Gearbox assembly with lubricant extraction volume ratio

Patent metadata

Field	Value
Publication number	US-12320418-B2
Application number	US-202418972185-A
Country	US
Kind code	B2
Filing date	Dec 6, 2024
Priority date	Jun 22, 2022
Publication date	Jun 3, 2025
Grant date	Jun 3, 2025

Abstract

A gearbox assembly includes a gearbox having a gear assembly and a gutter for collecting a gearbox lubricant scavenge flow from the gearbox. The gutter is characterized by a lubricant extraction volume ratio between 0.01 and 0.3, inclusive of the endpoints. The lubricant extraction volume ratio is defined by
V G V G ⁢ B . V G
is a gutter volume of the gutter and V GB is a gearbox volume. A gas turbine engine includes the gearbox assembly and a lubrication system. The lubrication system includes a sump that is a primary reservoir having a first lubricant level and a secondary reservoir in the gearbox assembly. The secondary reservoir has a second lubricant level. The lubrication system fills the secondary reservoir with a lubricant between the first lubricant level and the second lubricant level. The gear assembly collects the lubricant in the secondary reservoir to supply the lubricant to the gear assembly.

First claim

The invention claimed is:

1. A gas turbine engine comprising:
a gearbox assembly comprising:
a gearbox including a gear assembly and having a gearbox volume defined by an outer diameter of the gearbox and a gearbox length of the gearbox; and
a gutter for collecting a gearbox lubricant scavenge flow from the gearbox, the gutter having a gutter volume defined by an inner surface of a gutter wall of the gutter and being characterized by a lubricant extraction volume ratio between 0.01 and 0.3, inclusive of the endpoints, the lubricant extraction volume ratio defined by:

V
G

V

G
⁢
B

,

wherein V G is the gutter volume of the gutter and V GB is the gearbox volume; and

a lubrication system comprising:
a sump in fluid communication with the gearbox assembly, the sump being a primary reservoir having a first lubricant level; and
a secondary reservoir in the gearbox assembly, the secondary reservoir having a second lubricant level that is greater than the first lubricant level, wherein the lubrication system fills the secondary reservoir with a lubricant between the first lubricant level and the second lubricant level, and the gear assembly collects the lubricant in the secondary reservoir to supply the lubricant from the secondary reservoir to the gear assembly.

2. The gas turbine engine of claim 1 , wherein the first lubricant level of the sump is below the gear assembly such that the gear assembly is prevented from contacting the lubricant in the sump during operation of the gas turbine engine, and the second lubricant level is positioned such that at least a portion of the gear assembly contacts the lubricant in the secondary reservoir.

3. The gas turbine engine of claim 1 , wherein the gear assembly includes one or more scuppers that scoop the lubricant within the secondary reservoir onto the gear assembly as the gear assembly rotates.

4. The gas turbine engine of claim 1 , further comprising a tank that stores the lubricant therein, a lubricant pump, and a lubricant supply line in fluid communication with the tank and the gearbox assembly, the lubricant pump pumping the lubricant from the tank to the gearbox assembly through the lubricant supply line during operation of the gas turbine engine.

5. The gas turbine engine of claim 4 , wherein the sump includes a sump line in fluid communication with the sump and the tank, and the lubricant drains from the sump to the tank through the sump line.

6. The gas turbine engine of claim 5 , further comprising a drain valve within the sump line, the drain valve opening to allow the lubricant to drain through the sump line and closing to prevent the lubricant from draining through the sump line.

7. The gas turbine engine of claim 6 , wherein the drain valve opens or closes based on at least one of a pressure of the lubricant in the lubrication system, a pressure of fuel in the gas turbine engine, or a pressure of hydraulics in the gas turbine engine.

8. The gas turbine engine of claim 1 , wherein the lubrication system includes a first drain port in fluid communication with the sump, the lubricant draining from the sump through the first drain port.

9. The gas turbine engine of claim 8 , wherein the first drain port is positioned at approximately a six o'clock position of the gearbox assembly.

10. The gas turbine engine of claim 8 , wherein the lubrication system includes a second drain port in fluid communication with the secondary reservoir, the lubricant draining from the secondary reservoir through the second drain port.

11. The gas turbine engine of claim 10 , wherein the second drain port is positioned at approximately the second lubricant level such that the lubricant drains through the second drain port at the second lubricant level.

12. The gas turbine engine of claim 10 , further comprising a third drain port positioned on a first circumferential side of the first drain port, and a fourth drain port positioned on a second circumferential side of the first drain port, wherein the lubricant drains through the third drain port or the fourth drain port when the gearbox assembly rotates clockwise or counterclockwise.

13. The gas turbine engine of claim 12 , wherein the fourth drain port is positioned between the first drain port and the second drain port.

14. A gas turbine engine comprising:
a gearbox assembly comprising:
a gearbox including a gear assembly and having a gearbox volume defined by an outer diameter of the gearbox and a gearbox length of the gearbox; and
a gutter for collecting a gearbox lubricant scavenge flow from the gearbox, the gutter having a gutter volume defined by an inner surface of a gutter wall of the gutter and being characterized by a lubricant extraction volume ratio between 0.01 and 0.3, inclusive of the endpoints, the lubricant extraction volume ratio defined by:

V
G

V

G
⁢
B

,

wherein V G is the gutter volume of the gutter and V GB is the gearbox volume; and

a lubrication system comprising:
a sump in fluid communication with the gearbox assembly, the sump being a primary reservoir having a first lubricant level of a lubricant that is below the gear assembly such that the gear assembly is prevented from contacting the lubricant in the sump during operation of the gas turbine engine;
a secondary reservoir in the gearbox assembly, the secondary reservoir having a second lubricant level that is greater than the first lubricant level and is positioned such that at least a portion of the gear assembly contacts the lubricant in the secondary reservoir;
a first drain port in fluid communication with the sump, the lubricant draining from the sump through the first drain port; and
a second drain port in fluid communication with the secondary reservoir,
wherein the lubrication system fills the secondary reservoir with the lubricant between the first lubricant level and the second lubricant level and a portion of the lubricant drains through the second drain port, and the gear assembly collects the lubricant in the secondary reservoir to supply the lubricant from the secondary reservoir to the gear assembly.

15. The gas turbine engine of claim 14 , wherein the gear assembly includes one or more scuppers that scoop the lubricant within the secondary reservoir onto the gear assembly as the gear assembly rotates.

16. The gas turbine engine of claim 14 , wherein the second drain port is positioned at approximately the second lubricant level such that the lubricant drains through the second drain port at the second lubricant level.

17. The gas turbine engine of claim 14 , further comprising a third drain port positioned on a first circumferential side of the first drain port, and a fourth drain port positioned on a second circumferential side of the first drain port, wherein the lubricant drains through

Assignees

• Gen Electric
• Ge Avio Srl

Inventors

• Ertas Bugra H
• Zhang Xiaohua
• Manzoni Miriam
• Turi Flavia
• Piazza Andrea
• Sibbach Arthur W
• Miller Brandon W

Classifications

• F02C7/06

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

• F16H57/0479

  Gears or bearings on planet carriers · CPC title

• F16H57/0409

  characterised by increasing efficiency, e.g. by reducing splash losses · CPC title

• F16H57/0441

  Arrangements of pumps · CPC title

• F16H57/0435

  Pressure control for supplying lubricant; Circuits or valves therefor · CPC title