Patent ID: 6371724
Filing Date: 2002-04-16
Classification: F04D,F05B,F05D

Abstract:
A centrifugal fluid machine comprising:a volute casing; a rotating shaft within said volute casing, said rotating shaft having a longitudinally extending axis of rotation; a plurality of centrifugal impeller vanes fixed to said rotating shaft; and at least one volute tongue fixed to said volute casing, said volute tongue cooperating with said plurality of centrifugal impeller vanes in at least one stage in each of which a trailing edge of each centrifugal impeller vane rotates about the axis of rotation and past a leading edge of a volute tongue; wherein, within each stage, of impeller vane trailing edges, radius at the center in the direction along the axis of rotation is made larger than radii at the two ends thereof in the direction along the axis of rotation and, of a volute tongue, radius at the center in the direction along the axis of rotation is made larger than radius at the two ends thereof in the direction along the axis of rotation.