Systems and methods for detecting chips in fluid of aircraft engine

Patent metadata

Field	Value
Publication number	US-10197488-B2
Application number	US-201715623460-A
Country	US
Kind code	B2
Filing date	Jun 15, 2017
Priority date	Jun 15, 2017
Publication date	Feb 5, 2019
Grant date	Feb 5, 2019

Abstract

There is described herein methods and systems for detecting electrically-conductive particles (chips) in fluid of an aircraft engine. The method comprises applying a plurality of excitation currents I i across a magnetic chip detector mounted to a fluid system of the aircraft engine and measuring a corresponding plurality of resistance values R i , where i is an integer that varies from 1 to N, and where N corresponds to a number of different excitation currents applied across the magnetic chip detector. The method further comprises determining a chip size indication Y from the plurality of resistance values R i , and detecting a chip in the fluid when the chip size indication Y exceeds a threshold Y thres .

First claim

The invention claimed is:

1. A method for detecting electrically-conductive particles (chips) in fluid of an aircraft engine, the method comprising:
applying a plurality of excitation currents I i across a magnetic chip detector mounted to a fluid system of the aircraft engine and measuring a corresponding plurality of resistance values R i , where i is an integer that varies from 1 to N, and where N corresponds to a number of different excitation currents applied across the magnetic chip detector;
determining a chip size indication Y from the plurality of resistance values R i ; and
detecting a chip in the fluid when the chip size indication Y exceeds a threshold Y thres .

2. The method of claim 1 , wherein determining the chip size indication Y comprises summing the plurality of resistance values R i together to obtain the chip size indication Y.

3. The method of claim 2 , wherein summing the plurality of resistance values R i together comprises applying weighting factors X i to the plurality of resistance values R i prior to summing the resistance values R i .

4. The method of claim 3 , wherein the weighting factors X i are different for each one of the resistance values R i .

5. The method of claim 3 , wherein at least one of the weighting factors X i is null.

6. The method of claim 3 , further comprising receiving an input and selecting the weighting factors X i based on the input.

7. The method of claim 6 , wherein the input depends on at least one of a type of the aircraft engine, an oil type, an oil flow rate, a rotational speed of the aircraft engine, a capture rate of the magnetic chip detector, a target chip size for detection.

8. The method of claim 1 , wherein applying the plurality of excitation currents I i comprises varying a continuous excitation current successively across the plurality of excitation currents I i .

9. The method of claim 8 , wherein varying the continuous excitation current successively across the plurality of excitation currents I i comprises scanning a range of excitation currents at specific intervals.

10. The method of claim 9 , wherein applying the plurality of excitation currents I i comprises repeating said varying a continuous excitation current for a plurality of frequencies.

11. A detection system for an aircraft engine, for electrically-conductive particles (chips), the detection 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:
causing a plurality of excitation currents I i to be applied across a magnetic chip detector mounted to a fluid system of the aircraft engine and receiving a corresponding plurality of resistance values R i , where i is an integer that varies from 1 to N, and where N corresponds to a number of different excitation currents applied across the magnetic chip detector;
determining a chip size indication Y from the plurality of resistance values R i ; and
detecting a chip in the fluid when the chip size indication Y exceeds a threshold Y thres .

12. The chip detection system of claim 11 , wherein determining the chip size indication Y comprises summing the plurality of resistance values R i together to obtain the chip size indication Y.

13. The chip detection system of claim 12 , wherein summing the plurality of resistance values R i together comprises applying weighting factors X i to the plurality of resistance values R i prior to summing the resistance values R i .

14. The chip detection system of claim 13 , wherein the weighting factors X i are different for each one of the resistance values R i .

15. The chip detection system of claim 13 , wherein at least one of the weighting factors X i is null.

16. The chip detection system of claim 13 , wherein the program instructions are further executable for receiving an input and selecting the weighting factors X i based on the input.

17. The chip detection system of claim 11 , wherein causing the plurality of excitation currents I i to be applied comprises varying a continuous excitation current successively across the plurality of excitation currents I i .

18. The chip detection system of claim 17 , wherein varying the continuous excitation current successively across the plurality of excitation currents I i comprises scanning a range of excitation currents at specific intervals.

19. The chip detection system of claim 18 , wherein causing the plurality of excitation currents I i to be applied comprises repeating said varying a continuous excitation current for a plurality of frequencies.

20. The chip detection system of claim 11 , further comprising the magnetic chip detector mounted to the fluid system of the aircraft engine and a resistance measurement circuit for applying the plurality of excitation currents I i across the magnetic chip detector and measuring the corresponding plurality of resistance values R i .

Assignees

• Pratt & Whitney Canada

Inventors

• Youssef Michael

Classifications

• G01V3/102

  by measuring amplitude · CPC title

• F01M11/10

  Indicating devices; Other safety devices · CPC title

• G01N27/74

  of fluids (G01N24/00 takes precedence) · CPC title

• G01N15/0656 Primary

  using electric, e.g. electrostatic methods or magnetic methods (by investigating individual particles G01N15/1031, G01N15/12) · CPC title

• G01N33/2858

  Metal particles · CPC title