Radial compressor stage

Abstract

A radial compressor stage includes: an impeller, rotatable relative to a stator, the impeller having multiple impeller blades on a rotor side; a diffuser positioned in a flow direction downstream of the impeller, the diffuser having multiple guide blades on the stator side; an impeller side gap formed between the impeller and the stator; and an intermediate flow channel extending between the impeller and the diffuser. A gap is formed between an outer edge of a downstream back side of the impeller and an opposite inner edge of the stator, the gap being sealed via a seal such that the seal seals the impeller side gap from the intermediate flow channel.

What is claimed is: 
     
         1 . A radial compressor stage comprising:
 an impeller ( 10 ), rotating relative to a stator ( 12 ), the impeller ( 10 ) having multiple impeller blades ( 11 ) on a rotor side;   a diffuser ( 19 ) positioned in a flow direction downstream of the impeller ( 10 ), the diffuser ( 19 ) having multiple guide blades ( 20 ) on the stator side;   an impeller side gap ( 28 ) formed between the impeller ( 10 ) and the stator ( 12 ); and   an intermediate flow channel ( 26 ) extending between the impeller ( 10 ) and the diffuser ( 19 ), wherein a gap ( 34 ) is formed between an outer edge ( 35 ) of a downstream back side ( 27 ) of the impeller ( 10 ) and an opposite inner edge ( 36 ) of the stator ( 12 ), the gap ( 34 ) being sealed via a seal ( 37 ) such that the seal ( 37 ) seals the impeller side gap ( 18 ) from the intermediate flow channel ( 26 ).   
     
     
         2 . The radial compressor stage according to  claim 1 , wherein the seal ( 37 ) is supported by the stator ( 12 ) and is located opposite the outer edge ( 35 ) of the downstream back side ( 27 ) of the impeller ( 10 ). 
     
     
         3 . A radial compressor stage comprising:
 an impeller ( 10 ), rotatable relative to a stator ( 12 ), the impeller ( 10 ) having multiple impeller blades ( 11 ) on a rotor side;   a diffuser ( 19 ) positioned in a flow direction downstream of the impeller ( 10 ), the diffuser having multiple guide blades ( 20 ) on the stator side; and   an impeller side gap ( 28 ) formed between the impeller ( 10 ) and the stator ( 12 ),   wherein a gap ( 34 ) is formed between an outer edge ( 35 ) of a downstream back side ( 27 ) of the impeller ( 10 ) and an opposite inner edge ( 36 ) of the stator ( 12 ), the gap ( 34 ), seen in a circumferential direction, has a varying gap dimension.   
     
     
         4 . The radial compressor stage according to  claim 3 , wherein the inner edge ( 36 ) of the stator ( 12 ), seen in a circumferential direction, has a wavelike contour. 
     
     
         5 . The radial compressor stage according to  claim 1 , wherein
 the guide blades ( 20 ) have flow inlet edges ( 22 ) on the stator side, wherein the flow inlet edges ( 22 ) lie on a first circle contour ( 29 ) such that the flow inlet edges ( 22 ) of all guide blades ( 20 ) on the stator side have an identical distance from the flow inlet edges ( 22 ) of the respective adjacent guide blades ( 20 ); and   the guide blades ( 20 ) have flow outlet edges ( 23 ) on the stator side, wherein the flow outlet edges ( 23 ) lie on a second circle contour ( 30 ), such that in at least one first circumferential position the flow outlet edge ( 23 ) of the respective guide blade ( 20 ) on the stator side has a distance to the flow outlet edge ( 23 ) that is different from the distance to the flow outlet edge ( 23 ) of at least one adjacent guide blade ( 20 ) in second circumferential positions.   
     
     
         6 . The radial compressor stage according to  claim 5 , wherein
 in the second circumferential positions the respective guide blades ( 20 ) on the stator side all have identical second stepping angles; and   in the, or each, first circumferential position the respective guide blades ( 20 ) on the stator side has a first stepping angle that deviates from the second stepping angle.   
     
     
         7 . The radial compressor stage according to  claim 6 , wherein the first stepping angle deviates from the second stepping angle by ±10°. 
     
     
         8 . The radial compressor stage according to  claim 1 , wherein at least one guide blade ( 20 ) on the stator side has a curvature that deviates from the other guide blades ( 20 ) on the stator side. 
     
     
         9 . The radial compressor stage according to  claim 1 , further comprising a plurality of diffuser flow channel sections ( 33 ) each formed between adjacent guide blades ( 20 ) on the stator side, wherein in at least one first circumferential position a diffuser flow channel section ( 33 ) formed between adjacent guide blades ( 20 ) on the stator side has a flow cross section that deviates relative to the diffuser flow channel sections formed in second circumferential positions. 
     
     
         10 . The radial compressor stage according to  claim 9 , wherein relative to the second circumferential positions in the, or each, first circumferential position between the adjacent guide blades ( 20 ) on the stator side at least one sidewall ( 31 ,  32 ) bounding the diffuser flow channel section ( 33 ) is curved inwardly into the diffuser flow channel section ( 33 ) so as to reduce the flow cross section and/or curved outwardly into the stator ( 12 ) subject so as to increase the flow cross section. 
     
     
         11 . The radial compressor stage according to  claim 6 , wherein the first stepping angle deviates from the second stepping angle by ±7°. 
     
     
         12 . The radial compressor stage according to  claim 6 , wherein the first stepping angle deviates from the second stepping angle by ±5°.