Title:
BALL SCREW
Document Type and Number:
WIPO Patent Application WO/2017/130951
Kind Code:
A1
Abstract:
The present invention addresses the problem of limiting ball screw production costs while increasing allowable load capacity. Provided is a recirculating ball screw (1) in which a threaded shaft (2) is inserted in a nut (3) and multiple balls (4) are disposed in a rolling path configured from a shaft-side thread groove (2A) and nut-side thread grooves (3A), wherein: nut-side thread grooves (3A) are provided at one end and the other end of the inner circumferential surface of the nut (3) in the axial direction so as to enlarge or reduce the diameter of the two axial direction ends of the inner circumferential surface and have a helical level difference configuration of roughly a single winding length; in the respective helical level difference configurations, the ends that are shifted from each other in the axial direction are connected by a smooth curved surface (3C) to form a ring; in the smooth curved surface in which the ends of the helical level difference configuration are connected to each other, a recess 3D that is recessed outward in the radial direction of the nut (3) is formed; and the level difference surface of the helical level difference configuration is formed as a curved surface that faces the shaft-side thread groove (2A).
Inventors:
SHIMIZU TATSUNORI (JP)
Application Number:
PCT/JP2017/002312
Publication Date:
August 03, 2017
Filing Date:
January 24, 2017
Export Citation:
Assignee:
NTN TOYO BEARING CO LTD (JP)
International Classes:
F16H25/22
Domestic Patent References:
| WO2007029716A1 | 2007-03-15 |
Attorney, Agent or Firm:
YANO INTERNATIONAL PATENT ATTORNEYS OFFICE, P.C. (JP)
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