Hydraulic machine
AssigneeHitachi, Ltd.
InventorsSeiichi Tanabe, Syoji Ito
Life of this patent
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Abstract
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.
Claims10
A hydraulic machine comprising:
- a runner having a crown ring, a shroud ring, a runner boss, and a plurality of blades interposed between said crown ring and said shroud ring, a runner crown chamber arranged between said crown ring and an upper cover disposed in spaced juxtaposed relation with the crown ring, a plurality of first balance hole means formed in said crown ring for communicating between said runner crown chamber and low pressure sections defined by said blades, and a plurality of second balance hole means formed in said crown ring for communicating between said runner crown chamber and the interior of said runner boss whereby said first and second balance holes means have reverse thrust characteristics with respect to each other so that a thrust of a substantially constant value is applied to said runner regardless of a variation in the number of revolutions of said runner.
Dependencies are inferred from the claim text.