New Structures of Synchronous Motor with Two Stators and Single Rotor, with High-Energy NdFeB Permanent Magnets Arranged on Both Rotor Bores

The first permanent magnet electric machines appeared in the first half of the last century and their evolution was continuous as magnets with high magnetic energies appeared and magnetic circuits were created that allowed for efficient use of the magnets. The solution of the asynchronous motor with two stators with a massive rotor described in previous work opened the way to a synchronous variant of the machine with two stators, using rare earth permanent magnets, which are arranged on both cylindrical surfaces of the rotor. In this way, the volume of the magnets and the flux of the machine can be increased. The rotor construction made of solid steel, mechanically robust, does not disturb from an electromagnetic point of view, because it rotates synchronously with the fundamental of the stator field, so it will no longer induce eddy currents in the rotor iron in a permanent regime. In the synchronous variant, part of the inductor flux is closed through the rotor, which can be an advantage for the optimal use of the active surfaces of the machine.