Wireless power transfer systems with shaped magnetic components

• US 9,842,687 B2
• Filed: 04/16/2015
• Issued: 12/12/2017
• Est. Priority Date: 04/17/2014
• Status: Active Grant

• Current Assignee: WiTricity Corporation
• Original Assignee: WiTricity Corporation
• Inventors: Kurs, Andre B.
• Primary Examiner(s): Lam, Tuan T
• Application Number:
  US14/688,103
• Publication Number:
  US 20150302985A1
• Time in Patent Office: 971 Days
• Field of Search: None
• CPC Class Codes: H01F 3/10 Composite arrangements of magnetic circuits
• CPC Class Codes: H01F 38/14 Inductive couplings for wireless supply or distribution of electric power using inductive coupling H02J50/10
• CPC Class Codes: H02J 50/05 using capacitive coupling
• CPC Class Codes: H02J 50/10 using inductive coupling
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/70 involving the reduction of electric, magnetic or electromagnetic leakage fields
• CPC Class Codes: H02J 50/80 involving the exchange of data, concerning supply or distribution of electric power, between transmitting devices and receiving devices

Abstract

In a first aspect, the disclosure features apparatuses for wireless power transfer, the apparatuses including a coil formed of a conductive material. The coil includes a plurality of loops, where the plurality of loops defines an internal region of the coil that extends along a coil axis. The apparatuses include a magnetic component, where the magnetic component is disposed in the internal region and extends in a first direction parallel to the coil axis and in a second direction perpendicular to the coil axis. A maximum dimension of the magnetic component measured in the second direction varies along the first direction.

Claims

1. An apparatus for wireless power transfer, the apparatus comprising:

a coil formed of a conductive material and comprising a plurality of loops, wherein the plurality of loops defines an internal region of the coil that extends along a coil axis; and

a magnetic component, wherein the magnetic component is disposed in the internal region and extends in a first direction parallel to the coil axis and in a second direction perpendicular to the coil axis,

wherein a maximum dimension of the magnetic component measured in the second direction varies along the first direction;

wherein a plurality of magnetic elements are joined to form the magnetic component and the plurality of magnetic elements are positioned in a row that extends in a direction parallel to the second direction; and

wherein one or more edges of the magnetic component have a stepped profile.

2. The apparatus of claim 1, wherein the magnetic component has an anisotropic magnetic permeability.

3. The apparatus of claim 1, wherein during operation of the apparatus, an average magnetic field generated by the coil at a given time in the magnetic component is oriented along a direction different from the second direction.

4. The apparatus of claim 1, wherein each one of the plurality of loops has a common diameter.

5. The apparatus of claim 1, wherein each one of the plurality of magnetic elements contacts adjacent magnetic elements within the row, and is connected to adjacent magnetic elements within the row by a dielectric material comprising an adhesive.

6. The apparatus of claim 1, wherein during operation, the apparatus is configured to wirelessly transfer power to, or receive power from, another coil.

7. The apparatus of claim 6, wherein during operation, the apparatus is configured to transfer power to an additional coil at an operating frequency within a range of one of:

85 kHz or less, and between about 80 kHz and about 145 kHz.

8. The apparatus of claim 6, wherein during operation, the apparatus is configured to transfer power from the coil to an additional coil at 3.3 kW or higher.

9. The apparatus of claim 6, wherein during operation of the apparatus, a magnetic field is generated when the coil is driven, the magnetic field having a magnetic flux density that varies in a range from about 10 mT to about 1000 mT.

10. An apparatus for wireless power transfer, the apparatus comprising:

a coil formed of a conductive material and comprising a plurality of loops, wherein the plurality of loops defines an internal region of the coil that extends along a coil axis; and

a magnetic component, wherein the magnetic component is disposed in the internal region and extends in a first direction parallel to the coil axis and in a second direction perpendicular to the coil axis,

wherein a maximum dimension of the magnetic component measured in the second direction varies along the first direction; and

wherein the magnetic component has one of an oval shape, a square shape, a hexagonal shape, and a bowtie shape.

11. The apparatus of claim 10, wherein:

a plurality of magnetic elements are joined to form the magnetic component;

the plurality of magnetic elements are positioned in a row that extends in a direction parallel to the second direction; and

one or more edges of the magnetic component have a smooth profile.

12. The apparatus of claim 11, wherein one or more edges of the magnetic component have a smooth linear profile.

13. The apparatus of claim 11, wherein one or more edges of the magnetic component have a smooth curved profile.

14. An apparatus for wireless power transfer, the apparatus comprising:

a coil formed of a conductive material and comprising a plurality of loops, wherein the plurality of loops defines an internal region of the coil that extends along a coil axis; and

a magnetic component, wherein the magnetic component is disposed in the internal region and extends in a first direction parallel to the coil axis and in a second direction perpendicular to the coil axis,

wherein a maximum dimension of the magnetic component measured in the second direction varies along the first direction; and

wherein at least some of the plurality of loops have different diameters, and the diameters of the plurality of loops vary based on positions of each of the loops relative to edges of the magnetic component.

15. An apparatus for wireless power transfer, the apparatus comprising:

a coil formed of a conductive material and comprising a plurality of loops, wherein the plurality of loops defines an internal region of the coil that extends along a coil axis; and

a magnetic component, wherein the magnetic component is disposed in the internal region and extends in a first direction parallel to the coil axis and in a second direction perpendicular to the coil axis,

wherein a maximum dimension of the magnetic component measured in the second direction varies along the first direction;

wherein a plurality of magnetic elements are joined to form the magnetic component and the plurality of magnetic elements are positioned in a row that extends in a direction parallel to the second direction; and

wherein each one of the plurality of magnetic elements has a length measured in a direction parallel to the first direction, and at least two magnetic elements have different lengths.

16. An apparatus for wireless power transfer, the apparatus comprising:

a coil formed of a conductive material and comprising a plurality of loops, wherein the plurality of loops defines an internal region of the coil that extends along a coil axis; and

a magnetic component, wherein the magnetic component is disposed in the internal region and extends in a first direction parallel to the coil axis and in a second direction perpendicular to the coil axis,

wherein a maximum dimension of the magnetic component measured in the second direction varies along the first direction;

wherein a plurality of magnetic elements are joined to form the magnetic component and the plurality of magnetic elements are positioned in a row that extends in a direction parallel to the second direction;

wherein one or more edges of the magnetic component have a smooth linear profile; and

wherein one of;

the magnetic elements are arranged such that a magnetic element with a longest length is positioned at a center of the row, and a magnetic element with a shortest length is positioned at an end of the row;

or

the magnetic elements are arranged such that a magnetic element with a longest length is positioned at an end of the row, and a magnetic element with a shortest length is positioned at a center of the row.

17. An apparatus for wireless power transfer, the apparatus comprising:

a coil formed of a conductive material and comprising a plurality of loops, wherein the plurality of loops defines an internal region of the coil that extends along a coil axis; and

a magnetic component, wherein the magnetic component is disposed in the internal region and extends in a first direction parallel to the coil axis and in a second direction perpendicular to the coil axis,

wherein a maximum dimension of the magnetic component measured in the second direction varies along the first direction;

wherein a plurality of magnetic elements are joined to form the magnetic component and the plurality of magnetic elements are positioned in a row that extends in a direction parallel to the second direction; and

wherein the plurality of magnetic elements are symmetrically arranged with respect to the coil axis.