Invention Grant
- Patent Title: Shaft member for fluid dynamic bearing device
- Patent Title (中): 流体动力轴承装置用轴构件
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Application No.: US12160654Application Date: 2006-12-26
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Publication No.: US08104963B2Publication Date: 2012-01-31
- Inventor: Kenji Hibi , Yasuhiro Yamamoto
- Applicant: Kenji Hibi , Yasuhiro Yamamoto
- Applicant Address: JP Osaka-shi, Osaka
- Assignee: NTN Corporation
- Current Assignee: NTN Corporation
- Current Assignee Address: JP Osaka-shi, Osaka
- Agency: Westerman, Hattori, Daniels & Adrian, LLP
- Priority: JP2006-011592 20060119; JP2006-013977 20060123
- International Application: PCT/JP2006/325894 WO 20061226
- International Announcement: WO2007/083491 WO 20070726
- Main IPC: F16C32/06
- IPC: F16C32/06 ; F16C33/12

Abstract:
Provided is a shaft member for a fluid dynamic bearing device, which is excellent in wear resistance and which can exert a high dynamic pressure effect. A shaft material (11) is rolled to form a recess (7) for causing a dynamic pressure effect of a lubricating oil in a radial bearing clearance (6). In this case, in a surface layer portion (14) of the recess (7) to be formed in an outer peripheral surface (11a) of the shaft material (11), a first hardened layer (14a) is formed by rolling. At the same time, also in a surface layer portion (15) of a surrounding region (8) of the recess (7), a first hardened layer (15a) is formed by rolling at a partial region thereof. After the recess (7) is formed by the rolling, barreling is applied to the shaft material (11). As a result, an outermost surface layer portion of the surface layer portion (15) is formed with a second hardened layer (15b) by the barreling. A hardness of the second hardened layer (15b) formed in the surrounding region (8) is higher by 50 Hv or more and 200 Hv or less than that of the first hardened layer (14a) formed in the recess (7).
Public/Granted literature
- US20100166343A1 SHAFT MEMBER FOR FLUID DYNAMIC BEARING DEVICE Public/Granted day:2010-07-01
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