Francis turbine or a francis pump or a francis pump turbine

Abstract

The present invention provides a Francis turbine or any other machine built according to the Francis principle. The machine includes a blade wheel that has multiple blades, with at least one of the blades being adjustable. A spiral housing encloses the blade wheel. A traverse ring with multiple traverses has a portion with larger traverses that extends over a portion of a circumference of the blade wheel and starts at a beginning of a spiral. The traverse ring also has a portion with smaller traverses that extends over a further circumference of the blade wheel up to an end of the spiral. An inner blade wheel ring is provided downstream of the traverse ring. Also included is an outer guide blade ring which is disposed upstream of the traverse ring.

Dependencies are inferred from the claim text.