Title:
BALL SCREW AND METHOD FOR MANUFACTURING BALL SCREW NUT
Document Type and Number:
WIPO Patent Application WO/2011/122053
Kind Code:
A1
Abstract:
Provided is a method for forming a recessed portion serving as a ball return path by plastic working directly on the inner circumferential surface of a nut workpiece without damage to a molding die even when manufacturing a nut that has an axially long length but a small inner diameter. The nut workpiece (1) is provided on the inner circumferential surface (11) with S-shaped recessed portions (15, 16) by pressing with the molding die that has a workpiece holder (2), a cam driver (6), cam sliders (7, 8), and a cylindrical member (5). The cam driver (6) has inclined planes (61b, 61d) the slope of which is the same as that of inclined planes (71, 81) of the cam sliders (7, 8). The cam sliders (7, 8) have S-shaped projected portions (73, 83) corresponding to the S-shaped recessed portions (15, 16) and are held in through-holes (52, 53) of the cylindrical member (5). Pressing the cam driver (6) from above with pressure causes the cam sliders (7, 8) to move each radially outwardly, whereby the S-shaped projected portions (73, 83) press and plastically deform the inner circumferential surface (11) of the nut workpiece (1).
Inventors:
WATANABE ATSUSHI (JP)
HARADA TORU (JP)
YOKOYAMA SHOUJI (JP)
OOTSUKA KIYOSHI (JP)
HASHIMOTO KOJI (JP)
KOBAYASHI KAZUTO (JP)
NAKAMURA TOSHIO (JP)
MOGI SHINOBU (JP)
SAITOU SHINGO (JP)
YAMASHITA TOMOFUMI (JP)
HARADA TORU (JP)
YOKOYAMA SHOUJI (JP)
OOTSUKA KIYOSHI (JP)
HASHIMOTO KOJI (JP)
KOBAYASHI KAZUTO (JP)
NAKAMURA TOSHIO (JP)
MOGI SHINOBU (JP)
SAITOU SHINGO (JP)
YAMASHITA TOMOFUMI (JP)
Application Number:
PCT/JP2011/001972
Publication Date:
October 06, 2011
Filing Date:
March 31, 2011
Export Citation:
Assignee:
NSK LTD (JP)
WATANABE ATSUSHI (JP)
HARADA TORU (JP)
YOKOYAMA SHOUJI (JP)
OOTSUKA KIYOSHI (JP)
HASHIMOTO KOJI (JP)
KOBAYASHI KAZUTO (JP)
NAKAMURA TOSHIO (JP)
MOGI SHINOBU (JP)
SAITOU SHINGO (JP)
YAMASHITA TOMOFUMI (JP)
WATANABE ATSUSHI (JP)
HARADA TORU (JP)
YOKOYAMA SHOUJI (JP)
OOTSUKA KIYOSHI (JP)
HASHIMOTO KOJI (JP)
KOBAYASHI KAZUTO (JP)
NAKAMURA TOSHIO (JP)
MOGI SHINOBU (JP)
SAITOU SHINGO (JP)
YAMASHITA TOMOFUMI (JP)
International Classes:
B21K1/70; B21J5/02; F16H25/22; F16H25/24
Foreign References:
| JP2008281063A | 2008-11-20 | |||
| JP2009050871A | 2009-03-12 | |||
| JP2004148385A | 2004-05-27 | |||
| JP2003207015A | 2003-07-25 | |||
| JP2005076844A | 2005-03-24 | |||
| JP2006144873A | 2006-06-08 |
Other References:
See also references of EP 2546006A4
Attorney, Agent or Firm:
MORI, Tetsuya et al. (JP)
Woods Tetsuya (JP)
Woods Tetsuya (JP)
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Claims: