Arrangement for cooling the rotor of an electric machine with a

Abstract

Arrangement for cooling the rotor of an electric machine, including a superconducting field winding, a cold shield surrounding the winding, and a mixing chamber containing a phase mixture of coolant fed in, a stream of liquid coolant for cooling the winding and a stream of partially evaporated coolant for cooling the cold shield, the second stream being conducted through the cold shield and returned from the machine in an outer loop, the first stream being conducted through inner loops, through cooling canal sections of conductors, and returned to the chamber, the coolant in the loops being transported by the self-pumping effect of the rotor, the inner loops having radial entrance and exit branches distributed over the length and circumference of the rotor and winding, chamber sections associated with the inner loops, the chamber sections having an axial length and radial height forming pockets leading into the entrance branches for coolant which is cooler than the average temperature of the liquid phase and produced by evaporation at liquid level, a device for fanning-up a directional loop flow from weight and pressure differences of the canal sections of the inner loops, the chamber sections being distributed over the axial length and inner circumference of the rotor with the placement of the inner loops, and being disposed concentrically about the longitudinal axis of the chamber, each of the chamber sections having an entrance spaced from the axis, and an exit near an inner loop.