Abstract: The annular cavity in the stator of a cryogenic electric machine is defined by the housing and by the cylindrical element holding the winding. An electrically non-conducting ferromagnetic liquid is introduced into the annular cavity and is permitted to flow therein. The ferromagnetic liquid also serves as a cooling liquid for the cryogenic electric machine. A cooling system is connected to the annular cavity and together they form a closed loop for the circulation of the ferromagnetic liquid. Axial ribs are provided on the inner surface of the housing to prevent rotation of the ferromagnetic liquid as it flows inside the annular cavity.

Abstract: The electric machine comprises a rotor, a stator filled with a cooling fluid and separated from the rotor by a sealed jacket forming chambers of end-connectors of the stator winding. Within the stator there are provided ducts for the cooling fluid to flow therein, which connect said chambers. An external pipeline, at least part of which is disposed above the stator, forms an ascending and descending branches of the cooling fluid circulation system, each of the branches being communicated with one of said chambers. The upper section of the descending branch includes a cooler which is thus comprised in the whole system of the cooling fluid natural circulation which is effected due to the difference in specific weights of heated and cooled fluid.