Patent US3740058A successfully refreshed from Google Patents.
US3740058A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Forward sealing assembly for stern tubes
Assignee: Delaware Capital Formation Inc
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Filing: 1971-07-26
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Granted: 1973-06-19
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Expires: 1991-07-26
Abstract
Abstract An annular casing which surrounds the tail shaft of a ship at the forward end of the stern tube has a first annular pocket within which a flexible annular lip seal is supported for sealing around the tail shaft liner. Aft of the seal, in another annular pocket which communicates with the oil chamber in the stern tube, is a floating ring having restricted clearance around the liner. A pump draws oil from the first pocket, causing oil to be drawn from the stern tube oil chamber through the restricted clearance space and the said first annular pocket, this oil being pumped back into the stern tube oil chamber. A pressure regulating valve is connected in parallel with the pump to maintain a substantially constant circulating pressure. A desired reduced pressure is thus maintained adjacent the seal to reduce the pressure difference across the seal lip.
Inventors
- 👤 W Gardner
- 👤 R Rafferty
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 07:10
CPC Classifications
F; F16; F16J; F16J15/00; F16J15/16; F16J15/40; B; B63; B63H; B63H23/00; B63H23/32; B63H23/321; B63H2023/327; Y; Y10; Y10S; Y10S277/00; Y10S277/927
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
182 words
A sealing assembly for effecting a seal adjacent an annular liquid chamber around a rotatable member, said assembly including an annular casing having a first annular pocket within which an annular lip seal is supported, the improvement comprising means providing a restricted inlet between said liquid chamber and said annular pocket, a liquid conduit connecting said annular pocket with said liquid chamber, a pump in said conduit arranged to pump liquid from said annular pocket to thereby draw liquid from said Liquid chamber through said restricted inlet into and out of said annular pocket to provide a liquid pressure in said pocket which is lower than the liquid pressure in the liquid chamber, and pressure regulator means having one end connected to said liquid conduit on the suction side of said pump and having the other end connected to said liquid conduit on the pressure side of said pump arranged to permit the regulated flow of part of the liquid from the pressure side of said pump back to said annular pocket to thereby maintain a constant pressure in said annular pocket.
Claim 2
Dependent Claim
182 words
A sealing assembly for effecting a seal adjacent an annular liquid chamber around a rotatable member, said assembly including an annular casing having a first annular pocket within which an annular lip seal is supported, the improvement comprising means providing a restricted inlet between said liquid chamber and said annular pocket, a liquid conduit connecting said annular pocket with said liquid chamber, a pump in said conduit arranged to pump liquid from said annular pocket to thereby draw liquid from said Liquid chamber through said restricted inlet into and out of said annular pocket to provide a liquid pressure in said pocket which is lower than the liquid pressure in the liquid chamber, and pressure regulator means having one end connected to said liquid conduit on the suction side of said pump and having the other end connected to said liquid conduit on the pressure side of said pump arranged to permit the regulated flow of part of the liquid from the pressure side of said pump back to said annular pocket to thereby maintain a constant pressure in said annular pocket.
Claim 3
Dependent Claim
50 words
A sealing assembly as claimed in claim 1 in which the means which provides a restricted inlet includes a second annular pocket in said casing, and a floating ring within said second pocket having an internal diameter to provide a restricted clearance space between the floating ring and rotatable member.
Claim 4
Dependent Claim
40 words
A sealing assembly as claimed in claim 2 in which there is an annular shoulder between the first annular pocket and the second annular pocket against which the floating ring is urged by the liquid pressure in the liquid chamber.
Claim 5
Dependent Claim
62 words
A sealing assembly as claimed in claim 1 in which the rotatable member is the tail shaft of a ship and in which the liquid chamber is the stern tube oil chamber containing oil under pressure, and in which the means for drawing liquid out of the first annular pocket maintains a reduced pressure adjacent the seal to prevent excessive distortion thereof.
Claim 6
Dependent Claim
38 words
A sealing assembly as claimed in claim 1 in which the pump withdraws liquid from the annular chamber at a sufficient rate to maintain the pressure in the annular pocket substantially below the pressure in the liquid chamber.
Claim 7
Dependent Claim
63 words
A sealing assembly as claimed in claim 2 in which the rotatable member is the tail shaft of a ship and in which the liquid chamber is the stern tube oil chamber containing oil under pressure, and in which the means for drawing liquid out of the first annular pocket maintains a reduced oil pressure adjacent the seal to prevent excessive distortion thereof.
Claim 8
Dependent Claim
62 words
A sealing assembly as claimed in claim 8 in which there is a pump for drawing oil out of the first annular pocket and for causing its return to the liquid chamber, and in which the pump withdraws the oil at a sufficient rate to maintain the pressure in the annular pocket substantially below the pressure in the stern tube oil chamber.
Claim 9
Dependent Claim
25 words
A sealing assembly as claimed in claim 1 in which the restricted inlet between the liquid chamber and the annular pocket is an annular inlet.
Claim 10
Dependent Claim
28 words
A sealing assembly as defined in claim 1 wherein said pressure regulator means comprises a pressure regulating valve to automatically maintain a constant pressure in said annular pocket.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-06-18 | 1976-12-18 | 1977-06-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-06-18 | 1980-12-18 | 1981-06-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-06-18 | 1984-12-18 | 1985-06-19 | $7700.00 | Window Closed / Lapsed |