is compared with a RFMM by using 2-D and 3-D finite-element methods (FEM).