Patent 9712006 was granted and assigned to Daikin Industries, Ltd. on July, 2017 by the United States Patent and Trademark Office.
A first rotor core including a plurality of gaps penetrating through the first rotor core along an axial direction is provided. A second rotor core being in contact with an axial end of the first rotor core and having a plurality of magnet-housing slots facing the gaps is also provided. The gaps have a magnetic resistance lower than that of the magnet-housing slots.