| 摘要 |
1,226,772. 772. Hydraulic turbines - sealing devices. ESCHER WYSS Ltd. July 1, 1968 [July 3, 1967], No.31320/68. Heading F1T. [Also in Division F2] In an hydraulic rotary machine comprising a runner 1 which is sealed by a labyrinth seal and rotates sometimes in water and sometimes in air, e.g. a Francis turbine, a centrifugal pump or a reversible pump turbine, the parts forming the sealing gap are relatively movable whereby the gap is variable from a comparatively small amount when the runner is operating in water to an increased amount when the runner is operating in air. The runner 1 is sealed to the housing parts 4, 5 and 6, 7 by labyrinth seals 2 and 3 respectively and the non-rotating parts 10, 11 of the seals are connected by members 12 to servomotors 13 connected by ducts 21 and 22 to a fluid-pressure source. The position shown in Fig. 1 is intended for normal operation with the runner 1 rotating in water, the sealing gaps 8, 9 then being at a minimum limited by conical surfaces 23 o', the parts 10 and 11 pressed against conical surfaces 24 on the housing parts 4 and 6 by water pressure in annular chambers 25 communicating via ducts 26 with the water pressure space 27 of the machine. For operation of the runner in air, the parts 10 and 11 are moved outwardly by the servomotors 13 to increase the sealing gap 8, 9 by one step width as in Fig. 2 (not shown). During sliding movement of the parts 10 and 11, pressure water is supplied to the sealing gaps to act as coolant through ducts 28 leading from chambers 29 supplied from an external water source. |
