Patent ID: 8543365

Claim:
A method for designing a rotor-stator structure for an electrodynamic machine, the method comprising: selecting active field pole members including coils at least one of which has a coil length parallel to an axis of rotation, selecting said active field pole members comprising: selecting pole faces to confront conical surfaces of rotors disposed axially from each other, selecting said pole faces comprising: determining a flux in a coil region of an active field pole member to produce a value of torque, said coil region being disposed within said coil length; selecting a magnet material to produce a flux density at an air gap formed between a surface of said magnet material and a pole face of said active field pole member; calculating, in a processor, a surface area of said pole face at which said flux density of said magnet material provides for said flux in said coil region to approximate said value of torque; and determining a non-orthogonal angle at which to orient said pole face relative to said axis of rotation to establish said surface area for said pole face; and sizing said coil length while maintaining a cross-sectional area associated with said active field pole members to adjust said value of torque as one or more performance characteristics.