Title:
BALL SCREW DEVICE
Document Type and Number:
WIPO Patent Application WO/2015/182761
Kind Code:
A1
Abstract:
The screw shaft of this ball screw device comprises high-carbon bearing steel having an Ms point of 172°C or lower and a DI value of 2.8 or above; and has an effective case layer of hardness of HV 500 or above formed in a specific area from the surface, an unhardened layer of hardness of less than HV 500 the metal structure of which contains a ferrite phase and a cementite phase, and a carbide area ratio of 1.5 area percent or greater at the raceway surface.
Inventors:
ABE NARUAKI (JP)
HIDAKA HIDEYUKI (JP)
WATANABE YASUMI (JP)
HIDAKA HIDEYUKI (JP)
WATANABE YASUMI (JP)
Application Number:
PCT/JP2015/065632
Publication Date:
December 03, 2015
Filing Date:
May 29, 2015
Export Citation:
Assignee:
NSK LTD (JP)
International Classes:
C21D9/00; F16H25/24; C21D1/10; C22C38/00; C22C38/44
Foreign References:
| JP2010255702A | 2010-11-11 | |||
| JP2004076823A | 2004-03-11 | |||
| JP2010090924A | 2010-04-22 | |||
| JP2005299720A | 2005-10-27 |
Attorney, Agent or Firm:
Eikoh Patent Firm, P. C. et al. (JP)
Patent business corporation glory patent firm (JP)
Patent business corporation glory patent firm (JP)
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