Abstract: The aim of the invention is to design a rotary electric machine, in particular a high-speed motor, whose cooling system ensures that the heat generated is eliminated without a non-uniform heat distribution building up in the motor. The motor has cooling ducts (5) in the stator (2), between the bundle of laminations (3) and the housing (4). Located on the housing (4) are connections (6) for the supply of the coolant and connections (7) for the discharge of the coolant. A two-phase mixture is used as the coolant for the housing. If the bundle of laminations (3) gives out heat uniformly in all directions, evaporation will take place continuously round the whole of the casing. The motor also has as second coolant circuit. Gaseous coolant is fed in through another set of connections (8) to cool the rotor. This gaseous coolant passes through ducts (9) in the bundle of laminations (3) and into the air gap (10) between the rotor (1) and the bundle of laminations (3).

Abstract: In a squirrel-cage rotor, the theoretical ideal groove cross section is divided radially into at least two zones, which are displaced relative to each other alternatively in and against the direction of rotation of the rotor, the groove cross section including protuberances that extend into the theoretical ideal groove cross section and bulges that extend from the theoretically ideal groove cross section in a manner that the width of a tooth between the individual grooves remains the same as the theoretical ideal groove cross section, thus preventing the conductor rods from shifting either as they cool after aluminum has been introduced into the grooves or at high rotational rotor speeds.

Abstract: In an electric motor the shaft projects beyond the bearing on the closed-end and has a central bore running from this side to close to the drive-end bearing. Centrally in the bore is secured a tube which either extends to close to the end of the bore or is secured in a blind hole in the end of the bore. The tube has a lateral bore in the region of the base of the bore. At the end of the shaft near the closed-end bearing outside the motor housing, a device is secured to the end-plate via which water, used as a coolant, passes into the tube and flows back via the space between the tube and the bore. The tube is held centrally in the bore by two discs, having axial holes, slid over the tube. This construction makes it possible to conduct the heat dissipated in the rotor winding and the rotor, which is transmitted to the shaft, away in the best possible way.