US3594010A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Shaft seal for turbines
Assignee: English Electric Co Ltd
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Filing: 1969-07-22
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Granted: 1971-07-20
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Expires: 1989-07-22
Abstract
Abstract A spring-loaded shaft seal for a steam turbine has a spring 15 which normally urges segments 7 lof the seal away from the rotor shaft 3. Thus a relatively large clearance is provided when the turbine is running up to speed and is on very light loads. An annular space 13 is provided around the segments 7 which is in communication with the higher pressure side of the seal via an opening 14. Thus the clearance between the seal and the rotor shaft 3 is substantially reduced when the turbine is loaded up due to a significant increase in the pressure difference across the seal. For testing, the springs 15 are set as shown dotted in FIG. 2 to urge their segments 7 towards the rotor shaft 3 so that the normal on-load running clearance may be measured and any high spots on the segment glands may be removed. The springs 15 are reset to their normal position after testing is completed.
Inventors
- 👤 Laurence Hugo Frederick Warth
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 22:59
CPC Classifications
F; F16; F16J; F16J15/00; F16J15/44; F16J15/441; F01; F01D; F01D11/00; F01D11/02; F01D11/025
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
202 words
For a turbine, a seal for sealing an annular clearance passage defined between a rotor and a stator, including: the stator having defined therein a circumferentially extending groove opening radially into the clearance passage; a sealing ring comprising a plurality of segments disposed in the groove and located axially thereby while being permitted limited radial movement; the segments defining with the walls of the groove a first annular space; duct means communicating between the upstream side of the seal and the first annular space for allowing, in normal operation of the turbine, turbine working fluid to urge the segments radially towards the rotor; a radially inwardly facing surface provided on each segment and a cooperating radially outwardly facing surface provided by the stator defining between them a second annular space; and spring means disposable for normal operation of the turbine in the said second annular space to resiliently urge the segments radially away from the rotor in opposition to the turbine working fluid, said spring means being transferable to the said first annular space to resiliently urge the segments radially towards the rotor in absence of turbine working fluid so that both running-in and clearance testing of the seal may be performed.
Claim 2
Dependent Claim
202 words
For a turbine, a seal for sealing an annular clearance passage defined between a rotor and a stator, including: the stator having defined therein a circumferentially extending groove opening radially into the clearance passage; a sealing ring comprising a plurality of segments disposed in the groove and located axially thereby while being permitted limited radial movement; the segments defining with the walls of the groove a first annular space; duct means communicating between the upstream side of the seal and the first annular space for allowing, in normal operation of the turbine, turbine working fluid to urge the segments radially towards the rotor; a radially inwardly facing surface provided on each segment and a cooperating radially outwardly facing surface provided by the stator defining between them a second annular space; and spring means disposable for normal operation of the turbine in the said second annular space to resiliently urge the segments radially away from the rotor in opposition to the turbine working fluid, said spring means being transferable to the said first annular space to resiliently urge the segments radially towards the rotor in absence of turbine working fluid so that both running-in and clearance testing of the seal may be performed.
Claim 3
Dependent Claim
54 words
A seal according to claim 1, wherein the spring means comprises a plurality of leaf springs, the said radially outwardly facing surface is provided on a spigot projecting axially from a wall of the groove, and the said radially inwardly facing surface is provided on an axially extending arcuate portion formed on each segment.
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) | 1974-07-19 | 1975-01-18 | 1975-07-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-07-19 | 1979-01-18 | 1979-07-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-07-19 | 1983-01-18 | 1983-07-20 | $7700.00 | Window Closed / Lapsed |