US4227756A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High temperature low friction surface coating
Assignee: Soluna Holdings Inc
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Filing: 1978-12-29
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Granted: 1980-10-14
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Expires: 1998-12-29
Abstract
Abstract A high temperature, low friction, flexible coating for metal surfaces which are subject to rubbing contact includes a mixture of three parts graphite and one part cadmium oxide, ball milled in water for four hours, then mixed with thirty percent by weight of sodium silicate in water solution and a few drops of wetting agent. The mixture is sprayed 12-15 microns thick onto an electro-etched metal surface and air dried for thirty minutes, then baked for two hours at 65° C. to remove the water and wetting agent, and baked for an additional eight hours at about 150° C. to produce the optimum bond with the metal surface. The coating is afterwards burnished to a thickness of about 7-10 microns.
Inventors
- 👤 Bharat Bhushan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 12:07
CPC Classifications
F; F16; F16C; F16C17/00; F16C17/02; F16C17/024; F16C33/00; F16C33/02; F16C33/04; F16C33/16; F16C2240/00; F16C2240/40; F16C2240/60; F16C2360/00; F16C2360/23; F16C33/06; F16C33/10; F16C33/1095; Y; Y10; Y10S; Y10S384/00; Y10S384/90; Y10S384/913
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
75 words
In a compliant hydrodynamic gas bearing for high temperature applications, a flexible bearing sheet with one bearing surface, and a relatively rotating rigid member with an opposing bearing surface, the improvement comprising: a flexible coating of less than 12 microns thickness on the bearing surface of the flexible bearing sheet, including a layer of CdO and graphite in proportions of about 1:3 by weight, dispersed in a fused matrix of 28%-32% by weight sodium silicate.
Claim 2
Dependent Claim
75 words
In a compliant hydrodynamic gas bearing for high temperature applications, a flexible bearing sheet with one bearing surface, and a relatively rotating rigid member with an opposing bearing surface, the improvement comprising: a flexible coating of less than 12 microns thickness on the bearing surface of the flexible bearing sheet, including a layer of CdO and graphite in proportions of about 1:3 by weight, dispersed in a fused matrix of 28%-32% by weight sodium silicate.
Claim 3
Dependent Claim
76 words
The bearing defined in claim 1, wherein said bearing sheet is a high temperature, nickel-based material, also containing chromium, iron and titanium, between 50 and 200 microns thick, which has been heat treated for hardness, resilience and strength, and has been electroetched on said bearing surface to remove the oxide film resulting from said heat treatment and to roughen said surface, primarily at the grain boundaries, to improve the bond of said coating on said surface.
Claim 4
Dependent Claim
22 words
The bearing defined in claim 2, wherein the surface roughness of said bearing sheet under said coating is approximately 0.23-0.33 microns rms.
Claim 5
Dependent Claim
89 words
In a hydrodynamic gas bearing, for high temperature applications, including a stationary member and a relatively rotating member, each member having a bearing surface facing the bearing surface of the other member, the improvement comprising: a hard oxide or carbide coating on the bearing surface of said rotating member; and a solid coating bonded to the bearing surface of said stationary member, including a dispersion of CdO and graphite powders, in proportions of about 1:3 by weight, in a fused matrix of about 28%-32% by weight of sodium silicate.
Claim 6
Dependent Claim
89 words
In a hydrodynamic gas bearing, for high temperature applications, including a stationary member and a relatively rotating member, each member having a bearing surface facing the bearing surface of the other member, the improvement comprising: a hard oxide or carbide coating on the bearing surface of said rotating member; and a solid coating bonded to the bearing surface of said stationary member, including a dispersion of CdO and graphite powders, in proportions of about 1:3 by weight, in a fused matrix of about 28%-32% by weight of sodium silicate.
References Cited (Backward Citations)
US3308524A
Cited
DE2356616A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-10-14 | 1984-04-14 | 1984-10-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-10-14 | 1988-04-14 | 1988-10-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-10-14 | 1992-04-14 | 1992-10-14 | $7700.00 | Window Closed / Lapsed |