Arrangement for cooling a super conducting field winding and a damper shield of the rotor of an electric machine

In an arrangement for cooling a superconducting field winding in the rotor of an electric machine, especially a turbo-generator, having at least one coolant space which, in the operating condition, contains a vaporous and a liquid phase of a cryogenic coolant which is fed at a connecting head under subcritical pressure into a corotating coolant feed line which is connected to the coolant space, and including coolant paths which are arranged through the field winding and are connected to the space occupied by the liquid phase;

• at least one coolant discharge line which is connected to the space occupied by the vaporous phase;
• at least one coolant supply chamber containing liquid coolant;
• and at least one further coolant path which is arranged in loop-fashion, is thermally connected to a damper shield arranged around the field winding and is connected at its start and end to the coolant supply chamber, the improvement comprising:
• (a) a radial connecting line connecting the coolant supply chamber directly to the coolant feed line;
• (b) the flow cross section of the radial connecting line as well as the flow cross section at least of the section of the coolant feed line between the connecting head and the point of connection of the radial connecting line to the feed line being large enough to ensure discharging gaseous coolant components from the coolant supply chamber toward the connecting head.