Aircraft engine having scroll case assembly
An aircraft engine, has: a combustion engine having an exhaust and drivingly engaged to a load rotatable relative to a central axis; a turbine section engaged with the load; and a scroll case assembly interconnecting the exhaust to the turbine section and having a plurality of sheet metal parts interconnected via braze or weld joints to define a conduit, the sheet metal parts including: a housing extending from a fore end to an aft end; a fore cover having a fore outer periphery secured to the fore end of the housing and a fore inner periphery, an aft cover extending radially from an aft outer periphery secured to the aft end to an aft inner periphery; and vanes distributed around the central axis and located radially between the housing and the fore cover, opposite ends the vanes secured to the radial portion of fore cover and to the aft cover.
1 . An aircraft engine, comprising:
a combustion engine having an exhaust, the combustion engine drivingly engaged to a load rotatable relative to a central axis;
a turbine section in driving engagement with the load to compound power with the combustion engine; and
a scroll case assembly interconnecting the exhaust of the combustion engine to the turbine section, the scroll case assembly having a plurality of sheet metal parts interconnected to one another via braze or weld joints to define a conduit extending around the central axis from an inlet fluidly connected to the exhaust to an outlet fluidly connected to the turbine section, the sheet metal parts including:
a housing defining the inlet and extending axially relative to the central axis from a fore end to an aft end;
a fore cover curving from a radial portion to an axial portion relative to the central axis, the radial portion having a fore outer periphery and the axial portion having a fore inner periphery, the fore outer periphery secured to the fore end of the housing;
an aft cover extending radially relative to the central axis from an aft outer periphery to an aft inner periphery, the aft outer periphery secured to the aft end of the housing, an outlet of the scroll case defined radially between the fore inner periphery of the fore cover and the aft inner periphery of the aft cover, the housing, the fore cover, and the aft cover conjointly defining a conduit extending around the central axis from the inlet to the outlet; and
vanes circumferentially distributed around the central axis and located radially between the housing and the axial portion of the fore cover, opposite ends the vanes secured to the radial portion of fore cover and to the aft cover.
2 . The aircraft engine of claim 1 , wherein the fore cover defines fore cut-outs and the aft cover defines aft cut-outs, the vanes in register with the fore cut-outs and the aft cut-outs.
3 . The aircraft engine of claim 2 , wherein the vanes are hollow.
4 . The aircraft engine of claim 3 , wherein the vanes have leading edges and trailing edges, the vanes including fifths braze or weld joints at one or both of the leading edges and the trailing edges.
5 . The aircraft engine of claim 1 , wherein the fore cover defines a fore flange at the fore outer periphery, the aft cover defining an aft flange at the aft outer periphery, a first weld or braze joint located radially between the fore flange and the housing, a second weld or braze joint located radially between the aft flange and the housing.
6 . The aircraft engine of claim 5 , wherein the fore flange and the aft flange are located radially inwardly of the housing relative to the central axis.
7 . The aircraft engine of claim 1 , wherein one or more of the housing, the fore cover, the aft cover, and the vanes are made of sheet metal.
8 . The aircraft engine of claim 1 , comprising a coupling secured to the housing via a coupling braze or weld joint, the coupling in register with the inlet, the coupling defining a connecting flange configured to be secured to an exhaust pipe of a combustion engine.
9 . A scroll case assembly for an aircraft engine, comprising:
a housing extending around a central axis and defining an aperture therethrough, the aperture being an inlet for receiving combustion gases, the housing extending axially relative to the central axis from a fore end to an aft end;
a fore cover curving from a radial orientation to a axial orientation relative to the central axis from a fore outer periphery to a fore inner periphery, the fore outer periphery secured to the fore end of the housing via a first weld or braze joint;
an aft cover extending radially relative to the central axis from an aft outer periphery to an aft inner periphery, the aft outer periphery secured to the aft end of the housing via a second weld or braze joint, an outlet of the scroll case defined radially between the fore inner periphery and the aft inner periphery, the housing, the fore cover, and the aft cover conjointly defining a conduit extending around the central axis from the inlet to the outlet; and
vanes circumferentially distributed around the central axis and located radially between the housing and the fore cover, the vanes extending from forward ends to rearward ends, the forward ends secured to the fore cover via third weld or braze joints, the rearward ends secured to the aft cover via fourth weld or braze joints.
10 . The scroll case of claim 9 , wherein the fore cover defines fore cut-outs and the aft cover defines aft cut-outs, the forward ends of the vanes in register with the fore cut-outs, the rearward ends of the vanes in register with the aft cut-outs.
11 . The scroll case of claim 10 , wherein the vanes are hollow.
12 . The scroll case of claim 11 , wherein the vanes have leading edges and trailing edges, the vanes including fifths braze or weld joints at one or both of the leading edges and the trailing edges.
13 . The scroll case of claim 9 , wherein the fore cover defines a fore flange at the fore outer periphery, the aft cover defining an aft flange at the aft outer periphery, the first weld or braze joint located radially between the fore flange and the housing, the second weld or braze joint located radially between the aft flange and the housing.
14 . The scroll case of claim 13 , wherein the fore flange and the aft flange are located radially inwardly of the housing relative to the central axis.
15 . The scroll case of claim 1 , wherein one or more of the housing, the fore cover, the aft cover, and the vanes are made of sheet metal.
16 . The scroll case of claim 9 , comprising a coupling secured to the housing via a coupling braze or weld joint, the coupling in register with the inlet, the coupling defining a connecting flange configured to be secured to an exhaust pipe of a combustion engine.
17 . A method for assembly a scroll case of an aircraft engine, the scroll case configured to receive combustion gases in a generally radial orientation and to expel the combustion gases in a generally axial orientation, comprising:
brazing or welding a fore outer periphery of a fore cover to a housing at a fore end thereof;
disposing vanes radially between the housing and a portion of the fore cover and brazing or welding the vanes to the fore cover; and
brazing or welding an aft cover to both of the vanes and to an aft end of the housing.
18 . The method of claim 17 , comprising perforating the fore cover and the aft cover to define fore cut-outs and aft cut-outs, the vanes in register with the fore cut-outs and the aft cut-outs.
19 . The method of claim 17 , comprising making the vanes by folding a rectangular strip of sheet metal and by welding or brazing together opposite edges of the rectangular strip.
20 . The method of claim 17 , further comprising brazing or welding a coupling to the housing and in register with an aperture defined through the housing.