Horizontal stabiliser actuator with freeplay detecting features and method thereof

Patent metadata

Field	Value
Publication number	US-11035445-B2
Application number	US-201415532184-A
Country	US
Kind code	B2
Filing date	Dec 1, 2014
Priority date	Dec 1, 2014
Publication date	Jun 15, 2021
Grant date	Jun 15, 2021

Abstract

A screw ( 20 ) assembly for an actuator ( 10 ) is described comprising: a screw ( 20 ); a nut ( 22 ) threaded on said screw ( 20 ), such that rotation of said screw ( 20 ) causes axial movement of said nut ( 22 ); a stop located at an end of said screw ( 20 ) and defining an axial limit of said nut ( 22 ); a first feature located on said nut ( 22 ); and a second feature located on said stop; wherein said first and second features are configured to cooperate with one another substantially upon contact of said nut ( 22 ) with said stop so as to indicate an amount of free movement between said nut ( 22 ) and said screw ( 20 ).

First claim

The invention claimed is:

1. A screw assembly for an actuator, comprising:
a screw;
a nut threaded on said screw, such that rotation of said screw causes axial movement of said nut;
a stop located at an end of said screw and defining an axial limit of said nut;
a first feature located on said nut; and
a second feature located on said stop;
wherein said first and second features cooperate with one another upon contact of said nut with said stop so as to indicate an amount of backlash that exists between said nut and said screw during movement of said nut towards said stop;
wherein said first and second features are positioned such that, upon contact of said nut with said stop, the relative positions of the first and second features is dependent on the amount of backlash to provide a measure of said backlash.

2. The screw assembly as claimed in claim 1 , wherein said first feature comprises a first mark and said second feature comprises a second mark.

3. The screw assembly as claimed in claim 2 , wherein, upon contact of said nut with said stop, said first and second features align with one another if the amount of backlash between said nut and said screw is within a predetermined limit, and do not align with one another if the amount of said backlash is outside of said predetermined limit.

4. The screw assembly as claimed in claim 1 , wherein a rotational position of said second feature upon contact of said nut with said stop is adjustable by adjusting the rotational position of the stop with respect to the nut.

5. The screw assembly as claimed in claim 1 , wherein one of said first feature and second feature comprises a first lug arranged to contact a cooperating lug of the other of said first feature and second feature to define an initial axial limit of said nut.

6. The screw assembly as claimed in claim 5 , wherein said one of said first feature and second feature comprises a second lug configured to contact said cooperating lug of the other of said first feature and second feature.

7. The screw assembly as claimed in claim 6 , wherein said contact between said second lug and said cooperating lug of the other of said first feature and second feature limits axial movement of said nut.

8. The screw assembly as claimed in claim 7 , wherein said first and second lugs are located at different circumferential positions on said one of said nut and stop.

9. The screw assembly as claimed in claim 7 , wherein said first and second lugs are located at different circumferential positions on said one of said nut and stop, and the rotational movement of at least one of said nut and said stop is limited such that a clearance is provided between said second lug and said cooperating lug on the other of said nut and stop in the final turn of said screw.

10. The screw assembly as claimed in claim 9 , wherein said first lug contacts said cooperating lug on the other of said nut and stop if the amount of said backlash is within a clearance limit, and said second lug contacts said cooperating lug on the other of said nut and stop if the amount said backlash is outside of said clearance limit.

11. The screw assembly as claimed in claim 6 , wherein
said nut comprises said first and second lugs, and said first and second lugs include said first feature, and said cooperating lug on said stop includes said second feature.

12. The screw assembly as claimed in claim 6 , wherein said stop comprises said first and second lugs, and said first and second lugs include said second feature, and said cooperating lug on said stop includes said first feature.

13. An actuator for an aircraft comprising a screw assembly as claimed in claim 1 .

14. The screw assembly as claimed in claim 1 , wherein said first feature comprises a first tactile feature and said second feature comprises a second tactile feature.

Assignees

• Goodrich Actuation Systems Sas

Inventors

• Moulon Thomas
• Medina Raphaël

Classifications

• G01M13/02

  Gearings; Transmission mechanisms · CPC title

• B64C13/28

  mechanical · CPC title

• F16H25/00 Primary

  Gearings comprising primarily only cams, cam-followers and screw-and-nut mechanisms · CPC title

• B64C5/16

  about spanwise axes · CPC title

• B64C5/02

  Tailplanes · CPC title