Gearbox assembly for an aircraft propulsion system

An aircraft propulsion system comprising:

• a propeller configured for rotation about a rotational axis;
• a gas turbine engine including a bladed turbine rotor and a shaft connected to the bladed turbine rotor;
• and
• a reduction gear box including a gear assembly connected to the shaft and the propeller, the gear assembly configured to drive the propeller at a reduced rotational speed relative to the shaft, the gear assembly including a sun gear, a plurality of planet gears, and a first ring gear, and a second ring gear,
• the sun gear is rotatable about a rotational axis, the sun gear includes a first double helical gear pattern, and
• each planet gear of the plurality of planet gears includes a main gear, a first lateral gear, and a second lateral gear, the main gear includes a second double helical gear pattern engaged with the first double helical gear pattern, the first lateral gear is engaged with the first ring gear, and the second lateral gear is engaged with the second ring gear;
• wherein each of the first ring gear and the second ring gear includes a first spur gear pattern and each of the first lateral gear and the second lateral gear includes a second spur gear pattern.

An assembly for an aircraft propulsion system, the assembly comprising:

• an output shaft;
• and
• a gear assembly configured to drive rotation of the output shaft, the gear assembly including a sun gear, a plurality of planet gears, a first ring gear, and a second ring gear,
• the sun gear is rotatable about a rotational axis, the sun gear includes a first double helical gear pattern,
• each planet gear of the plurality of planet gears includes a main gear, a first lateral gear, and a second lateral gear, the main gear includes a second double helical gear pattern engaged with the first double helical gear pattern, the first lateral gear is engaged with the first ring gear, and the second lateral gear is engaged with the second ring gear, and
• each of the first ring gear and the second ring gear includes a first spur gear pattern and each of the first lateral gear and the second lateral gear includes a second spur gear pattern.