US 10,851,715 B1Granted

High power epicyclic gearbox and operation thereof

AssigneeROLLS-ROYCE plc

InventorMark Spruce

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Abstract

A gas turbine engine for an aircraft including: an engine core including a turbine, a compressor, and a core shaft connecting the turbine to the compressor; a fan located upstream of the engine core, the fan including a plurality of fan blades; a gearbox that receives an input from the core shaft and outputs drive to a fan shaft via an output of the gearbox so as to drive the fan at a lower rotational speed than the core shaft; and a fan shaft mounting structure arranged to mount the fan shaft within the engine, the fan shaft mounting structure including at least two supporting bearings connected to the fan shaft. A fan-gearbox axial distance is defined as the axial distance between the output of the gearbox and the fan axial centreline, the fan-gearbox axial distance being greater than or equal to 0.35 m.

Claims20

Dependent claims

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, the fan having a fan axial centreline;
a gearbox that is configured to:
receive an input from the core shaft, and
output drive to a fan shaft via an output of the gearbox so as to drive the fan at a lower rotational speed than the core shaft;
and
a fan shaft mounting structure arranged to mount the fan shaft within the engine, the fan shaft mounting structure comprising at least two supporting bearings connected to the fan shaft, and wherein:
a fan-gearbox axial distance is defined as an axial distance between the output of the gearbox and the fan axial centreline, the fan-gearbox axial distance being greater than or equal to 0.35 m;
a system radial bending stiffness is defined as:
1
(
1
a
⁢
⁢
radial
⁢
⁢
bending
stiffness
⁢
⁢
of
the
⁢
⁢
fan
⁢
⁢
shaft
mounting
⁢
⁢
structure
)
+
(
1
a
⁢
⁢
radial
⁢
⁢
bending
stiffness
⁢
⁢
of
⁢
⁢
the
⁢
fan
⁢
⁢
shaft
⁢
⁢
at
the
⁢
⁢
output
⁢
⁢
of
the
⁢
⁢
gearbox
)
and
a fan shaft mounting radial bending stiffness ratio of:
the
⁢
⁢
system
⁢
⁢
radial
⁢
⁢
bending
⁢
⁢
stiffness
the
⁢
⁢
radial
⁢
⁢
bending
⁢
⁢
stiffness
⁢
⁢
of
⁢
⁢
the
⁢
⁢
fan
⁢
⁢
shaft
mounting
⁢
⁢
structure
is greater than or equal to 1.0×10−3.

111 more elements

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, the fan having a fan axial centreline;
a gearbox that is configured to:
receive an input from the core shaft, and
output drive to a fan shaft via an output of the gearbox so as to drive the fan at a lower rotational speed than the core shaft;
and
a fan shaft mounting structure arranged to mount the fan shaft within the engine, the fan shaft mounting structure comprising at least two supporting bearings connected to the fan shaft, and wherein:
a fan-gearbox axial distance is defined as an axial distance between the output of the gearbox and the fan axial centreline, the fan-gearbox axial distance being greater than or equal to 0.35 m;
a system tilt stiffness is defined as:
1
(
1
a
⁢
⁢
tilt
⁢
⁢
stiffness
of
⁢
⁢
the
⁢
⁢
fan
⁢
⁢
shaft
mounting
⁢
⁢
structure
)
+
(
1
a
⁢
⁢
tilt
⁢
⁢
stiffness
of
⁢
⁢
the
⁢
⁢
fan
⁢
⁢
shaft
at
⁢
⁢
the
⁢
⁢
output
of
⁢
⁢
the
⁢
⁢
gearbox
)
;
and
a fan shaft mounting tilt stiffness ratio of:
the
⁢
⁢
system
⁢
⁢
tilt
⁢
⁢
stiffness
the
⁢
⁢
tilt
⁢
⁢
stiffness
⁢
⁢
of
⁢
⁢
the
⁢
⁢
fan
⁢
⁢
shaft
⁢
⁢
mounting
⁢
⁢
structure
is greater than or equal to 1.5×10−3.

105 more elements

Dependencies are inferred from the claim text.

Facts

Application: 16/821,227Filed 17 Mar 2020
Priority: GB 1917773.25 Dec 2019
Granted: 1 Dec 2020
Term ends: Not estimatedThe source records don’t support an estimate.

Classification13 codes

F02C 7/36
Features, components parts, details or accessories, not provided for in, or of interest apart form groups F02C1/00 - F02C6/00; Air intakes for…:…
F02K 3/06
The plant including ducted fans, i.e. fans with high volume, low pressure outputs, for augmenting the jet thrust, e.g. of double-flow type: with…
F05D 2200/14
Basic functions: division
F05D 2220/323
In gas turbines: for aircraft propulsion, e.g. jet engines