Turbomachine with axial force recovery at the fan via pressurized gas feed

Patent metadata

Field	Value
Publication number	US-11274554-B2
Application number	US-201916552950-A
Country	US
Kind code	B2
Filing date	Aug 27, 2019
Priority date	Aug 28, 2018
Publication date	Mar 15, 2022
Grant date	Mar 15, 2022

Abstract

A turbomachine having a fan shaft supported by a first bearing positioned downstream of the fan, the first bearing including an outer ring attached to an annular support secured to the stator. The turbomachine includes at least one gas feed duct leading into an enclosure positioned against the disc, the gas feed duct being adapted to be fed at a second end with pressurized gas taken from an airstream of a high-pressure compressor of the turbomachine, so that the gas applies an axial force towards upstream on the disc during some operating phases of the turbomachine. The turbomachine further includes a ferrule imperviously sealing the enclosure.

First claim

The invention claimed is:

1. A turbomachine comprising a fan driven in rotation by a shaft in relation to an inlet casing of the turbomachine, the fan comprising blades mounted on a fan disc, the shaft being supported by a first bearing positioned downstream of the fan, said first bearing comprising an outer ring attached to the inlet casing,
wherein the turbomachine comprises at least one gas feed duct with a first end opening into an enclosure positioned against the disc and a second end positioned in an airstream of a high-pressure compressor, the turbomachine further comprising a ferrule imperviously sealing the enclosure,
wherein the at least one gas feed duct is adapted to be fed at the second end by pressurized gas taken from the airstream of the high pressure compressor,
wherein the gas feed duct is provided with a valve to control the conveying of said pressurized gas into the enclosure,
wherein the turbomachine further comprises a processing unit configured to control the valve so that:
the valve opens when an engine speed is below a threshold rotation speed, the turbomachine being then considered to be operating in flight idling or approach phase, so that said conveyed pressurized gas applies an axial upstream force on the disc,
and the valve is closed when the engine speed is above the threshold rotation speed, the turbomachine being then considered to be in take-off or cruising phase.

2. The turbomachine according to claim 1 , wherein the enclosure is longitudinally limited by the disc and by a bearing support surrounding the shaft and the first bearing, and wherein the at least one gas feed duct comprises a gas feed duct leading into the enclosure via a piercing made in the bearing support.

3. The turbomachine according to claim 1 , wherein the at least one gas feed duct comprises a gas feed duct which leads into the enclosure at a piercing facing a side portion of the disc.

4. The turbomachine according to claim 3 , wherein the gas feed duct which leads into the enclosure, leads into the enclosure in the vicinity of an outer wall of smaller radius of the enclosure.

5. The turbomachine according to claim 1 , wherein the shaft is also supported by a second bearing positioned upstream of the first bearing, said second bearing comprising an outer ring attached to an annular support secured to the inlet casing, and wherein the at least one feed duct comprises a gas feed duct opening in the vicinity of said second bearing.

6. The turbomachine according to claim 1 , wherein the ferrule is arranged opposite vanes of a first-stage airflow straightener.

7. The turbomachine according to claim 1 , wherein the ferrule comprises a labyrinth seal or dual-brush seal.

8. The turbomachine according to claim 1 , further comprising at least one pressurization tube opening into the enclosure, the pressurization tube comprising a check valve.

9. The turbomachine according to claim 1 , further comprising reduction gearing to modify a rotational speed of the fan.

10. A turbomachine comprising a fan driven in rotation by a shaft in relation to an inlet casing of the turbomachine, the fan comprising blades mounted on a fan disc, the shaft being supported by a first bearing positioned downstream of the fan, said first bearing comprising an outer ring attached to a bearing support, said bearing support surrounding the shaft and the first bearing, said bearing support further extending radially as far as a flange that is fixed relative to the inlet casing underneath a first-stage airflow straightener,
wherein the turbomachine comprises at least one gas feed duct with a first end opening into an enclosure positioned against the disc and a second end positioned in an airstream of a high-pressure compressor,
wherein the at least one gas feed duct is adapted to be fed at the second end by pressurized gas taken from the airstream of the high pressure compressor so that said gas applies an axial upstream force on the disc during some operating phases of the turbomachine,
wherein the turbomachine further comprises a ferrule imperviously sealing the enclosure, said ferrule being arranged opposite vanes of the first-stage airflow straightener between the flange and a wall of large radius delimiting an area of largest radius of the enclosure, said wall of large radius extending against the first-stage airflow straightener.

11. The turbomachine of claim 10 , further comprising a valve to control the conveying of said pressurized gas into the enclosure and a processing unit configured to control the valve so that:
the valve opens when an engine speed is below a threshold rotation speed, the turbomachine being then considered to be operating in flight idling or approach phase, so that said conveyed pressurized gas applies an axial upstream force on the disc, and
the valve is closed when the engine speed is above the threshold rotation speed, the turbomachine being then considered to be in take-off or cruising phase.

12. The turbomachine according to claim 10 , wherein the enclosure is longitudinally limited by the disc and by the bearing support, and wherein the at least one gas feed duct comprises a gas feed duct leading into the enclosure via a piercing made in the bearing support.

13. The turbomachine according to claim 10 , wherein the at least one gas feed duct comprises a gas feed duct which leads into the enclosure at a piercing facing a side portion of the disc.

14. The turbomachine according to claim 13 , wherein the gas feed duct which leads into the enclosure, leads into the enclosure in the vicinity of an outer wall of smaller radius of the enclosure.

15. The turbomachine according to claim 10 , wherein the shaft is also supported by a second bearing positioned upstream of the first bearing, said second bearing comprising an outer ring attached to an annular support secured to the inlet casing, and wherein the at least one feed duct comprises a gas feed duct opening in the vicinity of said second bearing.

16. The turbomachine according to claim 10 , wherein the ferrule comprises a labyrinth seal or dual-brush seal.

17. The turbomachine according to claim 10 , further comprising at least one pressurization tube opening into the enclosure, the pressurization tube comprising a check valve.

18. The turbomachine according to claim 10 , further comprising reduction gearing to modify a rotational speed of the fan.

Assignees

• Safran Aircraft Engines

Inventors

• Brault Michel Gilbert Roland
• Becoulet Julien Fabien Patrick
• Chassagne Amelie Argie Antoinette
• Yvon Didier Jean-Louis

Classifications

• F02C7/06

  Arrangements of bearings (bearings F16C); Lubricating ({of turbo machines F01D25/18; of machines or} engines in general F01M) · CPC title

• F01D3/04

  axial thrust being compensated by thrust-balancing dummy piston or the like · CPC title

• F05D2240/56

  Brush seals · CPC title

• F01D3/00 Primary

  Machines or engines with axial-thrust balancing effected by working-fluid · CPC title

• F05D2240/52

  Axial thrust bearings · CPC title