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Patent Searching and Data


Title:
ROTOR CORE STEEL SHEET, METHOD FOR MANUFACTURING SAID ROTOR CORE STEEL SHEET, AND ROTOR
Document Type and Number:
WIPO Patent Application WO/2018/012599
Kind Code:
A1
Abstract:
The present invention achieves mass production at low cost while improving the fatigue strength of a rotor core. A rotor core steel sheet (10) comprises an electromagnetic steel sheet, is used to form the rotor core, and also has formed therein a magnet holding hole (14) for holding a permanent magnet, a portion of the edge part of the magnet holding hole (14) being used locally as a narrow bridge part (B). The end surface of the bridge part (B) is configured to include a shear surface (22), and a crushed surface (28) at which a fracture surface is crushed at an incline in relation to a direction perpendicular to the surface. The crushed surface (28) has less surface roughness than does the fracture surface. The fatigue strength of the rotor core is thereby improved. Moreover, it is sufficient for the fracture surface, which is a location on the end surface of the bridge part (B) where stress concentrates particularly easily, to be crushed at an incline in relation to the direction perpendicular to the surface; therefore, it is possible to employ a method for implementing a coining process on the fracture surface of said location.

Inventors:
HIRAMA, Michinobu (4056, Nakatsu, Aikawa-machi, Aiko-gu, Kanagawa 03, 〒2430303, JP)
ONO, Yoshiki (10, Fukuura 3-chome, Kanazawa-ku, Yokohama-sh, Kanagawa 04, 〒2360004, JP)
KAMEDA, Yohei (10, Fukuura 3-chome, Kanazawa-ku, Yokohama-sh, Kanagawa 04, 〒2360004, JP)
YODA, Yu (10, Fukuura 3-chome, Kanazawa-ku, Yokohama-sh, Kanagawa 04, 〒2360004, JP)
Application Number:
JP2017/025589
Publication Date:
January 18, 2018
Filing Date:
July 13, 2017
Export Citation:
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Assignee:
NHK SPRING CO., LTD. (10 Fukuura 3-chome, Kanazawa-ku Yokohama-sh, Kanagawa 04, 〒2360004, JP)
International Classes:
H02K1/22; B21D22/02; B21D28/02; B21D28/16; H02K15/02
Foreign References:
JP2005130604A2005-05-19
JP2006174537A2006-06-29
JP2012217283A2012-11-08
JPH04331444A1992-11-19
JP2006006017A2006-01-05
JP2000050579A2000-02-18
Attorney, Agent or Firm:
NAKAJIMA, Jun et al. (TAIYO, NAKAJIMA & KATO Seventh Floor, HK-Shinjuku Bldg., 3-17, Shinjuku 4-chome, Shinjuku-k, Tokyo 22, 〒1600022, JP)
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