US3834775A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ferrohydrodynamic low-friction bearing with improved volume compensation and fluid seal
Assignee: Northrop Grumman Guidance and Electronics Co Inc
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Filing: 1972-05-26
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Granted: 1974-09-10
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Expires: 1992-05-26
Abstract
Abstract A self-contained, full film hydrodynamic bearing is provided having a ferrofluid (colloidal suspension of magnetic particles) with magnetic properties which facilitates retention of the fluid within the bearing where the bearing retains the ferrofluid over a wide temperature range and concomitantly compensates for ferrofluid expansion and contraction.
Inventors
- 👤 R Tuffias
- 👤 H Larson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:08
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
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
157 words
A bearing assembly comprising: a. bearing means for the support of a load including at least first and second members developing a chamber having an adjustable volume, b. compensator means connected to said first member having a temperature responsive region movable in a first direction in response to a predetermined temperature range, said compensator means automatically adjusting said chamber volume in response to temperature, c. limit stop means connected to said second member having a temperature responsive region movable in a second direction in response to the predetermined temperature range, said second direction in opposition to said first direction, d. magnetizable fluid means within said chamber developing a lubricant film contact with said first and second members, and e. magnetic seal means acting upon and retaining said magnetizable fluid to develop a resulting magnetic fluid seal, f. said limit stop means and said compensator means impinging at a predetermined temperature to develop a resulting physical fluid seal.
Claim 2
Dependent Claim
157 words
A bearing assembly comprising: a. bearing means for the support of a load including at least first and second members developing a chamber having an adjustable volume, b. compensator means connected to said first member having a temperature responsive region movable in a first direction in response to a predetermined temperature range, said compensator means automatically adjusting said chamber volume in response to temperature, c. limit stop means connected to said second member having a temperature responsive region movable in a second direction in response to the predetermined temperature range, said second direction in opposition to said first direction, d. magnetizable fluid means within said chamber developing a lubricant film contact with said first and second members, and e. magnetic seal means acting upon and retaining said magnetizable fluid to develop a resulting magnetic fluid seal, f. said limit stop means and said compensator means impinging at a predetermined temperature to develop a resulting physical fluid seal.
Claim 3
Dependent Claim
61 words
The bearing assembly of claim 1 in which said magnetic seal means includes: a. magnetic means on said second member Developing a magnetic flux field, and b. a magnetic flux concentrator portion of said compensator means spaced apart from said limit stop means concentrating the developed magnetic flux field through said magnetizable fluid means at and generally adjacent said concentrator portion.
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
31 words
The bearing assembly of claim 2 in which said compensator means develops a magnetic flux path for said magnetic flux field between said magnet means and said magnetic flux concentrator portion.
Claim 7
Dependent Claim
16 words
The bearing assembly of claim 1 in which said magnetizable fluid means is a ferromagnetic fluid.
Claim 8
Dependent Claim
27 words
The bearing assembly of claim 1 in which said limit stop means and said compensator means are flexible members having a predetermined deflection in response to temperature.
Claim 9
Dependent Claim
16 words
The bearing assembly of claim 7 in which said first and second members are bimetallic elements.
Claim 10
Dependent Claim
60 words
The bearing assembly of claim 1 in which said compensator means has a maximum deflection distance X in said first direction and said limit stop means has a maximum deflection distance Y in said second direction so that a maximum running gap X + Y is developed between said compensator means and said limit stop means at a predetermined temperature.
Claim 11
Dependent Claim
60 words
The bearing assembly of claim 9 in which said limit stop means includes at least first and second temperature responsive members interconnected to develop a maximum deflection distance Z1 by said first temperature responsive member and a maximum deflection distance Z2 by said second temperature responsive member so that a maximum running gap X + Z1 + Z2 is developed.
Claim 12
Dependent Claim
18 words
The bearing assembly of claim 10 in which said first and second temperature responsive members are series connected.
Claim 13
Dependent Claim
32 words
The bearing assembly of claim 10 in which said limit stop means includes a plurality of temperature responsive members and each of said temperature responsive members has a maximum deflection distance Z.
Claim 14
Dependent Claim
16 words
The bearing assembly of claim 12 in which said temperature responsive members are series-connected bimetallic elements.
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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) | 1977-09-09 | 1978-03-11 | 1978-09-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-09 | 1982-03-11 | 1982-09-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-09 | 1986-03-11 | 1986-09-10 | $7700.00 | Window Closed / Lapsed |