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. 04, 2000
Filed:
Dec. 29, 1997
Yeong-Der Yao, Taipei, TW;
Jain-Chang Wang, Miao Li Hsien, TW;
Chin-Po Liao, Yun Lin Hsien, TW;
Der-Ray Huang, Hsinchu, TW;
Chi-Mou Chao, Taipei Hsien, TW;
Industrial Technology Research Institute, Hsinchu, TW;
Abstract
A new type of stator design and arc shaping method that is used in a diametrically wound and diametrical air gap type of brushless motor. After arc shaping, the stator of this brushless motor has an external profile composed of a central arc and two modified arcs located on each side of the central arc. The central arc subtends an angle twice that of angle A and the modified arcs each has a radius r, both angle A and r are given by the following formulae: ##EQU1## Through arc shaping the stator, the cogging torque is lowered while a certain standard value for the torque constant is still maintained. Thus, the overall efficiency of the brushless motor is raised.