FLOW RESTRICTOR FOR LUBRICATION LINE

• US 20100154427A1
• Filed: 12/22/2008
• Published: 06/24/2010
• Est. Priority Date: 12/22/2008
• Status: Active Grant

• Current Assignee: Pratt & Whitney Canada Corporation (Rtx Corporation)
• Original Assignee: Pratt & Whitney Canada Corporation (Rtx Corporation)
• Inventors: Logan, Adam
• Granted Patent: US 8,997,449 B2
• Time in Patent Office: Days
• US Class Current: 60/772
• CPC Class Codes: F01D 25/18 Lubricating arrangements of machines or engines in general F01M
• CPC Class Codes: F16N 2270/22 with restrictions
• CPC Class Codes: F16N 7/40 in a closed circulation system

Abstract

A flow restrictor is provided for a lubrication circulation system. The flow restrictor comprises a body configured to obstruct a flow of lubricant within the lubricant circulation system. The body has one or more through holes communicating with upstream and downstream portions of the lubrication circulation system. Each of the one or more holes has a cross-sectional area sufficiently small, and a length sufficiently long, to prevent turbulent lubricant flow therethrough at temperatures below a first predetermined reference temperature. The one or more holes have sufficient aggregate cross-sectional area to allow a desired lubricant flow rate through the body at temperatures at or above a second predetermined reference temperature.

Claims

1. A gas turbine engine lubrication system comprising a flow restrictor having a body configured to obstruct a flow of lubricant within a lubricant supply line, the body having a plurality of through holes communicating with upstream and downstream portions of the lubricant supply line;

each of the plurality of through holes having a cross-sectional area sufficiently small, and a length sufficiently long, to prevent turbulent lubricant flow therethrough at temperatures below a first predetermined reference temperature; and

the through holes having sufficient aggregate cross-sectional area to allow a desired lubricant flow rate through the body at temperatures at or above a gas turbine engine operating temperature.

2. The gas turbine engine lubrication system of claim 1, wherein the body is cylindrical and has an axis, and wherein the through holes extend substantially axially through the body.

3. The gas turbine engine lubrication system of claim 2, wherein the through holes comprise a plurality of circular holes of constant diameter.

4. The gas turbine engine lubrication system of claim 2, wherein the through holes comprise a plurality of circular holes, the circular holes having differing diameters, with each circular hole having a substantially constant diameter over the length of the hole.

5. The gas turbine engine lubrication system of claim 1, wherein a diameter of each of the one or more holes is between approximately 0.020 inches and 0.060 inches.

6. The gas turbine engine lubrication system of claim 2, wherein a length of the flow restrictor is between approximately 1 inch and 2 inches.

7. The gas turbine engine lubrication system of claim 1, wherein the lubricant includes oil.

8. The gas turbine engine lubrication system of claim 1, wherein the lubrication system supplies lubricant to bearings in a bearing cavity of the gas turbine engine, the flow restrictor being positioned between the bearing cavity and a supply pump of the lubrication system.

9. The gas turbine engine lubrication system of claim 1, wherein the first predetermined reference temperature is approximately 100 degrees Fahrenheit and the gas turbine engine operating temperature is approximately greater than 200 degrees Fahrenheit.

10. A turbine engine comprising a lubrication system, the lubrication system having at least one lubrication flow restrictor, the at least one lubrication flow restrictor comprising:

a body configured to obstruct a flow of lubricant within the lubrication system, the body having one or more through holes communicating with upstream and downstream portions of the lubrication system;

each of the one or more through holes having a cross-sectional area sufficiently small, and a length sufficient long, to prevent turbulent lubricant flow therethrough at temperatures below a first predetermined reference temperature; and

the one or more holes having sufficient aggregate cross-sectional area to allow a desired lubricant flow rate through the body at temperatures at or above a second predetermined reference temperature.

11. The turbine engine of claim 10, wherein the body is cylindrical having an axis and the one or more through holes extend substantially axially through the body.

12. The turbine engine of claim 11, wherein the one or more through holes comprise a plurality of circular holes of constant diameter.

13. The turbine engine of claim 11, wherein the one or more through holes comprise a plurality of circular holes, the circular holes having differing diameters, with each circular hole having a substantially constant diameter over the length of the hole.

14. The turbine engine of claim 10, wherein a diameter of each of the one or more holes is between approximately 0.020 inches and 0.050 inches.

15. The turbine engine of claim 11, wherein a length of the flow restrictor is between approximately 1 inch and 2 inches.

16. The turbine engine of claim 10, wherein the first predetermined reference temperature is approximately 100 degrees Fahrenheit and the second predetermined reference temperature is approximately 200 degrees Fahrenheit.

17. A method of operating a gas turbine engine in cold weather, the gas turbine engine having a lubrication system, the method comprising:

providing a flow restrictor in a lubricant supply line of the lubrication system;

preventing turbulent lubricant flow through the lubrication system at temperatures below a first predetermined reference temperature; and

allowing a desired lubricant flow rate through the lubrication system at temperatures at or above a gas turbine engine operating temperature.

18. The method according to claim 17, wherein the flow restrictor has a body configured to obstruct the flow of lubricant within the lubricant supply line, the body having a plurality of through holes communicating with upstream and downstream portions of the lubricant supply line, each of the plurality of through holes having a cross-sectional area sufficiently small and a length sufficiently long to prevent turbulent lubricant flow through the lubrication system at temperatures below the first predetermined reference temperature, and the through holes having sufficient aggregate cross-sectional area to allow a desired lubricant flow rate through the body at temperatures at or above the gas turbine engine operating temperature.

19. The method of claim 18, wherein a diameter of each of the one or more holes is between approximately 0.020 inches and 0.060 inches and a length of the flow restrictor is between approximately 1 inch and 2 inches.

20. The method of claim 18, wherein the first predetermined reference temperature is approximately 100 degrees Fahrenheit and the gas turbine engine operating temperature is approximately greater than 200 degrees Fahrenheit.