US5675201A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Composite bearing structure
Assignee: Sumitomo Electric Industries Ltd
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Filing: 1994-01-04
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Granted: 1997-10-07
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Expires: 2014-01-04
Abstract
Abstract PCT No. PCT/JP94/00002 Sec. 371 Date Aug. 24, 1994 Sec. 102(e) Date Aug. 24, 1994 PCT Filed Jan. 4, 1994 PCT Pub. No. WO94/16233 PCT Pub. Date Jul. 21, 1994A composite bearing structure that has a high rotational accuracy and that can withstand high-speed rotation comprises first bearing means, second bearing means, third bearing means and fourth bearing means. The first bearing means supports a radial impact force which is applied to a rotator during rotation, and is formed by an inner ring (1) and an outer ring (2) consisting of silicon nitride ceramics sintered bodies. The second bearing means supports an axial load which is applied to the rotator while maintaining a prescribed clearance with the rotator, and is formed by a magnetic bearing body of two permanent magnets (12) and (13) which are thrust-directionally opposed to each other. The third bearing means maintains the radial rotational accuracy of the rotator, and is formed by a radial dynamic pressure producing groove (5) which is formed in a cylindrical surface of the inner ring (1). The fourth bearing means maintains the thrust-directional rotational accuracy of the rotator, and is formed by an air dome portion (100) which is confined in a semi-closed state by the inner ring (1), the outer ring (2) and a cover (4).
Inventors
- 👤 Osamu Komura
- 👤 Tetsuya Katayama
- 👤 Akira Yamakawa
- 👤 Kenji Matsunuma
- 👤 Norio Yasuoka
- 👤 Matsuo Higuchi
- 👤 Masaya Miyake
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 18:05
CPC Classifications
F; F16; F16C; F16C32/00; F16C32/04; F16C32/0406; F16C32/0408; F16C32/0423; F16C32/0427; F16C17/00; F16C17/10; F16C17/102; F16C17/107; F16C32/0402; F16C32/0429; F16C32/0431; F16C33/00; F16C33/02; F16C33/04; F16C33/06; F16C33/10; F16C33/1005; F16C33/101; F16C33/1015; F16C33/1025; F16C33/106; F16C33/107; F16C39/00; F16C39/06; F16C39/063
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
99 words
A composite bearing structure for supporting a rotator that is adapted to rotate at a high speed, said composite bearing structure comprising: first bearing means (1, 2) including a ceramics sintered body for supporting a radial impact force that is applied to said rotator during rotation thereof; second bearing means for supporting an axial load that is applied to said rotator while maintaining a prescribed clearance of said second bearing means and said rotator; third bearing means for maintaining a radial rotational accuracy of said rotator; and fourth bearing means for maintaining a thrust-directional rotational accuracy of said rotator.
Claim 2
Dependent Claim
99 words
A composite bearing structure for supporting a rotator that is adapted to rotate at a high speed, said composite bearing structure comprising: first bearing means (1, 2) including a ceramics sintered body for supporting a radial impact force that is applied to said rotator during rotation thereof; second bearing means for supporting an axial load that is applied to said rotator while maintaining a prescribed clearance of said second bearing means and said rotator; third bearing means for maintaining a radial rotational accuracy of said rotator; and fourth bearing means for maintaining a thrust-directional rotational accuracy of said rotator.
Claim 3
Dependent Claim
21 words
The composite bearing structure in accordance with claim 1, wherein said ceramics sintered body includes a silicon nitride ceramics sintered body.
Claim 4
Dependent Claim
73 words
The composite bearing structure in accordance with claim 2, wherein said silicon nitride ceramics sintered body includes silicon nitride containing crystal grains with a linear density of at least 35 grains per length of 30 μm with a grain boundary phase volume ratio of not more than 15 volume %, and containing pores having a maximum diameter of not more than 20 μm, the content of said pores being not more than 3%.
Claim 5
Dependent Claim
36 words
The composite bearing structure in accordance with claim 1, wherein said second bearing means includes dynamic gas pressure bearing means (6) for supporting said axial load by a gas pressure produced by rotation of said rotator.
