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. 14, 2009
Filed:
May. 26, 2004
Kanako Nemoto, Hitachinaka, JP;
Yasushi Takano, Hitachinaka, JP;
Michiyuki Takagi, Hitachinaka, JP;
Fumio Tajima, Hitachi, JP;
Akira Nezu, Yokohama, JP;
Tsukasa Yamazaki, Yokohama, JP;
Shunji Ooki, Yokohama, JP;
Masahide Kimura, Yokohama, JP;
Yasushi Fujita, Yokohama, JP;
Kanako Nemoto, Hitachinaka, JP;
Yasushi Takano, Hitachinaka, JP;
Michiyuki Takagi, Hitachinaka, JP;
Fumio Tajima, Hitachi, JP;
Akira Nezu, Yokohama, JP;
Tsukasa Yamazaki, Yokohama, JP;
Shunji Ooki, Yokohama, JP;
Masahide Kimura, Yokohama, JP;
Yasushi Fujita, Yokohama, JP;
Hitachi, Ltd., Tokyo, JP;
Nissan Motor Co., Ltd., Yokohama-shi, JP;
Abstract
The vibration and noise excited by the electromagnetic exciting force in the radial direction of an electric motor are suppressed. In an electric motor, a rotoris divided into four rotor pieces, andfor an axial length of 2L of one group of the rotor core, and for example, the four rotor pieces, andare ideally 0.29L, 0.71L, 0.71L, and 0.29L in axial length in the axial direction, and permanent magnetsof the rotor pieces, andare arranged in the circumferential direction so that the phase differences of the electrical angle are 0, π, 0, and π. Further, when an effect is obtained even if the ideal axial length is changed, the tolerance of the aforementioned axial length is ±0.1L.