Horizontal stabilizer trim actuator failure detection system and method using position sensors

Patent metadata

Field	Value
Publication number	US-10065728-B2
Application number	US-201213540422-A
Country	US
Kind code	B2
Filing date	Jul 2, 2012
Priority date	Jun 30, 2011
Publication date	Sep 4, 2018
Grant date	Sep 4, 2018

Abstract

An actuator assembly having a primary load path for tightly coupling an actuated surface to a reference structure and a secondary load path having a backlash portion for coupling the actuated surface to the reference structure with backlash, wherein the secondary load path is unloaded during an operative state of the primary load path and loaded during a failure state of the primary load path. The actuator assembly includes at least one sensor configured to sense the failure state of the primary load path when a relative displacement between a portion of the primary load path and a portion of the secondary load path exceeds a predetermined value or is within a predetermined range of values.

First claim

What is claimed is:

1. An actuator system comprising:
a rotatable ball screw arranged between an actuated surface and a reference structure;
a primary load path for tightly coupling the actuated surface to the reference structure, the primary load path having a first primary attachment structure connected between the ball screw and the actuated surface and a second primary attachment structure connected between the ball screw and the reference structure, the first primary attachment structure having a primary ball nut that is axially translatable along the ball screw;
a secondary load path for coupling the actuated surface to the reference structure with backlash, wherein the secondary load path is unloaded during an operative state of the primary load path and loaded during a failure state of the primary load path, the secondary load path having a first secondary attachment structure connected between the ball screw and the actuated surface and a second secondary attachment structure connected between the ball screw and the reference structure, the first secondary attachment structure having a secondary ball nut that is axially translatable along the ball screw; and
a first sensor configured to sense the failure state of the first primary attachment structure of the primary load path, the first sensor having a linear variable differential transducer that is coupled between the primary ball nut and the secondary ball nut and configured to provide an output that is indicative of a relative displacement between the primary ball nut and the secondary ball nut for comparison to a predetermined value for identifying the failure state of the first primary attachment structure.

2. The actuator system of claim 1 , wherein the second primary attachment structure includes at least one of a main housing, gimbal, primary attachment pins, or the ballscrew.

3. The actuator system of claim 1 , wherein the first primary attachment structure includes at least one of a primary nut gimbal housing, primary ball nut assembly, or trunnion.

4. The actuator system of claim 1 , wherein the secondary load path includes at least one locking mechanism, that is actuatable when the primary load path is in the failure state.

5. The actuator system of claim 4 , wherein the at least one locking mechanism includes a set of spring-loaded anti-backlash keys that are releasable in response to relative displacement between the primary ball nut and the secondary ball nut.

6. The actuator system of claim 1 , wherein the actuator system is located in an aircraft and the sensor is configured to sense the failure state of the primary load path when the aircraft is in flight.

7. The actuator system of claim 1 , wherein the second secondary attachment structure includes a tie rod and the actuator system includes a second LVDT sensor coupled to the tie rod that is configured to provide an output indicative of a relative displacement between the tie rod and the second primary attachment structure and compare the output to a predetermined value for identifying a failure state of the second primary attachment structure of the primary load path.

8. The actuator system of claim 1 further comprising a set of anti-backlash keys arranged between the ball screw and the first secondary attachment structure and a second set of anti-backlash keys arranged between the ball screw and the second secondary attachment structure, the set of anti-backlash keys being releasable in response to the relative displacement between the primary ball nut and the secondary ball nut.

9. The actuator system of claim 1 further comprising two first sensors that are coupled between the primary ball nut and the secondary ball nut.

10. The actuator system of claim 1 , wherein the first primary attachment structure and the first secondary attachment structure are independently attached to the actuated surface.

11. The actuator system of claim 1 , wherein the second primary attachment structure and the second secondary attachment structure are independently attached to the reference structure.

12. An actuator system comprising:
a rotatable ball screw arranged between an actuated surface and a reference structure;
a primary load path for tightly coupling the actuated surface to the reference structure, the primary load path having a first primary attachment structure connected between the ball screw and the actuated surface and a second primary attachment structure connected between the ball screw and the reference structure, the first primary attachment structure having a primary ball nut that is axially translatable along the ball screw;
a secondary load path for coupling the actuated surface to the reference structure with backlash, wherein the secondary load path is unloaded during an operative state of the primary load path and loaded during a failure state of the primary load path, the secondary load path having a first secondary attachment structure connected between the ball screw and the actuated surface and a second secondary attachment structure connected between the ball screw and the reference structure, the first secondary attachment structure having a secondary ball nut that is axially translatable along the screw, the second secondary attachment structure having a tie rod;
a first sensor coupled between the primary ball nut and the secondary ball nut that is configured to provide an output indicative of a relative displacement between the primary ball nut and the secondary ball nut and compare the output to a predetermined value for identifying a failure state of the upper primary attachment structure of the primary load path; and
a second sensor coupled to the tie rod that is configured to provide an output indicative of a relative displacement between the tie rod and the second primary attachment structure and compare the output to a predetermined value for identifying a failure state of the second primary attachment structure of the primary load path.

13. The actuator system of claim 12 , wherein each of the first sensor and the second sensor includes a linear variable differential transducer.

14. An actuator system comprising:
a rotatable ball screw arranged between an actuated surface and a reference structure;
a primary load path for tightly coupling the actuated surface to the reference structure, the primary load path having an upper primary attachment structure connected between the ball screw and the actuated surface and a lower primary attachment structure connected between the ball screw and the reference structure; and
a secondary load path for coupling the actuated surface to the reference structure with backlash during a failure state of the primary load path, the secondary load path having an upper secondary attachment structure connected between the ball screw and the actuated surface independently from the upper primary attachment structure, the secondary load path having a lower secondary attachment structure connected between the ball screw and the reference structure independently from the lower primary attachment structure.

15. The actuator system of claim 14 , wherein the actuator system includes four connection brackets, the upper primary attachment structure and the upper secondary attachment structure being connected to the actuated surface via a first and second bracket, the lower primary attachment structure and the lower secondary attachment structure being connected to the reference structure via a third and fourth bracket.

Assignees

• Cyrot Luc P
• Parker Hannifin Corp

Inventors

• Cyrot Luc P

Classifications

• B64C13/506

  overriding of personal controls; with automatic return to inoperative position · CPC title

• B64C13/343

  overriding of personal controls; with automatic return to inoperative position · CPC title

• B64C13/505

  having duplication or stand-by provisions · CPC title

• B64C13/341 Primary

  having duplication or stand-by provisions · CPC title

• B64C13/42

  having duplication or stand-by provisions · CPC title