| 摘要 |
1,199,974. Turbines. UNITED AIRCRAFT CORP. Oct.9, 1967 [Nov. 2, 1966], No.46127/67. Heading F1T. Turbine rotor blades 6 are sealed at their tips by a circumferential sub strip 34 carried by a generally circumferential retainer 32 which can expand radially while being maintained concentric with the turbine axis by projections 30 radially slidable within radial slots 28 provided in a flange 16 (or by similar projections slidable within radial slots provided in a ring 24 which supports stator vanes 26), an annular baffle 36 extends within the annular space between the sub strip and the retainer to form a passageway 43 communicating with cooling-air passageways formed in the retainer, and the sub strip, retainer and baffle are connected by a pin 44 so that they expand radially as a unitary assembly. Another annular baffle 38 may be provided to afford a further passageway 39. The turbine forms part of a gas turbine engine having a compressor from which air is bled to pass between outer and inner casing walls 8, 10 and through openings in a ring 22 and thence through the above-mentioned passageways to cool the retainer 32. The thermal expansion of the seal assembly relative to that of the rotor 4 is thereby controlled to keep the blade tip clearance to a minimum under all operating conditions. To allow for the thermal expansion, the sub strip 34 is axially slotted or is divided into segments and the retainer 32 has axially extending grooves. |
