Abstract: A method and system for reducing bearing failure in a rotating electrical device includes installing a magnetic core around the rotor shaft between the rotor and the bearing. The magnetic core creates an electrical impedance which reduces the current which flows through the bearings, and therefore reduces bearing failure.

Abstract: An induction heating workcoil has a ferrite core on which are wound multiple layers of an electrically conductive material. To cool the winding, solid thermal conductors are inserted between the multiple layers of the winding to provide a thermal interface with the multiple layers. The workcoil can also have a hollow tube that is wound on the outside of the winding with the tube having a liquid circulating through it to cool the winding. The core can have a cross-shaped top and an I-shaped leg with the multiple layers of the winding wound on the leg of the core. The solid thermal conductors can extend above the height of the windings so that the heat to be dissipated is transferred to the upper portion of the workcoil. The multiple layers of the winding are tightly wound on the solid thermal conductors to maximize the thermal interface.

Abstract: An induction heating device or work coil for heating electroconductive material to a desired temperature that can be used on a roll or cylinder of any diameter. The work coil has an open core of ferrite material shaped in a U. Wire is wound around the opposing legs of the U so that on excitation one leg becomes the N pole and the other leg becomes the S pole and the polarity alternates as the polarity of the excitation current alternates. A substantially thin rectangular flat layer of ferrite can be attached to ends of each pole piece. Each layer of ferrite has having a length sufficient to cover bottom end of each leg and a width in the direction of an axis perpendicular to the face of the U that corresponds to the width of the desired control heating effect.

Abstract: There is disclosed an induction heating device or work coil for heating electroconductive material to a desired temperature. The work coil can be used on a roll or cylinder of any diameter. The work coil has an open core of ferrite material shaped in a U. Wire is wound around the opposing legs of the U so that on excitation one leg becomes the N pole and the other leg becomes the S pole and the polarity alternates as the polarity of the excitation current alternates. A substantially thin rectangular flat layer of ferrite can be attached to ends of each pole piece. Each layer of ferrite has having a length sufficient to cover bottom end of each leg and a width in the direction of an axis perpendicular to the face of the U that corresponds to the width of the desired control heating effect.