Patent ID: 7966716

Claim:
A method for assembling a direct drive generator assembly, said method comprising the steps of: placing a rotor having an inner wall over a stator so that there is an air gap between an inner wall of the rotor and the stator, and the air gap is variable during rotation of the rotor, wherein the stator includes a stator lamination stack having a plurality of teeth and a slot between teeth facing the air gap; assembling a magnetic hub assembly by attaching magnets to a plate in a linear arrangement, so that a column of magnets having a magnetic pole with a first orientation is adjacent to a column of magnets having a magnetic pole with a second orientation and the first magnetic pole orientation is opposite the second magnetic pole orientation; and positioning the magnetic hub assembly in a space between the rotor and a spacer, and aligning the magnetic hub assembly with predetermined apertures in the rotor and securing the plate to the rotor, such that application of an input torque to the rotor rotates the rotor in the variable air gap to generate a first cogging torque in a first direction by the corresponding column of magnets having a magnetic pole with the first orientation that offsets a second opposite cogging torque in a second direction by the column of magnets having a magnetic pole with the second orientation.