Coil assembly for wireless power transfer having a shaped flux-control body

A wireless-power transfer (WPT) system comprising:

• a system housing having a stage wall that separates a housing cavity of the system housing from an external space of the system housing, the stage wall having a charging surface that faces the external space and an interior surface that faces the housing cavity;
• a coil assembly disposed within the housing cavity adjacent to the interior surface of the stage wall, the coil assembly comprising:
• a flux-control body comprising a ferromagnetic material and having a body side that faces the interior surface of the stage wall, the flux-control body including a shield wall that defines a coil channel of the flux-control body that opens along the body side to an exterior of the flux-control body and toward the interior surface;
• and
• an electrical conductor positioned within the coil channel, the electrical conductor forming a power-transfer coil having co-planar windings that are configured to generate a magnetic flux within a spatial region that extends into the external space of the system housing, wherein the shield wall of the flux-control body is positioned directly between adjacent windings of the power-transfer coil, the shield wall controlling a distribution of the magnetic flux experienced within the spatial region.

A method of manufacturing a coil assembly, the method comprising:

• providing a body mold having an interior cavity that is shaped by interior surfaces;
• injecting a composite liquid into the interior cavity, the composite liquid including a binder material and ferromagnetic particles distributed therein;
• permitting the composite liquid to cure within the body mold, thereby providing a flux-control body, the flux-control body having a body side and a shield wall that defines a coil channel of the flux-control body that opens along the body side to an exterior of the flux-control body;
• and
• positioning an electrical conductor within the coil channel, the coil channel being shaped to form a power-transfer coil when the electrical conductor is positioned therein, the power-transfer coil having co-planar windings that are configured to generate a magnetic flux within a spatial region that is adjacent to the body side, wherein the shield wall of the flux-control body is positioned directly between adjacent windings of the power-transfer coil, the shield wall controlling a distribution of the magnetic flux experienced within the spatial region.