US 12,297,782 B2
Detecting condition of a shaft of a gas turbofan aircraft engine
Edward John Marotta, Longmeadow, MA (US); Geoffrey T. Blackwell, Vernon, CT (US); and James A. Gosse, Storrs, CT (US)
Assigned to HAMILTON SUNDSTRAND CORPORATION, Charlotte, NC (US)
Filed by Hamilton Sundstrand Corporation, Charlotte, NC (US)
Filed on Mar. 26, 2021, as Appl. No. 17/214,295.
Claims priority of provisional application 63/016,016, filed on Apr. 27, 2020.
Prior Publication US 2021/0332765 A1, Oct. 28, 2021
Int. Cl. F02C 9/46 (2006.01); F01D 21/00 (2006.01); F01D 21/14 (2006.01)
CPC F02C 9/46 (2013.01) [F01D 21/003 (2013.01); F01D 21/14 (2013.01); F05D 2220/323 (2013.01); F05D 2260/80 (2013.01); F05D 2270/09 (2013.01); F05D 2270/304 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A system for detecting a condition of a shaft of a gas turbofan engine, the system comprising:
a first rotation sensor mounted within the gas turbofan engine, the first rotation sensor configured to sense a rotation of a first member mechanically coupled to the shaft and to generate a first signal indicative of a rotation frequency of the first member;
a second rotation sensor mounted within the gas turbofan engine, the second rotation sensor configured to sense a rotation of a second member mechanically coupled to the shaft and to generate a second signal indicative of a rotation frequency of the second member, wherein pulse rates of the first signal and the second signal are substantially equal to one another at all times;
an up/down counter configured to increment a count total in response to each cycle of the first signal and to decrement the count total in response to each cycle of the second signal, wherein for an uncompromised shaft condition, each increment of the count total is followed (or led) by a decrement of the count total, thereby causing the up/down counter to generate the count total as approximately zero at all times;
a shaft-condition analyzer in electrical communication with the first rotation sensor and the second rotation sensor, the shaft-condition analyzer configured to determine the condition of the shaft of the gas turbofan engine based on the count total, the count total indicative of torsion of the shaft, wherein an increase or a decrease in the count total corresponds to an associated increase or decrease, respectively, in the torsion of the shaft; and
a fuel cut-off controller in electrical communication with the shaft-condition analyzer, the fuel cut-off controller configured to generate a fuel cut-off signal in response to the count total exceeding a minimum and/or a maximum threshold indicative of a design torsion threshold level, thereby indicating a compromised shaft condition.