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US 8,869,504 B1Granted
Geared turbofan engine gearbox arrangement
AssigneeUnited Technologies Corporation
InventorsFrederick M. Schwarz, William G. Sheridan
Life of this patent
Estimating the term…
Abstract
A three-spool turbofan engine (20) has a variable fan nozzle (35). The fan blades have a peak tip radius RT and an inboard leading edge radius RH at an inboard boundary of the flowpath. A ratio of RH to RT is less than about 0.40.
Claims29
A turbofan engine (20) comprising:
- a fan (28) having a plurality of blades;
- a transmission (60) configured to drive the fan;
- and
- three spools;
- wherein:
- the fan blades have a peak tip radius RT;
- the fan blades have an inboard leading edge radius RH at an inboard boundary of the flowpath;
- a ratio of RH to RT is less than 0.40;
- said three spools comprise:
- a first spool comprising:
- a first pressure turbine (50);
- and
- a first shaft (56) coupling the first pressure turbine to the transmission;
- a second spool comprising;
- a second pressure turbine (48);
- a first compressor (42);
- and
- a second spool shaft (54) coupling the second pressure turbine to the second spool compressor;
- a core spool comprising:
- a third pressure turbine (46);
- a second compressor (44);
- and
- a core shaft (52) coupling the third pressure turbine to second compressor;
- a combustor (45) is between the second compressor and the third pressure turbine;
- a first (160) of said main bearings engages a static support (164;
- 164′) and a forward hub (236) of the second spool;
- a second (162) of said main bearings engages the first shaft and the forward hub of the second spool;
- and
- the core shaft engages at least two of said main bearings, at least one of which is a thrust bearing.
26 more elements
A turbofan engine (20) comprising:
- a fan (28) having a plurality of blades;
- a transmission (60) configured to drive the fan;
- three spools comprising
- a first spool comprising:
- a first pressure turbine (50);
- and
- a first shaft (56) coupling the first pressure turbine to the transmission;
- a second spool comprising;
- a second pressure turbine (48);
- a first compressor (42);
- and
- a second spool shaft (54) coupling the second pressure turbine to the second spool compressor;
- a core spool comprising:
- a third pressure turbine (46);
- a second compressor (44);
- and
- a core shaft (52) coupling the third pressure turbine to second compressor;
- a combustor (45) between the second compressor and the third pressure turbine;
- and
- a plurality of main bearings wherein:
- the fan is a single stage fan driven by a ring gear of the transmission;
- the fan blades have a peak tip radius RT;
- the fan blades have an inboard leading edge radius RH at an inboard boundary of the flowpath;
- a ratio of RH to RT is less than 0.40;
- a first (160) of said main bearings engages a static support (164;
- 164′) and a forward hub (236) of the second spool;
- a second (162) of said main bearings engages the first shaft and the forward hub of the second spool;
- and
- the first spool shaft engages at least three of said main bearings.
26 more elements
A turbofan engine (20) comprising:
- a fan (28) having a plurality of blades;
- a transmission (60) configured to drive the fan;
- three spools comprising
- a first spool comprising:
- a first pressure turbine (50);
- and
- a first shaft (56) coupling the first pressure turbine to the transmission;
- a second spool comprising;
- a second pressure turbine (48);
- a first compressor (42);
- and
- a second spool shaft (54) coupling the second pressure turbine to the second spool compressor;
- a core spool comprising:
- a third pressure turbine (46);
- a second compressor (44);
- and
- a core shaft (52) coupling the third pressure turbine to second compressor;
- a combustor (45) between the second compressor and the third pressure turbine;
- and
- a plurality of main bearings wherein:
- the fan is a single stage fan driven by a ring gear of the transmission;
- the fan blades have a peak tip radius RT;
- the fan blades have an inboard leading edge radius RH at an inboard boundary of the flowpath;
- a ratio of RH to RT is less than 0.40;
- a first (160) of said main bearings engages a static support (164;
- 164′) and a forward hub (236) of the second spool;
- a second (162) of said main bearings engages the first shaft and the forward hub of the second spool;
- and
- one or more of:
- a length between said first of said main bearings and a center of gravity of a rotor of the first compressor is less than half of a disk-to-disk overall length of the first compressor;
- and
- a length between said first of said main bearings and a center of gravity of a rotor of the second spool compressor is less than a radius RI of the inboard boundary of the core flowpath at a leading stage of blades of the first compressor.
