BALL SCREW, MANUFACTURING METHOD OF NUT FOR BALL SCREW

Title:

BALL SCREW, MANUFACTURING METHOD OF NUT FOR BALL SCREW

Document Type and Number:

WIPO Patent Application WO/2011/114728

Kind Code:

A1

Abstract:

Disclosed is a ball screw having a formation, such as a flange, on the outer circumference of the nut, said formation being disposed on the portion of the outer circumferential surface of the nut corresponding to a ball circulation passage. A ball screw (1) is provided with a screw shaft (3) with thread grooves (3a) on the outer circumferential surface thereof, a nut (5) having thread grooves (5a) on the inner circumferential surface thereof opposite of the thread grooves (3a) on the screw shaft, multiple balls rollably loaded inside a helical ball rolling passage (7) configured by both thread grooves (3a, 5a), and a ball circulation passage (11) for circulating balls (9), returning said balls from the endpoint of the ball rolling passage (7) to the starting point thereof. The ball circulation passage (11) is a concave groove formed by hollowing out by plastic working a portion of the cylindrical inner circumferential surface of the nut (5). Further, a flange (13) is integrally formed in a portion of the outer circumferential surface of the nut (5) corresponding to the ball circulation passage (11) and the threading groove (5a).

Inventors:

HARADA TORU (JP)
HASHIMOTO KOJI (JP)
ITO TSUYOSHI (JP)
YAMASHITA TOMOFUMI (JP)
AOKI NAOYA (JP)

Application Number:

PCT/JP2011/001560

Publication Date:

September 22, 2011

Filing Date:

March 16, 2011

Export Citation:

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Assignee:

NSK LTD (JP)
HARADA TORU (JP)
HASHIMOTO KOJI (JP)
ITO TSUYOSHI (JP)
YAMASHITA TOMOFUMI (JP)
AOKI NAOYA (JP)

International Classes:

F16H25/24; B21K1/70

Foreign References:

JP2000297854A	2000-10-24
JP2007127152A	2007-05-24
JP2008281063A	2008-11-20
JPH0645149U	1994-06-14
JP2004150593A	2004-05-27
JP2009192033A	2009-08-27
US7013747B2	2006-03-21
JP2000297854A	2000-10-24
JP2008281063A	2008-11-20
JP2010096317A	2010-04-30
JP2004251367A	2004-09-09
JP4214371B2	2009-01-28

Other References: