Electromagnetic actuator

• US 5,661,446 A
• Filed: 06/07/1995
• Issued: 08/26/1997
• Est. Priority Date: 06/07/1995
• Status: Expired due to Fees

• Current Assignee: Parker Intangibles LLC (Parker-Hannifin Corporation)
• Original Assignee: MTS Systems Corporation (Illinois Tool Works Inc.)
• Inventors: Anderson, William G., McAdams, William C.
• Primary Examiner(s): DONOVAN, LINCOLN D
• Application Number:
  US08/484,866
• Time in Patent Office: 811 Days
• Field of Search: 335/179, 335/229-34, 335/256, 335/266, 310/13, 310/15, 310/20, 310/23, 310/28, 310/30, 310/36-8, 318/135
• US Class Current: 335/229
• CPC Class Codes: H02K 2201/18 Machines moving with multiple degrees of freedom
• CPC Class Codes: H02K 41/031 of the permanent magnet type

Abstract

An electromagnetic actuator includes an actuator rod having a plurality of magnetic assemblies disposed about a longitudinal axis of the actuator rod. Each plurality of magnetic assemblies develops alternating magnetic flux along the longitudinal axis. The electromagnetic actuator further includes a plurality of stator windings secured to a support structure and disposed about the longitudinal axis. Each stator winding has a pole facing a portion of one of the plurality of magnetic assemblies and the longitudinal axis.

Claims

1. An electromagnetic actuator comprising:

an actuator rod having a plurality of magnetic assemblies disposed about a longitudinal axis of the actuator rod, the plurality of magnetic assemblies developing alternate magnetic flux along the longitudinal axis;

a support structure; and

a plurality of stator winding assemblies secured to the support structure and disposed about the longitudinal axis, each stator winding assembly comprising;

a stator support core;

a stator winding supported by the core; and

a stator pole face secured to the stator support core between the stator winding and the actuator rod, the stator pole face having a surface spaced-apart from and conforming to an outer surface portion of the actuator rod proximate at least a portion of the magnetic assemblies.

2. The electromagnetic actuator of claim 1 wherein at least one stator winding is staggered relative to the other stator windings along the longitudinal axis.

3. The electromagnetic actuator of claim 1 wherein each stator winding comprises a set of three phase windings.

4. The electromagnetic actuator of claim 1 wherein each magnetic assembly comprises a plurality of magnets.

5. The electromagnetic actuator of claim 4 wherein each magnet is disposed within the actuator rod below the outer surface.

6. The electromagnetic actuator of claim 5 wherein the outer surface covers each magnet.

7. The electromagnetic actuator of claim 6 wherein the actuator rod comprises a plurality of subsections securable together along the longitudinal axis.

8. The electromagnetic actuator of claim 7 wherein a portion of at least one magnet is disposed within each subsection.

9. The electromagnetic actuator of claim 8 wherein each subsection comprises a plurality of laminates.

10. The electromagnetic actuator of claim 9 wherein each laminate includes a corresponding aperture for each magnet disposed in the subsection.

11. The electromagnetic actuator of claim 10 wherein the apertures of each laminate are spaced-apart at equal angular intervals.

12. The electromagnetic actuator of claim 1 wherein each stator support core includes spaced-apart recesses for wire portions of each corresponding stator winding.

13. The electromagnetic actuator of claim 12 wherein each stator support core comprises a plurality of core laminates, each laminate having spaced-apart recesses.

14. The electromagnetic actuator of claim 12 wherein each stator pole face comprises a plurality of pole laminates.

15. The electromagnetic actuator of claim 14 wherein the stator pole faces are joined together.

16. The electromagnetic actuator of claim 1 wherein the actuator rod comprises a plurality of rod laminates and wherein the stator pole faces are integral formed from a plurality of stator pole laminates separable from the rod laminates.

21. The electromagnetic actuator of claim 1 and further comprising:

a stator assembly joined to the support structure; and

wherein a portion of the actuator rod includes a plurality of magnets spaced-apart from the plurality of magnetic assemblies, the portion of the actuator rod and the stator assembly forming an electric motor for rotating the actuator rod about the longitudinal axis.

17. A method of constructing an electromagnetic actuator having an actuator rod moveable relative to a stator winding, the actuator rod having a magnetic assembly, the method comprising the steps of:

providing a plurality of laminates;

forming a plurality of stator pole laminates and a plurality of rod laminates from the plurality of laminates;

securing the rod laminates together to form the actuator rod; and

securing the plurality of stator pole laminates together to form a stator pole face on a stator winding, the stator pole face having a surface conforming to and facing the actuator rod.

18. The method of claim 17 wherein the step of securing the rod laminates together includes forming a plurality of subsections of rod laminates secured together and then securing the plurality of subsections together to form the actuator rod.

19. The method of claim 18 wherein the step of forming the plurality of subsections includes disposing at least one magnet in each subsection.

20. The method of claim 17 and further comprising:

winding a stator winding on a stator support core; and

attaching the stator pole face to the stator support core.