Patent ID: 11916440
Assignee: NIDEC CORPORATION
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H | IPC H

Claim 6:
7. A motor, comprising:
a rotor including:
a rotor core rotatable about a central axis; and
a rotor magnet fixed to an outer peripheral surface of the rotor core, wherein

the rotor magnet includes a plurality of magnetized portions arranged in a Halbach array along a circumferential direction of the rotor core,
the plurality of magnetized portions includes:
a plurality of radially magnetized portions whose magnetization directions are a radial direction of the rotor core; and
a plurality of non-radially magnetized portions whose magnetization directions are different from the radial direction,

the rotor core is a non-magnetic member that has a hole recessed from a surface on one side in an axial direction of the rotor core to another side in the axial direction and is made of a non-magnetic material,
an entirety of the hole is located (i) on a radially inner side of the plurality of radially magnetized portions and (ii) on a radially outer side of a radial center line of the rotor core,
the hole is separated radially inward from the outer peripheral surface of the rotor core
the hole has a line-symmetric shape with respect to a circumferential center line passing through a circumferential center of one of the plurality of radially magnetized portions when viewed along the axial direction, and
the radial center line is a virtual line passing through a radial center between an inner peripheral surface of the rotor core and the outer peripheral surface of the rotor core.