29 more elements
A turbofan engine (20) comprising:
- a fan (28) having a plurality of blades;
- a transmission (60) configured to drive the fan;
- three spools comprising
- a first spool comprising:
- a first pressure turbine (50);
- and
- a first shaft (56) coupling the first pressure turbine to the transmission;
- a second spool comprising;
- a second pressure turbine (48);
- a first compressor (42);
- and
- a second spool shaft (54) coupling the second pressure turbine to the second spool compressor;
- a core spool comprising:
- a third pressure turbine (46);
- a second compressor (44);
- and
- a core shaft (52) coupling the third pressure turbine to second compressor;
- a combustor (45) between the second compressor and the third pressure turbine;
- and
- a plurality of main bearings wherein:
- the fan is a single stage fan driven by a ring gear of the transmission;
- the fan blades have a peak tip radius RT;
- the fan blades have an inboard leading edge radius RH at an inboard boundary of the flowpath;
- a ratio of RH to RT is less than 0.40;
- a first (160) of said main bearings engages a static support (164;
- 164′) and a forward hub (236) of the second spool;
- a second (162) of said main bearings engages the first shaft and the forward hub of the second spool;
- the forward hub extends forward from a disk of the first compressor;
- and
- the first compressor has at least one disk forward of said disk.
27 more elements
A turbofan engine (20) comprising:
- a fan (28) having a plurality of blades;
- a transmission (60) configured to drive the fan;
- three spools comprising:
- a first spool comprising:
- a first pressure turbine (50);
- and
- a first shaft (56) coupling the first pressure turbine to the transmission;
- a second spool comprising;
- a second pressure turbine (48);
- a first compressor (42);
- and
- a second spool shaft (54) coupling the second pressure turbine to the second spool compressor;
- a core spool comprising:
- a third pressure turbine (46);
- a second compressor (44);
- and
- a core shaft (52) coupling the third pressure turbine to second compressor;
- a combustor (45) between the second compressor and the third pressure turbine;
- and
- a plurality of main bearings wherein:
- the fan blades have a peak tip radius RT;
- the fan blades have an inboard leading edge radius RH at an inboard boundary of the flowpath;
- a ratio of RH to RT is less than about 0.40;
- a first (160) of said main bearings engages a static support (164;
- 164′) and a forward hub (236) of the second spool;
- a second (162) of said main bearings engages the first shaft and the forward hub of the second spool;
- the first bearing and the second bearing are non-thrust roller bearings;
- and
- rollers of the first bearing and the second bearing are at least partially longitudinally overlapping.
26 more elements
A turbofan engine (20) comprising:
- a fan (28) having a plurality of blades;
- a transmission (60) configured to drive the fan;
- three spools comprising:
- a first spool comprising:
- a first pressure turbine (50);
- and
- a first shaft (56) coupling the first pressure turbine to the transmission;
- a second spool comprising:
- a second pressure turbine (48);
- a first compressor (42);
- and
- a second spool shaft (54) coupling the second pressure turbine to the second spool compressor;
- a core spool comprising:
- a third pressure turbine (46);
- a second compressor (44);
- and
- a core shaft (52) coupling the third pressure turbine to second compressor;
- a combustor (45) between the second compressor and the third pressure turbine;
- and
- a plurality of main bearings wherein:
- the fan blades have a peak tip radius RT;
- the fan blades have an inboard leading edge radius RH at an inboard boundary of the flowpath;
- a ratio of RH to RT is less than 0.40;
- a first (160) of said main bearings engages a static support (164;
- 164′) and a forward hub (236) of the second spool;
- a second (162) of said main bearings engages the first shaft and the forward hub of the second spool;
- and
- an inter-shaft bearing (170) axially locates the first spool shaft.
25 more elements
Dependencies are inferred from the claim text.