Una turbina francis que comprende una rueda de paletas, una carcasa espiral, un anillo poligonal, un anillo de paletas interiores, un anillo de paletas guias dispuesto corriente arriba del anillo ploligonal, donde una porcion de anillo poligonal se extiende sobre una porcion de circunferencia de la rueda de paletas, y una parte del anillo poligonal se extiende sobre la circunferencia adicional de la rueda de paletas.

摘要

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.