Turbine exhaust case design

In an axial flow gas turbine engine including a turbine section comprising at least one turbine rotor stage, a turbine exhaust case assembly disposed downstream from said rotor stage and including means defining an axially extending annular gas flow path, the exhaust case assembly comprising:

• inner case means;
• outer case means spaced radially outwardly from said inner case means;
• a stage of turbine exit guide vanes disposed in said gas flow path for straightening the flow of gases exiting said turbine rotor stage, said guide vanes having radially outer ends attached to said outer case means in a manner permitting rocking of said vanes in an upstream and downstream direction about the point at which they are attached to said outer case means;
• a plurality of circumferentially disposed struts extending radially across the flow path downstream of said guide vanes and having inner ends fixedly attached to said inner case means and outer ends fixedly attached to said outer case means;
• and
• fairing means having an upstream end and downstream end, said fairing means including sheet metal wall means having an upstream end, said wall means being disposed between said inner case means and outer case means defining the radially inner surface of said annular gas flow path immediately downstream of said exit guide vanes, said fairing means being cantilever supported from its downstream end from said inner case means downstream of said struts, each of said struts passing through an opening in said wall means, said upstream end of said fairing means engaging said inner ends of said exit guide vanes to provide axial support for said guide vanes, said fairing means comprising a support ring integral with said upstream end of said sheet metal wall means, said support ring providing stiffness to said wall means and having an annular outwardly facing channel disposed therein, said inner ends of said exit guide vanes including tangs extending radially inwardly into said channel, the width of said channel in the axial direction being wider than the thickness of said tangs in the axial direction, permitting axial movement of the inner ends of said vanes, said inner ends of said exit guide vanes being free to move radially relative to said fairing means.