Eddy current inductive drive electromechanical linear actuator and switching arrangement
First Claim
1. A linear actuator comprising (a) an electromagnetic drive that has a drive coil electromagnetically coupling with an armature comprised of one of a non-magnetic electrically conductive material and a paramagnetic electrically conductive material, wherein the armature is linearly movable relative to the drive coil when electric current is applied to the drive coil inducing eddy currents in the armature;
- and (b) a steady state magnetic field focusing eddy currents induced in the armature by the drive coil causing the armature to linearly move relative to the drive coil.
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Accused Products
Abstract
The present invention is directed to an inductively driven electromagnetic linear actuator arrangement employing eddy currents induced by a fixed drive coil to drive its armature. Eddy current focusing fields are employed to direct the eddy currents using Lorentz forces to maximize armature speed. The armature includes a shorted driven coil in a DC magnetic field. This can be supplied by a permanent magnet. When current is applied, a force is felt by the coil in a direction perpendicular to the magnetic field. Such an actuator is well suited for electrical switching applications including transfer switching applications, circuit breaker applications, and ground fault interrupter applications.
155 Citations
28 Claims
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1. A linear actuator comprising (a) an electromagnetic drive that has a drive coil electromagnetically coupling with an armature comprised of one of a non-magnetic electrically conductive material and a paramagnetic electrically conductive material, wherein the armature is linearly movable relative to the drive coil when electric current is applied to the drive coil inducing eddy currents in the armature;
- and (b) a steady state magnetic field focusing eddy currents induced in the armature by the drive coil causing the armature to linearly move relative to the drive coil.
- View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. A linear actuator comprising:
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(a) an electromagnetic drive that has a drive coil inductively coupling with an armature comprised of one of a non-magnetic electrically conductive material and a paramagnetic electrically conductive material, wherein the armature is linearly movable relative to the drive coil when electric current is applied to the drive coil inducing eddy currents in the armature; and (b) a steady state magnetic field focusing eddy currents induced in the armature by the drive coil; and wherein the electromagnetic drive comprises a stator comprised of an armature-receiving seat defined by a sidewall disposed outwardly of the armature when the armature is seated in the armature-receiving seat and a center post disposed interiorly of the armature when the armature is seated in the armature-receiving seat, with the sidewall comprising a first permanent magnet with one of its poles facing inwardly toward the armature and the center post comprising a second permanent magnet with one of its poles facing outwardly toward the armature, the first and second permanent magnets providing the steady state magnetic field urging eddy current flow induced in the armature during inductive coupling in a general axial direction relative to the armature. - View Dependent Claims (17, 18, 19)
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20. A linear actuator comprising:
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an electromagnetic drive comprising a ferromagnetic stator having a post spaced inwardly from a sidewall defining an armature guide therebetween, a drive coil carried by one of the post and the sidewall, and an armature that is linearly movable relative to the drive coil comprising a shorted turn coil of one of a non-magnetic electrically conductive material and a paramagnetic electrically conductive material disposed between the drive coil and the other one of the post and the sidewall in the armature guide in which eddy currents are induced by the drive coil when electric current is applied to the drive coil; and wherein one of the post and the sidewall comprises a first permanent magnet with the permanent magnet oriented with one of its poles facing toward and located adjacent the armature directing eddy currents induced in the shorted turn coil when electric current is applied to the drive coil in an axial direction along the shorted turn coil; and wherein the other one of the post and the sidewall comprises a second permanent magnet oriented with the other one of its poles facing toward and located adjacent the armature directing eddy currents induced in the shorted turn coil when electric current is applied to the drive coil in the same axial direction along the shorted turn coil that the first permanent magnet directs eddy currents. - View Dependent Claims (21, 22, 23, 24, 25, 26)
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27. A linear actuator comprising:
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(a) an electromagnetic drive that includes (1) a permanent magnet providing an eddy current directing magnetic field, (2) an electromagnetic drive coil that produces a magnetic field when electrical current is applied thereto, and (3) a driven element guide; (b) an armature that includes a driven element movably received in the driven element guide, the driven element is electrically conductive and comprised of one of a non-magnetic material and a paramagnetic material; and wherein electric current applied to the electromagnetic drive coil inductively couples with the driven element of the armature inducing eddy currents in the driven element causing relative movement between the armature and electromagnetic drive; and wherein the eddy current directing magnetic field of the permanent magnet directs eddy currents induced in the driven element by the electromagnetic drive coil in the direction of relative movement between the armature and the electromagnetic drive.
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28. A linear actuator comprising:
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(a) an electromagnetic drive that includes (1) a plurality of permanent magnets arranged with opposite poles spaced apart defining a gap therebetween and opposing one another, (2) an electromagnetic drive coil that produces a drive coil magnetic field when electrical current is applied thereto, and (3) a driven element guide; (b) an armature that includes a driven element movably received in the driven element guide and disposed in the gap between the permanent magnets, the driven element is electrically conductive and comprised of one of a non-magnetic material and a paramagnetic material; and (c) a power supply that supplies electrical current to the electromagnetic drive coil generating a drive coil magnetic field, inducing eddy currents in the driven element directed by steady state magnetic fields of the permanent magnets in a direction generally parallel to a lengthwise direction of the armature displacing the armature.
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Specification