Aircraft engine
AssigneeROLLS-ROYCE plc
InventorMark Spruce
Life of this patent
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Abstract
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 having a fan diameter and a gearbox arranged to receive an input from the core shaft and to output drive to the fan so as to drive the fan at a lower rotational speed than the core shaft, thereby defining a gear ratio. The gearbox being an epicyclic gearbox. A gearbox diameter is defined as the pitch circle diameter of the ring gear; and a geared-fan value defined by a product of the fan diameter and gear ratio, which are divided by the gearbox diameter, being greater than 12.
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 having a fan diameter;
- and
- a gearbox arranged to receive an input from the core shaft and to output drive to the fan so as to drive the fan at a lower rotational speed than the core shaft, thereby defining a gear ratio, the gearbox being an epicyclic gearbox comprising:
- a sun gear, a plurality of planet gears, a ring gear, and a planet carrier on which the plurality of planet gears are mounted,
- and wherein:
- a gearbox diameter is defined as the pitch circle diameter of the ring gear;
- and
- a geared-fan value defined by:
- (
- (
- fan
-
- diameter
-
- (
- m
- )
- ×
- gear
-
- ratio
- )
- /
- gearbox
-
- diameter
-
- (
- m
- )
- )
- is greater than 12.00.
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 having a fan diameter;
- and
- a gearbox arranged to receive an input from the core shaft and to output drive to the fan so as to drive the fan at a lower rotational speed than the core shaft, thereby defining a gear ratio, the gearbox being an epicyclic gearbox comprising:
- a sun gear, a plurality of planet gears, a ring gear, and a planet carrier on which the plurality of planet gears are mounted,
- and wherein:
- a gearbox diameter is defined as the pitch circle diameter of the ring gear;
- a fan hub-to-tip ratio is defined as the ratio of the radius of a fan blade at its hub to the radius of the fan blade at its tip;
- and
- a second geared-fan value defined by:
- (
- (
- fan
-
- diameter
-
- (
- m
- )
- ×
- gear
-
- ratio
- )/
- gearbox
-
- diameter
-
- (
- m
- )
- ×
- fan
-
- hub
- -
- to
- -
- tip
-
- ratio
- )
- is in a range from 40.00 to 86.86.
Dependencies are inferred from the claim text.