Diffuser assembly comprising diffuser vanes pivoting about the leading edge

Abstract

Embodiments of a diffuser assembly incorporate a diffuser vane with a trailing edge that changes position to improve flow performance of a compressor device. In one embodiment, the trailing edge rotates about the leading edge. This configuration maintains the position of the leading edge on the diffuser vanes relative to the orientation of the working fluid.

What is claimed is: 
     
         1 . A diffuser assembly for a compressor, said diffuser assembly comprising:
 a wall member;   a pivot element coupled with the wall member; and   a diffuser vane coupled with the pivot element, the diffuser vane having a leading edge, a trailing edge, and a rotation axis proximate the leading edge about which rotates the trailing edge of the diffuser vane.   
     
     
         2 . The diffuser assembly of  claim 1 , wherein the pivot element aligns with the rotation axis. 
     
     
         3 . The diffuser assembly of  claim 1 , wherein the diffuser vane has an airfoil shape that converges at the leading edge to a tip with a center axis and a curvilinear outer surface. 
     
     
         4 . The diffuser assembly of  claim 3 , wherein the curvilinear outer surface is defined by a radius from the center axis, and wherein the rotation axis is found within an area defined by the radius. 
     
     
         5 . The diffuser assembly of  claim 3 , wherein the rotation axis is coaxial with the center axis of the tip. 
     
     
         6 . The diffuser assembly of  claim 1 , wherein the rotation axis resides within 5% or less of a chord length measured from the leading edge, and wherein the chord length measures the straight-line distance between the leading edge and the trailing edge. 
     
     
         7 . The diffuser assembly of  claim 1 , wherein the rotation axis aligns with a pivot boundary that defines the circumferential location of the leading edge relative to an impeller of the compressor. 
     
     
         8 . The diffuser assembly of  claim 7 , wherein the pivot element prevents translation of the leading edge from the pivot boundary when the trailing edge rotates between a first position and a second position. 
     
     
         9 . The diffuser assembly of  claim 7 , wherein the diffuser vane is part of an array of diffuser vanes that circumscribes the impeller. 
     
     
         10 . A diffuser assembly for a compressor, said diffuser assembly comprising:
 a wall member;   a diffuser vane having a leading edge secured to the wall member to permit rotation of a trailing edge about the leading edge between a first position and a second position that is angularly offset from the first position.   
     
     
         11 . The diffuser assembly of  claim 10 , wherein the diffuser vane has an airfoil shape that converges at the leading edge to a tip with a center axis and a curvilinear outer surface. 
     
     
         12 . The diffuser assembly of  claim 11 , wherein the curvilinear outer surface is defined by a radius from the center axis, and wherein the diffuser vane rotates about a rotation axis that found within an area defined by the radius. 
     
     
         13 . The diffuser assembly of  claim 11 , wherein the rotation axis is coaxial with the center axis of the tip. 
     
     
         14 . The diffuser assembly of  claim 10 , wherein the diffuser vane has a rotation axis that resides within 5% or less of a chord length measured from the leading edge, and wherein the chord length measures the straight-line distance between the leading edge and the trailing edge. 
     
     
         15 . The diffuser assembly of  claim 10 , wherein the leading edge has a center axis that aligns with a pivot boundary that defines the circumferential location of the leading edge relative to an impeller axis. 
     
     
         16 . A compressor, comprising:
 a diffuser assembly comprising a wall member and an array of diffuser vanes having a leading edge and a trailing edge, wherein the diffuser vanes secure to the wall member at the leading edge to permit rotation of the trailing edge about the leading edge between a first position and a second position that is angularly offset from the first position.   
     
     
         17 . The diffuser assembly of  claim 16 , further comprising an impeller with an impeller axis, wherein the array of diffuser vanes circumscribe the impeller, and wherein the leading edge has a center axis that aligns with a pivot boundary that defines a circumferential location of the leading edge relative to the impeller axis. 
     
     
         18 . The diffuser assembly of  claim 16 , wherein the diffuser vane has an airfoil shape that converges at the leading edge to a tip with a center axis and a curvilinear outer surface, wherein the curvilinear outer surface is defined by a radius from the center axis, and wherein the diffuser vane rotates about a rotation axis that found within an area defined by the radius. 
     
     
         19 . The diffuser assembly of  claim 18 , wherein the rotation axis is coaxial with the center axis of the tip. 
     
     
         20 . The diffuser assembly of  claim 18 , wherein the rotation axis resides within 5% or less of a chord length measured from the leading edge, wherein the chord length measures the straight-line distance between the leading edge and the trailing edge.