Patent ID: 7394174
Filing Date: 2008-07-01
Classification: F02M,H02K,Y10S

Abstract:
1. A brushless direct current motor comprising: a wound stator and a permanent magnet rotor, the rotor having a laminated core, said laminated core being overmolded with overmolding material magnetized subsequent to molding; wherein the stator surrounds the rotor and has an outer ring, a plurality of angularly spaced pole pieces extending inwardly from the outer ring and a plurality of flux pieces extending inwardly from the outer ring and located between adjacent pairs of the pole pieces, the outer ring forming a plurality of slots on an inner surface thereof for slidably receiving the flux pieces after applying windings to the pole pieces; wherein the overmolding material forms an integral ring and is magnetized to act as an encoding disk; wherein the core of the rotor has a plurality of angularly spaced slots extending inwardly from its outer peripheral surface and the slots are filled with said material; and wherein at least some of the laminations have a plurality of spaced apertures therein.