Electromechanically actuated brake with supplemental back drive

Patent metadata

Field	Value
Publication number	US-9527584-B2
Application number	US-201514598388-A
Country	US
Kind code	B2
Filing date	Jan 16, 2015
Priority date	Jan 16, 2015
Publication date	Dec 27, 2016
Grant date	Dec 27, 2016

Abstract

An electromechanical actuator in an aircraft brake system may include a stationary body, an actuator drive unit in an actuator drive unit housing, a ball screw coupled to the actuator drive unit, and a ball nut piston coupled to the ball screw. A supplemental back drive mechanism may be disposed between the ball screw and the stationary body. The supplemental back drive mechanism may comprise a spring and a clutch. The spring may store back drive potential energy when the electromechanical actuator is actuated to drive the ball nut piston forward, and may supply back drive energy to the retract the ball nut piston.

First claim

What is claimed is:

1. An electromechanical actuator (“EMA”) comprising:
a stationary body;
an actuator drive unit (“ADU”) housing;
an ADU housed within and operably coupled to the ADU housing;
a ball screw operably coupled to the ADU;
a ball nut piston operably coupled to the ball screw;
a back drive mechanism comprising a torsion spring disposed between the stationary body and the ball screw, wherein the torsion spring comprises a stationary end and a rotating end configured to rotate about the ADU housing and wherein the stationary end is at least one of directly or indirectly coupled to the stationary body and the rotating end is coupled to the ball screw; and
a clutch attached to the stationary end of the torsion spring, wherein the clutch is configured to control a back drive potential energy stored in the torsion spring.

2. The EMA of claim 1 , wherein a forward rotation of the ball screw is produced in response to actuation of the EMA, wherein the forward rotation of the ball screw produces a forward rotation of the rotating end of the torsion spring, and wherein the back drive potential energy is accumulated in the torsion spring in response to the forward rotation of the rotating end of the torsion spring.

3. The EMA of claim 2 , wherein the back drive potential energy is suitable to produce a reverse rotation of the ball screw, and wherein the ball nut piston is retracted in response to the reverse rotation of the ball screw.

4. The EMA of claim 3 , wherein the ball nut piston is retracted without application of a reverse electromechanical drive.

5. The EMA of claim 1 , wherein the clutch is at least one of a mechanical slip clutch or an electronic clutch.

6. The EMA of claim 1 , wherein the clutch is configured to control loading of the torsion spring and thereby is configured to control initiation of storage of the back drive potential energy in the torsion spring.

7. A method comprising:
applying a forward drive to a ball screw in response to a first condition to produce a forward rotation of the ball screw;
increasing an angular deflection of a torsion spring by the forward rotation of the ball screw to produce a back drive potential energy, wherein the torsion spring is attached to a clutch;
storing the back drive potential energy in the torsion spring; and
controlling the back drive potential energy via the clutch.

8. The method of claim 7 , further comprising releasing the back drive potential energy in response to a second condition.

9. The method of claim 8 , wherein the releasing the back drive potential energy produces a reverse rotation of the ball screw, and wherein the reverse rotation of the ball screw is translated to a retraction of a ball nut piston.

10. The method of claim 9 , wherein the ball nut piston is translated to a running clearance position.

11. The method of claim 10 , wherein the ball nut piston is translated without application of a reverse electromechanical drive.

12. The method of claim 7 , further comprising a puck coupled to a ball nut, wherein increasing the angular deflection of the torsion spring is subsequent to the puck reaching a zero clearance position with respect to a brake stack of an aircraft.

Assignees

• Goodrich Corp

Inventors

• Rehfus Kevin
• Drennen David

Classifications

• B60T13/741 Primary

  acting on an ultimate actuator · CPC title

• F16D2121/24

  using motors · CPC title

• B64C25/44 Primary

  Actuating mechanisms · CPC title

• F16D2127/02

  Release mechanisms · CPC title

• F16D2125/36

  Helical cams, Ball-rotating ramps · CPC title