Blade outer seal assembly

Apparatus for locking a blade outer air seal (BOAS) in place about a turbine rotor stage for a jet engine that includes:

• an engine casing that surrounds said rotor stage, said casing having a circular radially disposed wall and an axially disposed groove adjacent said wall, said groove having an inner wall and an outer wall, said outer wall extending outwardly beyond the entrance to said groove;
• an annular hanger for supporting the BOAS, said hanger having a plurality of circumferentially spaced hanger elements that extend into said groove, said hanger further having a front face that is adjacent to the radial wall of the casing and an opposing rear face;
• an annular segmented assembly wherein each segment includes an arcuate shaped radially disposed panel and a plurality of hooks attached to said panel and passing between the hanger elements into said groove, each panel having a first sealing pad extending along its radially outer rim that rests in sealing contact against the outer wall of said groove and a second sealing pad extending along the front face of the panel that rests in sealing contact against the rear face of the annular hanger;
• each hook having a contact portion which engages said groove inner wall which acts as a fulcrum to apply a torque to the associated panel through said lever arm;
• and
• means to prevent axial movement of said segmented assembly.

A method for securing an outer seal assembly of a turbine rotor stage to the turbine casing comprising the steps of:

• providing a plurality of radially outwardly extending arms on said outer seal assembly, said arms having a rear surface and a plurality of axially forwardly extending hanger elements;
• providing a mounting flange on the inner side of said casing and having a radially inwardly extending leg and an axially rearwardly extending leg with a radially outer surface which, together with the inner side of said casing, forms a circumferential groove for receiving said hanger elements therein;
• providing a plurality of arcuate elements having an angle-shaped cross section comprising a radially extending panel with a plurality of axially forward extending hooks adapted to be received in said circumferential groove and having at least one axially forwardly extending flange for engaging said arm rear surface of said outer seal assembly;
• and
• locking said outer seal assembly and said angle-shaped flange in their installed positions within said groove.