Patent Number: 6,528,920

Title: Permanent magnet rotary machine and electric vehicle using the same

Abstract: At least one groove and two grooves extending toward an axial direction of a rotor and is provided on an outer periphery of a rotor iron core or at least one hole is provided in the rotor iron core. By providing the groove and the two grooves on the outer periphery of the rotor iron core or by providing the hole in the rotor iron core, cogging torque is generated to negate the cogging torque which is generated according to the magnetic fluctuation between the magnetic field of the permanent magnets and a stator. As a result, the overall cogging toque in a permanent magnet type rotary machine is reduced.

Inventors: Matsunobu; Yutaka (Hitachi, JP), Tajima; Fumio (Juou-machi, JP), Kawamata; Shouichi (Hitachi, JP), Shibukawa; Suetaro (Hitachinaka, JP), Koizumi; Osamu (Ibaraki-machi, JP)

Assignee: Hitachi, Ltd.

International Classification: H02K 1/27 (20060101); H02K 29/03 (20060101); H02K 021/12 (); H02K 021/14 ()

Expiration Date: 03/04/2020