Patent attributes
Apparatuses, circuits, and methods for driving an axial field electric motor, and systems using the same. The electric motor generally comprises a fixed magnet assembly having a plurality of fixed magnets arranged circularly around a shaft, a coil assembly including a plurality of coil layers, and a controller configured to provide each of a plurality of drive signals to one of the coil layers. Each of the drive signals generally has a different phase (e.g., each drive signal may pulse and/or oscillate with different phase offsets). The fixed magnets generally have north-south axes parallel to the shaft (e.g., the magnetic field is axial to the shaft). Each of the coil layers generally comprises a plurality of electromagnetic coils arranged circularly around the shaft in plane that is substantially perpendicular to the shaft. Each of the electromagnetic coils comprises a conductive spiral wound in the plane of the coil layer. Each coil layer is mechanically coupled to another of the coil layers in the coil assembly. Electric motors according to the present invention are advantageously efficient and lightweight and provide for coil assemblies that can be stacked for additional torque.
