High power epicyclic gearbox and operation thereof
AssigneeROLLS-ROYCE plc
InventorMark Spruce
Life of this patent
Estimating the term…
Abstract
An engine for an aircraft includes an engine core having a turbine, a compressor, and a core shaft connecting the turbine to the compressor; a fan located upstream of the engine core, the fan having a plurality of fan blades; and a gearbox. The gearbox is an epicyclic gearbox and comprises a sun gear, a plurality of planet gears, a ring gear, and a planet carrier on which the planet gears are mounted. The radial bending stiffness of the planet carrier is equal to or greater than 1.20×109 N/m, and/or the tilt stiffness of the planet carrier is greater than or equal to 6.00×108 Nm/rad. A method of operation of such an engine is also disclosed.
Claims20
A gas turbine engine for an aircraft comprising:
- an engine core comprising a turbine, a compressor, and a core shaft connecting the turbine to the compressor;
- a fan located upstream of the engine core, the fan comprising a plurality of fan blades;
- and
- a gearbox arranged to receive an input from the core shaft and to output drive to the fan via a fan shaft so as to drive the fan at a lower rotational speed than the core shaft, wherein:
- a fan diameter is in the range of 360 cm to 420 cm;
- a ratio of a radius of a fan blade at its hub to a radius of the fan blade at its tip is less than 0.25;
- each fan blade is manufactured at least in part from carbon fibre;
- and
- a torsional stiffness of the fan shaft is equal to or greater than 1.3×107 Nm/rad or in a range from 1.3×107 Nm/rad to 2.5×109 Nm/rad.
A gas turbine engine for an aircraft comprising:
- an engine core comprising a turbine, a compressor, and a core shaft connecting the turbine to the compressor;
- a fan located upstream of the engine core, the fan comprising a plurality of fan blades;
- a gearbox arranged to receive an input from the core shaft and to output drive to the fan via a fan shaft so as to drive the fan at a lower rotational speed than the core shaft;
- and
- a gearbox support arranged to at least partially support the gearbox in a fixed position within the engine, wherein:
- a fan diameter is in the range of 340 cm to 420 cm;
- a ratio of a radius of a fan blade at its hub to a radius of the fan blade at its tip is less than 0.25;
- and
- a torsional stiffness of the gearbox support is equal to or greater than 4.2×107 Nm/rad.
A gas turbine engine for an aircraft comprising:
- an engine core comprising a turbine, a compressor, and a core shaft connecting the turbine to the compressor;
- a fan located upstream of the engine core, the fan comprising a plurality of fan blades;
- and
- a gearbox arranged to receive an input from the core shaft and to output drive to the fan via a fan shaft so as to drive the fan at a lower rotational speed than the core shaft, wherein:
- a fan diameter is greater than 340 cm;
- a ratio of a radius of a fan blade at its hub to a radius of the fan blade at its tip is less than 0.25;
- each fan blade is manufactured at least in part from carbon fibre;
- and
- a gear ratio of the gearbox is at least 3.7.
Dependencies are inferred from the claim text.