Patent US3761205A successfully refreshed from Google Patents.
US3761205A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Easily maintainable gas turbine engine
Assignee: Avco Corp
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Filing: 1972-03-20
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Granted: 1973-09-25
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Expires: 1992-03-20
Abstract
Abstract A differential gas turbine engine is constructed so that the power module may be removed as a unit from the output gearbox. Additional features enable major hot section components to be removed for inspection or replacement without major disassembly of the engine.
Inventors
- 👤 V Cronstedt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 19:40
CPC Classifications
F; F02; F02C; F02C7/00; F02C7/20; F02C3/00; F02C3/04; F02C3/107; F02C3/113; Y; Y10; Y10S; Y10S415/00; Y10S415/914
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
216 words
A gas turbine engine structure comprising: an output gearbox including a housing, at least one splined input shaft and an aft cover abutting the aft end of said gearbox housing, said cover having an opening through which said input shaft extends; a gas generator module including a generally annular main support structure, an outer housing abutting said main support structure, and at least one rotor journaled by said annular support structure and including a splined output shaft coaxial with and releasably connectable with said gearbox input shaft, said gas generator module having an annular air inlet surrounding said output shaft; a frame structure positioned between said gearbox and gas generator module and including: a forward ring abutting the aft cover of said gearbox housing, an aft ring abutting the main support structure of said power module and a plurality of struts extending between and structurally interconnecting said rings thereby permitting air to pass to said inlet; means for releasably connecting said gearbox housing, aft cover and forward ring permitting selective removal of said gearbox from said engine without disconnecting said housing and said aft cover; and means for releasably connecting said aft ring, main support structure and outer housing permitting selective removal of said outer housing without disconnecting said aft ring and said main support structure.
Claim 2
Dependent Claim
216 words
A gas turbine engine structure comprising: an output gearbox including a housing, at least one splined input shaft and an aft cover abutting the aft end of said gearbox housing, said cover having an opening through which said input shaft extends; a gas generator module including a generally annular main support structure, an outer housing abutting said main support structure, and at least one rotor journaled by said annular support structure and including a splined output shaft coaxial with and releasably connectable with said gearbox input shaft, said gas generator module having an annular air inlet surrounding said output shaft; a frame structure positioned between said gearbox and gas generator module and including: a forward ring abutting the aft cover of said gearbox housing, an aft ring abutting the main support structure of said power module and a plurality of struts extending between and structurally interconnecting said rings thereby permitting air to pass to said inlet; means for releasably connecting said gearbox housing, aft cover and forward ring permitting selective removal of said gearbox from said engine without disconnecting said housing and said aft cover; and means for releasably connecting said aft ring, main support structure and outer housing permitting selective removal of said outer housing without disconnecting said aft ring and said main support structure.
Claim 3
Dependent Claim
34 words
A gas turbine engine structure as in claim 1 wherein said aft cover of said gearbox has a flange extending radially outward from said housing, said flange providing a primary mount for said engine.
Claim 4
Dependent Claim
69 words
A gas turbine engine structure as in claim 1 further comprising a forward generally annular support structure for journaling said rotor within said frame structure, said forward support structure being sandwiched between said aft cover and said forward ring, said forward support structure being releasably secured to said forward ring so as to permit removal from said aft cover without disconnecting said forward support structure from said forward ring.
Claim 5
Dependent Claim
140 words
A gas turbine engine structure as in claim 1 wherein said gas generator module comprises: a bladed radial inflow turbine wheel positioned on the aft end of said rotor; an annular turbine inlet nozzle and shroud surrounding the periphery of said turbine wheel for directing a hot gas stream in a generally inward direction relative to said turbine; an annular turbine inlet duct directing gases into said turbine inlet nozzle and shroud, said turbine inlet duct being removable from said turbine inlet nozzle in an aft direction whereby it may be removed when said outer cover is removed; and said turbine inlet nozzle and shroud being secured to said annular support structure radially outward from the tip of said turbine wheel so that said nozzle and shroud may be removed in an axial direction without removal of said turbine wheel.
