US3746407A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ferrohydrodynamic low friction bearing
Assignee: Northrop Grumman Guidance and Electronics Co Inc
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Filing: 1971-08-13
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Granted: 1973-07-17
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Expires: 1991-08-13
Abstract
Abstract A self-contained, full-film hydrodynamic bearing utilizing (1) the hydrodynamic properties of a ferrofluid (colloidal suspension of magnetic particles) to produce support pressures in the bearing by an applied viscous pumping action, and (2) the magnetic properties of the ferrofluid to retain the fluid within the bearing.
Inventors
- 👤 J Stiles
- 👤 R Tuffias
- 👤 R Blakely
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 09:41
CPC Classifications
F; F16; F16J; F16J15/00; F16J15/16; F16J15/40; F16J15/43; F16C; F16C17/00; F16C17/02; F16C17/026; F16C33/00; F16C33/02; F16C33/04; F16C33/06; F16C33/10; F16C33/1025; F16C33/103; F16C33/1035; F16C33/106; F16C33/1065; F16C33/107; F16C33/30; F16C33/66; F16C33/6637; F16C33/664; F16C33/6644; F16C33/72; F16C2210/00; F16C2210/02; F16C2210/06; Y; Y02; Y02T; Y02T10/00; Y02T10/80; Y02T10/86
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
69 words
A bearing assembly comprising: a. bearing means for the support of a load including at least first and second members, b. single magnetizable fluid means developing a selected seal and lubricant film contact with said first and second members, and c. magnetic seal means acting upon and retaining said single magnetizable fluid so that the desired lubricant film contact as developed is maintained without leakage of said fluid means.
Claim 2
Dependent Claim
69 words
A bearing assembly comprising: a. bearing means for the support of a load including at least first and second members, b. single magnetizable fluid means developing a selected seal and lubricant film contact with said first and second members, and c. magnetic seal means acting upon and retaining said single magnetizable fluid so that the desired lubricant film contact as developed is maintained without leakage of said fluid means.
Claim 3
Dependent Claim
55 words
The bearing assembly of claim 1 in which said magnetic seal means includes: a. manget means developing a magnetic flux field, and b. magnetic flux concentrator means on said second member spaced apart from said first member concentrating the developed magnetic flux field through said magnetizable fluid means at and generally adjacent said concentrator means.
Claim 4
Dependent Claim
15 words
The bearing assembly of claim 2 in which said magnet means is a permanent magnet.
Claim 5
Dependent Claim
14 words
The bearing assembly of claim 2 in which said magnet means is an electromagnet.
Claim 6
Dependent Claim
17 words
The bearing assembly of claim 1 in which said single magnetizable fluid means is a ferromagnetic fluid.
Claim 7
Dependent Claim
32 words
The bearing assembly of claim 5 in which said ferromagnetic fluid includes: a. a carrier liquid, and b. magnetic particles of subdomain size collodially dispersed in said carrier liquid by Brownian movement.
Claim 8
Dependent Claim
14 words
The bearing assembly of claim 6 in which said magnetic particles are magnetic ferrite.
Claim 9
Dependent Claim
35 words
The bearing assembly of claim 1 in which said bearing means includes: a. fluid path means controlling the developed lubricant film contact; and b. pump means forcing said fluid means along said fluid path means.
Claim 10
Dependent Claim
47 words
The bearing assembly of claim 8 in which said fluid path means includes: a. a pumping and stabilizing region between said first and second members, and b. pressure relief means in fluid communication with said region for the controlled movement of said fluid means in said region.
Claim 11
Dependent Claim
18 words
The bearing assembly of claim 9 in which said pressure relief means is a plurality of spaced ports.
Claim 12
Dependent Claim
41 words
The bearing assembly of claim 8 in which said pump means includes a plurality of selectively spaced grooves formed in at least one of said first and second members and oriented to force said fluid means along said fluid path means.
Claim 13
Dependent Claim
53 words
The bearing assembly of claim 11 in which said first member includes an intermediate portion having said grooves and said second member is positioned outwardly adjacent to said intermediate portion and operatively spaced therefrom by said developed lubricant film contact therebetween so that a desired radial support is developed by the bearing assembly.
Claim 14
Dependent Claim
53 words
The bearing assembly of claim 12 in which said first member further includes thrust means having said grooves and being positioned laterally adjacent to said second member and operatively spaced therefrom by said developed lubricant film contact therebetween so that both a desired radial and axial support are developed by the bearing assembly.
Claim 15
Dependent Claim
26 words
The bearing assembly of claim 13 in which said thrust means includes at least first and second thrust pad members with said intermediate portion positioned therebetween.
Claim 16
Dependent Claim
28 words
The bearing assembly of claim 11 in which said grooves are outwardly diverging in the direction of rotation of said rotatable one of said first and secoNd members.
Claim 17
Dependent Claim
38 words
The bearing assembly of claim 1 in which said bearing means is a rolling-contact bearing having a plurality of rolling elements and said first and second members are respectively first and second races separated by said rolling elements.
Claim 18
Dependent Claim
30 words
The bearing assembly of claim 16 in which said magnetic seal means is a magnetized separator positioning associated ones of said rolling elements in a spaced relationship to each other.
Claim 19
Dependent Claim
13 words
The bearing assembly of claim 17 in which said rolling elements are balls.
Claim 20
Dependent Claim
26 words
The bearing assembly of claim 16 in which said magnetic seal means is a magnetized one of at least one of said first and second races.
Claim 21
Dependent Claim
15 words
The bearing assembly of claim 19 in which said first and second races are magnetized.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-07-16 | 1977-01-15 | 1977-07-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-16 | 1981-01-15 | 1981-07-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-16 | 1985-01-15 | 1985-07-17 | $7700.00 | Window Closed / Lapsed |