Methods for forming shield materials onto inductive coils
Methods of and systems for directing flux from a transmit coil to a receive coil within an inductive power transfer system are disclosed. For example, a transmit coil can be shielded with a contoured shield made from a ferromagnetic material. The contoured shield can contour to several surfaces of the transmit coil so as to define a single plane through which flux is directed to the receive coil.
1. A shield for an annular coil comprising:
an outer portion contoured to an outer sidewall of the annular coil;
an inner portion contoured to an inner sidewall of the annular coil; and
a top portion contoured to a top portion of the annular coil;
wherein the top portion couples the inner portion to the outer portion.
2. The shield of claim 1 , wherein the annular coil is contained within a first housing.
3. The shield of claim 1 , wherein the shield is made from soft magnetic material.
4. The shield of claim 3 , wherein the shield is made from at least one of iron, iron silicates, iron-cobalt, manganese-zinc, nickel, or nickel-zinc.
5. The shield of claim 1 , wherein the shield is made from a doped material selected from plastic, glass, or composite material.
6. The shield of claim 5 , wherein the doped material comprises a dopant made from a metal powder.
7. The shield of claim 1 , wherein the outer portion comprises a plurality of individual petals.
8. The shield of claim 7 , further comprising a filler material disposed between adjacent individual petals of the plurality of individual petals.
9. The shield of claim 1 , wherein the inner portion comprises a plurality of individual petals.
10. The shield of claim 9 , further comprising a filler material disposed between adjacent individual petals of the plurality of individual petals.
11. The shield of claim 1 , further comprising an adhesive layer disposed between the shield and the annular coil.
12. The shield of claim 11 , wherein the adhesive layer comprises a heat activated film.
13. The shield of claim 11 , wherein the adhesive layer is made from a doped material.
14. The shield of claim 13 , wherein the doped material comprises a dopant made from a metal powder.
15. An inductive charging system comprising:
an electronic device comprising:
a rechargeable battery;
a receive coil electrically associated with the rechargeable battery; and
a shield contoured over at least two surfaces of the receive coil defining a receiving area of the receive coil for concentrating magnetic flux therethrough.
16. The inductive charging system of claim 15 , wherein the shield is a first shield, and the inductive charging system further comprises:
an inductive charging device comprising:
a housing comprising an interface surface for receiving the electronic device;
a transmit coil within the housing and positioned below the interface surface; and
a second shield contoured over at least two surfaces of the transmit coil defining a transmitting area of the receive coil for concentrating magnetic flux therefrom;
wherein:
the transmitting area is oriented to face the interface surface.
17. The inductive charging system of claim 16 , wherein when the electronic device is received on the interface surface, the receiving area is oriented to face the transmitting area.
18. A method of manufacturing a contoured shield for an electromagnetic coil, the method comprising:
forming a shield sheet comprising a plurality of petals;
placing the shield sheet on a surface of the electromagnetic coil; and
folding each of the plurality of petals to contour to the surface of the electromagnetic coil.
19. The method of claim 18 , further comprising:
positioning a heat activated film between the shield sheet and the electromagnetic coil to form a shielded coil assembly;
heating the shielded coil assembly to activate the heat activated film.
20. The method of claim 18 , further comprising disposing a filler material between adjacent petals of the plurality of petals.
21. The method of claim 18 , further comprising pressing to fit the contoured shield and electromagnetic coil assembly onto a mold having a selected shape.
22. The method of claim 21 , wherein the selected shape is a cone.