Patent ID: 7438521
Filing Date: 2008-10-21
Classification: F03B,Y02E

Abstract:
1. A hydraulic turbine, comprising: a spiral casing; a stay ring disposed within the spiral casing for changing a flow direction from the spiral casing; a plurality of adjustable guide vanes disposed within the stay ring, the guide vanes being arranged in an array with spaces therebetween in a circumferential direction thereof; and a runner disposed within the guide vanes rotated by water guided by the guide vanes; wherein the stay ring includes a ring-shaped upper wall, a ring-shaped lower wall arranged below the upper wall, and a plurality of stay vanes, the upper wall and the lower wall forming a ring-shaped flow channel therebetween, and the plurality of stay vanes being arranged in an array with spaces therebetween in a peripheral direction in the ring-shaped flow channel and being rigidly secured to the upper and lower walls, wherein the upper wall and the lower wall are inclined at least near an inlet end to reduce a height of the ring-shaped flow channel toward an outlet end thereof, and wherein straightening bodies are arranged at least near the inlet end, below the upper wall and above the lower wall to reduce inclination of water flow in the stay ring.