Variable guide vane sealing

Abstract

A variable guide vane assembly is provided for a turbine defining a core air flowpath. The variable guide vane assembly includes an airfoil band defining a flowpath surface and a cavity. The variable guide vane assembly further includes an airfoil including a first end extending at least partially into the cavity of the airfoil band and an opposite second end, the airfoil extending generally along an axis between the first end and the second end and being moveable generally about the axis relative to the airfoil band. The variable guide vane assembly further includes a sealing element operable to form a seal between the first end of the airfoil and the airfoil band.

What is claimed is: 
     
         1 . A variable guide vane assembly for a machine defining a core air flowpath, the variable guide vane assembly comprising:
 an airfoil band defining a surface exposed to the core air flowpath;   an airfoil comprising a first end and an opposite second end, the airfoil extending along an axis between the first end and the second end and being moveable about the axis relative to the airfoil band; and   a sealing element positioned at the first end to contact and form a seal between the first end of the airfoil and the surface of the airfoil band.   
     
     
         2 . The variable guide vane assembly of  claim 1 , wherein the first end of the airfoil includes an outer surface along the radial direction, and wherein the sealing element is configured to contact and form a seal between the radially outer surface of the outer end of the airfoil and the surface of the airfoil band. 
     
     
         3 . The variable guide vane assembly of  claim 1 , wherein the first end of the airfoil defines a channel for at least partially receiving the sealing element. 
     
     
         4 . The variable guide vane assembly of  claim 1 , wherein the machine is a gas turbine engine. 
     
     
         5 . The variable guide vane assembly of  claim 4 , wherein the airfoil is a variable stator vane configured for a turbine section of the gas turbine engine. 
     
     
         6 . The variable guide vane assembly of  claim 4 , wherein the airfoil is a variable stator vane configured for a high pressure turbine of a turbine section of the gas turbine engine. 
     
     
         7 . The variable guide vane assembly of  claim 1 , wherein the airfoil extends between a leading edge and a trailing edge, and wherein the sealing element extend along a length of the airfoil between the leading edge and the trailing edge. 
     
     
         8 . The variable guide vane assembly of  claim 1 , wherein the sealing element extends from a location forward of the axis to a location aft of the axis. 
     
     
         9 . The variable guide vane assembly of  claim 1 , wherein the airfoil band is an outer airfoil band. 
     
     
         10 . The variable guide vane assembly of  claim 9 , wherein the sealing element is location inward of the surface of the airfoil band along a radial direction. 
     
     
         11 . A gas turbine engine comprising:
 a compressor section;   a combustion section; and   a turbine section, the compressor section, combustion section, and turbine section in serial flow order and defining at least in part a core air flowpath, the turbine section comprising a variable guide vane assembly comprising
 an airfoil band defining a surface exposed to the core air flowpath; 
 an airfoil comprising a first end and an opposite second end, the airfoil extending along an axis between the first end and the second end and being moveable about the axis relative to the airfoil band; and 
 a sealing element positioned at the first end to contact and form a seal between the first end of the airfoil and the surface of the airfoil band. 
   
     
     
         12 . The gas turbine engine of  claim 11 , wherein the first end of the airfoil includes an outer surface along the radial direction, and wherein the sealing element is configured to contact and form a seal between the radially outer surface of the outer end of the airfoil and the surface of the airfoil band. 
     
     
         13 . The gas turbine engine of  claim 11 , wherein the first end of the airfoil defines a channel for at least partially receiving the sealing element. 
     
     
         14 . The gas turbine engine of  claim 11 , wherein the airfoil is a variable stator vane configured for a turbine section of the gas turbine engine. 
     
     
         15 . The gas turbine engine of  claim 11 , wherein the airfoil is a variable stator vane configured for a high pressure turbine of a turbine section of the gas turbine engine. 
     
     
         16 . The gas turbine engine of  claim 11 , wherein the airfoil extends between a leading edge and a trailing edge, and wherein the sealing element extend along a length of the airfoil between the leading edge and the trailing edge. 
     
     
         17 . The gas turbine engine of  claim 11 , wherein the sealing element extends from a location forward of the axis to a location aft of the axis. 
     
     
         18 . The gas turbine engine of  claim 11 , wherein the airfoil band is an outer airfoil band. 
     
     
         19 . The gas turbine engine of  claim 18 , wherein the sealing element is location inward of the surface of the airfoil band along a radial direction.