Patent ID: 7109631

Claim:
A low cogging and easy-to-downsize spindle motor structure comprising: a stator assembly that further comprises a terraced deck caved in the middle, a set of thin windings, and a stator housing, with said thin windings stacked on top of the deck, and said stator enveloped by said stator housing; and a rotor assembly seated on top of said thin windings and comprising a spindle, at least one bearing, a permanent magnetic ring, and a rotor housing, with said spindle being in the center of said rotor assembly, said bearing being between said stator assembly and said rotor assembly, said permanent magnetic ring being on the bottom of said rotor assembly, and said rotor being enveloped by said rotor housing, wherein the outer periphery part of said at least one bearing is the stationary part and is in contact with said stator assembly; with the inner part of said bearings being the rotating part and in contact with said rotor assembly that when said rotor rotates, said spindle in said rotor's center is brought into rotation, too.