Impeller for turbine

Abstract

An impeller for a turbine includes an impeller body formed by alternately stacking and fixing two or more types of disk blades, a base plate, and a rotating shaft. A plurality of pressed vane sections projecting from one surface are formed on the base plate of each disk blade, and recessed spaces are formed in the pressed vane sections, respectively. The projecting rear sections of the pressed vane sections are affixed to the other surface of the base plate of the adjacent disk blade, and disposed in the recessed spaces of the pressed vane sections of the adjacent disk blade in the mutually crossing direction. A part of a working gas is moved in the recessed spaces, and moved forward in the rotating direction over the projecting rear sections.

1 . An impeller for a turbine, which is rotated by an impulsive force of a working gas which is ejected, the impeller for a turbine comprises:
 an impeller body which is made by fixing two or more types of press-formed disk blades in an alternately stacked state using brazing method;   a base plate to which the impeller body is fixed; and   a rotating shaft which is fixed to the base plate,   wherein the disk blade has a basal portion formed in annular disk-shape, and a plurality of elongated pressed vane portions which are disposed so as to connect an inner circumferential edge and an outer circumferential edge of the basal portion and which projects from one surface side of the basal portion, thereby being capable of applying the impulsive force of the working gas, is provided at the basal portion, and   a recessed space, where an other surface side of the basal portion is in an opened state, is formed in each pressed vane portion, and where the pressed vane portion is configured such that a projecting rear portion which is the most protruded ridge portion thereof is disposed so as to be fixed to the surface of the other side of the basal portion of the adjacent disk blade using brazing method and to intersect the recessed space of the pressed vane portion of the adjacent disk blade at an intersecting communication space portion, and the pressed vane portion is configured such that a portion of the working gas which imparts the impulsive force to the pressed vane portion moves in the recessed space of the adjacent disk blade through the intersecting communication space portion and moves forward in the rotational direction beyond the projecting rear portion of the pressed vane portion in the intersecting communication space portion.   
     
     
         2 . The impeller for a turbine according to  claim 1 , wherein the pressed vane portions of one type of disk blade are disposed in the radial direction from the inner circumferential edge toward the outer circumferential edge of the basal portion. 
     
     
         3 . The impeller for a turbine according to  claim 2 , wherein the pressed vane portions of the other type of disk blade are disposed in a direction in which a position in the outer circumferential edge is displaced backward in the rotational direction from a standard direction, which is the radial direction from the inner circumferential edge toward the outer circumferential edge of the basal portion. 
     
     
         4 . The impeller for a turbine according to  claim 2 , wherein the pressed vane portions of the other type of disk blade are disposed in a direction in which a position in the outer circumferential edge is displaced forward in the rotational direction from a standard direction, which is the radial direction from the inner circumferential edge toward the outer circumferential edge of the basal portion. 
     
     
         5 . The impeller for a turbine according to  claim 1  wherein the inner circumferential edge of the basal portion of one type of disk blade has a larger diameter than the inner circumferential edge of the other type of disk blade, or the inner circumferential edge of the basal portion of the other type of disk blade has a larger diameter than the inner circumferential edge of one type of disk blade. 
     
     
         6 . The impeller for a turbine according to  claim 1 , wherein the outer circumferential edge of the basal portion of one type of disk blade has a smaller diameter than the outer circumferential edge of the other type of disk blade, or the outer circumferential edge of the basal portion of the other type of disk blade has a smaller diameter than the outer circumferential edge of one type of disk blade.