US3782737A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Spiral groove seal
Assignee: National Aeronautics and Space Administration
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Filing: 1972-01-24
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Granted: 1974-01-01
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Expires: 1992-01-24
Abstract
Abstract Mating flat surfaces inhibit leakage of a fluid around a stationary shaft. A spiral groove pattern produces a pumping action toward the fluid when the shaft rotates which prevents leakage while a generated hydraulic lifting force separates the mating surfaces to minimize wear. Provision is made for placing these spiral grooves in communication with the fluid to accelerate the generation of the hydraulic lifting force.
Inventors
- 👤 L Ludwig
- 👤 T Strom
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 06:40
CPC Classifications
F; F16; F16J; F16J15/00; F16J15/16; F16J15/34; F16J15/3404; F16J15/3408; F16J15/3412; F16J15/342
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
192 words
Apparatus for forming a seal about a rotatable shaft extending into a container of liquid comprising a pair of juxtaposed members extending about said shaft adjacent said liquid, one of said members comprising a seat mounted on said shaft for rotation therewith and the other of said members comprising a tubular member mounted for reciprocable movement along said shaft, mating surfaces on said members, one edge of each of said surfaces being in contact with said liquid and the opposite edge being exposed to ambient pressure, means for biasing said tubular member toward said seat for moving said surfaces into sealing engagement when said shaft is stationary, spiral grooves in said seat at its mating surface, said spiral groove being separated by lands substantially coplanar with said mating surface whereby rotation of said shaft pumps a portion of said adjacent contained liquid between said lands to generate a hydraulic lifting force thereby separating said members in opposition to said biasing means while inhibiting leakage, and passage means in one of said members for placing said spiral grooves in communication with said contained liquid to accelerate the generation of said hydraulic lifting force.
Claim 2
Dependent Claim
192 words
Apparatus for forming a seal about a rotatable shaft extending into a container of liquid comprising a pair of juxtaposed members extending about said shaft adjacent said liquid, one of said members comprising a seat mounted on said shaft for rotation therewith and the other of said members comprising a tubular member mounted for reciprocable movement along said shaft, mating surfaces on said members, one edge of each of said surfaces being in contact with said liquid and the opposite edge being exposed to ambient pressure, means for biasing said tubular member toward said seat for moving said surfaces into sealing engagement when said shaft is stationary, spiral grooves in said seat at its mating surface, said spiral groove being separated by lands substantially coplanar with said mating surface whereby rotation of said shaft pumps a portion of said adjacent contained liquid between said lands to generate a hydraulic lifting force thereby separating said members in opposition to said biasing means while inhibiting leakage, and passage means in one of said members for placing said spiral grooves in communication with said contained liquid to accelerate the generation of said hydraulic lifting force.
Claim 3
Dependent Claim
36 words
Apparatus for forming a seal about a rotatable shaft as claimed in claim 1 wherein the contained liquid is located outwardly of said grooves so that the pumping of said liquid is aided by centrifugal force.
Claim 4
Dependent Claim
35 words
Apparatus for forming a seal about a rotatable shaft as claimed in claim 1 wherein the passage means comprises a plurality of passages extending through said tubular member for directing liquid into said spiral grooves.
Claim 5
Dependent Claim
42 words
Apparatus for forming a seal about a rotatable shaft as claimed in claim 3 including a feed groove in communication with each of said passages, said feed groove being cut in the bottom of said spiral grooves and extending through said lands.
Claim 6
Dependent Claim
31 words
Apparatus for forming a seal about a rotatable shaft as claimed in claim 1 including a dam surrounding the grooves to increase the hydrodynamic lifting force when the shaft is rotated.
Claim 7
Dependent Claim
40 words
Apparatus for forming a seal about a rotatable shaft as claimed in claim 5 wherein the passage means comprises a plurality of passages extending through said tubular member for placing the grooves in communication with the liquid in the container.
Claim 8
Dependent Claim
39 words
Apparatus for forming a seal about a rotatable shaft as claimed in claim 6 including a feed groove aligned with said passages, said feed groove being cut in the bottom of said spiral grooves and extending through said lands.
References Cited (Backward Citations)
US2354478A
Cited
US3109658A
Cited
GB1009940A
Cited
US3527465A
Cited
US3499653A
Cited
US3675935A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-12-31 | 1977-07-02 | 1978-01-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-31 | 1981-07-02 | 1982-01-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-31 | 1985-07-02 | 1986-01-01 | $7700.00 | Window Closed / Lapsed |