Stator vane segment for aircraft engine and method of producing the same
A method of manufacturing a stator for a turbine of an aircraft engine, the stator having an inner shroud, an outer shroud, and airfoils extending from the inner shroud to the outer shroud, the method includes: obtaining raw vane segments including inner shroud raw segments, outer shroud raw segments, and airfoils extending from the inner shroud raw segments to the outer shroud raw segments; determining a desired angle defined between chords of the airfoils and a central axis of the stator based on a desired throat area defined between adjacent airfoils; removing material from the inner shroud raw segments and the outer shroud raw segments based on the desired angle to obtain vane segments having inner shroud segments of the inner shroud and outer shroud segments of the outer shrouds; and assembling the vane segments together to obtain the stator by disposing the vane segments circumferentially around the central axis.
1 . A method of manufacturing a stator for a turbine of an aircraft engine, the stator having an inner shroud, an outer shroud, and airfoils extending from the inner shroud to the outer shroud, the method comprising:
obtaining raw vane segments including inner shroud raw segments, outer shroud raw segments, and airfoils extending from the inner shroud raw segments to the outer shroud raw segments, the inner shroud raw segments and the outer shroud raw segments having opposite inner and outer lateral faces facing baseline directions defining baseline angles with the central axis of the stator, chords of the airfoils defining raw angles with a central axis of the stator;
determining a desired angle defined between the chords of the airfoils and the central axis of the stator based on a desired throat area defined between adjacent airfoils;
removing material from the inner and outer lateral faces of the inner shroud raw segments and the outer shroud raw segments based on the desired angle to change the baseline directions of the inner and outer lateral faces to obtain vane segments having inner shroud segments of the inner shroud and outer shroud segments of the outer shrouds, including changing the raw angles defined between the chords of the airfoil and the central axis to the desired angle by changing angles defined between the central axis and directions normal to the inner and outer lateral faces; and
assembling the vane segments together to obtain the stator by disposing the vane segments circumferentially around the central axis.
2 . The method of claim 1 , wherein the obtaining of the raw vane segments includes obtaining the raw vane segments each including a single airfoil.
3 . The method of claim 1 , wherein the removing of the material from the inner shroud raw segments and the outer shroud raw segments includes:
removing material from faces extending between the opposite inner and outer lateral faces such that the faces face a direction being devoid of a circumferential component relative to the central axis.
4 . The method of claim 1 , wherein the removing of the material from the inner shroud raw segments and the outer shroud raw segments includes machining interlocking features in the inner shroud segments and the outer shroud segments.
5 . The method of claim 4 , wherein the machining of the interlocking features includes machining male members on first inner lateral faces of the inner shroud segments and on first outer lateral faces of the outer shroud segments and machining female members on second inner lateral faces opposite the first inner lateral faces and on second outer lateral faces opposite the first outer lateral faces.
6 . The method of claim 5 , wherein the machining of the interlocking features includes machining the interlocking features using a wire-electrical discharge machining method.
7 . The method of claim 5 , wherein the machining of the male members includes machining half-firtrees, the machining of the female members includes machining half-firtree slots.
8 . The method of claim 7 , wherein the half-firtrees and the half-firtree slots are engageable within each other in a circumferential direction relative to the central axis.
9 . The method of claim 7 , wherein the half-firtrees and the half-firtree slots are engageable within each other in an axial direction relative to the central axis.
10 . The method of claim 1 , wherein the removing of the material from the inner shroud raw segments and the outer shroud raw segments further includes machining slots in first inner lateral faces of the inner shroud segments, first outer lateral faces of the outer shroud segments, second inner lateral faces opposite the first inner lateral faces, and second outer lateral faces opposite the first outer lateral faces.
11 . The method of claim 10 , wherein the assembling of the vane segments includes inserting feather seals in the slots.
12 . The method of claim 1 , wherein the assembling of the vane segments includes abutting each of the inner shroud segments against two adjacent ones of the inner shroud segments and abutting the outer shroud segments against two adjacent ones of the outer shroud segments.
13 . The method of claim 1 , further comprising installing the stator in a turbine section of the aircraft engine, the aircraft engine being devoid of variable guide vanes in the turbine section.
14 . The method of claim 1 , wherein the determining of the desired angle includes determining a first angle and a second angle different than the first angle, the removing of the material includes:
obtaining first vane segments having the first angle by removing material from first inner shroud raw segments of the inner shroud raw segments and first outer shroud raw segments of the outer shroud raw segments; and
obtaining second vane segments having the second angle by removing material from second inner shroud raw segments of the inner shroud raw segments and second outer shroud raw segments of the outer shroud raw segments,
the assembling of the vane segments includes:
assembling the first vane segments and the second vane segments in alteration around the central axis to obtain a mistuned stator.