Centrifugal fluid machine

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, a ratio of a radius of each centrifugal impeller vane trailing edge to a volute tongue leading edge is made constant in a direction along the axis of rotation, and, on a plane developed from a circular cylindrical development on which is projected one stage of centrifugal impeller vane trailing edges and a volute tongue leading edge, a difference (l.sub.1 -l.sub.2) between a maximum value (l.sub.1) and a minimum value (l.sub.2) of a peripheral distance between an adjacent pair of a centrifugal impeller vane trailing edge and a volute tongue leading edge is equal to a peripheral distance (l.sub.3) between adjacent centrifugal vane trailing edges divided by 1 or an integer n greater than 1.

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, a distance between each centrifugal impeller vane trailing edge and a volute tongue leading edge is made constant in a direction along the axis of rotation, and, on a plane developed from a circular cylindrical development on which is projected one stage of centrifugal impeller vane trailing edges and a volute tongue leading edge, a difference (l.sub.1 -l.sub.2) between a maximum value (l.sub.1) and a minimum value (l.sub.2) of a peripheral distance between an adjacent pair of a centrifugal impeller vane trailing edge and a volute tongue leading edge is equal to a peripheral distance (l.sub.3) between adjacent centrifugal vane trailing edges divided by 1 or an integer n greater than 1.

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, on a plane developed from a circular cylindrical development on which is projected one stage of centrifugal impeller vane trailing edges and a volute tongue leading edge, peripheral positions of centrifugal impeller vane trailing edges are varied in a direction along the axis of rotation and a difference (l.sub.1 -l.sub.2) between a maximum value (l.sub.1) and a minimum value (l.sub.2) of a peripheral distance between an adjacent pair of a centrifugal impeller vane trailing edge and a volute tongue leading edge is equal to a peripheral distance (l.sub.3) between adjacent centrifugal vane trailing edges.

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, on a plane developed from a circular cylindrical development on which is projected one stage of centrifugal impeller vane trailing edges and a volute tongue leading edge, a difference (l.sub.1 -l.sub.2) between a maximum value (l.sub.1) and a minimum value (l.sub.2) of a peripheral distance between an adjacent pair of a centrifugal impeller vane trailing edge and a volute tongue leading edge is equal to a peripheral distance (l.sub.3) between adjacent centrifugal vane trailing edges divided by an integer n greater than 1.

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, on a plane developed from a circular cylindrical development on which is projected one stage of centrifugal impeller vane trailing edges and a volute tongue leading edge, the centrifugal impeller vane trailing edges are perpendicular to the volute tongue leading edge.