A rotary transformer for an electrical machine includes a rotary printed circuit board and a stator printed circuit board. The rotary printed circuit board is operatively connected to the stator printed circuit board for relative rotation with respect to the stator printed circuit board. A conductor is fixed to the one of the printed circuit boards and includes a spiral coil for transferring electrical energy between the rotary printed circuit board and stator printed circuit board.

A rotary transformer for an electrical machine includes a rotary printed circuit board and a stator printed circuit board. The rotary printed circuit board is operatively connected to the stator printed circuit board for relative rotation with respect to the stator printed circuit board. A conductor is fixed to the one of the printed circuit boards and includes a spiral coil for transferring electrical energy between the rotary printed circuit board and stator printed circuit board.

A manufacturing method for laminated iron cores includes processing a metal sheet to form product sheets, in each of which iron core pieces are arranged inside an outer frame piece and the iron core pieces are connected to the outer frame piece in such a way that outer peripheral sides of the iron core pieces are connected to nearest parts of the outer frame piece through bridge pieces, laminating the product sheets and temporarily fixing the product sheets adjacent to each other in a vertical direction together to form a sheets laminated body including iron core pieces laminated parts and bridge pieces laminated parts, sealing the iron core pieces laminated parts by a resin while being pressurized to form pre-formed laminated iron cores, and separating the bridge pieces laminated parts from the pre-formed laminated iron cores to form the laminated iron cores which are individually separated.

A magnetic inductor for heating parts by means of induction having a geometry with a density greater than or equal to 99.9% (absence of pores), produced by a plurality of welded layers formed by metal dust particles of a conductive, non-magnetic material (such as, inter alia, copper, tin, aluminium, gold, or silver), preferably copper or a copper-based alloy, having a spherical shape and a grain size between 40 and 100 μm, and in a single-piece part including electrical and mechanical connections. Also, a method for producing the magnetic inductor with EBM technology (electron beam melting/production technology based on electron beam fusion), using a system comprising an electron gun, a vacuum chamber, a working chamber and a manipulation system.

A winding method of forming a coil by edgewise bending a flat rectangular conductor comprises a step of edgewise bending the rectangular conductor to form edgewise bending portions so that two predetermined two adjacent bent portions are formed so that an outward bulging portion to be generated by edgewise-bending of the flat rectangular conductor is generated in a concentrated manner in a side between the two edgewise bent portions, and the side having the bulging portion constitutes each of a pair of opposite sides of the coil.

A method for producing a silicon steel normalizing substrate comprises steelmaking, hot rolling and normalizing steps. A normalizing furnace is used in the normalizing step, and along a moving direction of strip steel, the normalizing furnace sequentially comprises: a preheating section, a nonoxidizing heating section, a furnace throat, furnace sections for subsequent normalizing processing, and a delivery seal chamber. Furnace pressures of the normalizing furnace are distributed as follows: the furnace pressure of a downstream furnace section adjacent to the furnace throat along the moving direction of the strip steel is the highest, the furnace pressure decreases gradually from the furnace section with the highest furnace pressure to a furnace section in an inlet direction of the normalizing furnace, and the furnace pressure decreases gradually from the furnace section with the highest furnace pressure to a furnace section in an outlet direction of the normalizing furnace.

A method for producing a silicon steel normalizing substrate comprises steelmaking, hot rolling and normalizing steps. A normalizing furnace is used in the normalizing step, and along a moving direction of strip steel, the normalizing furnace sequentially comprises: a preheating section, a nonoxidizing heating section, a furnace throat, furnace sections for subsequent normalizing processing, and a delivery seal chamber. Furnace pressures of the normalizing furnace are distributed as follows: the furnace pressure of a downstream furnace section adjacent to the furnace throat along the moving direction of the strip steel is the highest, the furnace pressure decreases gradually from the furnace section with the highest furnace pressure to a furnace section in an inlet direction of the normalizing furnace, and the furnace pressure decreases gradually from the furnace section with the highest furnace pressure to a furnace section in an outlet direction of the normalizing furnace.

A method of stabilizing electromagnetically charged particles, which includes coating electromagnetically charged particles with a protective layer; and etching the protective layer to produce a porous protective layer on the electromagnetically charged.

A method to form a choke is disclosed, wherein the method comprises: encapsulating a hollow coil by a molding body; forming a first core, wherein the first core comprises a pillar; and disposing at least one first portion of the pillar inside the encapsulated hollow coil. The method avoids the overflow or vertical flow issue during a molding process for encapsulating a coil that has been wound on a core already.

An inductor module comprising one or several wound inductors in a metallic housing, held in place by potting compound, wherein a surface of the metallic housing is a mechanical and thermal interface to a heat sink, and the distance between the coils and the inner side of the surface is predetermined by a suitable insulating space of potting compound. The invention may be used as PFC inductor in an on-board vehicle charger, among other uses.