US 12,253,021 B2
Transmission and method for control of boost spool
Paul R. Hanrahan, Sedona, AZ (US); and Daniel B. Kupratis, Wallingford, CT (US)
Assigned to RTX CORPORATION, Farmington, CT (US)
Filed by RTX Corporation, Farmington, CT (US)
Filed on Jan. 5, 2024, as Appl. No. 18/405,801.
Application 18/405,801 is a division of application No. 17/662,195, filed on May 5, 2022, granted, now 11,898,490.
Prior Publication US 2024/0384682 A1, Nov. 21, 2024
Int. Cl. F02C 3/107 (2006.01); F02C 7/32 (2006.01); F02C 9/28 (2006.01); F02C 9/40 (2006.01)
CPC F02C 3/107 (2013.01) [F02C 7/32 (2013.01); F02C 9/28 (2013.01); F02C 9/40 (2013.01); F05D 2220/323 (2013.01); F05D 2260/40311 (2013.01); F05D 2270/304 (2013.01)] 7 Claims
OG exemplary drawing
 
1. A method of operating a gas turbine engine having an operational power range that includes an intermediate power range comprising 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:
providing the gas turbine engine having a primary combustor rotationally coupled to epicyclic differential and a boost spool having a secondary combustor rotationally coupled to the epicyclic differential wherein the epicyclic differential includes a locking member that is disengaged based on the power lever angle less than the second power subrange and engaged based on the power lever angle greater than the first power subrange;
supplying a first fuel flow rate to the primary combustor of the gas turbine engine contemporaneously with supplying a second fuel flow rate to the secondary combustor of the boost spool based on the power lever angle indicative of the first power subrange of the intermediate power range, wherein: the first fuel rate varies based on the power lever angle; and the second fuel flow rate varies based on a rotational speed of an accessory gearbox including the epicyclic differential; and
engaging the locking member based on a power lever angle greater than the first power subrange.