US 11,988,154 B2
Direct drive electrically-geared turbofan
Lijun Gao, Renton, WA (US); and Shengyi Liu, Sammamish, WA (US)
Assigned to THE BOEING COMPANY, Arlington, VA (US)
Filed by THE BOEING COMPANY, Chicago, IL (US)
Filed on Nov. 24, 2021, as Appl. No. 17/535,325.
Claims priority of provisional application 63/124,020, filed on Dec. 10, 2020.
Prior Publication US 2022/0243664 A1, Aug. 4, 2022
Int. Cl. F02C 9/00 (2006.01); F02C 7/36 (2006.01)
CPC F02C 9/00 (2013.01) [F02C 7/36 (2013.01); F05D 2220/36 (2013.01); F05D 2260/4031 (2013.01); F05D 2260/404 (2013.01); F05D 2270/02 (2013.01); F05D 2270/304 (2013.01)] 13 Claims
OG exemplary drawing
 
1. A system, comprising:
a first magnetic gearbox assembly connected to a fan of a turbofan engine;
a second magnetic gearbox assembly connected to a spool shaft of the turbofan engine; and
a speed controller configured to adjust a rotational speed of the fan based on a rotational speed of the spool shaft by selectively coupling and decoupling the first magnetic gearbox assembly with the second magnetic gearbox assembly,
wherein the first magnetic gearbox assembly is configured to couple and decouple with the second magnetic gearbox assembly by opening and closing a switch in a winding circuit,
wherein the adjustment of the rotational speed of the fan is based on a difference between a reference speed for the fan and a measured speed of the fan,
wherein the reference speed is based on operating conditions of the fan and thrust profile for the turbofan engine,
wherein the measured speed is based on a measured magnitude of a magnetic field, and
wherein the speed controller controls the rotational speed of the fan, based on the difference between the reference speed for the fan and the measured speed of the fan, by increasing or decreasing a duty cycle of the switch, said duty cycle including how often the switch is open or closed.