Geared gas turbine engine with gear driving low pressure compressor and fan at a common speed and a shear section to provide overspeed protection

Patent metadata

Field	Value
Publication number	US-11384657-B2
Application number	US-202016940538-A
Country	US
Kind code	B2
Filing date	Jul 28, 2020
Priority date	Jun 12, 2017
Publication date	Jul 12, 2022
Grant date	Jul 12, 2022

Abstract

A turbine engine has a fan and a low pressure compressor that rotate at a common speed and in a common direction. A fan drive turbine drives a gear reduction to, in turn, drive the low pressure compressor and the fan at a speed which is slower than a speed of the fan drive turbine. A combustor intermediate the low pressure compressor and the fan drive turbine and a thrust bearing mount the fan drive turbine, the thrust bearing being aft of a location of the combustor. A shear section in a drive connection connecting the fan drive turbine to the gear reduction is weaker than other portions of the drive connection. The shear section is aft of the thrust bearing.

First claim

The invention claimed is:

1. A gas turbine engine comprising:
a fan and a low pressure compressor, said fan and said low pressure compressor configured for rotating at a common speed and in a common direction;
a fan drive turbine configured for driving a gear reduction, in turn configured for driving said low pressure compressor and said fan at speed which is slower than a speed of said fan drive turbine;
a combustor intermediate said low pressure compressor and said fan drive turbine and a thrust bearing configured for mounting said fan drive turbine, said thrust bearing being aft of a location of said combustor;
said fan drive turbine is configured to be supported on said thrust bearing and on a second bearing which is aft of said thrust bearing;
a shear section in a drive connection configured for connecting said fan drive turbine to said gear reduction;
said gear reduction is configured to be supported on a third bearing forward of said gear reduction and on a fourth bearing which is aft of said gear reduction;
said fan delivering air into a bypass duct as propulsion air, and delivering air into said low pressure compressor, and a bypass ratio of the volume of air delivered into the bypass duct divided by the volume of air delivered into the low pressure compressor is between 10 and 30
wherein there is a high pressure turbine and a high pressure compressor and said shear section is aft of a plurality of blades on said high pressure turbine; and
wherein said shear section is between 1.5 and 2.0 times weaker than any other portion of the drive connection between said fan drive turbine and said gear reduction.

2. The gas turbine engine as set forth in claim 1 , wherein said shear section is provided by a thin portion of the drive connection.

3. The gas turbine engine as set forth in claim 2 , wherein said thin portion is in a hub of the drive connection configured for connecting said fan drive turbine to a shaft of said drive connection.

4. The gas turbine engine as set forth in claim 1 , wherein said gear reduction is an epicyclic gear reduction.

5. A gas turbine engine comprising:
a fan and a low pressure compressor, said fan and said low pressure compressor configured for rotating at a common speed and in a common direction;
a fan drive turbine configured for driving an epicyclic gear reduction, in turn, configured for driving said low pressure compressor and said fan at speed which is slower than a speed of said fan drive turbine;
a combustor intermediate said low pressure compressor and said fan drive turbine and a thrust bearing configured for mounting said fan drive turbine, said thrust bearing being aft of a location of said combustor;
a shear section in a drive connection configured for connecting said fan drive turbine to said gear reduction;
said drive connection further comprising a shaft section and a hub of said fan drive turbine;
said gear reduction configured to be supported on a second bearing forward of said gear reduction and on a third bearing which is alt of said gear reduction;
wherein said shear section is between 1.5 and 2.0 times weaker than any other portion of the drive connection between said fan drive turbine and said gear reduction;
said fan delivering air into a bypass duct as propulsion air, and delivering air into said low pressure compressor, and a bypass ratio of the volume of air delivered into the bypass duct divided by the volume of air delivered into the low pressure compressor is between 10 and 30; and
wherein said shear section is provided by connections configured for connecting the shaft section of the drive connection extending toward said gear reduction to j hub of said fan drive turbine.

6. The gas turbine engine as set forth in claim 5 , wherein there is a high pressure turbine and a high pressure compressor and said shear section is aft of blades on said high pressure turbine.

7. The gas turbine engine as set forth in claim 5 , wherein said connections are one of bolts and pins.

8. A gas turbine engine comprising:
a fan and a low pressure compressor, said fan and said low pressure compressor configured for rotating at a common speed and in a common direction;
a fan drive turbine configured for driving an epicyclic gear reduction, in turn, configured for driving said low pressure compressor and said fan at speed which is slower than a speed of said fan drive turbine;
a combustor intermediate said low pressure compressor and said fan drive turbine and a thrust bearing configured for mounting said fan drive turbine, said thrust bearing being aft of a location of said combustor;
a shear section in a drive connection configured for connecting said fan drive turbine to said gear reduction;
said gear reduction configured to be supported on a second bearing forward of said gear reduction and on a third bearing which is alt of said gear reduction;
said shear section is between 1.15 and 1.5 times weaker than any other portion of the drive connection between said fan drive turbine and said gear reduction; and
said fan delivering air into a bypass duct as propulsion air, and delivering air into said low pressure compressor, and a bypass ratio of the volume of air delivered into the bypass duct divided by the volume of air delivered into the low pressure compressor is between 10 and 30; and
wherein there is a high pressure turbine and a high pressure compressor and said shear section is aft of a plurality of blades on said high pressure turbine.

9. The gas turbine engine as set forth in claim 8 , wherein said drive connection further comprises a shaft section and a hub of said fan drive turbine, and said shear section is provided by connections configured for connecting the shaft section extending toward said gear reduction to the hub of said fan drive turbine.

10. The gas turbine engine as set forth in claim 9 , wherein said connections are one of bolts and pins.

11. The gas turbine engine as set forth in claim 8 , wherein said shear section is provided by a thin portion of the drive connection.

12. The gas turbine engine as set forth in claim 11 , wherein said thin portion is in a hub configured for connecting said fan drive turbine to a shaft of said drive connection.

13. The gas turbine engine as set forth in claim 8 , wherein said drive connection further comprises a shaft section and a hub of said fan drive turbine, and said shear section is provided by connections configured for connecting the shaft section extending toward said gear reduction to the hub of said fan drive turbine.

Assignees

• Raytheon Tech Corp

Inventors

• Sheridan William G

Classifications

• F05D2260/40311

  of the epicyclical, planetary or differential type · CPC title

• F01D21/006

  Arrangements of brakes (brakes per se F16D) · CPC title

• F02C3/107

  with two or more rotors connected by power transmission · CPC title

• F01D25/16

  Arrangement of bearings; Supporting or mounting bearings in casings (bearings per se F16C) · CPC title

• F01D21/045 Primary

  special arrangements in stators or in rotors dealing with breaking-off of part of rotor · CPC title