Electromagnetic levitator

Patent metadata

Field	Value
Publication number	US-9979259-B2
Application number	US-201514837924-A
Country	US
Kind code	B2
Filing date	Aug 27, 2015
Priority date	Aug 27, 2015
Publication date	May 22, 2018
Grant date	May 22, 2018

Abstract

A levitator is disclosed. The levitator may include a repulsion wire coil having a vertical coil axis, a position control wire coil having a vertical coil axis, a rotation control wire coil having a horizontal coil axis, and a controller coupled to each of the repulsion wire coil, position wire coil, and rotation wire coil, where the controller is configured to independently control currents provided to each of the repulsion wire coil, position wire coil, and rotation wire coil to levitate an item.

First claim

What is claimed is:

1. A levitator, comprising:
a repulsion wire coil having a vertical coil axis;
a position control wire coil having a vertical coil axis;
a rotation control wire coil having a horizontal coil axis; and
a controller coupled to each of the repulsion wire coil, position wire coil, and rotation wire coil, wherein the controller is configured to independently control currents provided to each of the repulsion wire coil, position wire coil, and rotation wire coil.

2. The levitator of claim 1 , comprising:
a position sensor that senses the position of a levitated item,
wherein the current provided to each of the repulsion wire coil, position wire coil, and rotation wire coil is based on the position of the levitated item.

3. The levitator of claim 2 , wherein the position sensed by the position sensor includes the linear position and angular position of the levitated item.

4. The levitator of claim 2 , wherein the position sensor is a magnetic field sensor.

5. The levitator of claim 2 , wherein the position sensor has a variable output based on the strength of an incident magnetic field.

6. The levitator of claim 2 , wherein the position sensor is a Hall-effect sensor.

7. The levitator of claim 1 , comprising a plurality of position sensors that together sense the position of a levitated item,
wherein the current provided to each of the repulsion wire coil, position wire coil, and rotation wire coil is based on the position of the levitated item.

8. The levitator of claim 1 , comprising a plurality of repulsion wire coils, wherein the plurality of repulsion wire coils comprise:
a single central repulsion coil; and
a plurality of peripheral repulsion coils positioned at equal intervals around the central repulsion coil.

9. The levitator of claim 8 , wherein the central repulsion wire coil is circular, and
wherein each of the peripheral repulsion wire coils has a shape defined by a longer outer arc and a shorter inner arc connected by two side segments.

10. The levitator of claim 8 , wherein each of the plurality of repulsion wire coils has a coil axis parallel to coil axes of the others of the plurality of repulsion wire coils.

11. The levitator of claim 8 , wherein the plurality of peripheral repulsion coils consists of six peripheral repulsion coils.

12. The levitator of claim 1 , comprising a plurality of position wire coils, wherein the plurality of position wire coils are disposed above the repulsion wire coil and positioned at equal intervals around a central vertical axis of the levitator.

13. The levitator of claim 12 , wherein each of the position wire coils has a shape defined by an outer arc and two side segments extending from ends of the outer arc and meeting at an inner apex.

14. The levitator of claim 12 , wherein each of the plurality of position wire coils has a coil axis parallel to coil axes of the others of the plurality of position wire coils.

15. The levitator of claim 12 , wherein each of the plurality of position wire coils is positioned opposite another of the plurality of position wire coils.

16. The levitator of claim 12 , wherein the plurality of peripheral position wire coils consists of four position wire coils.

17. The levitator of claim 1 , comprising a plurality of rotation wire coils, wherein the plurality of rotation wire coils are positioned at equal intervals around a central vertical axis of the levitator.

18. The levitator of claim 17 , comprising a plurality of repulsion wire coils positioned at equal intervals around the central vertical axis of the levitator, and
wherein each of the rotation wire coils is disposed between two adjacent repulsion wire coils.

19. The levitator of claim 17 , wherein each of the plurality of rotation wire coils has a coil axis non-parallel to a coil axis of at least one of the others of the plurality of rotation wire coils.

20. The levitator of claim 17 , wherein each of the plurality of rotation wire coils has a coil axis tangential to an imaginary circle centered on the central vertical axis of the levitator.

21. The levitator of claim 17 , wherein each of the plurality of rotation wire coils is positioned opposite another of the plurality of rotation wire coils.

22. The levitator of claim 1 , comprising:
a plurality of repulsion wire coils, wherein the plurality of repulsion wire coils comprise:
a single central repulsion coil centered around a central vertical axis of the levitator; and
a plurality of peripheral repulsion coils positioned at equal intervals around the central repulsion coil;

a plurality of position wire coils, wherein the plurality of position wire coils are disposed above the plurality of repulsion wire coils and positioned at equal intervals around the central vertical axis of the levitator; and
a plurality of rotation wire coils, wherein the plurality of rotation wire coils are positioned at equal intervals around the central vertical axis of the levitator.

23. The levitator of claim 22 , wherein the controller is coupled to each of the plurality of repulsion wire coils, each of the plurality of position wire coils, and each of the plurality of rotation wire coils, and
wherein the controller is configured to independently control current provided to each of the plurality of repulsion wire coils, each of the plurality of position wire coils, and each of the plurality of rotation wire coils.

24. The levitator of claim 23 , comprising:
a position sensor that senses the position of a levitated item,
wherein the currents provided to each of the plurality of repulsion wire coils, each of the plurality of position wire coils, and each of the plurality of rotation wire coils are based on the position of the levitated item.

25. A levitation system comprising:
a levitator comprising wire coils that produce a magnetic field when energized;
a magnetic-field-producing item that becomes levitated above the energized wire coils by the magnetic field when the magnetic-field-producing item is disposed above the energized wire coils; and
a controller that can dynamically control the position of the magnetic-field-producing item by controlling the current energizing the wire coils,
wherein the controller can selectively rotate the magnetic-field-producing item and control its speed of rotation and orientation by controlling the current energizing the coils.

26. The levitation system of claim 25 , wherein the controller can dynamically control the vertical and lateral position of the magnet by controlling the current energizing the coils.

27. The levitation system of claim 25 , comprising a feedback sensor that can sense the position of the levitated magnetic-field-producing item.

28. The levitation system of claim 27 , wherein the position sensed by the feedback sensor includes the lateral position, vertical position, and angular position of the levitated magnetic-field-producing item.

29. The levitation system of claim 25 , wherein the magnetic field produced by the magnetic-field-producing item is irregular about a central axis of the magnetic field produced by the magnetic-field-producing item.

30. The levitation system of claim 29 , wherein the irregularity in the magnetic field produced by the magnetic-field-producing item is due to an irregularity in the substance of the magnetic-field-produ

Assignees

• Apple Inc

Inventors

• Puskarich Paul
• Della Silva Clark D
• Schwalbach Charles A
• Kumka David Samuel
• Weidner Andy
• Mustafa Paulina
• Gery Jean-Marc

Classifications

• F16C32/0446 Primary

  Determination of the actual position of the moving member, e.g. details of sensors · CPC title

• F16C32/0444

  Details of devices to control the actuation of the electromagnets · CPC title

• F16C32/0453

  for controlling two axes, i.e. combined control of x-axis and y-axis · CPC title

• H02K7/09 Primary

  with magnetic bearings · CPC title

• H02K11/215

  Magnetic effect devices, e.g. Hall-effect or magneto-resistive elements · CPC title