An
axial field motor / generator having a rotor that includes at least three annular discs magnetized to provide multiple sector-shaped poles. Each sector has a polarity opposite that of an adjacent sector, and each sector is polarized through the thickness of the disc. The poles of each
magnet are aligned with opposite poles of each adjacent
magnet.
Metal members adjacent the outermost two magnets contain the flux. The motor / generator also has a
stator that includes a
stator assembly between each two adjacent magnets. Each
stator assembly includes one or more conductors or windings. Although the conductors may be formed of wire having a round, uniform cross-section, they may alternatively be formed of conductors having a tapered cross-section that corresponds to the taper of the sectors in order to maximize the density of the conductor in the gap between axially adjacent poles. The conductors may also alternatively be formed of traces in a printed circuit, which may have one or more
layers. Each stator
assembly may be removably connectable to another stator assembly to provide
modularity in manufacturing and to facilitate selection of the
voltage at which the motor / generator is to operate.
Electrical contacts, such as pins extending from the casing, may removably connect the conductors of adjacent stator assemblies. A
magnet may be dynamically balanced on the shaft by hardening a thin ring of cross-linked resin between the magnet and the shaft while the shaft is spun, using
ultraviolet light to polymerize the resin.