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公开(公告)号：DE69922748D1
公开(公告)日：2005-01-27
申请号：DE69922748
申请日：1999-03-10
Applicant: SUMITOMO ELECTRIC INDUSTRIES
Inventor： MURABE KAORU , KOMURA OSAMU
Abstract: A dynamic gas bearing structure comprising a cylindrical shaft body (1) and a hollow cylindrical bearing body (2) opposed to the shaft body (1) with a clearance provided between them in radial direction, either of the shaft body (1) and the bearing body (2) having a projected polygonal shape with 10 or more corner parts in a lateral cross-section vertical to the center axes of the shaft body (1) and the bearing body (2), whereby a practicable dynamic gas bearing structure capable of suppressing a 1/2 whirl and a deflection due to rotation can be obtained even at a high speed of 20,000 rpm or higher.
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公开(公告)号：DE69627260D1
公开(公告)日：2003-05-15
申请号：DE69627260
申请日：1996-09-18
Applicant: CANON KK , SUMITOMO ELECTRIC INDUSTRIES
Inventor： FUKITA TAKU , NAKASUGI MIKIO , SATO ISSHIN , KATAYAMA TETSUYA , KOMURA OSAMU , MURABE KAORU
IPC: F16C20060101 , F16C33/10 , H04N1/00
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公开(公告)号：DE69618051T2
公开(公告)日：2002-06-20
申请号：DE69618051
申请日：1996-03-12
Applicant: CANON KK , SUMITOMO ELECTRIC INDUSTRIES
Inventor： MURABE KAORU , KATAYAMA TETSUYA , KOMURA OSAMU , NAKASUGI MIKIO , FUKITA TAKU , SATO ISSHIN
Abstract: A dynamic-pressure gas bearing structure includes a columnar shaft made of a silicon-nitride-based ceramic sintered body, a hollow cylindrical sleeve opposed to the shaft as keeping a clearance in a radial direction, the sleeve being made of a silicon-nitride-based ceramic sintered body, and at least three flat face portions located on a peripheral surface of the shaft and at equal intervals to the circumference along the peripheral surface. The flat face portion includes a plurality of unit planes continuously formed at predetermined angles to a direction of the circumference on the peripheral surface of the shaft. The unit planes are formed so as to extend substantially in parallel with an axial direction of the shaft.
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公开(公告)号：DE69615245D1
公开(公告)日：2001-10-25
申请号：DE69615245
申请日：1996-03-11
Applicant: SUMITOMO ELECTRIC INDUSTRIES
Inventor： MURABE KAORU , KOMURA OSAMU
Abstract: Provided is a dynamic pressure gas bearing structure which is applicable to a high-speed rotation driving part such as a hard disk driver or the like and has high rotational accuracy in high-speed rotation. The dynamic pressure gas bearing structure comprises a shaft body (1) and a bearing body (2). When the shaft body (1) and the bearing body (2) are so arranged that central axes (50) thereof are aligned with each other, a substantially cylindrical gap (3) is defined between the outer peripheral surface of the shaft body (1) and the inner peripheral surface of the bearing body (2). The gap (3) has at least one gap change portion whose thickness is changed with respect to a central angle corresponding to the circumference along the outer peripheral surface of the shaft body (1). The gap change rate alpha is at least 1.0 x 10 / DEG and less than 10.0 x 10 / DEG .
