Hydraulic machine

摘要

A hydraulic machine comprising a runner of the Francis type having a crown ring with a plurality of first and second balance holes. The first balance holes are formed in the crown ring for communicating between a runner crown chamber defined between the crown ring and an upper cover disposed in spaced juxtaposed relation with the crown ring and low pressure sections defined by blades interposed between the crown ring and a shround ring. The second balance holes are formed in the crown ring for communicating between the runner crown chamber and the interior of a runner boss whereby the first and second balance hole means have reverse thrust characteristics with respect to each other.