Air purge for gas turbine engine fuel injector assembly

Abstract

An assembly is provided for a gas turbine engine. This assembly includes an air swirler structure, an injector nozzle and a nozzle guide. The air swirler structure includes an inner bore and an air swirler passage. The inner bore extends axially along an axis through the air swirler structure. The air swirler passage extends radially into the air swirler structure to the inner bore. The injector nozzle projects axially into the inner bore. The nozzle guide couples the injector nozzle to the air swirler structure. The nozzle guide includes a guide foot and an air purge passage radially outboard of the guide foot. The guide foot is configured to radially engage the injector nozzle. The air purge passage extends across the nozzle guide and axially to the inner bore.

What is claimed is: 
     
         1 . An assembly for a gas turbine engine, comprising:
 an air swirler structure including an inner bore and an air swirler passage, the inner bore extending axially along an axis through the air swirler structure, and the air swirler passage extending radially into the air swirler structure to the inner bore;   an injector nozzle projecting axially into the inner bore; and   a nozzle guide coupling the injector nozzle to the air swirler structure, the nozzle guide including a guide foot and an air purge passage radially outboard of the guide foot, the guide foot configured to radially engage the injector nozzle, and the air purge passage extending across the nozzle guide and axially to the inner bore.   
     
     
         2 . The assembly of  claim 1 , wherein the air purge passage extends axially through the nozzle guide to the inner bore. 
     
     
         3 . The assembly of  claim 1 , wherein
 the nozzle guide further includes a plurality of purge passage vanes; and   the plurality of purge passage vanes are arranged circumferentially about the axis, and each of the plurality of purge passage vanes extends radially across the air purge passage.   
     
     
         4 . The assembly of  claim 3 , wherein a leading edge of a first of the plurality of purge passage vanes is spaced an axial distance from an inlet to the air purge passage. 
     
     
         5 . The assembly of  claim 3 , wherein a trailing edge of a first of the plurality of purge passage vanes is spaced an axial distance from an outlet from the air purge passage. 
     
     
         6 . The assembly of  claim 1 , wherein
 the air purge passage includes a plurality of purge passage apertures and a purge passage groove;   the plurality of purge passage apertures are arranged circumferentially about the axis, and each of the plurality of purge passage apertures extends into the nozzle guide to the purge passage groove; and   the purge passage groove extends circumferentially about the axis within the nozzle guide, and the purge passage groove extends axially into the nozzle guide, from the inner bore, to the plurality of purge passage apertures.   
     
     
         7 . The assembly of  claim 6 , wherein the purge passage groove is an annular groove circumscribing the guide foot. 
     
     
         8 . The assembly of  claim 6 , wherein a first of the plurality of purge passage apertures projects radially into the nozzle guide to the purge passage groove. 
     
     
         9 . The assembly of  claim 1 , wherein
 the air swirler structure further includes a radial air swirler comprising the air swirler passage, and the radial air swirler is configured to direct a first quantity of air through the air swirler passage and radially into the inner bore; and   the nozzle guide further includes an axial air swirler comprising the air purge passage, and the axial air swirler is configured to direct a second quantity of air through the air purge passage and axially into the inner bore along a tip portion of the injector nozzle.   
     
     
         10 . The assembly of  claim 9 , wherein
 the radial air swirler is configured to swirl the first quantity of air directed through the air swirler passage in a first direction about the axis; and   the axial air swirler is configured to swirl the second quantity of air directed through the air purge passage in a second direction about the axis that is opposite the first direction.   
     
     
         11 . The assembly of  claim 9 , wherein
 the radial air swirler is configured to swirl the first quantity of air directed through the air swirler passage in a first direction about the axis; and   the axial air swirler is configured to swirl the second quantity of air directed through the air purge passage in the first direction about the axis.   
     
     
         12 . The assembly of  claim 9 , wherein the first quantity of air is greater than the second quantity of air. 
     
     
         13 . The assembly of  claim 1 , wherein the air purge passage is configured to purge air from an interior corner between the nozzle guide and the injector nozzle. 
     
     
         14 . The assembly of  claim 1 , wherein
 the air swirler passage is a first air swirler passage, and the air swirler structure further includes a second air swirler passage;   the first air swirler passage is axially between the second air swirler passage and the nozzle guide; and   the second air swirler passage extends radially into the air swirler structure to the inner bore.   
     
     
         15 . The assembly of  claim 1 , wherein
 the air swirler passage is a first air swirler passage, and the air swirler structure further includes an annulus and a second air swirler passage;   the annulus is radially outboard from the inner bore, and the annulus extends circumferentially about and axially along the inner bore; and   the second air swirler passage extends radially into the air swirler structure to the annulus.   
     
     
         16 . An assembly for a gas turbine engine, comprising:
 an air swirler structure including an inner bore and an air swirler passage, the inner bore extending axially along an axis, and the air swirler passage extending radially into the air swirler structure to the inner bore;   an injector nozzle projecting axially into the inner bore, the air swirler passage circumscribing the injector nozzle; and   a nozzle guide projecting out from the injector nozzle to the air swirler structure, the nozzle guide including an air purge passage that extends across the nozzle guide and axially to the inner bore, the air purge passage configured to purge air from an interior corner between the nozzle guide and the injector nozzle, and an outlet from the air swirler passage arranged axially between a tip of the injector nozzle and an outlet from the air purge passage.   
     
     
         17 . The assembly of  claim 16 , wherein
 the nozzle guide further includes a guide foot radially inboard of the outlet from the air purge passage; and   the guide foot is configured to radially engage and move axially along the injector nozzle.   
     
     
         18 . The assembly of  claim 16 , wherein
 the nozzle guide further includes a plurality of purge passage vanes; and   the plurality of purge passage vanes are arranged circumferentially around the axis, and each of the plurality of purge passage vanes extends across the air purge passage.   
     
     
         19 . The assembly of  claim 16 , wherein
 the air purge passage includes a plurality of purge passage apertures and a purge passage groove;   the plurality of purge passage apertures are arranged circumferentially around the axis, and each of the plurality of purge passage apertures extends into the nozzle guide to the purge passage groove; and   the purge passage groove extends circumferentially around the axis within the nozzle guide, and the purge passage groove extends axially into the nozzle guide to the plurality of purge passage apertures.   
     
     
         20 . An assembly for a gas turbine engine, comprising:
 a fuel injector nozzle extending axially along an axis; and   a nozzle guide circumscribing and slidable axially along the fuel injector nozzle, the nozzle guide including an air purge passage and a plurality of purge passage vanes, the air purge passage extending across the nozzle guide between an inlet to the air purge passage and an outlet from the air purge passage, the plurality of purge passage vanes disposed within the air purge passage and arranged circumferentially about the axis, and each of the plurality of purge passage vanes extending radially across the air purge passage.