Patent ID: 6364607
Filing Date: 2002-04-02
Classification: F04D,F05B,F05D

Abstract:
A centrifugal fluid machine comprising:a casing; a rotating shaft within said casing, said rotating shaft having a longitudinally extending axis of rotation; a plurality of centrifugal impeller vanes fixed to said rotating shaft; and a plurality of centrifugal diffuser vanes fixed to said casing, said plurality of centrifugal diffuser vanes 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 each of the centrifugal diffuser vanes; wherein, within at least one stage, each of said centrifugal impeller vanes extends between a front shroud and a main shroud along the axis of rotation, and wherein, within each stage, said front shroud and said main shroud have an unequal diameter; wherein said centrifugal fluid machine includes a plurality of stages and wherein, in each of one half of the plurality of stages, the diameter of the front shroud is larger than the diameter of the main shroud and in each of another half of the plurality of stages, the diameter of the front shroud is smaller than the diameter of the main shroud; and wherein, on a plane developed from a circular cylindrical development on which is projected one stage of centrifugal impeller vane trailing edges and centrifugal diffuser vane leading edges, a difference (l1âˆ’l2) between a maximum value (l1) and a minimum value (l2) of a peripheral distance between an adjacent pair of a centrifugal impeller vane trailing edge and a centrifugal diffuser vane leading edge is equal to a peripheral distance (l3) between adjacent centrifugal vane trailing edges divided by 1 or an integer n greater than 1.