Magnetically permeable core and an inductive power transfer coil arrangement

• US 10,325,719 B2
• Filed: 05/14/2015
• Issued: 06/18/2019
• Est. Priority Date: 05/19/2014
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Abdolkhani, Ali, Hu, Aiguo
• Primary Examiner(s): Nguyen, Tuyen T
• Application Number:
  US15/312,398
• Publication Number:
  US 20170092419A1
• Time in Patent Office: 1,496 Days
• CPC Class Codes: H01F 21/04 by relative movement of turns or parts of windings
• 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: H01F 38/18 Rotary transformers
• CPC Class Codes: H02J 50/10 using inductive coupling
• CPC Class Codes: H02J 50/70 involving the reduction of electric, magnetic or electromagnetic leakage fields

Abstract

An inductive power transfer coil assembly including: a magnetically permeable core including a base having a pair of spaced apart limbs extending therefrom; and a winding located between and above the pair of spaced apart limbs.

Claims

1. An inductive power transfer coil assembly including:

i. a magnetically permeable core including a base having a pair of spaced apart limbs extending therefrom, the base and the pair of spaced apart limbs forming a U core, each of the pair of spaced apart limbs having a first end adjacent the base and a second end opposed to the first end; and

ii. a winding located between the limbs and over the second end of each of the pair of spaced apart limbs.

2. An inductive power transfer coil assembly as claimed in claim 1 wherein the ratio of the height of the limb above the base to the height of the limb and winding above the base is selected from the group consisting of:

less than about 90%

less than about 70%;

between about 20% and about 70%;

between about 40% and about 600; and

about 50%.

3. An inductive power transfer coil assembly as claimed in claim 1 including one or more core provided along an annular path.

4. An inductive power transfer coil assembly as claimed in claim 3 including a plurality of cores, wherein the winding follows the annular path between the limbs of each core.

5. An inductive power transfer coil assembly as claimed in claim 3 including a single annular core, wherein the winding follows the annular path between the limbs of the core.

6. An inductive power transfer coil assembly as claimed in claim 3 having a through hole at the centre of the annular path.

7. An inductive power transfer coil assembly as claimed in claim 1 including one or more core provided along a linear path.

8. An inductive power transfer coil assembly as claimed in claim 7 including a plurality of cores.

9. An inductive power transfer coil assembly as claimed in claim 7 including a single linear core.

10. An inductive power transfer coil assembly as claimed in claim 8 wherein the winding is provided between and over each core.

11. An inductive power transfer coil assembly as claimed in claim 1 wherein each core has three or more limbs extending from the base.

12. An inductive power transfer coil assembly as claimed in claim 1 wherein the transition from the base to each limb is curved.

13. An inductive power transfer coil arrangement comprising:

i. a first coil assembly comprising a first magnetically permeable core including a base having a pair of spaced apart limbs extending therefrom, the pair of spaced apart limbs forming a U core, each of the pair of spaced apart limbs having a first end adjacent the base and a second end opposed to the first end; and

a winding located between the limbs and over the second end of each of the pair of spaced apart limbs; and

ii. a second coil assembly having a second magnetically permeable core, the second coil assembly being arranged with respect to the first coil assembly such that there is effective magnetic coupling between the first and second magnetically permeable cores.

14. An inductive power transfer coil arrangement as claimed in claim 13 wherein the first and second coil assemblies are arranged in relatively moveable relationship.

15. An inductive power transfer coil arrangement as claimed in claim 13 wherein there is an air gap greater than about 3.5 mm between the first and second coil assemblies.

16. An inductive power transfer coil arrangement as claimed in claim 13 wherein there is an air gap between the first and second coil assemblies greater than the distance between the limbs of the first coil assembly or the limbs of the second coil assembly.

17. An inductive power transfer coil arrangement as claimed in claim 13 wherein each of the first and second coil assemblies includes either:

a plurality of cores arranged along an annular path;

or a single annular core provided along an annular path, wherein the winding of each coil assembly follows the annular path between the limbs of the or each core.

18. An inductive power transfer coil arrangement as claimed in claim 17 wherein the limbs of the first and second coil assemblies are generally radially directed.

19. An inductive power transfer coil arrangement as claimed in claim 17 wherein the limbs of the first and second coil assemblies are generally axially directed.