Device for cooling a superconducting field winding and a damper shield of the rotor of an electric machine

Claim 1

In a device for cooling a superconducting field winding in the rotor of an electric machine, especially a turbo-generator, said device including at least one coolant space which contains, in the operating condition, a vaporous and a liquid phase of a cryogenic coolant which is fed in from outside the rotor; coolant paths going through the field winding which are connected to the liquid space of the coolant space occupied by the liquid phase; at least one coolant exhaust line which leads to outside the rotor and is connected to the vapor space of the coolant space occupied by the gaseous phase, said exhaust line connected thermally to an end piece at the end face of a torque transmitting hollow-cylindrical rotor body part; and at least one coolant line extending along a damper shield which surrounds the field winding and is to be deep-cooled, and arranged in the region of the superconducting field winding at the torque-transmitting rotor body part, said damper shield thermally insulated from the field winding by a hollow cylindrical body of solid insulating material, the improvement comprising the coolant line of the damper shield being a section of the coolant exhaust gas line, said section of the coolant exhaust gas line arranged, as seen in the flow direction of the coolant exhaust gas, ahead of the line section of the coolant exhaust line which is thermally connected to the end piece of the torque-transmitting rotor body part at the end face.