GB1439956A - Electrical machines - Google Patents

Abstract

1439956 Seals KRAFTWERK UNION AG 14 June 1973 [14 June 1972] 28468/73 Heading F2B [Also in Division H2] A turbogenerator having a liquid cooled rotor 1 mounted in a gas-filled, gas-tight, housing 5 includes an annular liquid coolant collecting chamber 36 which opens on to the rotor shaft and which is bounded by a casing 65 (Fig. 2) within the housing 5, the chamber 36 being made liquid-tight with respect to the rotor shaft by means of an inflow of pressurized gas at the extremities 62, 63 of two sealing glands 38b, 38a at the ends of the chamber 36, the gas flowing in the arrowed direction 61 through the action of a rotor fan 12a. The gas, preferably hydrogen, flows from a chamber 39 in each gland back to the suction side of the fan 12a via a pipe system 40 and a drying system 44, 42, the gas providing supplementary cooling in the machine and giving up its heat at coolers 16. A further rotor fan 12b produces further gas circulation within the machine. The liquid coolant, i.e. water, flows from a tank 19 to a shaft pump 20 via a line 6, and some then passes to a ring distributer 17 for cooling a stator winding 4, and some to an exciter generator 24 via a shaft bore 22 and a bearing 23. The latter liquid proceeds through a bearing 25 of the main generator to a chamber 27 and set of radial ducts 26, and then flows via hoses 30 and tubes 29 to the rotor end turns 28 and rotor winding 3. From the opposite end turns 31, it passes to the chamber 36 by way of further tubes and hoses 32/33, a chamber 34, and an annular duct 35, and from chamber 36 it drains to a vessel 45 for re-circulation. The glands 38a, 38b include flowback chambers 54 which allow any water which flows past axially inward extremities 53 of the glands to return to chamber 36 via bores 55 in the lower parts of the seals.