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:
Nov. 04, 2008
Filed:
Aug. 19, 2004
Yuji Enomoto, Hitachi, JP;
Kenji Miyata, Hitachi, JP;
Yasuaki Motegi, Kiryu, JP;
Shoji Ohiwa, Kiryu, JP;
Yuji Enomoto, Hitachi, JP;
Kenji Miyata, Hitachi, JP;
Yasuaki Motegi, Kiryu, JP;
Shoji Ohiwa, Kiryu, JP;
Japan Servo Co., Ltd., Tokyo, JP;
Abstract
An outer rotor type hybrid stepping motor including a stator, a rotor, a magnet disposed axially in either the stator or rotor, a stator core disposed inward from a gap formed between the stator and rotor, the rotor disposed outside the gap, and a stator winding wound around the stator core. The outer rotor type hybrid stepping motor has a cross-sectional area A in the axial direction of the magnet, a gap portion diameter D, a lamination thickness of the stator core in the axial direction L and a residual magnetic flux density of the magnet Br. The lamination thickness of the stator core in the axial direction L and the residual magnetic flux density Br are determined according to the equation D×L/A=k×Br with the condition that coefficient k is kept in a range of 0.56-0.66(1/T). The resulting optimized design parameters for L and Br provide a reduction in size of the outer rotor type hybrid stepping motor, a high output and a high resolution.