IMPROVEMENTS IN AND RELATING TO ELECTROMECHANICAL ACTUATORS

• US 20180238411A1
• Filed: 01/05/2016
• Published: 08/23/2018
• Est. Priority Date: 01/07/2015
• Status: Active Grant

• Current Assignee: BAE Systems Plc
• Original Assignee: BAE Systems Plc
• Inventors: SHARKH, SULEIMAN MAHMOUD, DALEY, STEPHEN, HUANG, HUI
• Granted Patent: US 10,458,502 B2
• Time in Patent Office: Days
• CPC Class Codes: F16F 2222/08 Inertia
• CPC Class Codes: F16F 2228/007 of solids, e.g. hardness
• CPC Class Codes: F16F 2230/18 Control arrangements
• CPC Class Codes: F16F 2238/026 wound- or coil-like
• CPC Class Codes: F16F 7/1011 by electromagnetic means
• CPC Class Codes: F16F 7/104 the inertia member being resiliently mounted F16F7/1022 takes precedence
• CPC Class Codes: H02K 2201/18 Machines moving with multiple degrees of freedom
• CPC Class Codes: H02K 33/06 with polarised armatures

Abstract

The present invention concerns electromechanical actuators. More particularly, but not exclusively, this invention concerns actuators operable in multiple degrees of freedom.

There is provided an actuator comprising a proof-mass and at least two coils arranged such that current flowing through the coil produces a force that acts on the proof-mass, the proof-mass being mounted for movement in at least two degrees of freedom, wherein one of the at least two degrees of freedom is a translational degree of freedom.

Claims

1. An actuator comprising a proof-mass and at least two coils arranged such that current flowing through the coils produces a force that acts on the proof-mass, the proof-mass being mounted for movement in at least two degrees of freedom, wherein one of the at least two degrees of freedom is a translational degree of freedom.

2. The actuator according to claim 1, wherein the actuator comprises at least two permanent magnet pole pairs, each coil being associated with a corresponding pole pair such that current flowing through the coil in the presence of the magnetic field of the pole pair induces a force that acts on the proof-mass.

3. The actuator according to claim 2, wherein the actuator comprises six permanent magnet pole pairs and six coils, each coil being associated with a magnet such that current flowing through the coil in the presence of the magnetic field of the pole pair induces a force that acts on the proof-mass, the proof-mass being mounted for movement in six degrees of freedom.

4. The actuator according to claim 1, in which the at least two coils are arranged such that current flowing through the coils produces forces that act radially, tangentially, or both radially and tangentially on the proof-mass.

5. The actuator according to claim 3, wherein the proof-mass is cuboidal, and a pole pair and a coil are associated with each face of the cuboid.

6. The actuator according to claim 1, wherein the proof-mass is located within a volume defined by the coils.

7. The actuator according to claim 1, wherein the proof-mass is located outside a volume defined by the coils.

8. The actuator according to claim 1, wherein the actuator comprises a suspension system biased to return the proof-mass to a central configuration.

9. The actuator according to claim 1, wherein the actuator comprises a control system to control the flow of current to the coils.

10. The actuator according to claim 9, wherein the control system comprises one or more sensors arranged to detect the location of the proof-mass within the actuator.

11. A structure comprising an actuator in accordance with claim 1.

16. An actuator according to claim 4, wherein the proof-mass is cuboidal, and a pole pair and a coil are associated with each face of the cuboid.

17. The actuator according to claim 2, in which the at least two coils are arranged such that current flowing through the coils produces forces that act radially, tangentially, or both radially and tangentially on the proof-mass.

18. The actuator according to claim 2, wherein the actuator comprises a suspension system biased to return the proof-mass to a central configuration.

19. The actuator according to claim 2, wherein the actuator comprises a control system to control the flow of current to the coils.

20. The actuator according to claim 19, wherein the control system comprises one or more sensors arranged to detect the location of the proof-mass within the actuator.

12. A method of damping vibration in a structure, using an actuator comprising a proof-mass and at least two coils, the method comprising:

passing a current through at least two of the coils to produce translation of the proof-mass in a first degree of freedom; and

passing a current through at least one of the coils to produce movement of the proof-mass in a second degree of freedom.

13. The method according to claim 12, wherein the actuator comprises at least two permanent magnet pole pairs, each pole pair being arranged such that a force is generated when current passes through the coil in the presence of the magnetic field of the pole pair.

14. A method according to any of claim 12, wherein the proof-mass forms part of the structure to be damped.

15. A generator comprising at least two coils and a proof-mass, the proof-mass mounted for movement in at least two degrees of freedom, wherein one of the at least two degrees of freedom is a translational degree of freedom, and wherein the coils are arranged such that movement of the proof-mass induces a current in the at least two coils.