ROTOR FOR PERMANENT-MAGNET-EMBEDDED ELECTRIC MOTOR, ELECTRIC MOTOR INCLUDING THE ROTOR, COMPRESSOR INCLUDING THE ELECTRIC MOTOR, AND AIR CONDITIONER INCLUDING THE COMPRESSOR

摘要

A rotor for a permanent-magnet-embedded electric motor includes slit holes each axially formed near opposite ends of a magnetic pole between an outer peripheral face of a rotor core and a magnet insertion hole, and forming a symmetrical shape in an approximately truncated chevron shape along the outer peripheral face of the rotor core, based on a centerline of each of the magnetic poles, wherein a thickness of each of permanent magnets is set to be twice or more of an air gap, a width of a shortest magnetic path in which a distance between the slit hole and the permanent magnet becomes shortest is set to be twice or more of the air gap, and an inclination of the slit hole with respect to a width direction of the permanent magnet orthogonal to a radial direction is set to be in a range from 0 to 30 degrees.

主权项

1. A rotor for a permanent-magnet-embedded electric motor, rotatably held on an inner peripheral face of a stator, the rotor comprising:
a rotor core formed by laminating a plurality of electromagnetic steel plates; a plurality of magnet insertion holes formed along an outer periphery in a circumferential direction of the rotor core; tabular permanent magnets inserted into the magnet insertion holes with alternating polarities, to form a plurality of magnetic poles; and elongated slit holes each formed in the vicinity of opposite ends of the magnetic pole between an outer peripheral face of the rotor core and the magnet insertion hole wherein an inclination of a longitudinal axis of each of the slit holes opened towards a center of the magnetic pole with respect to a width direction of the permanent magnet is set to be in a range from 0 to 30 degrees, and a magnetic path between the outer peripheral face of the rotor core and the slit hole extends toward a center side of the magnetic pole.