Abstract: A rotor winding of an electric machine, the coil ends of which are provided with coolant conduits for supplying thereto a cooling liquid. The coolant conduits have radial and axial portions the axial portions being disposed in axial slots of the rotor shaft. The coolant conduits are fixedly secured with respect to the coil ends of the rotor winding by means of insulating supporting blocks at positions where the radial portions of the conduits bend into the axial portions thereof, the end parts of the axial portions being fixedly secured by means of insulating gaskets at a predetermined distance from the position of the supporting insulating blocks. This method of securing the coolant conduits provides considerable reduction of stresses caused therein by radial displacements of the tread ring with respect to the rotor shaft, and by centrifugal forces.