Patent US5211534A successfully refreshed from Google Patents.
US5211534A
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Blade tip clearance control apparatus
Assignee: Rolls Royce PLC
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Filing: 1991-12-24
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Granted: 1993-05-18
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Expires: 2011-12-24
Abstract
Abstract A blade clearance control apparatus (46) for a gas turbine engine (10) comprises a series of segments (42) which define a casing in the rotor path of high pressure shroudless turbine blades (30). The segments (42) are attached to plates (78) having surfaces co-operating with chordal lengths (74) of a number of pressure tubes (68) which are located in a frame (46). The application and release of pressure to the pressure tubes (68) causes the segments (42) to move between inner and outer positions in order to control clearance X between the tips of blades (30) and the segments (42).
Inventors
- 👤 Ronald Catlow
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 08:41
CPC Classifications
F; F01; F01D; F01D11/00; F01D11/08; F01D11/14; F01D11/20; F01D11/22
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
106 words
A gas turbine engine blade tip clearance control apparatus comprising a plurality of circumferentially arranged spaced wall members located adjacent a rotor path of a plurality of blades of the engine, at least one pressure tube for moving each wall member from a first radial stop to a second radial stop, the at least one pressure tube having a plurality of chordal lengths to which the wall members are operationally attached, the chordal lengths being preloaded to hold the wall members against the first radial stop, the pressure tube being pressurizable to deflect the chordal length and move the wall member against the second radial stop.
Claim 2
Dependent Claim
106 words
A gas turbine engine blade tip clearance control apparatus comprising a plurality of circumferentially arranged spaced wall members located adjacent a rotor path of a plurality of blades of the engine, at least one pressure tube for moving each wall member from a first radial stop to a second radial stop, the at least one pressure tube having a plurality of chordal lengths to which the wall members are operationally attached, the chordal lengths being preloaded to hold the wall members against the first radial stop, the pressure tube being pressurizable to deflect the chordal length and move the wall member against the second radial stop.
Claim 3
Dependent Claim
20 words
An apparatus as claimed in claim 1, wherein each chordal length is preloaded by being formed as a radiussed arc.
Claim 4
Dependent Claim
59 words
An apparatus as claimed in claim 1, wherein a plurality of equi-spaced pressure tubes are circumferentially arranged within a frame, each pressure tube having at least one chordal length and having end supports in the frame located between at lease one chordal length, the wall members being operably connected to the tubes in the region of the chordal lengths.
Claim 5
Dependent Claim
16 words
A apparatus as claimed in claim 3, wherein each pressure tube has three spaced chordal lengths.
Claim 6
Dependent Claim
37 words
An apparatus as claimed in claim 3, wherein the end support members have an outer surface shaped to conform to the surface of the respective pressure tube when pressure is applied to the interior of the tube.
Claim 7
Dependent Claim
35 words
An apparatus as claimed in claim 3, wherein each wall member is attached to a spring plate supported against the respective pressure tube in the region of the respective chordal length by the end supports.
Claim 8
Dependent Claim
24 words
An apparatus as claimed in claim 6, wherein each spring plate is preloaded to hold the respective wall member against the first radial stop.
Claim 9
Dependent Claim
29 words
An apparatus as claimed in claim 7, wherein each spring plate is preloaded by being formed with a radiussed arc corresponding to the radiussed arc of the chordal length.
Claim 10
Dependent Claim
20 words
An apparatus as claimed in claim 1, wherein the first radial stop is radially outermost of the second radial stop.
Claim 11
Dependent Claim
30 words
An apparatus as claimed in claim 1, wherein at lease one pressure tube has air supply means connected by a switch for supplying air to a source of pressurized air.
Claim 12
Dependent Claim
19 words
An apparatus as claimed in claim 10, wherein the switch is under the control of an engine control system.
Claim 13
Dependent Claim
22 words
An apparatus as claimed in claim 3, wherein the frame includes openings to allow cooling air to impinge upon the wall members.
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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) | 1996-05-17 | 1996-11-16 | 1997-05-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-05-17 | 2000-11-16 | 2001-05-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-05-17 | 2004-11-16 | 2005-05-18 | $7700.00 | Window Closed / Lapsed |