Methods for forming shield materials onto inductive coils

Abstract

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 may be shielded with a contoured shield made from a ferromagnetic material. The contoured shield may contour to several surfaces of the transmit coil so as to define a single plane through which flux may be directed to a receive coil.

What is claimed is: 
     
         1 . A shield for an annular coil comprising:
 a first portion contoured over a surface of the annular coil such that the first portion fills within at least a portion of void spaces defined between stacked coils positioned along the surface of the annular coil.   
     
     
         2 . The shield of  claim 1  wherein the shield is made from soft magnetic material. 
     
     
         3 . The shield of  claim 2  wherein the shield is made from at least one of iron, iron silicates, iron-cobalt, manganese-zinc, nickel, or nickel-zinc. 
     
     
         4 . The shield of  claim 1  wherein the shield is made from a doped material selected from plastic, glass, or composite material. 
     
     
         5 . The shield of  claim 4  wherein the doped material comprises a dopant made from a metal powder. 
     
     
         6 . The shield of  claim 1  further comprising a second portion and a third portion coupled to the first and second portions. 
     
     
         7 . The shield of  claim 1  further comprising an adhesive layer disposed between the shield and the annular coil. 
     
     
         8 . The shield of  claim 7  wherein the adhesive layer comprises a heat activated film. 
     
     
         9 . The shield of  claim 7  wherein the adhesive is made from a doped material comprising a dopant made from a metal powder. 
     
     
         10 . The shield of  claim 1  wherein:
 the annular coil comprises a plurality of windings of an electrical conductor defining an interior coil sidewall, an exterior coil sidewall and a back surface extending between the interior and exterior coil sidewalls; 
 the first portion is contoured to either the interior or exterior sidewall; and 
 the second portion comprises a ring contoured to the back surface. 
 
     
     
         11 . The shield of  claim 1  wherein the annular coil is contained within a first housing. 
     
     
         12 . A shield for an annular coil comprising:
 a first portion comprising a plurality of individual petals, wherein the first portion is contoured over a surface of the annular coil such that the first portion fills within at least a portion of void spaces defined between stacked coils positioned along the surface of the annular coil.   
     
     
         13 . The shield of  claim 12  further comprising a filler material disposed between adjacent individual petals of the plurality of individual petals. 
     
     
         14 . The shield of  claim 12  further comprising a second portion and a third portion coupled to the first portion, wherein the second portion is disposed between the first and third portions. 
     
     
         15 . The shield of  claim 14  wherein the third portion comprises a plurality of individual petals positioned across the second portion from the plurality of individual petals of the first portion. 
     
     
         16 . The shield of  claim 14  further comprising a filler material disposed between adjacent individual petals of the plurality of individual petals. 
     
     
         17 . An inductive charging system comprising:
 an electronic device comprising:
 an annular receive coil; and 
 a shield contoured over a surface of the receive coil such that the shield fills within at least a portion of void spaces defined between stacked coils positioned along the surface of the receive coil. 
   
     
     
         18 . The inductive charging system of  claim 17  wherein the shield defines a receiving area of the receive coil for concentrating magnetic flux therethrough. 
     
     
         19 . The inductive charging system of  claim 18  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 transmitter 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 transmitter area of the receive coil for concentrating magnetic flux therefrom; 
 
 wherein:
 the transmitting area is oriented to face the interface surface. 
 
 
     
     
         20 . The inductive charging system of  claim 19  wherein the electronic device is received on the interface surface, the receiving area is oriented to face the transmitting area.