Patent ID: 7530233

Claim:
A gas turbine engine, comprising: a rotationally mounted rotor having a longitudinal axis; an axial compressor arranged coaxially along the rotor that produces a compressed intake fluid flow; a combustion chamber arranged downstream of the compressor which receives the fluid flow and a fuel, and combusts the fluid flow and the fuel to form a hot working medium flow; a turbine that receives and extracts mechanical energy from the hot working medium flow; a rotationally fixed inner casing wherein the hot working medium flows through a passage within the inner casing, the inner casing comprising: a front ring having a collar portion extending in the axial direction arranged coaxially with the rotor, and a rear ring having a collar portion extending in the axial direction arranged coaxially and down stream of the front ring with respect to the direction of flow of the working medium, the front and rear rings forming an annular gap in an area where the collars partially overlap, and a single element spring arranged to seal the annular gap from the hot working medium having a first end, a radially free second end and a spring region arranged between the first and second ends, the first end secured in a circumferential groove of either the front ring or the rear ring and the second end in intimate contact with a bearing surface of the collar of the other inner casing ring sealing the annular gap from the hot working medium such that the second end accommodates both radial and axial relative motions between the front and rear rings, wherein a width of the circumferential groove is smaller than a width of the spring element first end to provide a secure and sole retention of the spring element in the circumferential groove due to an interference between the spring element first end and the circumferential groove.