Flow restrictor for lubrication line

• US 8,997,449 B2
• Filed: 12/22/2008
• Issued: 04/07/2015
• Est. Priority Date: 12/22/2008
• Status: Active Grant

• Current Assignee: Pratt & Whitney Canada Corporation (Raytheon Technologies Corporation d/b/a RTX)
• Original Assignee: Pratt & Whitney Canada Corporation (Raytheon Technologies Corporation d/b/a RTX)
• Inventors: Logan, Adam
• Primary Examiner(s): Wongwian, Phutthiwat
• Assistant Examiner(s): Mantyla, Michael B
• Application Number:
  US12/341,140
• Publication Number:
  US 20100154427A1
• Time in Patent Office: 2,297 Days
• Field of Search: 60/390.8, 607/72, 184/6.11, 184/7.3, 184/7.4, 138/40
• US Class Current: 60/39.08
• 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 for supplying lubricant to a gas turbine engine, the 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, the lubricant supply line and the flow restrictor being connected in fluid flow communication with a source of lubricant and the gas turbine engine at engine start-up and during normal engine operating conditions, the flow restrictor being positioned so that all the lubricant flowing from the source to the engine has to flow through the flow restrictor;

each of the plurality of through holes having a cross-sectional area sufficiently small, and a length sufficiently long, to prevent turbulence in the lubricant flowing therethrough at temperatures below a first predetermined reference temperature and automatically restrict the flow of lubricant to the engine during engine cold start-up conditions; and

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

wherein the body has an upstream end, a downstream end, and a cylindrical body between the two ends, and wherein each of the plurality of through holes extend substantially axially through the upstream end, the cylindrical body and the downstream end;

wherein the plurality of through holes comprise a plurality of circular holes, each circular hole having a substantially constant diameter over the length of the hole, and wherein the diameter of each hole is smaller than the length of the respective hole.

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

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

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

5. 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.

6. 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.

7. A turbine engine comprising a lubrication system, the lubrication system having at least one lubrication flow restrictor, the at least one lubrication flow restrictor being connected in fluid flow communication with a source of lubricant and the engine at engine start-up as well as during normal engine operation, the at least one lubrication flow restrictor being positioned so that all the lubricant flowing from the source to the engine has to flow through the at least one lubricant flow restrictor, the at least one lubrication flow restrictor being disposed to provide a variable lubricant flow to the engine based on the lubricant temperature, the at least one lubrication flow restrictor comprising:

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

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

the plurality of through 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;

wherein the body has an upstream end, a downstream end, and a cylindrical body between the two ends, and wherein the plurality of through holes extend substantially axially through the upstream end, the cylindrical body and the downstream end;

wherein the plurality of through holes comprise a plurality of circular holes, each circular hole having a substantially constant diameter over the length of the hole, and wherein the diameter of each hole is smaller than the length of the respective hole.

8. The turbine engine of claim 7, wherein the plurality of 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.

9. The turbine engine of claim 7, wherein a diameter of each of the plurality of through holes is between approximately 0.020 inches and 0.050 inches.

10. The turbine engine of claim 7, wherein a length of the flow restrictor is between approximately 1 inch and 2 inches.

11. The turbine engine of claim 7, wherein the first predetermined reference temperature is approximately 100 degrees Fahrenheit and the second predetermined reference temperature is approximately 200 degrees Fahrenheit.

12. A method of operating a gas turbine engine in cold weather, the gas turbine engine having a lubrication system supplying a lubricant to the engine, the method comprising:

in response to a temperature of the engine being below a first predetermined temperature and the lubricant having a first viscosity, restricting a lubricant flow with a flow restrictor in a lubricant supply line of the lubrication system and preventing turbulence in the lubricant flow through the lubrication system, the flow restrictor being connected in fluid flow communication with a source of the lubricant and the engine at engine start-up and during normal engine operation; and

in response to a temperature of the engine being at or above a second predetermined temperature and the lubricant having a second viscosity higher than the first viscosity, allowing the lubricant to flow through the flow restrictor at a desired lubricant flow rate;

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 turbulence in the lubricant flow through the lubrication system at temperatures below the first predetermined 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 second predetermined temperature;

wherein the body has an upstream end, a downstream end, and a cylindrical body between the two ends, and wherein the plurality of through holes extend substantially axially through the upstream end, the cylindrical body and the downstream end;

wherein the plurality of through holes comprise a plurality of circular holes, each circular hole having a substantially constant diameter over the length of the hole, and wherein the diameter of each hole is smaller than the length of the respective hole.

13. The method of claim 12, wherein a diameter of each of the plurality of through 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.

14. The method of claim 12, wherein the first predetermined temperature is approximately 100 degrees Fahrenheit and the second predetermined temperature is approximately 200 degrees Fahrenheit.