Reliable gearbox for gas turbine engine

Abstract

A gas turbine engine for an aircraft includes an engine core having a turbine, a compressor, and a core shaft interconnecting the turbine and compressor. A fan with multiple fan blades is positioned upstream of the engine core and is driven at a reduced rotational speed through an epicyclic gearbox coupled to the core shaft. The gearbox includes a sun gear, a plurality of planet gears mounted on a planet carrier, and a ring gear. The planet carrier has an effective linear torsional stiffness, and the gearbox includes defined gear mesh stiffnesses between the planet gears and both the sun and ring gears. The respective stiffness values are selected to provide desired dynamic behavior and vibration characteristics of the gearbox, such that the relationship between the gear mesh stiffnesses contributes to efficient torque transmission, reduced noise, and enhanced durability of the fan drive system.