Title:
BALL SCREW
Document Type and Number:
Japanese Patent JP2005232543
Kind Code:
A
Abstract:
To provide a ball screw having excellent wear resistance and further having a long service life even under high speed use.
In the ball screw, a ball is subjected to nitriding treatment, and the concentration of nitrogen in the surface layer is 0.5 to 6.0 wt.%, preferably, 1.5 to 4.5. The surface layer is the region from any depth in the range of 3 μm to 1 mm from the ball surface to the ball surface. The Vickers hardness in the ball surface and in the depth of 2% in the diameter of the ball is desirably ≥850 and ≥500, respectively. Also, the total content of carbon and nitrogen in the depth of 2% in the ball diameter is desirably ≥0.5 wt.%.
Inventors:
YOSHIOKA HIROYASU
OKITA SHIGERU
OKITA SHIGERU
Application Number:
JP2004043754A
Publication Date:
September 02, 2005
Filing Date:
February 20, 2004
Export Citation:
Assignee:
NSK LTD
International Classes:
F16H25/22; C21D1/06; C21D9/00; C22C38/00; C22C38/18; C23C8/02; C23C8/26; C23C8/50; (IPC1-7): C23C8/26; C21D1/06; C21D9/00; C22C38/00; C22C38/18; C23C8/02; C23C8/50; F16H25/22
Attorney, Agent or Firm:
Masao Okabe
Nobuaki Kato
Kazuo
Shinichi Usui
Ikuo Fujino
Takao Ochi
Teruhisa Motomiya
Norimichi Takanashi
Asahi Shinmitsu
Seiichiro Takahashi
Koji Yoshizawa
Nobuaki Kato
Kazuo
Shinichi Usui
Ikuo Fujino
Takao Ochi
Teruhisa Motomiya
Norimichi Takanashi
Asahi Shinmitsu
Seiichiro Takahashi
Koji Yoshizawa