Abstract: An engine assembly defining an axial direction (A) and including a gearbox, an engine core including at least one rotor, and a flexible coupling shaft having a first end and a second end along the axial direction (A). The first end of the flexible coupling shaft is connected to the engine core and the second end of the flexible coupling shaft is connected to the gearbox. A damper system is positioned at the second end of the flexible coupling shaft. The damper system is configured to reduce vibrations to the flexible coupling shaft during operation of the engine assembly.

Abstract: An aircraft engine component (100) may include a wall (200) comprising an aluminum alloy and/or a magnesium alloy, and a protective coating (108) covering the wall (200). The protective coating (108) may include a prime layer (206), a silicone elastomer layer (208), and an abrasion resistant layer (210). The prime layer (206) may at least partially cover a surface (202) of the wall (200). The prime layer (206) may include a silane coupling agent and an organic titanate. The silicone elastomer layer (208) may at least partially cover the prime layer (206). The silicone elastomer layer (208) may include one or more filler materials dispersed in a matrix of cross-linked silicone polymers. The abrasion resistant layer (210) may at least partially cover the silicone elastomer layer (208). The abrasion resistant layer (210) may include a fiber-reinforced elastomeric material.

Abstract: A gearbox assembly for a gas turbine engine includes a planetary gear set comprising a sun gear, a planet gear, and a ring gear, the sun gear configured for connection to a first drive shaft of the gas turbine engine and the ring gear configured for connection to a second drive shaft of the gas turbine engine, and an electric machine assembly comprising an input and an electric machine. The electric machine comprising a rotor coupled to the input and a stator fixedly positioned within the gearbox assembly, the input of the electric machine assembly coupled to one of the sun gear, the ring gear, or the planet gear of the planetary gear set.

Abstract: An engine assembly defining an axial direction (A) and including a gearbox, an engine core including at least one rotor, and a flexible coupling shaft having a first end and a second end along the axial direction (A). The first end of the flexible coupling shaft is connected to the engine core and the second end of the flexible coupling shaft is connected to the gearbox. A damper system is positioned at the second end of the flexible coupling shaft. The damper system is configured to reduce vibrations to the flexible coupling shaft during operation of the engine assembly.

Abstract: A gearbox assembly for a gas turbine engine includes a planetary gear set comprising a sun gear, a planet gear, and a ring gear, the sun gear configured for connection to a first drive shaft of the gas turbine engine and the ring gear configured for connection to a second drive shaft of the gas turbine engine, and an electric machine assembly comprising an input and an electric machine. The electric machine comprising a rotor coupled to the input and a stator fixedly positioned within the gearbox assembly, the input of the electric machine assembly coupled to one of the sun gear, the ring gear, or the planet gear of the planetary gear set.