# US 2018/0151288 A1 · Inductive device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2018/0151288 A1 - Document ID: US20180151288A1 - Status: Published application - Kind: A1 - Application number: 15/816,114 - Filed: 2017-11-17 - Published: 2018-05-31 - Earliest claimed: 2016-11-30 - Assignees: Visedo Oy - Applicants: Visedo Oy - Inventors: Mikko Piispanene; Matti Iskanius; Tero Jarvelainen; Anssi Suuronen - Web page: https://patentgrep.com/patent/US20180151288A1 ## CPC - H01F 27/2895: {Windings disposed upon ring cores} - H01F 27/025: {Constructional details relating to cooling} - H01F 27/16: Water cooling - H01F 27/22: Cooling by heat conduction through solid or powdered fillings - H01F 27/245: made from sheets, e.g. grain-oriented (H01F27/26 takes precedence) - H01F 27/2823: {Wires (H01F27/2866 takes precedence)} - H01F 27/324: {Insulation between coil and core, between different winding sections, around the coil; Other insulation structures} - H01F 37/00: Fixed inductances not covered by group H01F17/00 - H01F: MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES ## Abstract An inductive device includes a toroidal core and at least one electric conductor wound around the toroidal core and constituting at least one winding. The inductive device includes a cooling element constituting a cylindrical cavity that contains the toroidal core and the electric conductor so that the axial direction of the toroidal core is parallel with the axial direction of the cylindrical cavity. The shape of the cylindrical cavity and the cross-section of the electric conductor are adapted to match each other so as to improve heat transfer from the electric conductor to the wall of the cylindrical cavity. The cylindrical cavity can have for example a circular base and the electric conductor can have for example a rectangular cross-section that matches the shape of the wall of the cylindrical cavity better than a round electric conductor. ## Claims ### Claim 1 An inductive device comprising: a toroidal core, at least one electric conductor wound around the toroidal core and constituting at least one winding, portions of the electric conductor on an outer perimeter of the winding being straight and parallel with an axial direction of the toroidal core, and a cooling element constituting a cylindrical cavity containing the toroidal core and the electric conductor so that the axial direction of the toroidal core is parallel with an axial direction of the cylindrical cavity and distances from a wall of the cylindrical cavity to different ones of the portions of the electric conductor are substantially equal, wherein a shape of the wall of the cylindrical cavity and a cross-sectional shape of the electric conductor are adapted to match each other so that at least one of the following deviates from a circular shape so as to improve heat transfer from the electric conductor to the wall of the cylindrical cavity: i) the cross-sectional shape of the electric conductor and ii) a cross-sectional shape of the cylindrical cavity in a geometric plane perpendicular to the axial direction of the cylindrical cavity. ### Claim 2 (depends on 1) An inductive device according to claim 1, wherein the cross-sectional shape of the electric conductor is substantially rectangular and the cross-sectional shape of the cylindrical cavity is circular. ### Claim 3 (depends on 1) An inductive device according to claim 1, wherein gaps between the wall of the cylindrical cavity and the portions of the electric conductors are filled with electrically insulating solid material. ### Claim 4 (depends on 3) An inductive device according to claim 3, wherein an electrically insulating outer lining of the electric conductor constitutes at least a part of the electrically insulating solid material. ### Claim 5 (depends on 3) An inductive device according to claim 3, wherein an electrically insulating inner lining of the cylindrical cavity constitutes at least a part of the electrically insulating solid material. ### Claim 6 (depends on 4) An inductive device according to claim 4, wherein an electrically insulating inner lining of the cylindrical cavity constitutes at least a part of the electrically insulating solid material. ### Claim 7 (depends on 1) An inductive device according to claim 1, wherein the cooling element comprises cooling fins. ### Claim 8 (depends on 1) An inductive device according to claim 1, wherein the cooling element comprises one or more cooling ducts for conducting cooling fluid. ### Claim 9 (depends on 1) An inductive device according to claim 1, wherein the cooling element comprises a bottom section constituting a bottom of the cylindrical cavity and being in a heat conductive relation with the electric conductor. ### Claim 10 (depends on 9) An inductive device according to claim 9, wherein gaps between the bottom section and the electric conductor are filled with electrically insulating solid material. ### Claim 11 (depends on 9) An inductive device according to claim 9, wherein the bottom section comprises cooling fins. ### Claim 12 (depends on 9) An inductive device according to claim 9, wherein the bottom section comprises one or more cooling ducts for conducting cooling fluid. ### Claim 13 (depends on 1) An inductive device according to claim 1, wherein the toroidal core comprises ferromagnetic material. ### Claim 14 (depends on 13) An inductive device according to claim 13, wherein the toroidal core comprises an elongated band of steel coated with electrically insulating material and reeled to constitute the toroidal core. ### Claim 15 (depends on 13) An inductive device according to claim 13, wherein the toroidal core comprises ring-shaped and planar sheets of steel coated with electrically insulating material and stacked in the axial direction of the toroidal core.