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公开(公告)号：DE69703999T2
公开(公告)日：2001-05-23
申请号：DE69703999
申请日：1997-04-24
Applicant: SUMITOMO ELECTRIC INDUSTRIES
Inventor： PARK JIN-JOO , MOCHIDA YASUSHI , KUIBIRA AKIRA , KOMURA OSAMU , YAMAGUCHI AKIRA
IPC: C04B35/584 , C04B35/593 , C04B35/64 , C04B38/00 , F16C33/24 , C10M103/06 , F16C33/04
Abstract: A silicon nitride ceramic sliding material comprising silicon nitride crystal grains and a grain boundary phase and having a porosity of 2 to 10% and a maximum pore size of 20 to 100 mu m. The silicon nitride ceramic sliding material preferably has a textural structure wherein the proportion of the total area of silicon nitride crystal grains of 0.1 to 10 mu m in area to the total area of all the silicon nitride crystal grains present in an arbitrary two-dimensional cross section is 30 to 90% and the proportion of the number of silicon nitride crystal grains of 2 to 10 in aspect ratio to the number of all the silicon nitride crystal grains present in that cross section is at least 20%. The material is produced by mixing a silicon nitride powder with a sintering aid powder, molding the resulting mixture, then heat-treating the resulting molded body in a nitrogen-containing atmosphere under reduced pressure at 1,000 to 1,500 DEG C, and then sintering it in a nonoxidizing atmosphere under ordinary pressure or under pressure, at 1,550 to 1,800 DEG C.
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Patent Agency Ranking
公开(公告)号：DE69703999D1
公开(公告)日：2001-03-08
申请号：DE69703999
申请日：1997-04-24
Applicant: SUMITOMO ELECTRIC INDUSTRIES
Inventor： PARK JIN-JOO , MOCHIDA YASUSHI , KUIBIRA AKIRA , KOMURA OSAMU , YAMAGUCHI AKIRA
IPC: C04B35/584 , C04B35/593 , C04B35/64 , C04B38/00 , F16C33/24 , C10M103/06 , F16C33/04
Abstract: A silicon nitride ceramic sliding material comprising silicon nitride crystal grains and a grain boundary phase and having a porosity of 2 to 10% and a maximum pore size of 20 to 100 mu m. The silicon nitride ceramic sliding material preferably has a textural structure wherein the proportion of the total area of silicon nitride crystal grains of 0.1 to 10 mu m in area to the total area of all the silicon nitride crystal grains present in an arbitrary two-dimensional cross section is 30 to 90% and the proportion of the number of silicon nitride crystal grains of 2 to 10 in aspect ratio to the number of all the silicon nitride crystal grains present in that cross section is at least 20%. The material is produced by mixing a silicon nitride powder with a sintering aid powder, molding the resulting mixture, then heat-treating the resulting molded body in a nitrogen-containing atmosphere under reduced pressure at 1,000 to 1,500 DEG C, and then sintering it in a nonoxidizing atmosphere under ordinary pressure or under pressure, at 1,550 to 1,800 DEG C.
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公开(公告)号：DE69217769T2
公开(公告)日：1997-10-02
申请号：DE69217769
申请日：1992-08-05
Applicant: SUMITOMO ELECTRIC INDUSTRIES
Inventor： KOMURA OSAMU , MATSUNUMA KENJI , YASUOKA NORIO , HIGUCHI MATSUO , MIYAKE MASAYA , KATAYAMA TETSUYA , YAMAKAWA AKIRA
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公开(公告)号：DE69838522D1
公开(公告)日：2007-11-15
申请号：DE69838522
申请日：1998-02-23
Applicant: SUMITOMO ELECTRIC INDUSTRIES
Inventor： TAKEUCHI HISAO , MURABE KAORU , KOMURA OSAMU , AWAZU TOMOYUKI
Abstract: Provided is a hydrodynamic gas bearing structure which can prevent occurrence of whirl not only in high-speed rotation but also in low-speed rotation, reduces such frequency that a floating rotational frequency in starting or stoppage of rotation increases, and is capable of shifting the floating rotational frequency to a low rotational frequency side. The hydrodynamic gas bearing structure comprises a shaft body (1) and a bearing body (2). A groove (11) is formed on the outer peripheral surface of the shaft body (1). The groove (11) consists of at least two concave parts, whose depths substantially differ from each other, which are formed serially in the circumferential direction, and has a circumferentially asymmetrical shape in a cross section perpendicular to the axis. The circumferential distance a between the intersection point (15) of a line (C) connecting the deepest point (14) of the groove (11) and the center (O) of the shaft body (1) and the outer peripheral line (Q) of the shaft body (1) and one edge (16) of the groove (11) positioned downward an air current (P) generated in rotation in relation to the intersection point (15) is larger than the circumferential distance b between the intersection point (15) and the other edge (17) of the groove (11) positioned upstream the air current (P) in relation to the intersection point (15). The ratio (d2/d1) of the mean depth d2 of a relatively shallow part of the groove (11) to the mean depth di of a relatively deep part of the groove (11) is less than 0.3. The hydrodynamic gas bearing structure is suitable for employment for a rotation driving part of a magnetic recording apparatus or a laser beam printer.
