Patent ID: 7868723
Filing Date: 2011-01-11
Classification: A61B,H01F

Abstract:
1. A power coupling device for coupling power to a rotating member, said power coupling device comprising: a. a primary magnetic core including a primary winding; b. a secondary magnetic core including a secondary winding; wherein said primary and secondary cores are arranged so as to form an air gap therebetween, said air gap permitting relative rotation of said cores about an axis of rotation while allowing power to be transferred across the air gap, and wherein at least one of said primary and said secondary windings comprises a fractional turn winding; c. conductive shielding configured as two continuous, circular half toroidal shells, each shell surrounding a respective one of the primary and secondary cores except for a portion adjacent the air gap, wherein when power is transferred across the air gap, oscillating magnetic fields will induce currents in the shielding, which induced currents tend to cancel the oscillating magnetic fields in a region outside the shielding.