US4938611A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Bearing apparatus
Assignee: Hitachi Ltd
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Filing: 1989-06-20
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Granted: 1990-07-03
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Expires: 2009-06-20
Abstract
Abstract A bearing apparatus comprises a housing formed of a non-magnetizable material and having a bottom portion, a fluid lubricating type radial bearing device provided coaxial with the housing and having a magnetic fluid sealing section and a radial bearing section, a thrust bearing device provided at the bottom portion of the housing, and a rotating shaft of a permeable material rotatably supported by the radial bearing device and thr thrust bearing device to extend through the radial bearing device. The magnetic fluid sealing section is disposed on the opening side of the housing with a predetermined spacing away from the radial bearing section whereby a space is provided between the magnetic fluid sealing section and a liquid surface of fluid lubricant filled in the radial bearing section.
Inventors
- 👤 Katsutoshi Nii
- 👤 Kazuhiko Kawaike
- 👤 Hiroo Hiroyama
- 👤 Satoshi Uno
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 05:51
CPC Classifications
F; F16; F16J; F16J15/00; F16J15/16; F16J15/40; F16J15/43; F16C; F16C33/00; F16C33/02; F16C33/04; F16C33/06; F16C33/10; F16C33/1025; F16C33/103; F16C33/1035; F16C33/72; F16C33/74; F16C33/741; F16C33/743; F16C33/746
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
131 words
A bearing apparatus comprising a housing formed of a non-magnetizable material and having a bottom portion; a fluid lubricating type radial bearing means coaxially disposed with respect to said housing and having a magnetic fluid sealing section and a radial bearing section; a thrust bearing means provided at the bottom portion of said housing; and a rotating shaft of a permeable material rotatably supported by said radial bearing means and said thrust bearing means so as to extend through said radial bearing means; said magnetic fluid sealing section being disposed on and open side of said housing with a predetermined spacing away from said radial bearing section whereby a space is provided between said magnetic fluid sealing section and a liquid surface of fluid lubricant filled in said radial bearing section.
Claim 2
Dependent Claim
131 words
A bearing apparatus comprising a housing formed of a non-magnetizable material and having a bottom portion; a fluid lubricating type radial bearing means coaxially disposed with respect to said housing and having a magnetic fluid sealing section and a radial bearing section; a thrust bearing means provided at the bottom portion of said housing; and a rotating shaft of a permeable material rotatably supported by said radial bearing means and said thrust bearing means so as to extend through said radial bearing means; said magnetic fluid sealing section being disposed on and open side of said housing with a predetermined spacing away from said radial bearing section whereby a space is provided between said magnetic fluid sealing section and a liquid surface of fluid lubricant filled in said radial bearing section.
Claim 3
Dependent Claim
32 words
A bearing apparatus as set forth in claim 1, wherein said fluid lubricant filled in said radial bearing section is the same magnetic fluid as that in said magnetic fluid sealing section.
Claim 4
Dependent Claim
43 words
A bearing apparatus as set forth in one of claims 1 or 2, wherein said fluid lubricant filled in said radial bearing section is a magnetic fluid having a lower viscosity than that of the magnetic fluid in said magnetic fluid sealing section.
Claim 5
Dependent Claim
23 words
A bearing apparatus as set forth in claim 3, wherein the fluid lubricant circulates between opposite end surfaces of said radial bearing section.
Claim 6
Dependent Claim
45 words
A bearing apparatus as set forth in claim 4, wherein an area, at which a circulating passage of said fluid lubricant contacts with said rotating shaft, is larger around the lower end surface of said radial bearing section than around the upper end surface thereof.
Claim 7
Dependent Claim
57 words
A bearing apparatus as set forth in claim 5, further comprising a passage means extended between the opposite end surfaces of said radial bearing section for passing a fluid lubricant therethrough and provided on and outer periphery of said radial bearing section in communication with a bearing clearance between said radial bearing section and said rotating shaft.
Claim 8
Dependent Claim
68 words
A bearing apparatus as set forth in claim 6, wherein a surface opposite to a sliding surface of said thrust bearing section which bears an axial load of said rotating shaft cooperates with the bottom of said housing to define therebetween a chamber, and a passage means for the fluid lubricant is provided on central and outer peripheral portions of said sliding surface to communicate with said chamber.
Claim 9
Dependent Claim
44 words
A bearing apparatus as set forth in claim 7, further comprising at least one groove provided on one of the sliding surface of said radial bearing section or on the sliding surface of said rotating shaft to serve for circulation of the fluid lubricant.
Claim 10
Dependent Claim
33 words
A bearing apparatus as set forth in claim 8, wherein the fluid lubricant flows along the sliding surface of said radial bearing from the open side of said housing to the bottom thereof.
Claim 11
Dependent Claim
33 words
A bearing apparatus as set forth in claim 1, wherein said magnetic fluid sealing section disposed on the open side of said housing comprises a ring-shaped permanent magnet and a single pole piece.
Claim 12
Dependent Claim
60 words
A bearing apparatus as set forth in claim 10, further comprising a non-magnetizable disk, and wherein said pole piece is disposed on a side of said radial bearing section and said non-magnetizable disk is disposed on the open side of said housing such that said pole piece and said non-magnetizable disk are disposed in close proximity to said permanent magnet.
Claim 13
Dependent Claim
48 words
A bearing apparatus as set forth in claim 11, wherein a gap between said non-magnetizable disk and said rotating shaft is one of equal in size to a bearing clearance about said radial bearing section or smaller than a gap between said pole piece and said rotating shaft.
Claim 14
Dependent Claim
32 words
A bearing apparatus as set forth in claim 12, wherein said non-magnetizable disk is formed of a material having a lower hardness than that of a material which forms said rotating shaft.
Claim 15
Dependent Claim
19 words
A bearing apparatus as set forth in claim 10, wherein said permanent magnet is substantially L-shaped in axial section.
Claim 16
Dependent Claim
27 words
A bearing apparatus as set forth in one of claims 1 or 2, wherein the fluid lubricant circulates between opposite end surfaces of said radial bearing section.
Claim 17
Dependent Claim
45 words
A bearing apparatus as set forth in claim 15, wherein an area, at which a circulating passage of said fluid lubricant contacts with said rotating shaft, is larger around the lower end surface of said radial bearing section than around the upper end surface thereof.
Claim 18
Dependent Claim
56 words
A bearing apparatus as set forth in claim 16, further comprising passage means extending between the opposite end surfaces of said radial bearing section for passing therethrough a fluid lubricant and provided on an outer periphery of said radial bearing section and communication with a bearing clearance between said radial bearing section and said rotating shaft.
Claim 19
Dependent Claim
68 words
A bearing apparatus as set forth in claim 17, wherein a surface opposite to a sliding surface of said thrust bearing section which bears an axial load of said rotating shaft cooperates with the bottom of said housing to define therebetween a chamber, and a passage means for the fluid lubricant is provided on central and outer peripheral portions of said sliding surface to communicate with said chamber.
Claim 20
Dependent Claim
44 words
A bearing apparatus as set forth in claim 18, further comprising at least one groove provided on one of the sliding surface of said radial bearing section or on the sliding surface of said rotating shaft to serve for circulation of the fluid lubricant.
Claim 21
Dependent Claim
34 words
A bearing apparatus as set forth in claim 19, wherein the fluid lubricant flows along the sliding surface of said radial bearing section from the open side of said housing to the bottom thereof.
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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) | 1993-07-02 | 1994-01-01 | 1994-07-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-07-02 | 1998-01-01 | 1998-07-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-07-02 | 2002-01-01 | 2002-07-03 | $7700.00 | Window Closed / Lapsed |