Abstract: An electric machine is described, having a stator and a rotor, the rotor comprising a rotor shaft which is configured as a hollow shaft, a closed cavity being formed in the hollow shaft, in which closed cavity a vacuum prevails, and in which closed cavity a heat-transporting medium is received, and the hollow shaft having an evaporating region (hot zone) and a condensing region (cold zone), and a steam channel being provided in the cavity, and the surface of the cavity having structures which bring about transport of the condensate of the heat-transporting medium as a result of the rotation.

Abstract: An electric machine is described, having a stator and a rotatably mounted rotor which is surrounded by the stator, the stator having a laminated core, having a winding groove in the laminated core, which winding groove receives a winding, and at least one cooling ring which adjoins the laminated core in the region of the winding heads, a heat conduction tube in the form of a heat pipe being inserted in the winding groove between the winding and the bottom of the winding groove, the heat dissipation region of the heat conduction tube lying in the region of the cooling ring.