Patent ID: 8350655

Claim:
A shielded power coupling device configured to transfer electric power between a stationary subsystem and a rotatable subsystem that is inductively coupled to and arranged in close proximity to the stationary subsystem and that, during operation of the shielded power coupling device, is capable of rotating about an axis of rotation which is also substantially an axis of symmetry for both the stationary subsystem and the rotating subsystem, the shielded power coupling device comprising: a) an inductive field generating element capable of converting electric power to an inductive coupling field; b) an inductive coupling field receiving element capable of converting the inductive coupling field to electric power; c) an inductive coupling efficiency increasing element capable of increasing inductive coupling between the inductive field generating element and the inductive coupling field receiving element, wherein the inductive coupling efficiency increasing element comprises a primary core and a secondary core separated by a core airgap, and wherein the inductive field generating element and the inductive coupling field receiving element are disposed in mutually opposed core recesses of the primary core and secondary core, respectively; and d) shielding peripheral to the inductive coupling efficiency increasing element that is capable of substantially eliminating leakage of electromagnetic radiation from the shielded power coupling device when the shielded power coupling device is operated at power levels exceeding 2.5 kW, wherein the shielding comprises first and second shields separated by a shield airgap, wherein the primary and secondary cores are disposed in mutually opposed shield recesses of the first and second shields, respectively, and wherein the shield airgap is greater than the core airgap.