Fixed end electronic detection of secondary load path engagement of aircraft flight control actuator

Patent metadata

Field	Value
Publication number	US-10974846-B2
Application number	US-201715834426-A
Country	US
Kind code	B2
Filing date	Dec 7, 2017
Priority date	Dec 9, 2016
Publication date	Apr 13, 2021
Grant date	Apr 13, 2021

Abstract

A detection system for detecting failure in a primary load path of a flight control actuator and annunciating engagement in a secondary load path of the flight control actuator. The failure in the primary load path causes axial movement in a secondary rod of the secondary load path. The detection system includes a secondary mounting assembly that guides axial movement of the secondary rod; and a sensor that electronically detects relative axial displacement between the secondary rod and the secondary mounting assembly upon a primary load path failure and annunciates transition to engagement in the secondary load path.

First claim

What is claimed is:

1. A detection system for detecting failure in a primary load path of a flight control actuator and annunciating transition to engagement in a secondary load path of the flight control actuator, wherein failure in the primary load path causes axial movement in a secondary rod of the secondary load path, the detection system comprising:
a secondary mounting assembly that guides axial movement of the secondary rod; and
a sensor that electronically detects relative axial displacement between the secondary rod and the secondary mounting assembly upon a primary load path failure and annunciates transition to engagement in the secondary load path;
a spherical joint that couples the secondary rod to the secondary mounting assembly to allow articulation of the secondary rod relative to the secondary mounting assembly;
wherein the spherical joint includes a spherical race that is slidable axially with the secondary rod in an axially extending cavity defined by the secondary mounting assembly;
a wall and a retainer at axially opposite ends of the cavity that restrict the amount of axial movement of the spherical race within the cavity;
wherein the spherical race includes a compression indicating target, a neutral target, and a tensing indicating target that move with the spherical race and that are detectable by the sensor to indicate respective axial positions of the spherical race relative to the secondary mounting assembly.

2. The detection system of claim 1 , wherein the sensor is a bi-directional sensor that upon a primary load path failure electronically detects either a tensile load in the secondary rod at a first axial end of the secondary mounting assembly or a compressive load in the secondary rod at a second end of the secondary mounting assembly, and annunciates transition to engagement in the secondary load path.

3. The detection system of claim 1 , wherein the spherical race and the secondary mounting assembly are axially keyed to prevent rotation of the spherical race within the cavity of the secondary mounting assembly.

4. The detection system of claim 1 , wherein upon primary load path failure, the secondary rod along with the secondary race translates axially until the spherical race bottoms on the wall to thereby engage the secondary rod in compression, and wherein the sensor detects the compression indicating target to annunciate that the primary load path has failed and transition to engagement in the secondary load path.

5. The detection system of claim 1 , wherein upon primary load path failure, the secondary rod along with the secondary race translates axially until the spherical race bottoms on the retainer to thereby engage the secondary rod in tension, and wherein the sensor detects the tension indicating target to annunciate that the primary load path has failed and transition to engagement in the secondary load path.

6. The detection system of claim 1 , wherein the spherical race includes one or more targets that move with the spherical race and that are detectable by the sensor to indicate respective axial positions of the spherical race relative to the secondary mounting assembly.

7. The detection system of claim 6 , wherein the targets include a first target that the sensor detects as the spherical race being in a neutral position relative to the secondary mounting assembly to indicate that primary load path is intact.

8. The detection system of claim 1 , wherein the retainer is axially adjustable to increase or decrease the axial span of the cavity to allow for respectively greater or less axial movement of the spherical race within the cavity.

9. The detection system of claim 1 , wherein the sensor is configured to annunciate engagement in the secondary load path before the secondary rod is loaded in tension or compression.

10. A detection system for detecting failure in a primary load path of a light control actuator and annunciating transition to engagement in a secondary load path of the flight control actuator, wherein failure in the primary load path causes axial movement in a secondary rod of the secondary load path, the detection system comprising:
a secondary mounting assembly that guides axial movement of the secondary rod; and
a sensor that electronically detects relative axial displacement between the secondary rod and the secondary mounting assembly upon a primary load path failure and annunciates transition to engagement in the secondary load path;
a spherical joint that couples the secondary rod to the secondary mounting assembly to allow articulation of the secondary rod relative to the secondary mounting assembly;
wherein the spherical joint includes a spherical race that is slidable axially with the secondary rod in an axially extending cavity defined by the secondary mounting assembly;
wherein the spherical race includes one or more targets that move with the spherical race and that are detectable by the sensor to indicate respective axial positions of the spherical race relative to the secondary mounting assembly;
wherein the targets include second and third targets, the second target of which the sensor detects the spherical race as being displaced relative to the secondary mounting assembly in a second direction to annunciate the primary load path has failed and transition to engagement in the secondary load path, and the third target of which the sensor detects the spherical race as being displaced relative to the secondary mounting assembly in a third direction to annunciate the primary load path has failed and transition to engagement in the secondary load path, the third direction being opposite that of the second direction.

11. The detection system of claim 10 , wherein the second target indicates a secondary load path engagement in which the secondary rod is loaded in compression and the third target indicates a secondary load path engagement in which the secondary rod is loaded in tension.

12. A flight control actuator, comprising:
a primary load path;
a secondary load path including a secondary rod, wherein failure in the primary load path causes axial movement in the secondary rod of the secondary load path; and
a detection system including:
a secondary mounting assembly that guides axial movement of the secondary rod; and

a sensor that electronically detects relative axial displacement between the secondary rod and the secondary mounting assembly upon a primary load path failure and annunciates transition to engagement in the secondary load path;
further comprising first, second, and third targets that move axially with axial movement of the secondary rod relative to the secondary mounting assembly and that are detectable by the sensor to indicate respective neutral, compressive, and tensile axial positions of the secondary rod.

13. The flight control actuator of claim 12 , wherein the secondary mounting assembly is mounted to an aircraft structure by fasteners and wherein, when the primary load path is intact and the fasteners are removed, the secondary mounting assembly is slidable axially relative to the secondary rod.

14. The flight control actuator of claim 13 , wherein when the secondary rod is in the neutral axial position the first target overlaps with the sensor to allow for verification of detection of the first target by the sensor.

15. The flight control actuator of claim 13 , wherein the secondary mounting assembly is slidable axially relative to the secondary rod in a direction toward a base of the aircraft structure to overlap the second target with the sensor to allow for verification of detection of the second t

Assignees

• Parker Hannifin Corp

Inventors

• Hale Brian Curtis
• Charafeddine Abbas M

Classifications

• F16H25/205 Primary

  comprising alternate power paths, e.g. for fail safe back-up · CPC title

• F16C17/24

  with devices affected by abnormal or undesired positions, e.g. for preventing overheating, for safety · CPC title

• F16C11/0614

  the female part of the joint being open on two sides · CPC title

• B64C13/341

  having duplication or stand-by provisions · CPC title

• B64D45/00

  Aircraft indicators or protectors not otherwise provided for · CPC title