Patent ID: 6628020
Filing Date: 2003-09-30
Classification: H02K

Abstract:
A cooling gas ventilation circuit for an end winding of a rotary machine having a rotor, a plurality of radial slots provided in said rotor, and a plurality of coils respectively seated in said radial slots, said coils each comprising a plurality of radially stacked turns, said coils extending beyond a pole face of the rotor to form an end winding, cavities being defined between adjacent pairs of said coils, said ventilation circuit comprising:a cooling gas passage defined in at least one turn of each said coil of said end winding, said cooling gas passage extending from an inlet port in communication with the cavity on one longitudinal side of said turn to one of (1) a radial chimney defined through a plurality of the turns of the coil within said respective radial slot and (2) an exit port defined on the other longitudinal side of said turn, said cooling gas passage extending along at least a portion of the longitudinal extent of said turn; and wherein at least a portion of a surface of said cooling gas passage is knurled so as to have a non-planar surface profile for enhanced heat transfer.