Coolant circulation system for the rotor of an electric machine having a superconductive excitation winding

Claim 1

Coolant circulation system for the rotor of an electric machine having a superconductive excitation winding and carried by a rotary shaft comprising a radially outer cold shield surrounding the superconductive excitation winding, a coolant junction head surrounding the shaft at an end thereof adjacent the excitation winding, said coolant junction head having an inlet communicating with an axial bore formed in the shaft, means for refrigerating a coolant, means for conducting liquid coolant from said refrigerating means through said coolant junction head to said shaft bore, means defining a collection chamber surrounding the shaft and communicating with bore means formed in the shaft for discharging the coolant from the shaft, first cooling channels located in the radially inwardly disposed excitation winding and communicating with said shaft bore, and second cooling channels located in said radially outwardly disposed refrigerating shield, said first and said second cooling channels being serially connected and being successively traversible by the same coolant conducted to said shaft bore, said coolant flowing through said shaft bore and said serially connected cooling channels changing to the gaseous phase and discharging from said second channel at a pressure higher than said liquid coolant entering said shaft bore, said machine rotor forming a cold gas compressor for said refrigerating means and is connected thereto through said coolant junction head.