GB798939A - Improvements relating to the cooling of dynamo electric machines - Google Patents

Abstract

798,939. Cooling dynamo-electric machines. SOC. GENERALE DE CONSTRUCTIONS ELECTRIQUES ET MECANIQUES, ALSTHOM. May 25, 1956 [May 25, 1955], No. 16276/56. Class 35. A machine has axial ducts through the rotor conductors divided into axially displaced sections along the rotor, the sections having independent cooling circuits terminated by radial inlet and outlet ducts connecting the axial ducts with the air gap. In all the forms described, there are axially extending ducts through all the conductors with interconnecting radial ducts to supply fluid from the airgap to all or selected axial ducts. In Fig. 4, fluid reaches the axial duct 3 in the outermost conductor from inlet 23 and flows to outlet 24 while fluid flows similarly through sections of all the other conductors in the slot. The flow of fluid from one inlet could be in two opposite directions in all or some conductors only the fluid from one inlet all flowing the same way applying to the others. There may be a separate radial passage for each conductor level, or each radial passage may feed all axial ducts, i.e. at all levels, or may feed groups only of such ducts. In Fig. 7, the conductors in the upper half of the slot provide two axial ducts 3 in each layer and these are fed in parallel by radial passage 70 from the air gap, the fluid then flowing axially part way along the rotor and returning to the air gap by another radial passage similar to 70. In the lower half of the slot, there is one duct 3 per layer, these ducts being fed in parallel by another radial passage, deeper but otherwise similar to 70, but axially displaced therefrom, but the two ducts 3 per layer could be used for all layers. In all cases the coolant path described relates to part only of the rotor length, similar coolant paths being provided all along the rotor. The end windings are cooled by fluid passing from inlets in the end portions, along axial ducts in the conductors and flowing to the air gap by radial passages just inside the slotted portion of the rotor. Specification 746,168 is referred to.