Turbofan engine main bearing arrangement

Patent metadata

Field	Value
Publication number	US-9732629-B2
Application number	US-201414207722-A
Country	US
Kind code	B2
Filing date	Mar 13, 2014
Priority date	Mar 15, 2013
Publication date	Aug 15, 2017
Grant date	Aug 15, 2017

Abstract

A turbofan engine ( 20; 300; 400 ) comprises a fan ( 28 ), a fan drive gear system ( 60 ), a fan shaft ( 120 ) coupling the fan drive gear system to the fan, a low spool, an intermediate spool, and a core spool. The low spool engages at least three main bearings of which at least two are non-thrust bearings and at least one is a thrust bearing. The fan shaft engages at least two bearings ( 148, 150 ). The core spool engages at least two bearings ( 250, 260 ). The intermediate spool engages at least two of said bearings ( 220, 200, 230; 220, 200, 230 - 2; 200, 220, 230 - 3 ).

First claim

What is claimed is:

1. A turbofan engine ( 20 ) comprising:
a fan ( 28 );
a fan drive gear system ( 60 );
a fan shaft ( 120 ) coupling the fan drive gear system to the fan;
a low spool comprising:
a low pressure turbine ( 50 ); and
a low shaft ( 56 ) coupling the low pressure turbine to the fan drive gear system;

an intermediate spool comprising:
an intermediate pressure turbine ( 48 ); and
a compressor ( 42 );

a core spool comprising:
a high pressure turbine ( 46 ); and
a compressor ( 44 ); and

a plurality of main bearings,

wherein:
the low spool engages four of said main bearings, of which at least two are non-thrust bearings ( 170 , 230 , 172 ) and a single one is a thrust bearing ( 200 );
of said at least two non-thrust bearings engaged by the low spool, at least one is a non-thrust bearing ( 230 ) engaging the low spool and the intermediate spool;
the fan shaft engages at least two of said main bearings ( 148 , 150 );
the core spool engages at least two of said main bearings ( 250 , 260 ); and
the intermediate spool engages at least two of said main bearings ( 220 , 200 , 230 ).

2. The engine of claim 1 , wherein:
said thrust bearing is a non-duplex ball bearing.

3. The engine of claim 1 , wherein:
said non-thrust bearings and said thrust bearing are rolling element bearings.

4. The engine of claim 3 , wherein:
said non-thrust bearings are roller bearings; and
said thrust bearing is a ball bearing.

5. The engine of claim 1 , wherein:
there are exactly nine said main bearings.

6. The engine of claim 5 , wherein:
each of said nine said main bearings is either a single stage rolling element bearing or a multi-stage bearing wherein an interstage gap is no more than 30 mm.

7. The engine of claim 5 , wherein:
of the at least two bearings that engage the core spool, at least one is a non-thrust bearing and at least one is a thrust bearing.

8. The engine of claim 5 , wherein:
of the at least two bearings that engage the intermediate spool, at least one is a non-thrust bearing and at least one is a thrust bearing.

9. The engine of claim 1 , wherein:
of the at least two bearings that engage the fan shaft, at least one is a non-thrust bearing and at least one is a thrust bearing.

10. The engine of claim 9 , wherein:
of the at least two bearings that engage the core spool, at least one is a non-thrust bearing and at least one is a thrust bearing.

11. The engine of claim 9 , wherein:
of the at least two bearings that engage the intermediate spool, at least one is a non-thrust bearing and at least one is a thrust bearing.

12. The engine of claim 1 wherein:
one of said at least two non-thrust bearings engaging the low spool engages a turbine exhaust frame.

13. The engine of claim 1 , wherein:
one of the bearings engaging the fan shaft is a thrust bearing ( 148 ) and one the bearings engaging the fan shaft is a non-thrust bearing ( 150 ).

14. The engine of claim 1 , wherein:
one of the bearings engaging the core spool is a thrust bearing ( 250 ) and one the bearings engaging the core spool is a non-thrust bearing ( 260 ).

15. A turbofan engine ( 300 ; 400 ) comprising:
a fan ( 28 );
a fan drive gear system ( 60 );
a fan shaft ( 120 ) coupling the fan drive gear system to the fan;
a low spool comprising:
a low pressure turbine ( 50 ); and
a low shaft ( 56 ) coupling the low pressure turbine to the fan drive gear system;

an intermediate spool comprising:
an intermediate pressure turbine ( 48 ); and
a compressor ( 42 );

a core spool comprising:
a high pressure turbine ( 46 ); and
a compressor ( 44 ); and

a plurality of main bearings,

wherein:
there are exactly nine said main bearings;
the low spool engages three of said main bearings, of which exactly two are non-thrust bearings ( 170 , 230 - 2 , 172 - 3 ; 170 , 230 - 3 , 172 ) and a single one is a thrust bearing ( 200 );
the fan shaft engages at least two of said main bearings ( 148 , 150 );
the core spool engages at least two of said main bearings ( 250 , 260 );
the intermediate spool engages at least two of said main bearings ( 220 , 200 , 230 - 2 ; 200 , 220 , 230 - 3 ); and
said one thrust bearing engaging the low spool also engages the intermediate shaft.

16. The engine of claim 15 , wherein:
said two non-thrust bearings engaging the low spool also engage a case ( 22 ).

17. The engine of claim 15 wherein:
one of said at least two non-thrust bearings engaging the low spool engages an inter-turbine frame.

18. A turbofan engine ( 300 ; 400 ) comprising:
a fan ( 28 );
a fan drive gear system ( 60 );
a fan shaft ( 120 ) coupling the fan drive gear system to the fan;
a low spool comprising:
a low pressure turbine ( 50 ); and
a low shaft ( 56 ) coupling the low pressure turbine to the fan drive gear system;

an intermediate spool comprising:
an intermediate pressure turbine ( 48 ); and
a compressor ( 42 );

a core spool comprising:
a high pressure turbine ( 46 ); and
a compressor ( 44 ); and

a plurality of main bearings,

wherein:
there are exactly nine said main bearings;
the low spool engages at least three of said main bearings, of which at least two are non-thrust bearings ( 170 , 230 - 2 , 172 - 3 ; 170 , 230 - 3 , 172 ) and a single one is a thrust bearing ( 200 );
the fan shaft engages at least two of said main bearings ( 148 , 150 );
the core spool engages at least two of said main bearings ( 250 , 260 );
the intermediate spool engages at least two of said main bearings ( 220 , 200 , 230 - 2 ; 200 , 220 , 230 - 3 ); and
of the at least two bearings that engage the fan shaft, at least one is a non-thrust bearing and at least one is a thrust bearing.

19. The engine of claim 18 wherein:
one of said at least two non-thrust bearings engaging the low spool engages an inter-turbine frame.

20. The engine of claim 18 wherein:
one of said at least two of said main bearings engaging the intermediate spool is a non-thrust bearing engaging an inter-turbine frame.

Assignees

• United Technologies Corp

Inventors

• Sheridan William G
• Schwarz Frederick M

Classifications

• F02C7/36

  Power transmission arrangements between the different shafts of the gas turbine plant, or between the gas-turbine plant and the power user ({F02C3/107 - F02C3/13 and} F02C7/32 take precedence; couplings for transmitting rotation F16D; gearing in general F16H) · CPC title

• F01D5/02

  Blade-carrying members, e.g. rotors (rotors of non-bladed type F01D1/34; stators F01D9/00 {; selecting particular materials F01D5/28}) · CPC title

• F05D2260/40311

  of the epicyclical, planetary or differential type · CPC title

• F05D2240/52

  Axial thrust bearings · CPC title

• F05D2240/24

  for turbines · CPC title