Patent ID: 7768166

Claim:
Compact, high power, power conversion apparatus comprising a shaft, a stator, and a rotor, the shaft, stator, and rotor being coaxially disposed with the rotor mounted on the shaft, the stator including at least one winding, and the rotor including a plurality of permanent magnets disposed proximate to the stator, separated from the stator by a predetermined gap distance, such that relative motion of the rotor and stator causes magnetic flux from the magnets to magnetically interact with the stator winding, wherein: the shaft has a predetermined diameter and includes a shaft tapered portion disposed between the ends of the shaft at a predetermined position relative to the stator, the diameter of the shaft tapered portion varying in accordance with a predetermined taper from a minimum diameter greater than the predetermined diameter to a predetermined maximum diameter greater than the shaft predetermined diameter; the rotor includes a hub and a central through-bore having the predetermined taper corresponding to that of the shaft tapered portion of the shaft, the diameter of the tapered through-bore varying in accordance with the predetermined taper from a minimum through-bore diameter greater than the shaft predetermined diameter to a predetermined maximum through-bore diameter; and the rotor hub is disposed with the shaft journaled and extending through the hub through-bore, with the shaft tapered portion received in the through-bore with interior surface of the through bore and exterior surface of the shaft tapered portion in mating contact, wherein cooperation of the tapered rotor bore in surface contact with the shaft tapered portion positions the rotor both axially and radially with respect to the shaft and stator, coupling the rotor to the shaft for rotation therewith.