Claim 6
Dependent Claim
41 words
The composite bearing structure in accordance with claim 4, wherein said dynamic gas pressure bearing means includes a rotating member (2) rotating with said rotator, and a fixed member (3) arranged opposite said rotating member with said clearance maintained axially therebetween.
Claim 7
Dependent Claim
51 words
The composite bearing structure in accordance with claim 5, wherein said rotating member and said fixed member include ceramics sintered bodies, and wherein at least one of said rotating member and said fixed member has a groove (6) therein for introducing a gas into said clearance for producing said gas pressure.
Claim 8
Dependent Claim
34 words
The composite bearing structure in accordance with claim 1, wherein said second bearing means includes magnetic bearing means (12, 13; 10, 17; 15, 16) for supporting said axial load through magnetic attraction or repulsion.
Claim 9
Dependent Claim
40 words
The composite bearing structure in accordance with claim 7, wherein said magnetic bearing means includes a rotating member (2) rotating with said rotator, and a fixed member (3; 13) arranged opposite said rotating member with said clearance maintained axially therebetween.
Claim 10
Dependent Claim
35 words
The composite bearing structure in accordance with claim 8, wherein said rotating member and said fixed member include magnets (12, 13; 10, 17; 15, 16) for producing said magnetic attraction or repulsion in said clearance.
Claim 11
Dependent Claim
39 words
The composite bearing structure in accordance with claim 1, wherein said third bearing means includes a ceramics sintered body for maintaining said radial rotational accuracy while maintaining a prescribed second clearance of said third bearing means and said rotator.
Claim 12
Dependent Claim
36 words
The composite bearing structure in accordance with claim 1, wherein said third bearing means includes dynamic gas pressure bearing means (5) for maintaining said rotational accuracy by a gas pressure produced by rotation of said rotator.
Claim 13
Dependent Claim
41 words
The composite bearing structure in accordance with claim 11, wherein said dynamic gas pressure bearing means includes a rotating member (2, 4) rotating with said rotator, and a fixed member (1) arranged opposite said rotating member with a radial clearance therebetween.
Claim 14
Dependent Claim
52 words
The composite bearing structure in accordance with claim 12, wherein said rotating member and said fixed member include ceramics sintered bodies, and wherein at least one of said rotating member and said fixed member has a groove (5) therein for introducing a gas into said radial clearance for producing said gas pressure.
Claim 15
Dependent Claim
53 words
The composite bearing structure in accordance with claim 1, wherein said third bearing means includes magnetic bearing means (8, 10, 11; 7, 8, 9, 10; 7, 8, 14, 15) for maintaining said rotational accuracy through magnetic attraction or repulsion while maintaining a prescribed second clearance of said third bearing means and said rotator.
Claim 16
Dependent Claim
40 words
The composite bearing structure in accordance with claim 14, wherein said magnetic bearing means includes a rotating member (2) rotating with said rotator, and a fixed member (1) arranged opposite said rotating member with said second clearance maintained radially therebetween.
Claim 17
Dependent Claim
41 words
The composite bearing structure in accordance with claim 15, wherein said rotating member and said fixed member include magnets (8, 10, 11; 7, 8, 9, 10; 7, 8, 14, 15) for producing said magnetic attraction or repulsion in said second clearance.
Claim 18
Dependent Claim
38 words
The composite bearing structure in accordance with claim 16, wherein said rotating member and said fixed member consist of bodies including said ceramics sintered body, and wherein said magnets (11) are embedded in an interior of said bodies.
Claim 19
Dependent Claim
53 words
The composite bearing structure in accordance with claim 1, wherein said fourth bearing means includes a rotating member (4) rotating with said rotator, a fixed member (1) arranged at least axially opposite said rotating member, and a gas dome (100) confined in a semi-closed state between said rotating member and said fixed member.
Claim 20
Dependent Claim
67 words
The composite bearing structure in accordance with claim 18, wherein said rotating member includes a first rotating portion (2) that is arranged radially opposite said fixed member (1) with a second clearance radially therebetween, and a second rotating portion (4) that is arranged axially opposite said fixed member (1) with said gas dome (100) axially interposed therebetween, and that is fixed to said first rotating portion (2).
