Finite element analysis of axial-gap induction motors

Axial-gap motors have flat profiles which make them suitable for use as wheel motors for electric vehicles or as shaft-less centrifugal pumps. We present the investigation of an induction type of axial-gap motor using three-dimensional time-stepping finite element analysis. Unlike conventional radial-gap motor with circular cross-section throughout a relatively long axial length, axial-gap motors are not so suitable to be investigated by two-dimensional finite element analysis. Three-dimensional finite element analysis requires a higher order of technology, which has only now beginning to reach maturity. Time-stepping version of three-dimensional finite element software is now available, and we have applied it to study the characteristics of a flat rotor induction motor. Several interesting conclusions were drawn regarding various possible geometries of axial gap induction motors.