The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 06, 1991
Filed:
May. 09, 1989
Jun Matsubayashi, Ibaraki, JP;
Fumio Tajima, Ibaraki, JP;
Kunio Miyashita, Hitachi, JP;
Kazuaki Takada, Katsuta, JP;
Kuniaki Kubokura, Hitachi, JP;
Eiji Toyoda, Hitachi, JP;
Hitachi, Ltd., Tokyo, JP;
Hitachi Taga Engineering, Ltd., Ibaraki, JP;
Abstract
A rotor of a permanent magnet type synchronous motor facing a stator having a number of slots comprises a rotor core fixed to a motor shaft and an even number of permanent magnets in a circumferential direction of the rotor core. Projecting portions are formed in the shape of a protruding portion of the rotor core over each permanent magnet. The width (A) of each projecting portion is different from the pitch (B) of the slots of the stator. A position detector for detecting the permanent magnet position of the rotor comprises detectors of the normal rotation and other detectors of the reverse rotation. These detectors are arranged having predetermined phase differences (.alpha., .beta.) to a center line. A pattern generating circuit is provided for switching the conducting position to the stator winding corresponding to the phase differences.