Rotational inerter and method for damping an actuator

Patent metadata

Field	Value
Publication number	US-10088006-B2
Application number	US-201615159706-A
Country	US
Kind code	B2
Filing date	May 19, 2016
Priority date	May 19, 2016
Publication date	Oct 2, 2018
Grant date	Oct 2, 2018

Abstract

An apparatus for damping an actuator includes an inerter. The inerter includes a first terminal and a second terminal movable relative to one another along an inerter axis and configured to be mutually exclusively coupled to a support structure and a movable device actuated by an actuator. The inerter further includes a rod coupled to and movable with the first terminal and a threaded shaft coupled to and movable with the second terminal. The inerter further includes a flywheel having a flywheel annulus coupled to one of the rod and the threaded shaft. The flywheel is configured to rotate in proportion to axial acceleration of the rod relative to the threaded shaft in correspondence with actuation of the movable device by the actuator.

First claim

What is claimed is:

1. An apparatus for damping an actuator, comprising: an inerter, including: a first terminal and a second terminal movable relative to one another along an inerter axis mutually exclusively couplable to a support structure and a movable device actuated by the actuator; a rod coupled to and movable with the first terminal; a threaded shaft coupled to and movable with the second terminal; a flywheel having a flywheel annulus coupled to at least one of the rod and the threaded shaft; and the flywheel rotatable in proportion to axial acceleration of the rod relative to the threaded shaft in correspondence with actuation of the movable device by the actuator.

2. The apparatus of claim 1 , wherein:
the threaded shaft is non-rotatably coupled to the second terminal; and
the flywheel is rotatably coupled to the rod and threadably engaged to the threaded shaft in a manner such that axial acceleration of the rod relative to the threaded shaft causes proportional rotational acceleration of the flywheel.

3. The apparatus of claim 1 , wherein:
the inerter is integrated into a linear electro-mechanical actuator.

4. The apparatus of claim 1 , wherein: the actuator is a linear actuator having a rod end and a cap end axially movable relative to one another during actuation of the movable device, the rod end and cap end mutually exclusively coupled to one of the support structure and the movable device.

5. The apparatus of claim 4 , wherein: the inerter is integrated into the actuator, the actuator is a hydraulic actuator having a piston coupled to an end of the rod and axially slidable within a housing; one of the rod end and the cap end of the actuator functioning as the first terminal of the inerter, a remaining one of the rod end and the cap end functioning as the second terminal; and the flywheel is rotatably coupled to one of the piston and the rod at the flywheel annulus, the flywheel threadably coupled to the threaded shaft to rotationally accelerate in proportion to axial acceleration of the piston relative to the threaded shaft.

6. The apparatus of claim 4 , wherein:
the inerter is integrated into the actuator, the actuator is a hydraulic actuator having a piston coupled to an end of the rod and axially slidable within a housing, the piston dividing the housing into a cap end chamber and a rod end chamber;
one of the rod end and the cap end of the actuator functioning as the first terminal of the inerter, a remaining one of the rod end and the cap end functioning as the second terminal;
the flywheel is rotatably coupled to the second terminal;
the threaded shaft is fixedly coupled to the flywheel and rotatable in unison with the flywheel; and
the piston is fixedly coupled to the rod and threadably engaged to the threaded shaft in a manner such that linear translation of the rod relative to the threaded shaft causes rotation of the flywheel and threaded shaft in correspondence with actuation of the movable device by the actuator.

7. The apparatus of claim 1 , wherein:
the flywheel includes a plurality of flywheel protrusions extending outwardly from the flywheel and generating viscous damping during rotation of the flywheel.

8. The apparatus of claim 1 , wherein; the actuator is a hydraulic actuator operatable under a working pressure of at least 5000 psi.

9. The apparatus of claim 1 , further comprising: a motor to actively control rotation of the flywheel in correspondence with relative axial movement of the rod and threaded shaft.

10. The apparatus of claim 9 , wherein:
the motor is a permanent magnet direct current motor including one or more permanent magnets mounted to a flywheel perimeter and one or more windings mounted to one of a piston inner wall and a housing side wall.

11. The apparatus of claim 9 , wherein: the actuator includes a linear position sensor to sense a linear position of a piston within the actuator; and the motor commutating in correspondence with the linear position of the piston.

12. The apparatus of claim 1 , further comprising:
a brake operatively coupled to the flywheel and configured to decelerate the flywheel.

13. The apparatus of claim 1 , wherein: the movable device controls a direction of travel of a vehicle.

14. The apparatus of claim 1 , wherein:
the movable device is a flight control surface of an aircraft.

15. An aircraft, comprising: a flight control surface pivotably coupled to a support structure; a hydraulic actuator to actuate the flight control surface; an inerter, including: a first terminal and a second terminal mutually exclusively coupled to the support structure and the flight control surface; a rod movable with the first terminal; a threaded shaft movable with the second terminal; a flywheel coupled to at least one of the rod and the threaded shaft; and the flywheel rotatable in proportion to axial acceleration of the rod relative to the threaded shaft in correspondence with actuation of the flight control surface by the actuator.

16. A method of damping an actuator, comprising:
actuating, using an actuator, a movable device;
axially accelerating, using an inerter coupled to the movable device, a first terminal relative to a second terminal of the inerter simultaneous with and in proportion to actuation of the movable device;
rotationally accelerating a flywheel of the inerter in proportion to and simultaneous with the axial acceleration of the first terminal relative to the second terminal; and
reducing actuator load oscillatory amplitude of the movable device and actuator in response to rotationally accelerating the flywheel.

17. The method of claim 16 , wherein the step of reducing actuator load oscillatory amplitude includes:
reducing actuator load oscillatory amplitude at resonance of the movable device.

18. The method of claim 16 , wherein the step of reducing actuator load oscillatory amplitude includes:
reducing actuator load oscillatory amplitude at a resonant frequency of up to approximately 20 Hz.

19. The method of claim 16 , wherein:
the movable device is a flight control surface of an aircraft.

20. The method of claim 16 , wherein:
the inerter is integrated into the actuator, the actuator is a hydraulic actuator having a piston coupled to an end of a rod and axially slidable within a housing; and
the flywheel is rotatably coupled to one of the piston and the rod, the flywheel is threadably coupled to a threaded shaft.

21. The method of claim 16 , further comprising the step of:
actively controlling rotation of the flywheel in correspondence with actuation of the movable device by the actuator.

22. The method of claim 21 , wherein the step of actively controlling rotation of the flywheel comprises at least one of:
accelerating and decelerating the flywheel using a motor.

23. The method of claim 21 , wherein the step of actively controlling rotation of the flywheel includes:
accelerating, using a motor, the flywheel during initiation of actuation by the actuator of the movable device toward a commanded position.

24. The method of claim 16 , wherein the step of actively controlling rotation of the flywheel includes:
dynamically braking, using at least one of a motor and a brake, the flywheel as the actuator approaches a commanded position of the movable device.

Assignees

• Boeing Co

Inventors

• Fox Michael T
• Roach Jeffrey M

Classifications

• F16F2232/06

  Translation-to-rotary conversion · CPC title

• F16F7/1022

  the linear oscillation movement being converted into a rotational movement of the inertia member, e.g. using a pivoted mass · CPC title

• F15B2015/206

  Combined actuation, e.g. electric and fluid actuated · CPC title

• F15B15/227

  having an auxiliary cushioning piston within the main piston or the cylinder end face · CPC title

• F15B15/22

  for accelerating or decelerating the stroke · CPC title