Compressor impeller and method for manufacturing same

Abstract

A compressor impeller includes: a hub; and a blade group including a plurality of blades arranged along a circumferential direction on an outer peripheral surface of the hub, the blade group being configured such that hub-side ends of leading edges of the respective blades are aligned on the same circle. The plurality of blades include at least one first blade and at least one second blade having a different shape from the at least one first blade. When comparing a blade angle of a leading edge of the at least one first blade to a blade angle of a leading edge of the at least one second blade at the same position in a radial direction of the compressor impeller, the blade angle of the leading edge of the at least one first blade is different from the blade angle of the leading edge of the at least one second blade, at least in a partial range in the radial direction of the compressor impeller.

1 . A compressor impeller, comprising:
 a hub; and   a blade group including a plurality of blades arranged along a circumferential direction on an outer peripheral surface of the hub, the blade group being configured such that hub-side ends of leading edges of the respective blades are aligned on the same circle,   wherein the plurality of blades include at least one first blade and at least one second blade having a different shape from the at least one first blade, and   wherein, when comparing a blade angle of a leading edge of the at least one first blade to a blade angle of a leading edge of the at least one second blade at the same position in a radial direction of the compressor impeller, the blade angle of the leading edge of the at least one first blade is different from the blade angle of the leading edge of the at least one second blade, at least in a partial range in the radial direction of the compressor impeller.   
     
     
         2 . The compressor impeller according to  claim 1 ,
 wherein the at least one first blade includes a plurality of first blades,   wherein the at least one second blade includes a plurality of second blades,   wherein the number of the second blades in the blade group is smaller than the number of the first blades in the blade group, and   wherein the plurality of second blades include a pair of second blades between which the first blade is not disposed.   
     
     
         3 . The compressor impeller according to  claim 1 ,
 wherein the number of the second blades in the blade group is smaller than the number of the first blades in the blade group, and   wherein, when comparing the blade angle of the leading edges of the first blades to the blade angle of the leading edges of the second blades at the same position in the radial direction of the compressor impeller, the blade angle of the leading edges of the second blades is greater than the blade angle of the leading edges of the first blades at least in a partial range in the radial direction of the compressor impeller.   
     
     
         4 . The compressor impeller according to  claim 3 ,
 wherein the blade angle of tip-side ends of the leading edges of the second blades is greater than the blade angle of tip-side ends of the leading edges of the first blades.   
     
     
         5 . The compressor impeller according to  claim 4 ,
 wherein the blade angle of the tip-side ends of the leading edges of the second blades is greater than the blade angle of the tip-side ends of the leading edges of the first blades by five degrees or more.   
     
     
         6 . The compressor impeller according to  claim 4 ,
 wherein the blade angle of hub-side ends of the leading edges of the second blades is equal to the blade angle of hub-side ends of the leading edges of the first blades.   
     
     
         7 . The compressor impeller according to  claim 6 ,
 wherein, when comparing the blade angle of the leading edges of the first blades to the blade angle of the leading edges of the second blades at the same position in the radial direction of the compressor impeller,   the blade angle of the leading edges of the second blades is greater than the blade angle of the leading edges of the first blades in a range to the tip-side ends from a predetermined position of not less than 50% of a blade height of the second blades in the radial direction of the compressor impeller, and is equal to the blade angle of the leading edges of the first blades in a range to the predetermined position from the hub-side ends of the second blades in the radial direction of the compressor impeller.   
     
     
         8 . The compressor impeller according to  claim 4 ,
 wherein the first blades and the second blades have different shapes only in an upstream region of a reference position in an axial direction of the compressor impeller, and have the same shape in a downstream region of the reference position in the axial direction of the compressor impeller.   
     
     
         9 . The compressor impeller according to  claim 8 ,
 wherein the reference position is a position upstream of an intersection between a suction surface of the second blade and a perpendicular line to the suction surface of the second blade from the tip-side end of the leading edge of the blade next to the suction surface of the second blade.   
     
     
         10 . A method for manufacturing the compressor impeller according to  claim 1 , comprising:
 a first blade forming step of forming a plurality of first blades having the same shape; and   a second blade forming step of forming at least one second blade by performing a bending process on a leading-edge side portion of a part of the first blades formed in the first blade forming step.