US4062186A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for windmill starts in gas turbine engines
Assignee: General Electric Co
•
Filing: 1976-05-13
•
Granted: 1977-12-13
•
Expires: 1996-05-13
Abstract
Abstract A torque converter is interconnected between the fan and core rotor of a turbofan engine such that the speed of the core rotor can be boosted from windmill speed to a speed sufficient to allow an in-flight start by selectively extracting power from the windmilling fan during the start sequence of the engine. Control logic is included to automatically drain the oil from, and thereby unload, the torque converter whenever the engine is in the operating speed region. Further assurance is provided by an overrunning clutch which decouples the system when the core rotational speed exceeds the converter output.
Inventors
- 👤 Barton H. Snow
- 👤 Frank R. Homan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 12:39
CPC Classifications
F; F02; F02C; F02C7/00; F02C7/26; F02C7/268; F02C7/275; F02C7/262; F05; F05D; F05D2220/00; F05D2220/50; Y; Y02; Y02T; Y02T50/00; Y02T50/60
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
70 words
An improved air-start system for a turbofan engine of the type having compressor rotor and fan rotor assemblies independently driven by separate turbine means wherein the improvement comprises a torque converter drivingly connectable between said compressor and fan rotors during periods of in-flight windmilling such that the fan can be made to impart rotary motion to the compressor to accelerate it to a speed sufficient to accommodate an air start.
Claim 2
Dependent Claim
70 words
An improved air-start system for a turbofan engine of the type having compressor rotor and fan rotor assemblies independently driven by separate turbine means wherein the improvement comprises a torque converter drivingly connectable between said compressor and fan rotors during periods of in-flight windmilling such that the fan can be made to impart rotary motion to the compressor to accelerate it to a speed sufficient to accommodate an air start.
Claim 3
Dependent Claim
39 words
An improved air-start system as set forth in claim 1 and including an overrunning clutch on the output side of said torque converter to prevent the compressor rotor from imparting energy back into the torque converter following engine start.
Claim 4
Dependent Claim
43 words
An improved air-start system as set forth in claim 1 and including control means responsive to certain operational parameters to automatically suspend transmission of energy through said torque converter during the existence of predetermined conditions and resume transmission of energy during nonexistence thereof.
Claim 5
Dependent Claim
20 words
An improved air-start system as set forth in claim 3 wherein one of said operational parameters is engine throttle position.
Claim 6
Dependent Claim
19 words
An improved air-start system as set forth in claim 3 wherein one of said operational parameters is compressor speed.
Claim 7
Dependent Claim
27 words
An improved air-start system as set forth in claim 3 wherein said control means is capable of selectivity removing and replacing hydraulic fluid in said torque converter.
Claim 8
Dependent Claim
89 words
An improved turbofan engine of the type having a compressor and a fan adapted to bypass a portion of the airflow around the compressor during engine operation, and separate turbine means for driving the compressor and fan, wherein the improvement comprises a torque converter connected at its one end to the fan rotor and at its other end to the compressor rotor for imparting rotary motion during periods of in-flight windmilling from the fan to the compressor to accelerate it to a speed sufficient to accommodate an air start.
Claim 9
Dependent Claim
89 words
An improved turbofan engine of the type having a compressor and a fan adapted to bypass a portion of the airflow around the compressor during engine operation, and separate turbine means for driving the compressor and fan, wherein the improvement comprises a torque converter connected at its one end to the fan rotor and at its other end to the compressor rotor for imparting rotary motion during periods of in-flight windmilling from the fan to the compressor to accelerate it to a speed sufficient to accommodate an air start.
Claim 10
Dependent Claim
25 words
An improved turbofan engine as set forth in claim 7 and including an overrunning clutch connected between said torque converter other end and the compressor.
Claim 11
Dependent Claim
32 words
An improved turbofan engine as set forth in claim 7 and including means for directing the flow of hydraulic fluid to and from said torque converter in response to certain operational parameters.
Claim 12
Dependent Claim
20 words
An improved turbofan engine as set forth in claim 9 wherein one of said operational parameters is engine throttle position.
Claim 13
Dependent Claim
19 words
An improved turbofan engine as set forth in claim 9 wherein one of said operational parameters is compressor speed.
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) | 1980-12-12 | 1981-06-13 | 1981-12-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-12-12 | 1985-06-13 | 1985-12-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-12-12 | 1989-06-13 | 1989-12-13 | $7700.00 | Window Closed / Lapsed |