GB412073A - Improvements in or relating to turbines, centrifugal pumps, and the like - Google Patents

Abstract

412,073. Turbines; centrifugal pumps; stuffing-box substitutes. MEININGHAUS, U., 4, Margaretenplatz, Mulheim, Ruhr, Germany. Sept. 20, 1933, No. 25970. [Classes 110 (i), 110 (iii), and 122 (v).] A packing device, wherein the interpenetration of the media from two different regions, such as the fluid from the working space and oil from the bearing housing of a steam or gas turbine or centrifugal pump, is prevented by a labyrinth packing with different zones to which lead collecting channels for the supply and draw-off of sealing fluids such as steam and air has the collecting channels disposed around one of the spaces to be packed ; for example, the collecting channels surround the hearing bush. These collectingchannels are formed by radially spaced cylindrical or conical members surrounding the bearing bush and secured at their outer ends to walls in the bearing housing recess of the end cover of the turbine exhaust while their inner ends carry the fixed members of the labyrinth packings. Fig. 1 shows the packing arrangements for a turbine wheel 16 mounted on a shaft 6 which rotates in the bearing bush 10 carried in the housing 1. Sealing steam is supplied to chamber 23 to prevent any air passing through the labyrinth packing 13 to the condenser. Air is supplied to chamber 25 and after leaking through the labyrinth 15 passes together with leakage sealing steam from the labyrinth 14 to the draw-off chamber 24. The labyrinth packing for the oil chamber 26 comprises a fixed disc 2 with labyrinth fins on both sides and a double disc arrangement 5 8 caulked directly on the shaft 6. The disc 5 is formed with a conical flange 19 to throw back the centrifugally moving oil into the oil chamber. Any oil seeping down the wall 4 to the fins 20 will drop on the flange 19 and so will likewise be returned to the chamber 26. The various chambers 23-26 are formed by cylindrical or conical members 29, 28, 27, 4 surrounding the bearing bush 10 and caulked to the bearing housing as at 30. Working steam leaking along the shaft passes by ducts 18 to the labyrinth packing 15 and cannot gain access to the bearing 10 by reason of the caulking 7 for the disc 5. Fig. 2 shows the complete turbine which comprises a Curtis wheel 31 for the first stage, radial-flow blading 34 for the intermediate stages and axial-flow blading for the low pressure region these two bladings being both carried on the wheel 16. The Curtis wheel 31 is carried on a hub extension of the wheel 16 and the whole is detachably mounted on the shaft 6. For dismantling in order to give access to the bearing 10 the rotor parts are clamped to the end and cylindrical walls 62, 54 of the casing by centralizing jigs and the bolt 56 is unscrewed to free the rotor hub 53 from the shaft 6 whereupon the cylindrical casing can be withdrawn from the exhaust casing 22. The labyrinth packing discs 2, 5 are then removed by stripping the caulkings 3, 7, 9. In Fig. 5 is shown the low-pressure unit of a multi-stage turbine which drives the two ends of a shaft 6 of a generator 86 (only one end is shown). Here the bearing housing for the drive shaft of the various auxiliaries (such as exciter 78, governor 71 and pressureoil pump 72) is surrounded by collector channels 90 for the fluid leaking past a carbon stuffing box 89. The radial-flow rotor is carried on the main shaft 6 and the main shaft is packed by a labyrinth arrangement similar to that described above. The auxiliary shaft 80 is hollow and connected at its outer end to a thin drive shaft 81 which at its other end is fixed to an inner sleeve extension 88 from the rotor at the mid point of the main bearing 10. For dismantling purposes the hollow shaft 80 can be disconnected from shaft 81 and then centralized by a jig to permit withdrawal, at the flange 79, of the exciter 78 together with the thrust and journal bearings 76, 84.