No-back device for flight control surface actuator

Patent metadata

Field	Value
Publication number	US-10520070-B2
Application number	US-201615093793-A
Country	US
Kind code	B2
Filing date	Apr 8, 2016
Priority date	Apr 9, 2015
Publication date	Dec 31, 2019
Grant date	Dec 31, 2019

Abstract

Disclosed is an actuator for varying the position of a flight control surface on an aircraft, wherein the actuator comprises a no-back device including a backlash adjuster, which is arranged to select a plurality of different backlash lengths. The backlash adjuster may be a nut which moves relative a housing of the no-back device by rotating the nut. Also disclosed is a method of adjusting the backlash (B) in a flight control surface actuator, by moving the backlash adjuster axially to adjust the backlash (B) to a desired value.

First claim

The invention claimed is:

1. An actuator for varying the position of a flight control surface on an aircraft, the actuator comprising:
a ballscrew, having a screw; and
a no-back device positioned around an axial section of the screw and configured to prevent back-driving of the screw, and to allow a limited backlash (B), the backlash (B) being the possible amount of axial movement of the screw relative to the no-back device, wherein the no-back device comprises a backlash adjuster arranged to select a plurality of different backlash lengths.

2. The actuator of claim 1 , wherein the no-back device is configured such that moving the backlash adjuster axially relative to the screw adjusts the backlash (B).

3. The actuator of claim 2 , wherein the backlash adjuster comprises a threaded member, such as an adjustment nut, and moving the threaded member axially relative to the screw comprises rotating the threaded member relative to the screw.

4. The actuator of claim 1 , wherein the no-back device comprises:
a first brake assembly for preventing rotation of the screw in one direction;
a second brake assembly for preventing rotation of the screw in a second direction; and
a radially extending flange operatively connected to the screw for rotation therewith, wherein the flange is positioned between the first and second brake assemblies.

5. The actuator of claim 4 , wherein the no-back device further comprises a housing at least partially surrounding a portion of the screw, and the housing has a first end having an opening for receiving the backlash adjuster and a second opposed end, the first brake assembly is positioned between the flange and the backlash adjuster, the second brake assembly is positioned between the flange and the second end and moving the backlash adjuster axially relative to the screw causes the separation between the backlash adjuster and the second end to be varied accordingly.

6. The actuator of claim 4 , wherein the no-back device comprises one or more biasing members for urging the first and second brake assemblies towards the flange.

7. The actuator of claim 6 , wherein the one or more biasing members comprise one or more springs, and moving the backlash adjuster causes the compression on the one or more springs to be varied.

8. The actuator of any of claim 4 , wherein the first and second brake assemblies each comprise a friction plate for engagement with the flange and a ratchet wheel having one or more pawls associated therewith.

9. The actuator of claim 1 , wherein the backlash adjuster is arranged to select at least three, at least five or at least ten different backlash lengths.

10. The actuator of claim 1 , further comprising a lock for retaining the backlash adjuster in a chosen position.

11. The actuator of claim 10 , wherein the lock comprises one or more fastening members and a plate having one or more first apertures for receiving the one or more fastening members, and the backlash adjuster comprises one or more second apertures for receiving the one or more fastening members.

12. A method of adjusting the backlash (B) in a flight control surface actuator having the features of claim 1 , the method comprising moving the backlash adjuster axially relative to the screw to adjust the backlash (B) to a desired value.

13. The method claim 12 , wherein moving the backlash adjuster axially comprises rotating the backlash adjuster relative to the screw.

14. The method of claim 12 , wherein the no-back device comprises a lock having a plate and one or more fastening members and the method further comprises passing the one or more fastening members through one or more first apertures in the plate and into one or more second apertures in the backlash adjuster to secure the backlash adjuster axially.

15. The method of claim 14 , wherein the plate is configured such that, prior to inserting the fastening members, the backlash adjuster can be moved axially with the plate in place on the no-back device.

Assignees

• Goodrich Actuation Systems Sas

Inventors

• Turpin Pierre M
• Moulon Thomas M

Classifications

• B64C13/28

  mechanical · CPC title

• F16H2035/005

  Gearings or mechanisms preventing back-driving · CPC title

• F16H25/2454 Primary

  Brakes; Rotational locks · CPC title