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公开(公告)号：DE69835383D1
公开(公告)日：2006-09-07
申请号：DE69835383
申请日：1998-02-23
Applicant: SUMITOMO ELECTRIC INDUSTRIES
Inventor： TAKEUCHI HISAO , MURABE KAORU , KOMURA OSAMU , AWAZU TOMOYUKI
Abstract: Provided is a hydrodynamic gas bearing structure which can prevent occurrence of whirl not only in high-speed rotation but also in low-speed rotation, reduces such frequency that a floating rotational frequency in starting or stoppage of rotation increases, and is capable of shifting the floating rotational frequency to a low rotational frequency side. The hydrodynamic gas bearing structure comprises a shaft body (1) and a bearing body (2). A groove (11) is formed on the outer peripheral surface of the shaft body (1). The groove (11) consists of at least two concave parts, whose depths substantially differ from each other, which are formed serially in the circumferential direction, and has a circumferentially asymmetrical shape in a cross section perpendicular to the axis. The circumferential distance a between the intersection point (15) of a line (C) connecting the deepest point (14) of the groove (11) and the center (O) of the shaft body (1) and the outer peripheral line (Q) of the shaft body (1) and one edge (16) of the groove (11) positioned downward an air current (P) generated in rotation in relation to the intersection point (15) is larger than the circumferential distance b between the intersection point (15) and the other edge (17) of the groove (11) positioned upstream the air current (P) in relation to the intersection point (15). The ratio (d2/d1) of the mean depth d2 of a relatively shallow part of the groove (11) to the mean depth di of a relatively deep part of the groove (11) is less than 0.3. The hydrodynamic gas bearing structure is suitable for employment for a rotation driving part of a magnetic recording apparatus or a laser beam printer.
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公开(公告)号：DE69833422D1
公开(公告)日：2006-04-20
申请号：DE69833422
申请日：1998-02-23
Applicant: SUMITOMO ELECTRIC INDUSTRIES
Inventor： TAKEUCHI HISAO , MURABE KAORU , KOMURA OSAMU , AWAZU TOMOYUKI
Abstract: Provided is a hydrodynamic gas bearing structure which can prevent occurrence of whirl not only in high-speed rotation but also in low-speed rotation, reduces such frequency that a floating rotational frequency in starting or stoppage of rotation increases, and is capable of shifting the floating rotational frequency to a low rotational frequency side. The hydrodynamic gas bearing structure comprises a shaft body (1) and a bearing body (2). A groove (11) is formed on the outer peripheral surface of the shaft body (1). The groove (11) consists of at least two concave parts, whose depths substantially differ from each other, which are formed serially in the circumferential direction, and has a circumferentially asymmetrical shape in a cross section perpendicular to the axis. The circumferential distance a between the intersection point (15) of a line (C) connecting the deepest point (14) of the groove (11) and the center (O) of the shaft body (1) and the outer peripheral line (Q) of the shaft body (1) and one edge (16) of the groove (11) positioned downward an air current (P) generated in rotation in relation to the intersection point (15) is larger than the circumferential distance b between the intersection point (15) and the other edge (17) of the groove (11) positioned upstream the air current (P) in relation to the intersection point (15). The ratio (d2/d1) of the mean depth d2 of a relatively shallow part of the groove (11) to the mean depth di of a relatively deep part of the groove (11) is less than 0.3. The hydrodynamic gas bearing structure is suitable for employment for a rotation driving part of a magnetic recording apparatus or a laser beam printer.
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