Patent GB-1490171-A (GB)
Title: Fluid cooled dynamo-electric machine rotor
IPC: H02K9/00
Filed: 1975-01-06
Abstract: 1490171 Cooling dynamo-electric machines WESTINGHOUSE ELECTRIC CORP 6 Jan 1975 [18 Jan 1974] 377/75 Heading H2A The rotor winding of a dynamo-electric machine has passageways through which coolant flows, these connecting with a coolant collection chamber on a shaft portion of the rotor, which connects to a central axial bore through the rotor by a radial passage, the bore connecting to a discharge chamber via a radial conduit, the bore having a corrosion resistant liner surrounded by a bracing member, being closed at both ends and connecting to and communicating with corrosion resistant liners running through the radial passage and conduit, wherein the bore liner is prestressed against the bracing member. The turbine-generator shown has three cooling methods. Firstly, it has a gas-tight housing 14 containing hydrogen which is circulated to aid cooling, baffles being provided in the casing to generally direct the flow. Secondly, the stator 10 windings 16 are cooled by water passed via inlets 19, 17 through the hollow conductors of the windings via connectors 18. Thirdly, the rotor is cooled by a separate water supply. The rotor comprises a steel body having a central part 23 carrying windings in axial slots. The shaft portions 28 of the rotor are carried by gastight bearings 21 in the housing 14. The shaft 28 has a central bore 29 which allows ingress and exit of the cooling water as well as the passage of connections 30 to the rotor winding which forms the generator field winding. At the entrance end (left-side of Fig. 1), two concentric stainless steel tubes form a central tube for the connections 30 which communicate with the end-windings 24 via radial leads 31 and an outer annular space 32 for the cooling water. Radial passages 34 lined also with stainless steel transfer the water to an annular dispersal chamber 33 which is connected 35 to the passageways through the winding. These may be duets in the winding or hollow winding conductors. At the discharge end, an annular collection chamber 37 receives the cooling water from the winding and passes it via radial passages 38, to the central bore 29 which is lined by a stainless steel liner 46 closed at both ends. At the far end of the liner 46 radial conduits 39 transfer the water to a stationary annular discharge chamber 40 from which it escapes, 41, to be recycled. Since the liner 46 is welded to the radial liners 42, 44, it is braced against excessive stress due to expansion by a tube (62) surrounding it (Figs. 2-4, not shown). The tube (62) is open at the right-hand side and bears against a flange (56) on the liner. At the left-hand end, the tube (62) may be closed (Fig. 2) and the liner is put into tension by bolts passing through the tube end and screwing into the liner. Alternatively, the tube (62) is open at this end (Fig. 3) and an end-plate is bolted to the liner. Bolts passing through the end-plate bear against the tube to compress it and tense the liner. In a third embodiment (Fig. 4), the tube (62) is pre-compressed, e.g. hydraulically, is fitted over the liner and kept in compression by key-pieces (116) fitting in a circumferential slot (112) in the liner. Thermal insulation is placed between the liner and tube (62) in all embodiments.