Patent ID: 11248493

Abstract:
A gas turbine engine for an aircraft has an engine core including a turbine, a compressor, and a core shaft connecting the turbine to the compressor, the turbine being the lowest pressure turbine of the engine and the compressor being the lowest pressure compressor of the engine; a fan located upstream of the engine core; and a gearbox that receives an input from the core shaft and outputs drive to the fan. The engine core further has three bearings arranged to support the core shaft, and two rearward bearings, and wherein the forward most rearward bearing has a bearing stiffness defined by the radial displacement caused by the application of a radial force at the axial centerpoint of the bearing, and wherein a stiffness ratio of the bearing stiffness at the forward most rearward bearing to the minor span is in the range from 0.08 to 0.5 kN/mm2.