Self-locking no-back actuator

Patent metadata

Field	Value
Publication number	US-9863515-B2
Application number	US-201514661528-A
Country	US
Kind code	B2
Filing date	Mar 18, 2015
Priority date	Mar 18, 2014
Publication date	Jan 9, 2018
Grant date	Jan 9, 2018

Abstract

A self-locking actuator for moving a flight control surface of an aircraft and for self-locking in response to an external load applied to the actuator. The actuator includes a motor, a screw, and a drive gear that is rotatably driven by the motor to rotationally couple with the screw. A pawl support is coupled to and rotatable with the screw, and a swivel assembly is coupled to the pawl support for rotational movement with the screw and pivoting movement relative to the screw. The swivel assembly engages a cage that is fixed relative to the rotating screw, drive gear, and swivel assembly. Pivoting of the swivel assembly about a pivot axis engages the swivel assembly with the cage to positively lock with the cage and to prevent rotation of the screw in each of first and second opposite rotational directions of the screw about a rotational axis of the screw.

First claim

What is claimed is:

1. A self-locking actuator comprising:
an actuator housing;
a motor;
a screw supported in the housing for rotational movement;
a drive gear rotatably driven by the motor to rotationally couple the drive gear with the screw;
a cage fixed relative to the housing and having a plurality of circumferentially spaced apart cage slots;
a pawl support rotatable with the screw; and
a swivel assembly coupled to the pawl support for pivoting movement about a pivot axis parallel to a rotational axis of the drive gear, and having an arcuate arrangement of teeth in meshed engagement with the drive gear,
wherein the drive gear is disposed in a lost motion configuration with the screw such that the drive gear is driven to pivot the swivel assembly between engagement and disengagement with one of the plurality of cage slots prior to the drive gear being driven to engage the screw for rotational movement of the screw with the drive gear.

2. The self-locking actuator of claim 1 , wherein the swivel assembly pivots about the pivot axis to engage the swivel assembly with the cage to positively lock with the cage and to prevent rotation of the screw in each of first and second opposite rotational directions of the screw about the rotational axis.

3. The self-locking actuator of claim 1 , wherein the swivel assembly includes a pawl that is moved into and out of engagement with the one of the plurality of cage slots via pivoting of the swivel assembly.

4. The self-locking actuator of claim 3 , wherein the pawl is farther radially outwardly disposed than the arcuate arrangement of teeth relative to the rotational axis.

5. The self-locking actuator of claim 1 , wherein relative to a stationary drive gear, rotation of the screw in each of a clockwise and counterclockwise direction about the rotational axis drives the swivel assembly to pivot about the pivot axis to positively lock with the cage to prevent the rotation of the screw in its respective rotational direction.

6. The self-locking actuator of claim 1 , wherein the pivot axis is fixed relative to and rotates with the screw about the rotational axis such that the swivel assembly rotates with the screw.

7. The self-locking actuator of claim 1 , wherein the cage is translationally fixed relative to the screw.

8. The self-locking actuator of claim 1 , wherein the cage is circumferentially disposed about the screw, and wherein the cage slots open radially inwardly towards the rotational axis.

9. The self-locking actuator of claim 1 , wherein the drive gear is disposed about the screw.

10. A self-locking actuator comprising:
an actuator housing;
a screw supported in the housing for rotational movement;
a cage fixed relative to the housing;
a swivel plate for pivoting movement about a plate pivot axis parallel to a rotational axis of the screw, wherein the plate pivot axis is fixed relative to the screw and rotates with the screw about the rotational axis; and
a pawl coupled to the swivel plate for engagement with the cage, wherein the pawl is pivotally coupled to the swivel plate for pivoting movement about a pawl pivot axis parallel to the plate pivot axis, and wherein pivoting movement of the swivel plate moves the pawl between a first position engaged with the cage and a second position disengaged from the cage.

11. The self-locking actuator of claim 10 , further including a pair of pawls coupled to the swivel plate for engagement with the cage, each pawl coupled for pivoting movement about a respective pawl pivot axis parallel to the plate pivot axis.

12. The self-locking actuator of claim 10 , wherein the cage has a plurality of circumferentially spaced apart cage slots, and wherein the pawl pivots about the pawl pivot axis to engage and disengage the plurality of cage slots when the screw rotates in a first rotational direction about the rotational axis and the pawl positively locks with one of the plurality of cage slots when the screw rotates in a second rotational direction opposite the first rotational direction.

13. The self-locking actuator of claim 10 , wherein the pawl is biased towards the cage by a biasing element.

14. The self-locking actuator of claim 10 , wherein the pawl includes a ramp surface that cams outwardly and a catch surface that positively locks with the cage.

15. The self-locking actuator of claim 14 , wherein the cage has a plurality of circumferentially spaced apart cage slots, and wherein engagement of the ramp surface with a cage slot of the cage pivots the pawl about the pawl pivot axis while engagement of the catch surface with the cage slot or another cage slot of the cage positively locks the pawl with to the respective cage slot.

16. A self-locking actuator comprising:
an actuator housing;
a motor;
a screw supported in the housing and rotatable relative to the housing, the screw drivable by the motor;
a cage fixed relative to the housing; and
a swivel assembly coupled to the screw for rotation with the screw and pivotable about a pivot axis parallel to a rotational axis of the screw,
the swivel assembly pivotable about the pivot axis to prevent rotation of the screw in each of opposing first and second rotational directions of the screw about a rotational axis via engagement of the swivel assembly with the cage.

17. The self-locking actuator of claim 16 , wherein the motor is coupleable with swivel assembly to drive the swivel assembly, and wherein the swivel assembly is pivotable about the pivot axis in each of a first pivot direction or a second pivot direction opposite the first pivot direction via each of the motor or an external load external to the self-locking actuator rotating the screw.

18. The self-locking actuator of claim 16 , wherein the motor is coupleable with the screw to drive the screw, and wherein the swivel assembly is pivotable about the pivot axis to engage the cage prior to the motor coupling with the screw to drive rotation of the screw.

19. The self-locking actuator of claim 16 , wherein the swivel assembly and the cage are configured to positively lock with one another in response to a load external to the self-locking actuator urging the screw in either of the first or second rotational directions.

20. The self-locking actuator of claim 16 , wherein the swivel assembly is configured to pivot about the pivot axis to engage the cage while the screw is rotating via the motor and while the screw is not rotating via the motor.

Assignees

• Parker Hannifin Corp

Inventors

• Bernard Guy

Classifications

• F16H25/2454 Primary

  Brakes; Rotational locks · CPC title

• Y10T74/19637

  with brake means for gearing · CPC title

• B64C13/34

  using toothed gearing · CPC title

• B64C13/341

  having duplication or stand-by provisions · CPC title