Invention Grant
- Patent Title: Rolling bearing and heat treatment method for steel
- Patent Title (中): 钢的滚动轴承和热处理方法
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Application No.: US10586299Application Date: 2005-01-11
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Publication No.: US07641742B2Publication Date: 2010-01-05
- Inventor: Chikara Ohki , Kohei Fujita
- Applicant: Chikara Ohki , Kohei Fujita
- Applicant Address: JP Osaka
- Assignee: NTN Corporation
- Current Assignee: NTN Corporation
- Current Assignee Address: JP Osaka
- Agency: McDermott Will & Emery LLP
- Priority: JP2004-007568 20040115
- International Application: PCT/JP2005/000170 WO 20050111
- International Announcement: WO2005/068862 WO 20050728
- Main IPC: C23C8/00
- IPC: C23C8/00 ; C23C22/00

Abstract:
There is provided a rolling bearing which has long life against rolling fatigue and exhibits no decrease in fracture strength and no increase in rate of dimensional change over time, even if the part size thereof is large, and which can obtain higher strength by crystal grains being further refined, if it has a size equal to or smaller than a prescribed size. The rolling bearing according to the present invention includes a race and a rolling element. At least one member of the race and the rolling element has a nitrogen-enriched layer in its surface layer, and a surface layer portion contains austenite crystal grains having a grain size number of at least 11. The member has hardenability allowing a position exhibiting HRC50 in a hardenability test method for steel to be apart from a quenched end by a distance of at least 12.7 mm ( 8/16 inch).
Public/Granted literature
- US20070169850A1 Rolling bearing and heat treatment method for steel Public/Granted day:2007-07-26
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