Gas turbine engine bearing with fuel lubrication and cooling

Patent metadata

Field	Value
Publication number	US-11181007-B1
Application number	US-201916288704-A
Country	US
Kind code	B1
Filing date	Feb 28, 2019
Priority date	Feb 28, 2019
Publication date	Nov 23, 2021
Grant date	Nov 23, 2021

Abstract

A gas turbine engine with a bearing that is supplied with fuel and compressed air for both cooling and lubrication of the bearing. The bearing housing contains a serpentine flow cooling circuit with each leg formed from a plurality of parallel flow channels, and where fuel is supplied to the cooling circuit and then discharged into a combustor. Some of the fuel is also bled off and passed into the bearing compartment along with compressed air bled off from the compressor to both cool and lubricate the bearing.

First claim

The invention claimed is:

1. A gas turbine engine comprising:
a compressor;
a turbine;
a shaft connecting the compressor to the turbine;
a bearing supporting the shaft;
a bearing housing, the bearing being located between the shaft and the bearing housing; and
a coolant tube to deliver a coolant to the bearing housing, the coolant tube having a supply channel at an upstream end and a discharge channel at a downstream end, the bearing housing having an outer surface and a plurality of ribs on the outer surface, the plurality of ribs defining:
a first plurality of enclosed parallel cooling channels that are each in direct fluid communication with the supply channel and are configured to direct the coolant in a first flow direction;
a second plurality of enclosed parallel cooling channels that are configured to direct the coolant in a second flow direction opposite the first flow direction; and
a third plurality of enclosed parallel cooling channels that are each in direct communication with the discharge channel and are configured to direct the coolant in the first flow direction,
the first plurality of enclosed parallel cooling channels, the second plurality of enclosed parallel cooling channels, and the third plurality of enclosed parallel cooling channels together forming a serpentine flow cooling circuit around the bearing housing;
wherein,
the coolant flows from the coolant tube and through the serpentine flow cooling circuit to provide cooling to the bearing through the bearing housing.

2. The gas turbine engine of claim 1 , wherein:
the coolant tube also connects to a bearing compartment to supply some of the coolant to lubricate the bearing.

3. The gas turbine engine of claim 2 , wherein:
compressed air from the compressor is mixed with the coolant upstream from the bearing to cool and lubricate the bearing.

4. The gas turbine engine of claim 1 , wherein:
the first, second, and third pluralities of enclosed parallel cooling channels are annular cooling channels which cover substantially all of the bearing housing.

5. The gas turbine engine of claim 1 , wherein:
the serpentine flow cooling circuit is a three-pass serpentine flow cooling circuit.

6. The gas turbine engine of claim 1 , wherein the serpentine flow cooling circuit includes:
a first coolant turn channel between the first plurality of enclosed parallel cooling channels and the second plurality of enclosed parallel cooling channels; and
a second coolant turn channel between the second plurality of enclosed parallel cooling channels and the third plurality of enclosed parallel cooling channels.

7. The gas turbine engine of claim 1 , wherein the coolant is fuel for a combustor, the gas turbine engine further comprising:
a discharge tube that is in direct fluid communication with the discharge channel, the discharge tube connecting the serpentine flow cooling circuit of the bearing housing with the combustor such that a preheated fuel is discharged into the combustor.

8. A process for operating a gas turbine engine, the gas turbine engine having a compressor connected to a gas turbine through a shaft with a bearing to support the shaft, the bearing being within a bearing housing, the process comprising the steps of:
compressing air with the compressor for delivery to a combustor;
supplying a fuel to the combustor;
burning the fuel with the compressed air in the combustor to produce a hot gas flow;
passing the hot gas flow through the gas turbine to drive the compressor;
passing a first portion of the fuel through a serpentine flow cooling circuit formed within the bearing housing to cool the bearing through the bearing housing and to preheat the fuel, the passing the first portion of the fuel through the serpentine flow cooling circuit including:
passing the first portion of the fuel simultaneously through a first plurality of enclosed parallel cooling channels extending around the bearing housing in a clockwise direction; and
then passing the first portion of the fuel simultaneously through a second plurality of enclosed parallel cooling channels extending around the bearing housing in a counter-clockwise direction; and
discharging the preheated first portion of the fuel used to cool the bearing housing into the combustor.

9. The process for operating a gas turbine engine of claim 8 , and further comprising the step of:
after passing the first portion of the fuel simultaneously through the second plurality of enclosed parallel cooling channels, passing the first portion of the fuel simultaneously through a third plurality of enclosed parallel cooling channels extending around then bearing housing in the clockwise direction.

10. The process for operating a gas turbine engine of claim 8 , and further comprising the step of:
passing some a second portion of the fuel into a bearing compartment to provide lubrication and cooling to the bearing.

11. The process for operating a gas turbine engine of claim 10 , and further comprising the step of:
bleeding off some of the compressed air from the compressor; and
passing some of the compressed air into the bearing compartment to provide cooling for the bearing.

12. A bearing assembly comprising:
a shaft;
a bearing housing, the bearing housing having an annular shape with a plurality of enclosed parallel cooling channels formed therein, the bearing housing defining a bearing compartment;
a bearing with within the bearing compartment, the bearing having an inner race contacting the shaft and an outer race contacting the bearing housing; and
a fuel supply tube being connectable to a fuel source, the fuel supply tube defining a first flow path and a second flow path, the first flow path being in fluid communication with the bearing compartment and the second flow path being in communication with the plurality of enclosed parallel cooling channels, the fuel supply tube being configured such that at least a first portion of a fuel supplied from the fuel source through the fuel supply tube passes through the first flow path and into the bearing compartment to lubricate and cool the bearing and at least a second portion of the fuel supplied from the fuel source through the fuel supply tube passes through the second flow path and into the plurality of enclosed parallel cooling channels, the fuel being a coolant, the plurality of enclosed parallel cooling channels having a coolant inlet and a coolant outlet, the coolant inlet being in fluid communication with the fuel supply tube,
the fuel supplied to the plurality of enclosed parallel cooling channels providing cooling of the bearing through the bearing housing.

13. The bearing assembly of claim 12 , wherein:
the plurality of enclosed parallel cooling channels form a serpentine flow cooling circuit.

14. The bearing assembly of claim 13 , wherein:
the serpentine flow cooling circuit is a three-pass serpentine flow cooling circuit.

15. The bearing assembly of claim 13 , wherein the serpentine flow cooling circuit includes:
a first leg having a first plurality of the plurality of enclosed parallel cooling channels, the first plurality of the plurality of enclosed parallel cooling channels being defined by a first at least one rib extending from an outer surface of the bearing housing;
a second leg having a second plurality of the plurality of enclosed parallel cooling channels, the second plurality of the plurality of enclosed parallel cooling channels being defined by a second at least one rib extending from the outer surface of the bearing housing;
a third leg having a third plurality of the plurality of enclo

Assignees

• Florida Turbine Tech Inc

Inventors

• Ress Jr Robert A
• Taylor Brian E

Classifications

• Y02T50/60

  Efficient propulsion technologies, e.g. for aircraft · CPC title

• F05D2260/98

  Lubrication · CPC title

• F05D2260/232

  characterized by the cooling medium · CPC title

• F05D2240/50

  Bearings · CPC title

• F01D25/18

  Lubricating arrangements (of machines or engines in general F01M) · CPC title