GB863921A - Improvements relating to the rotors of dynamoelectric machines - Google Patents

Abstract

863,921. Cooling dynamo-electric machine coils. GENERAL ELECTRIC CO. Dec. 17, 1958 [Dec. 18, 1957], No. 40783/58. Class 35. In a rotor 1 for a dynamo-electric machine 2 e.g. a turbo-generator, comprising extending longitudinally within a core a plurality of electrical conductors 3, 6 joined together at their ends outside the core by end windings 4, 7 so as to form complete electrical circuits, a corrugated strip 13 of thermally conducting material projects from a radial surface of at least.one end winding, portions of the strip being in good thermal contact with the surface and intervening portions being spaced from the surface so as to provide a plurality of cooling fluid ducts extending radially over the surface. As shown applied to a distributed D.C. field winding, the strips, which form cooling fins, project axially from circumferential portions 4b of alternate strands of the end windings, but they may be provided also on the axial end winding portions 4a and on all strands if mutually insulated; they may be secured by brazing or welding and be of the same metal as the conductors 3, 6, i.e. copper or aluminium, so as to carry a small amount of winding current. Cooling gas is impelled through sub-slots 1d into underspace 10 by rotor pumping action which may be augmented by a fan 11, and passes through end winding openings 4c, 7c and hollow strands of the conductors 3, 6, to be discharged via a radial exhaust passage 16. The end winding axial portions 4a, 7a if not provided with strips 13, may be of larger cross-section than the circumferential portions 4b, 7b.