Claim 21
Dependent Claim
77 words
The composite bearing structure in accordance with claim 19, wherein said second bearing means includes dynamic gas pressure bearing means (6) that introduce a gas into said prescribed clearance by rotation of said rotator, for supporting said axial load by a gas pressure produced by said rotation of said rotator, and wherein said second rotating portion (4) has a hole (101) for discharging said gas introduced into said prescribed clearance by said dynamic gas pressure bearing means.
Claim 22
Dependent Claim
77 words
The composite bearing structure in accordance with claim 19, wherein said third bearing means includes dynamic gas pressure bearing means (5) that introduce a gas into said prescribed clearance by rotation of said rotator, for maintaining said rotational accuracy by a gas pressure produced by said rotation of said rotator, and wherein said second rotating portion (4) has a hole (101) for discharging said gas introduced into said prescribed clearance by said dynamic gas pressure bearing means.
Claim 23
Dependent Claim
243 words
A composite bearing comprising: a fixed member including a base plate and a cylindrical stub extending from said base plate; a rotatable member including a cylindrical sleeve rotatably arranged coaxially and radially outwardly around said cylindrical stub and axially adjacent said base plate, and an axial end cover axially adjacent an axial end of said cylindrical stub opposite said base plate; a radial impact supporting first bearing formed by said cylindrical sleeve rotatably arranged on said cylindrical stub, wherein at least one of said sleeve and said stub is a sintered ceramic body; an axial load supporting second bearing that is arranged between said cylindrical sleeve and said base plate and that maintains therebetween an axial clearance during rotation of said rotatable member relative to said fixed member; a radial rotational accuracy maintaining third bearing that is arranged between said cylindrical sleeve and said cylindrical stub and that maintains therebetween a radial clearance during rotation of said rotatable member relative to said fixed member; and an axial rotational accuracy maintaining fourth bearing that is arranged between said axial end of said cylindrical stub and said axial end cover; wherein said second bearing comprises at least one of a magnetic repulsion bearing and a dynamic gas pressure bearing, and said fourth bearing comprises a gas dome at least partially enclosed in a space formed between said axial end of said cylindrical stub, said axial end cover and an end portion of said cylindrical sleeve.
Claim 24
Dependent Claim
243 words
A composite bearing comprising: a fixed member including a base plate and a cylindrical stub extending from said base plate; a rotatable member including a cylindrical sleeve rotatably arranged coaxially and radially outwardly around said cylindrical stub and axially adjacent said base plate, and an axial end cover axially adjacent an axial end of said cylindrical stub opposite said base plate; a radial impact supporting first bearing formed by said cylindrical sleeve rotatably arranged on said cylindrical stub, wherein at least one of said sleeve and said stub is a sintered ceramic body; an axial load supporting second bearing that is arranged between said cylindrical sleeve and said base plate and that maintains therebetween an axial clearance during rotation of said rotatable member relative to said fixed member; a radial rotational accuracy maintaining third bearing that is arranged between said cylindrical sleeve and said cylindrical stub and that maintains therebetween a radial clearance during rotation of said rotatable member relative to said fixed member; and an axial rotational accuracy maintaining fourth bearing that is arranged between said axial end of said cylindrical stub and said axial end cover; wherein said second bearing comprises at least one of a magnetic repulsion bearing and a dynamic gas pressure bearing, and said fourth bearing comprises a gas dome at least partially enclosed in a space formed between said axial end of said cylindrical stub, said axial end cover and an end portion of said cylindrical sleeve.
Claim 25
Dependent Claim
69 words
The composite bearing in accordance with claim 22, wherein said sintered ceramic body comprises silicon nitride containing crystal grains with a linear density of at least 50 grains per length of 30 μm and a grain boundary phase volume ratio of not more than 15 volume %, and containing pores having a maximum diameter of not more than 20 μm with a pore content of not more than 3%.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2000-10-06 | 2001-04-07 | 2001-10-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-10-06 | 2005-04-07 | 2005-10-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-10-06 | 2009-04-07 | 2009-10-07 | $7700.00 | Window Closed / Lapsed |