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:
Jul. 29, 2008
Filed:
Aug. 05, 2004
Shinichi Yamaguchi, Tokyo, JP;
Haruyuki Kometani, Tokyo, JP;
Chiyo Fujino, Tokyo, JP;
Tomohiro Kikuchi, Tokkyo, JP;
Takashi Miyazaki, Tokyo, JP;
Shinichi Yamaguchi, Tokyo, JP;
Haruyuki Kometani, Tokyo, JP;
Chiyo Fujino, Tokyo, JP;
Tomohiro Kikuchi, Tokkyo, JP;
Takashi Miyazaki, Tokyo, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
A rotary electric machine includes a frame; a stator whose stator-slot number Ns is 12; a rotor whose rotor-pole number Np is 8, the rotor being disposed inside the stator. The frame has a frame thickness T(θ) at mechanical angle θ, with respect to a reference line that connects the inner circumferential center of the frame with an arbitrary point, other than the center, around the center that is circularly expanded in a Fourier series. The difference between the stator-slot number Ns and the rotor-pole number Np is k (=|Ns−Np|). Stress-relieving spaces and are located in portions of the frame in an arrangement that does not have 90-degree mechanical angle rotational symmetry, in such a way that the sum P of inclusion ratios for the k-th component Tand the Np-th component T, which are the Fourier series expansion coefficients for the frame thickness T(θ) expressed by equation (2) is less than 12%. According to this configuration, mechanical strength of the frame and its producibility are maintained, and cogging torque caused by magnetic-circuit distortion in an iron core generated due to the frame shape is also reduced.