Patent ID: 7012346

Claim:
An impeller mechanism incorporating a brushless dc motor, said mechanism comprising: a fixed portion further comprising a molded housing defining an internal axis of rotation and a lower portion of a peripheral volute, a separately fabricated stator assembly integrally molded within a base portion of the housing in an annular region between the axis and the volute, the stator assembly including a plurality of radially extending magnetizable teeth collectively defining a circumference of the stator assembly, and a respective electrical winding about each of the teeth for selectively magnetizing the individual teeth of the stator assembly, and a hollow bearing support concentric with the axis and extending though the stator assembly into the housing; a rotating portion further comprising a ring shaped brushless rotor assembly including a plurality of radially oriented permanently magnetized poles arranged about a circle, the rotor assembly encircling, in close proximity and concentric to the selectably magnetizable teeth of the stator assembly and separated therefrom by a cylindrical air gap concentric with a central axis and said air gap extending radially between the rotor assembly and the stator assembly, a ferromagnetic back-iron ring encircling the rotor assembly for providing a flux return path between two adjacent poles of the rotor assembly, a hat-shaped rotor support disposed about the axis and over the stator assembly, the rotor support including a downwardly extending outer lip on which is mounted the back-iron ring and a hollow crown extending upward of the outer lip, wherein the bearing support extends into the crown and the crown is above the stator assembly, an impeller assembly disposed on an upper side of the rotor support and over the air gap, a rotating shaft concentric with said axis and extending from an interior portion of the hollow bearing support into the crown of the rotating support; and a precision bearing assembly coupled between an interior surface of the hollow bearing support and an outer surface of the rotating shaft.