Claim 6
Dependent Claim
58 words
A gas turbine engine structure as in claim 4 further comprising an annular shroud positioned forward of said turbine wheel, said shroud being sandwiched between said annular support structure and said turbine nozzle and split in segments whereby removal of said turbine nozzle enables removal of said shroud in a radial direction without removal of said turbine wheel.
Claim 7
Dependent Claim
124 words
A gas turbine engine structure as in claim 1 wherein: said gas generator module has first and second independently rotatable rotors, the first rotor being telescoped over the second and both rotors having splined output shafts, said module comprising a compressor positioned on said first rotor in the forward portion of said gas generator module and journaled by said main support structure, and a turbine positioned on said second rotor and journaled aft of said compressor by said main support structure; said output gearbox comprises an output shaft and a pair of coaxial input shafts connected to each other and to said output shaft through a differential gearing, said input shafts being splined to connect with said compressor shaft and said turbine shaft, respectively.
Claim 8
Dependent Claim
71 words
A gas turbine engine structure as in claim 6 further comprising: a bearing assembly telescoped over and fixed on said turbine shaft, said bearing assembly being telescoped into said main support structure from an aft direction; a retaining nut threaded into said main support structure for holding said bearing assembly therein, said threaded element being rotatable from a radial direction whereby said turbine rotor may be removed without disturbing said compressor.
Claim 9
Dependent Claim
79 words
A gas turbine engine structure as in claim 7 further comprising a compressor bearing telescoped into the forward portion of said main support structure, said compressor rotor being telescopable into said compressor bearing from a forward direction; and a retaining clip restraining forward movement of said compressor relative to said compressor bearing assembly whereby said retaining clip may be removed when said turbine rotor is removed to permit forward removal of said compressor rotor from said main support structure.
Claim 10
Dependent Claim
35 words
A gas turbine engine structure as in claim 8 wherein said compressor bearing is telescopable against a shoulder in said main support structure from a forward direction and is held therein by a threaded element.
Claim 11
Dependent Claim
113 words
A gas turbine engine structure as in claim 9 wherein said turbine is a centripetal turbine having radially extending blades and said gas generator module comprisEs: a turbine inlet nozzle and shroud surrounding the periphery of said turbine for directing gases inward across the blades of said turbine wheel; an annular turbine inlet duct connecting with said inlet nozzle for directing a flow of hot gases therethrough; said turbine inlet duct being removable in an aft direction without disassembly of said inlet nozzle and said inlet nozzle and shroud being supported from said annular support structure radially outward of the tip of said blades to permit removal thereof without removal of said turbine.
Claim 12
Dependent Claim
62 words
A gas turbine engine structure as in claim 10 further comprising an annular heat shield positioned adjacent the back face of said turbine, said heat shield being sandwiched between said annular support structure and said inlet nozzle and being split whereby removal of said inlet nozzle permits said heat shield to be removed in a radial direction without disassembly of said turbine.
Claim 13
Dependent Claim
82 words
A gas turbine engine structure as in claim 11 further comprising: a forward annular support structure positioned within said frame structure and journaling the forward portion of said compressor rotor, said forward annular support structure being sandwiched between said gearbox module aft cover and said forward ring; and means for releasably connecting said forward annular support structure to said forward ring so that said gearbox may be removed from said engine without disconnecting said forward annular support structure and said forward ring.
Claim 14
Dependent Claim
98 words
A gas turbine engine structure as in claim 12 wherein said releasable connecting means comprises: a series of jury screws connecting only said aft cover and said gearbox housing; a series of jury screws connecting said forward support structure and said forward ring; a series of jury screws connecting said annular support structure and said aft ring; a first set of threaded assemblies sandwiching the gearbox housing, the aft cover and the forward annular support structure, the forward ring; and a second set of threaded assemblies sandwiching said aft ring, said annular support structure and said outer housing.
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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) | 1976-09-24 | 1977-03-26 | 1977-09-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-09-24 | 1981-03-26 | 1981-09-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-09-24 | 1985-03-26 | 1985-09-25 | $7700.00 | Window Closed / Lapsed |