Regulation of the oil flow in a cooling circuit of a turbomachine

Patent metadata

Field	Value
Publication number	US-10450959-B2
Application number	US-201715498850-A
Country	US
Kind code	B2
Filing date	Apr 27, 2017
Priority date	Apr 27, 2016
Publication date	Oct 22, 2019
Grant date	Oct 22, 2019

Abstract

A turbomachine including a turbine shaft supported by at least one bearing, at least one enclosure, housing the bearing of the turbine shaft, an oil cooling circuit of the enclosure including at least one jet configured to inject oil from the cooling circuit into the enclosure, and a regulator configured to regulate the flow of oil in the cooling circuit as a function of an oil temperature at output of the enclosure and a pressure difference at the level of the jet.

First claim

The invention claimed is:

1. A turbomachine comprising:
a turbine shaft assembly supported by at least two bearings,
at least one enclosure, housing at least one of the bearings of the turbine shaft assembly,
an oil cooling circuit of the enclosure, said cooling circuit comprising at least one jet configured to inject oil from the cooling circuit into the enclosure, and
a flow regulator, configured to regulate oil flow in the cooling circuit as a function of a temperature of the oil at an output of the enclosure and a pressure difference at a level of the jet.

2. The turbomachine as claimed in claim 1 , wherein the turbine shaft assembly comprises a low-pressure shaft and a high-pressure shaft, the enclosure housing a rear bearing of the high-pressure shaft.

3. The turbomachine as claimed in claim 1 , also comprising a combustion chamber, the enclosure being positioned under said combustion chamber.

4. The turbomachine as claimed in claim 1 , wherein the flow regulator is configured to regulate the flow of oil in the cooling circuit such that the pressure difference at the level of the jet is greater than or equal to a predefined pressure difference, said predefined pressure difference which can be equal to 0.9 bars.

5. The turbomachine as claimed in claim 1 , wherein the flow regulator is configured to regulate the flow of oil in the cooling circuit such that the temperature at output of the enclosure is less than or equal to an admissible predefined maximal temperature, said admissible maximal temperature which can be equal to 180° C.

6. The turbomachine as claimed in claim 1 , wherein the turbine shaft assembly comprises a low-pressure shaft and a high-pressure shaft, the turbomachine also comprising a fan shaft and a reduction mechanism coupling the low-pressure shaft and the fan shaft, the reduction mechanism comprising an epicyclic or planetary reducing gear and having a reduction ratio of between 2.5 and 5.

7. The turbomachine as claimed in claim 6 , having a dilution rate between 12 and 18.

8. The turbomachine as claimed in claim 6 , having a dilution rate greater than 10.

9. The turbomachine as claimed in claim 6 , wherein the fan shaft is supported by at least one fan bearing, the low-pressure shaft is supported by at least one front bearing and a rear bearing and the high-pressure shaft is supported by at least one front bearing and a rear bearing, the turbomachine also comprising:
a first enclosure housing the at least one fan bearing, the reduction mechanism and a front bearing of the low-pressure shaft,
a second enclosure housing the front bearing of the high-pressure shaft and optionally an angle gearbox between the high-pressure shaft and a transmission shaft of an accessory gearbox, and
a third enclosure housing the rear bearing of the low-pressure shaft,
the first, the second and the third enclosure being cooled by the cooling system.

10. The turbomachine as claimed in claim 9 , wherein the flow regulator is configured to regulate the oil flow in the cooling circuit such that:
a difference between an input temperature and an output temperature of the reduction mechanism is between 30° C. and 70° C., and/or
a difference between an input temperature and an output temperature at a level of the bearings is between 70° C. and 80° C., and/or
a difference between an input temperature and an output temperature at a level of the enclosures is between 70° C. and 80° C., and/or
a maximal temperature at output of the reduction mechanism is less than or equal to 150° C., and/or
a maximal temperature at output of the bearings is less than or equal to 180° C., and/or
a maximal temperature at output of the enclosures is less than or equal to 180° C.

11. The turbomachine as claimed in claim 9 , wherein a jet is associated with each enclosure and the flow regulator is configured to regulate the oil flow in the cooling circuit as a function of the pressure difference at a level of each jet.

12. The turbomachine as claimed in claim 1 , wherein the flow regulator comprises an oil supply pump having variable geometry or a derivation.

13. The turbomachine as claimed in claim 1 , wherein the flow regulator is configured to regulate the oil flow as a function of a maximal admissible temperature exiting the enclosure.

14. The turbomachine as claimed in claim 13 , wherein the flow regulator is configured to regulate the oil flow as a function of a minimal pressure difference at terminals of the jet.

15. The turbomachine as claimed in claim 14 , wherein the flow regulator is configured to regulate the oil flow such that, when the pressure difference at the terminals of the jet is less that a minimal pressure difference threshold, the flow regulator is configured to increase oil flow in the cooling circuit to boost said pressure difference and reach the minimal pressure difference threshold.

16. The turbomachine as claimed in claim 15 , wherein the flow regulator is configured to regulate the oil flow such that, when the temperature at the output of the enclosure exceeds a maximal temperature threshold, the flow regulator is configured to increase oil flow in the cooling circuit to lower said temperature.

Assignees

• Safran Aircraft Engines

Inventors

• Morreale Serge Rene

Classifications

• F01D25/20

  using lubrication pumps · CPC title

• 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

• F05D2260/40311

  of the epicyclical, planetary or differential type · CPC title

• F05D2240/35

  Combustors or associated equipment · CPC title

• F05D2240/60

  Shafts · CPC title