Controlling lubricant flow in epicyclic gearbox

Patent metadata

Field	Value
Publication number	US-2016208651-A1
Application number	US-201415022688-A
Country	US
Kind code	A1
Filing date	Sep 19, 2014
Priority date	Sep 26, 2013
Publication date	Jul 21, 2016
Grant date	—

Abstract

A disclosed lubrication system for a turbofan engine includes a pump for driving lubricant through a lubrication circuit, at least one sensor generating a signal indicative of an engine operating condition and at least one valve for controlling a flow of lubricant through the lubrication circuit. A controller controls operation of the valve to vary the flow of lubricant based on the engine operating condition to maintain lubricant flow within predefined operating limits.

First claim

What is claimed is:

1 . A lubrication system for a turbofan engine comprising:
a pump for driving lubricant through a lubrication circuit; at least one sensor for generating a signal indicative of an engine operating condition; at least one valve for controlling a flow of lubricant through the lubrication circuit; and a controller for controlling operation of the valve to vary the flow of lubricant based on the engine operating condition.

2 . The lubrication system as recited in claim 1 , wherein the engine operating condition comprises horsepower generated by at least one turbine section.

3 . The lubrication system as recited in claim 2 , wherein the controller is configured to vary the flow of lubricant to a speed reduction system.

4 . The lubrication system as recited in claim 1 , wherein the at least one sensor comprises a first sensor for generating a signal indicative of a pressure within a compressor section, a second sensor for generating a signal indicative of rotor speed, and a third sensor for generating a signal indicative of altitude.

5 . The lubrication system as recited in claim 4 , wherein the compressor section comprises a high-pressure compressor and a low-pressure compressor and the first sensor generates a signal indicative of a pressure proximate an exit of the high-pressure compressor.

6 . The lubrication system as recited in claim 1 , wherein the controller is configured to control the valve to vary the flow of lubricant to a speed change device for engine conditions between Sea Level Takeoff Thrust and a cruise condition.

7 . The lubrication system as recited in claim 5 , wherein the controller is configured to control the valve to vary a lubricant flow parameter of pounds of lubricant flow/hour/horsepower produced by a turbine section driving a speed change device in response to an engine power setting.

8 . A method of operating a turbofan engine comprising;
determining a plurality of desired lubricant flow rates to a speed change device for a corresponding plurality of engine power settings; generating a signal indicative of an engine power setting; and varying lubricant flow to the speed change device based on the determined plurality of desired lubricant flow rates.

9 . The method as recited in claim 8 , wherein the plurality of desired lubricant flow rates comprises a flow parameter of pounds lubricant/hour/horsepower applied to the speed change device.

10 . The method as recited in claim 8 , wherein generating a signal indicative of an engine power setting comprises sensing at least one of a pressure within a compressor exit section, a speed of a shaft, and an altitude.

11 . The method as recited in claim 10 , wherein the compressor section includes a high-pressure compressor and a low-pressure compressor and the pressure is sensed at an exit of the high-pressure compressor.

12 . The method as recited in claim 10 , including determining horsepower transmitted to the speed change device.

13 . The method as recited in claim 8 , including controlling a valve to vary lubricant flow to the speed change device.

14 . The method as recited in claim 8 , wherein generating a signal indicative of an engine power setting comprises sensing at least two of a pressure within a compressor exit section, a speed of a shaft, and an altitude.

15 . A turbofan engine comprising:
a fan including a plurality of fan blades rotatable about an axis; a turbine section; a geared architecture configured to be driven by the turbine section for rotating the fan about the axis; a lubrication system for supplying a flow of lubricant to the geared architecture; at least one sensor for generating a signal indicative of an engine operating condition; at least one valve for controlling a flow of lubricant through the lubrication circuit; and a controller for controlling operation of the valve to vary the flow of lubricant to the geared architecture based on the engine operating condition.

16 . The turbofan engine as recited in claim 15 , wherein the engine operating condition comprises horsepower generated by the turbine section for driving the geared architecture.

17 . The turbofan engine as recited in claim 15 , wherein the at least one sensor comprises a first sensor for generating a signal indicative of a pressure within a compressor exit section, a second sensor for generating a signal indicative of rotor speed, and a third sensor for generating a signal indicative of altitude.

18 . The turbofan engine as recited in claim 17 , wherein the compressor section comprises a high-pressure compressor and a low-pressure compressor and the first sensor is configured to generate a signal indicative of a pressure proximate an exit of the high-pressure compressor.

19 . The turbofan engine as recited in claim 18 , wherein the controller is configured to control the valve to vary the flow of lubricant to the geared architecture for engine operating conditions between Sea Level Takeoff Thrust and a cruise condition.

20 . The turbofan engine as recited in claim 19 , wherein the controller is configured to control the valve to vary a lubricant flow parameter of pounds of lubricant flow/hour/horsepower produced by the turbine section driving the geared architecture based on the engine operating condition.

Assignees

• United Technologies Corp

Inventors

• Dolman Paul H
• Mccune Michael E

Classifications

• F05D2260/98

  Lubrication · CPC title

• F01M2001/123

  using two or more pumps · CPC title

• F01M2001/126

  Dry-sumps · CPC title

• F16H57/0475

  Engine and gearing, i.e. joint lubrication or cooling or heating thereof · CPC title

• F05D2220/32

  in gas turbines · CPC title