US Patent 7755245 Synchronous motor with permanent-magnet rotor

A synchronous motor with permanent-magnet rotor, of the type comprising a stator with corresponding windings and a rotor arranged between pole shoes formed by the stator. The stator is constituted by two C-shaped ferromagnetic bodies whose ends form two pairs of pole shoes. Respective spools with windings are arranged along the ferromagnetic bodies. The two pairs of pole shoes are angularly mutually offset so that two pole shoes, each belonging to a distinct ferromagnetic body, are internal with respect to the angular configuration thus formed and the other two pole shoes are external with respect to the same angular configuration. The external pole shoes have a same axial height and wrap around a same axial portion of the rotor.