Transmission and method for control of boost spool
AssigneeRtx Corporation
InventorsPaul R. Hanrahan, Daniel B. Kupratis
Life of this patent
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Abstract
A gas turbine engine includes a first spool associated with a primary combustor, a second spool associated with a secondary combustor, and a third spool, each spool including a compressor and a turbine mounted to a shaft. A transmission and accessory gearing are enclosed within a housing of an accessory gearbox. The transmission rotationally couples the third spool to the second spool and accessory gearing. A method of operating the gas turbine engine includes supplying a first fuel flow rate to the primary combustor and supplying a second fuel flow rate to the secondary combustor within an intermediate speed range of the gas turbine engine.
Claims11
A method of operating a gas turbine engine having an operational power range that includes an intermediate power range consisting of a first power subrange and a second power subrange that is less than a maximum continuous power and greater than a minimum continuous power, the method comprising:
- supplying a first fuel flow rate to a primary combustor of the gas turbine engine contemporaneously with supplying a second fuel flow rate to a secondary combustor of the gas turbine engine based on a power lever angle indicative of the first power subrange of the intermediate power range, wherein:
- the first fuel flow rate varies based on the power lever angle;
- and
- the second fuel flow rate varies based on a rotational speed of an accessory gearbox, wherein the second fuel flow rate varies to minimize variation of the rotational speed of the accessory gearbox within the first power subrange, towards substantially achieving a constant rotational speed of the accessory gearbox;
- disengaging a first clutch uncoupling a tower shaft from the accessory gearbox based on the power lever angle less than the second power subrange;
- and
- engaging a second clutch coupling a second shaft of a boost spool to the accessory gearbox based on the power lever angle greater than the minimum continuous power up to and including the intermediate power range;
- wherein disengaging the first clutch and engaging the second clutch occur before supplying the first fuel flow rate to the primary combustor and supplying the second fuel flow rate to the secondary combustor.
Dependencies are inferred from the claim text.