JPS5741471A - Multi-stage hydraulic machine - Google Patents

Abstract

PURPOSE: To prevent the tmperature of runners from being raised at the time of an idling operation by a method wherein annular air-tight chambers are provided at the boundaries between lower covers or speed rings for runners and the outside thereof, the water stagnating in the outside peripheral area of each runner is discharged to the exterior.

CONSTITUTION: Some part of water leaked from fully closed movable guide vanes 8 into a high pressure stage runner chamber and the cooling water supplied to a runner seal part stagnates on the outside of a high pressure stage runner 2. This stagnating water is discharged to the exterior through a leakage water drain pipe 23, the air-tight chamber 22 and a leakage water drain pipe 24. On the other hand, the water stagnating on the outside of a medium pressure stage runner 3 is discharged to the exterior through a leakage water drain pipe 27, the air-tight chamber 26 and a leakage water drain pipe 28. In addition, the water stagnating on the outside of a runner 4 at the lowremost-pressure stage is directly discharged to the exterior through a leakage water drain pipe 30. Thus, the portions of water stagnating in the outside peripheral areas of the runners at differnt stages when an idling operation is conducted for a long period of time are separately discharged to the exterior, whereby the temperature of the runners is prevented from rising.

COPYRIGHT: (C)1982,JPO&Japio