Permanent Magnet Rotor Layout for Lower Electromagnetic Vibration

The patent applies local quality by forming magnetic resistance portions only at specific locations on the outer circumference of the rotor core - namely at magnetic pole center axes and at positions sandwiching the magnetic pole center axis. This localized approach creates magnetic resistance only where needed to suppress electromagnetic vibration forces, rather than forming grooves along the entire outer circumference. The selective placement of these magnetic resistance portions allows vibration suppression while maintaining smooth air flow paths in other areas, thereby avoiding the increase in windage loss and wind noise that would result from continuous grooving.

The patent employs local quality by positioning magnetic resistance portions at specific strategic locations - at magnetic pole center axes and at positions sandwiching the magnetic pole center axis - rather than distributing holes uniformly across the outer circumference. This localized placement targets the reduction of electromagnetic vibration forces at their source while preserving the continuous magnetic flux paths required for torque generation in other regions. The result is effective vibration suppression without the torque degradation that would occur with extensive hole formation.