Scavenge filter system for a gas turbine engine

Patent metadata

Field	Value
Publication number	US-9849411-B2
Application number	US-201514703918-A
Country	US
Kind code	B2
Filing date	May 5, 2015
Priority date	May 28, 2014
Publication date	Dec 26, 2017
Grant date	Dec 26, 2017

Abstract

A scavenge filter system according to an exemplary aspect of the present disclosure includes, among other things, a first scavenge pump stage positioned in a first flow path downstream of a first bearing compartment of a spool and a second scavenge pump stage positioned in a second flow path downstream of a second bearing compartment. The second bearing compartment houses a geared architecture mechanically coupled to the spool. A first scavenge filter fluidly couples the first scavenge pump stage to at least one oil reservoir. A second scavenge filter fluidly couples the second scavenge pump stage to the at least one oil reservoir. The first and second scavenge filters are separate and distinct. A method of filtering debris is also disclosed.

First claim

What is claimed is:

1. A scavenge filter system comprising:
a first scavenge pump stage positioned in a first flow path downstream of a first bearing compartment of a spool;
a second scavenge pump stage positioned in a second flow path downstream of a second bearing compartment, the second bearing compartment housing a geared architecture mechanically coupled to the spool to drive a fan, the fan and the geared architecture each extending along an engine central longitudinal axis;
a first scavenge filter fluidly coupling the first scavenge pump stage to at least one oil reservoir; and
a second scavenge filter fluidly coupling the second scavenge pump stage to the at least one oil reservoir, the first and second scavenge filters being separate and distinct.

2. The scavenge filter system as recited in claim 1 , wherein the first and second flow paths combine downstream of the first and second scavenge pump stages into a shared flow path, the shared flow path being distributed between the first and second scavenge filters.

3. The scavenge filter system as recited in claim 1 , comprising:
a pressure filter and a heat exchanger each located in a third flow path between the oil reservoir and the first and second bearing compartments.

4. The scavenge filter system as recited in claim 3 , wherein at least one of the first and second scavenge filters is operable to filter debris sized to a first level, and the pressure filter is operable to filter debris sized to a second level less than the first level.

5. The scavenge filter system as recited in claim 4 , wherein a ratio of the first level to the second level is between about 40:1 and about 1.33:1.

6. The scavenge filter system as recited in claim 5 , wherein the first level is equal to or greater than about 100 microns.

7. The scavenge filter system as recited in claim 6 , wherein the first level is between about 100 microns and about 200 microns, and the second level is between about 5 microns and about 75 microns.

8. The scavenge filter system as recited in claim 1 , comprising a first debris monitor operable to detect debris in the first scavenge filter, and a second debris monitor operable to detect debris in the second scavenge filter.

9. The scavenge filter system as recited in claim 1 , wherein fluid flow in the first flow path defines a first rate, and fluid flow in the second flow path defines a second rate greater than the first rate.

10. The scavenge filter system as recited in claim 1 , wherein the at least one oil reservoir is at least a first oil reservoir and a second oil reservoir, the first flow path defining a first filtration circuit and the second flow path defining a second filtration circuit fluidly isolated from the first filtration circuit, the first scavenge filter and first bearing compartment being located in the first filtration circuit, and the second scavenge filter and second bearing compartment being located in the second filtration circuit.

11. A gas turbine engine comprising:
a fan section including a fan shaft coupled to a fan;
a low speed spool and a high speed spool mounted for rotation within a plurality of spool bearing compartments, the low speed spool mechanically coupling the fan section and a compressor section to a turbine section;
a geared architecture housed within a gear bearing compartment and mechanically coupling the fan to the low speed spool to drive the fan at a lower speed than the low speed spool, the fan and the geared architecture each extending along an engine central longitudinal axis; and
a scavenge filter system including:
a plurality of spool scavenge pump stages each positioned downstream and fluidly coupled to one of the spool bearing compartments,
a gear scavenge pump stage positioned downstream and fluidly coupled to the gear bearing compartment;
a spool scavenge filter fluidly coupling the spool scavenge pump stages to at least one oil reservoir; and
a gear scavenge filter fluidly coupling the gear scavenge pump stage to the at least one oil reservoir, the spool and gear scavenge filters being separate and distinct.

12. The gas turbine engine as recited in claim 11 , wherein flow paths defined by the spool scavenge pump stages and a flow path of the gear scavenge pump stage combine downstream of the spool and gear scavenge pump stages into a shared flow path distributed between the spool and gear scavenge filters.

13. The gas turbine engine as recited in claim 12 , wherein the scavenge filter system includes only one debris monitor operable to detect debris circulated through the spool scavenge filter and the gear scavenge filter.

14. The gas turbine engine as recited in claim 11 , wherein fluid flow in the gear bearing compartment is greater than a combined fluid flow in the spool bearing compartments.

15. The gas turbine engine as recited in claim 11 , comprising:
a pressure filter and a heat exchanger located in a flow path between the at least one oil reservoir and the spool and gear bearing compartments.

16. The gas turbine engine as recited in claim 15 , wherein at least one of the spool and gear scavenge filters is operable to filter debris sized to a first level, and the pressure filter is operable to filter debris sized to a second level less than the first level.

17. The gas turbine engine as recited in claim 11 , comprising an accessory gearbox mechanically coupling the spool and gear pump stages to one of the spools, and the spool scavenge filter fluidly coupling the accessory gearbox to the at least one oil reservoir.

18. The gas turbine engine as recited in claim 17 , wherein the turbine section includes a low pressure turbine and a high pressure turbine extending along an engine central longitudinal axis, the compressor section includes a low pressure compressor and a high pressure compressor, the geared architecture extends along the engine central longitudinal axis, the low speed spool includes an inner shaft interconnecting the low pressure turbine and the fan, the high speed spool includes an outer shaft that is concentric with the inner shaft and interconnects the high pressure turbine and the high pressure compressor, and the inner and outer shafts are rotatable about the engine central longitudinal axis.

19. The gas turbine engine as recited in claim 18 , wherein the accessory gearbox is driven by the inner shaft or the outer shaft.

20. The gas turbine engine as recited in claim 11 , comprising a first debris monitor operable to detect debris circulated through an inlet of the spool scavenge filter, and a second debris monitor operable to detect debris circulated through an inlet of the gear scavenge filter.

21. A method of filtering debris comprising the steps of:
providing at least one spool mounted for rotation within a spool bearing compartment and a gear bearing compartment housing a geared architecture mechanically coupled to the spool to drive a fan, the fan and the geared architecture each extending along an engine longitudinal axis;
providing a spool scavenge pump stage fluidly coupled to the spool bearing compartment and a gear scavenge pump stage fluidly coupled to the gear bearing compartment;
positioning a spool scavenge filter within a first flow path downstream of the spool scavenge pump stage;
positioning a gear scavenge filter within a second flow path downstream of the gear scavenge pump stage, the spool and gear scavenge filters being separate and distinct;
filtering fluid within the first flow path with the first scavenge filter; and

Assignees

• United Technologies Corp

Inventors

• Sheridan William G

Classifications

• B01D35/005 Primary

  Filters specially adapted for use in internal-combustion engine lubrication or fuel systems · CPC title

• F05D2260/607

  Preventing clogging or obstruction of flow paths by dirt, dust, or foreign particles · CPC title

• F01M2001/1057

  comprising a plurality of filters, parallel or serial · CPC title

• F16N2250/32

  Inductive · CPC title

• F01M1/02

  using lubricating pumps (pumps in general F04; lubricating pumps per se F16N) · CPC title