Electromechanical actuator

Patent metadata

Field	Value
Publication number	US-12228197-B2
Application number	US-202217993203-A
Country	US
Kind code	B2
Filing date	Nov 23, 2022
Priority date	Nov 25, 2021
Publication date	Feb 18, 2025
Grant date	Feb 18, 2025

Abstract

An electromechanical actuator (EMA) includes a plurality of modes and includes an electrical motor having a motor shaft extending along an axis (A) and that drives the shaft to rotate about the axis and a gear assembly mounted around, and in geared connection with the shaft, to rotate with the shaft. The EMA output is connected to the gear assembly such that rotation of the motor shaft causes rotation of the output via the gear assembly, the output rotating at a speed which is a predetermined fraction of the speed of rotation of the motor shaft based on the gear ratio of the gear assembly. The EMA also includes a synchroniser comprising a first conical portion connected to an end of the motor shaft, and a second conical portion connected to a ratchet. The synchroniser has an engaged position and a disengaged position.

First claim

The invention claimed is:

1. An electromechanical actuator (EMA) having a plurality of modes, comprising:
an electrical motor having a motor shaft extending along an axis of the EMA, the motor driving the shaft to rotate about the axis;
a gear assembly mounted around, and in geared connection with the motor shaft, to rotate with the motor shaft;
an EMA output connected to the gear assembly such that rotation of the motor shaft causes rotation of the EMA output via the gear assembly, the EMA output rotating at a speed which is a predetermined fraction of the speed of rotation of the motor shaft based on a gear ratio of the gear assembly;
a synchroniser comprising a first conical portion connected to an end of the motor shaft, and a second conical portion connected to a ratchet, wherein the synchroniser has an engaged position in which rotation of the first conical portion is transmitted to the second conical portion, and a disengaged position wherein the second conical portion is axially spaced apart from the first conical portion, along the axis, such that rotation of the first conical portion is not transmitted to the second conical portion;
a solenoid connected to the second conical portion, the solenoid configured to pull the second conical portion along the axis away from the first conical portion when the solenoid is energised;
wherein, in an active mode of the plurality of modes, the solenoid is energised and wherein rotation of the motor shaft in either direction of rotation drives the EMA output to rotate;
wherein in an anti-extension mode of the plurality of modes, the solenoid is not energised and the EMA output shaft is connected for rotation, via the synchroniser, to the ratchet; and
a cam feature arranged to rotate with the EMA output, the cam feature having a cam profile such that when the EMA output is in a positive stroke and the solenoid is de-energised, the ratchet is engaged, wherein the ratchet is arranged to prevent rotation of the EMA output in a predetermined direction of rotation; and when the EMA output is in a negative stroke, the ratchet is disengage so as to allow rotation of the EMA output in either direction of rotation.

2. An EMA as claimed in claim 1 , further comprising a connecting rod connected to the EMA output and configured to connect the EMA and a surface or part to be controlled by the EMA.

3. An EMA as claimed in claim 2 , wherein the connecting rod is provided with an eye for connection to the surface or part to be controlled.

4. An EMA as claimed in claim 1 , wherein the gear assembly comprises a first gear stage in geared connection with the motor shaft and a second gear stage in geared connection with the first gear stage and with the EMA output.

5. An EMA as claimed in claim 1 , further comprising a position sensor to determine a position of rotation of the EMA output.

6. An EMA as claimed in claim 1 , wherein the synchroniser comprises the ratchet and a clutch.

7. An EMA as claimed in claim 1 , further comprising:
a maintenance mode lever extending through the motor shaft, the motor shaft having a decoupling portion in the form of a gap along the motor shaft that is bridge by the maintenance mode lever, in a first mode and whereby the maintenance mode lever is moved from the decoupling portion, to disconnect the motor from the gear assembly in a maintenance mode of the plurality of modes.

8. An EMA as claimed in claim 1 , wherein the synchroniser includes a spring that biases the synchroniser out of engagement with the motor in the active mode and engages the synchroniser and the motor shaft in the anti-extension mode when the solenoid is de-energised.

9. An EMA as claimed in claim 1 , wherein the cam feature comprises a pawl and a contact structure, wherein in a positive stroke when the solenoid is de-energised, the pawl engages with the ratchet wheel and in a negative stroke when the solenoid is de-energised, the contact surface is pressed by the cam profile to remove the pawl from engagement with the ratchet wheel.

10. An EMA as claimed in claim 9 , wherein the contact structure comprises a piston and a spring.

11. An EMA as claimed in claim 1 , to drive a spoiler of an aircraft between an extended position, a neutral position and a droop position.

Assignees

• Goodrich Actuation Systems Sas

Inventors

• Potier Karl
• Boitard Corentin
• Serrand Maxime
• Medina Raphael

Classifications

• H02K7/116

  with gears · CPC title

• H02K7/108

  with friction clutches · CPC title

• B64C13/50

  using electrical energy · CPC title

• H02K11/21

  Devices for sensing speed or position, or actuated thereby (specially adapted for machines having non-mechanical commutating devices H02K29/06, H02K29/14) · CPC title

• F16H37/122 Primary

  for interconverting rotary motion and oscillating motion · CPC title