BRIDGE-TYPE BALL SCREW AND METHOD FOR MANUFACTURING SAME

Title:

BRIDGE-TYPE BALL SCREW AND METHOD FOR MANUFACTURING SAME

Document Type and Number:

WIPO Patent Application WO/2016/125825

Kind Code:

A1

Abstract:

Provided is an inexpensive, highly reliable bridge-type ball screw in which the step of a ball transfer part is eliminated and smoothed out to prevent abnormal sounds, and durability is improved. A method for manufacturing a bridge-type ball screw 1 provided with a bridge member 5 which is fitted into a bridge window 6 formed in the body of a nut 3, the bridge member 5 having a linking groove 5a that has a rolling track as a circuital path in the inner periphery, wherein: after the bridge member 5 is fitted into the bridge window 6 of the nut 3, a columnar mandrel 8 having a projection 9 is inserted into the nut 3; with the mandrel 8 supported while horizontal, an upper die 10 arranged radially outward from the nut 3 is lowered, the upper die 10 restraining the upper surface of the bridge member 5; the upper die 10 is lowered while the nut 3 is held between the upper die 10 and the mandrel 8; a connecting part between the linking groove 5a of the bridge member 5 and a thread groove 3a of the nut 3 is subjected to plastic working by the projection 9 of the mandrel 8; the outer-peripheral part of the bridge member 5 is simultaneously plastically deformed by the upper die 10; and the bridge member 5 is secured by caulking in the bridge window 6 of the nut 3.

Inventors:

SHIMIZU TATSUNORI (JP)

Application Number:

PCT/JP2016/053208

Publication Date:

August 11, 2016

Filing Date:

February 03, 2016

Export Citation:

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Assignee:

NTN TOYO BEARING CO LTD (JP)

International Classes:

F16H25/22; B21D39/00; B21K1/70; B22F3/02; F16H25/24

Foreign References:

JP2005121042A	2005-05-12
JP2008281063A	2008-11-20
JP2008286353A	2008-11-27
JP2005299719A	2005-10-27

Other References: