Metering of oil flow to engine propeller

Patent metadata

Field	Value
Publication number	US-10072796-B2
Application number	US-201615209215-A
Country	US
Kind code	B2
Filing date	Jul 13, 2016
Priority date	Jul 13, 2016
Publication date	Sep 11, 2018
Grant date	Sep 11, 2018

Abstract

There is described herein methods and system for correcting steady state errors in propeller speed by calculating a leakage flow rate as a function of engine and propeller parameters.

First claim

The invention claimed is:

1. A method for metering oil flow to a propeller of an engine, the method comprising:
receiving, at a propeller control system, a requested propeller speed and an actual propeller speed;
generating an oil flow request based on a difference between the requested propeller speed and the actual propeller speed;
determining a leakage flow rate as a function of parameters of the engine and the propeller and generating a leakage compensation component;
combining the leakage compensation component with the oil flow request to obtain a compensated oil flow request; and
outputting, by the propeller control system, the compensated oil flow request to an oil metering unit of the propeller to meter the oil flow to the propeller.

2. The method of claim 1 , wherein determining the leakage flow rate as a function of parameters of the engine comprises estimating the leakage flow rate from a laminar flow model.

3. The method of claim 1 , wherein determining the leakage flow rate comprises using engine and propeller environmental parameters and engine geometric parameters to calculate the leakage flow rate.

4. The method of claim 3 , wherein the engine and propeller environmental parameters comprise temperature and pressure.

5. The method of claim 3 , wherein the engine geometric parameters comprise shaft propeller geometry.

6. The method of claim 1 , further comprising biasing the leakage flow rate towards a current value of the compensated oil flow request using at least one bias value.

7. The method of claim 6 , wherein the at least one bias value is updated when the engine is in a maintenance mode and the propeller is in a steady state.

8. The method of claim 6 , wherein the at least one bias value is updated upon at least one of engine start-up and engine reconfiguration.

9. The method of claim 6 , wherein the at least one bias value is updated when the engine is set to take-off power.

10. A system for metering oil flow to a propeller of an engine, the system comprising:
a processing unit; and
a non-transitory memory communicatively coupled to the processing unit and comprising computer-readable program instructions executable by the processing unit for:
receiving a requested propeller speed and an actual propeller speed;
generating an oil flow request based on a difference between the requested propeller speed and the actual propeller speed;
determining a leakage flow rate as a function of parameters of the engine and the propeller and generating a leakage compensation component;
combining the leakage compensation component with the oil flow request to obtain a compensated oil flow request; and
outputting the compensated oil flow request to an oil metering unit of the propeller.

11. The system of claim 10 , wherein determining the leakage flow rate as a function of parameters of the engine comprises estimating the leakage flow rate from a laminar flow model.

12. The system of claim 10 , wherein determining the leakage flow rate comprises using engine and propeller environmental parameters and engine geometric parameters to calculate the leakage flow rate.

13. The system of claim 12 , wherein the engine and propeller environmental parameters comprise temperature and pressure.

14. The system of claim 12 , wherein the engine geometric parameters comprise shaft propeller geometry.

15. The system of claim 10 , wherein the program instructions are further executable for biasing the leakage flow rate towards a current value of the compensated oil flow request using at least one bias value.

16. The system of claim 15 , wherein the at least one bias value is updated when the engine is in a maintenance mode and in a steady state.

17. The system of claim 15 , wherein the at least one bias value is updated upon at least one of engine start-up and engine reconfiguration.

18. The system of claim 15 , wherein the at least one bias value is updated when the engine is set to takeoff power.

19. A system for metering oil flow to a propeller of an engine, the system comprising:
means for receiving a requested propeller speed and an actual propeller speed;
means for generating an oil flow request based on a difference between the requested propeller speed and the actual propeller speed;
means for determining a leakage flow rate as a function of parameters of the engine and the propeller and generating a leakage compensation component;
means for combining the leakage compensation component with the oil flow request to obtain a compensated oil flow request; and
means for outputting the compensated oil flow request to an oil metering unit of the propeller.

20. The system of claim 19 , further comprising means for biasing the leakage flow rate towards a current value of the compensated oil flow request using at least one bias value.

Assignees

• Pratt & Whitney Canada

Inventors

• Pedrami Reza
• Jarvo James Robert
• Renaud Benjamin

Classifications

• F16N2250/08

  Temperature · CPC title

• B64C11/00

  Propellers, e.g. of ducted type; Features common to propellers and rotors for rotorcraft · CPC title

• F16N2210/08

  Aircraft · CPC title

• F16N2230/00

  Signal processing · CPC title

• F16N29/02 Primary

  for influencing the supply of lubricant · CPC title