US Patent 12024302 Hybrid starter motor-generator

An example hybrid propulsion system is described that includes a plurality of propulsors, a first drive shaft, a second drive shaft, a gas turbine engine, a motor-generator, and a clutch. The gas turbine engine includes a first turbine stage operatively coupled to the first drive shaft and a second turbine stage operatively coupled to the second drive shaft. The motor-generator is operatively coupled to the second drive shaft and is configured to generate electrical power to drive at least one propulsor of the plurality of propulsors and selectively drive the second shaft. The clutch is configured to operatively couple the second drive shaft to the first drive shaft.