Tdk Corporation

Kota Arasaki

Mitsunari Suzuki

Masahide Ohnishi

Disclosed herein is a coil unit that includes a coil formed by spirally winding a conductive wire, a capacitor electrically connected to the coil, a magnetic member covering the coil in an axial direction of the coil, a first metal shield covering the coil with the magnetic member interposed therebetween, and a second metal shield disposed between the magnetic member and the first metal shield so as to form a space for housing the capacitor. The second metal shield includes a flat plate part facing to the magnetic member, a side wall disposed around the capacitor, and a flange part formed by bending a leading end portion of the side wall extending toward the first metal shield. The flange part is disposed so as to be thermally connected to the first metal shield.

Coil unit, and power transmitting device, power receiving device and wireless power transmission system using the coil unit

Disclosed herein is a coil unit that includes a coil formed by spirally winding a conductive wire, a capacitor electrically connected to the coil, a magnetic member covering the coil in an axial direction of the coil, a first metal shield covering the coil with the magnetic member interposed therebetween, and a second metal shield disposed between the magnetic member and the first metal shield so as to form a space for housing the capacitor. The second metal shield is disposed so as to be thermally connected to the first metal shield. An outer dimension of the second metal shield as viewed in the axial direction of the coil is equal to or smaller than an outer dimension of the magnetic member.

Disclosed herein is a coil unit that includes a coil, a magnetic member having a first surface facing to the coil and a second surface opposite to the first surface, a first metal shield covering the second surface of the magnetic member, and a second metal shield disposed so as to surround the coil. The first metal shield is disposed spaced apart in the axial direction of the coil from the second surface in a region between an end portion of the magnetic member and the second metal shield. A length Lp of a protruding part of the second shield that protrudes forward from a reference plane that is coplanar with the first surface in the axial direction of the coil is smaller than a first distance Ly from the end portion of the magnetic member to the second metal shield.

A wireless power receiving device, for wirelessly receiving electric power from a wireless power feeding device, includes: a power receiving side resonant circuit having a power receiving coil wirelessly receiving power from a power feeding side and a power receiving side resonant capacitor; a rectifier circuit in which the power received by the power receiving coil is rectified to be output to a load; a power receiving side voltage detecting portion for detecting the output voltage of the rectifier circuit; a short circuit having a switching element connected between an output portion of the power receiving side resonant circuit and an output portion of the rectifier circuit, and a rectifying element inserted between the output portion of the power receiving side resonant circuit and the switching element; and a controlling circuit which operates the switching element when a value of the output voltage exceeds a preset reference voltage value.

Growing community of inventors

Tokyo, Japan

Kota Arasaki