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:
Apr. 22, 2003
Filed:
May. 22, 2001
Shoji Ohiwa, Yono, JP;
Kazuo Ohnishi, Kiryu, JP;
Atushi Yamamoto, Yono, JP;
Shinji Shimizu, Kiryu, JP;
Youji Unoki, Kiryu, JP;
Yukinori Kurita, Kiryu, JP;
Japan Servo Co., Ltd., Tokyo, JP;
Abstract
The magnetic pole position detector for an electric motor comprises a detection rotor, a detection stator, and magnetic flux concentration tips and magneto electro transducers. The detection rotor is fixed to an axis of rotation of the motor and comprised of disc-like rotors having first toothlike protrusions and a permanent magnet. The disc-like rotors are assembled so as to make the first toothlike protrusions coincide in the axial direction and the permanent magnet is fixed between the disc-like rotors. The detection stator is comprised of stator cores comprised of an annular yoke and stator teeth formed at regular intervals on the former. Second toothlike protrusions are formed on the inner end of the stator teeth. The stator cores are assembled with a gap in the axial direction so as to make respective second toothlike protrusions coincide in the axial direction. The magnetic flux concentration tips and the magneto electro transducers are placed in the gaps in the axial direction. The detection rotor and the detection stator are assembled with a gap in the radial direction. The magnetic pole position is obtained by detecting the magnetic flux flowing through the stator teeth that varies in accordance the rotation of the detection rotor.