Patent ID: 7588414

Claim:
An arrangement for internal passive turbine blade tip clearance control in a high-pressure turbine in which casing segments located above blade tips of a turbine rotor are supported at front and rear ends of outer platforms thereof by radially movable guide vane segments and concentric inner rings acting upon them whose thermal expansion and contraction behavior matches a load-dependent expansion/contraction of the rotor to provide controlled radial movement of the casing segments to control the blade tip clearance, wherein, an inner platform of each guide vane segment includes front and rear struts forming a U-shaped profile and which are mounted to a U-shaped downstream inner passive ring to form a torsion box which compensates for thermal expansions/contractions in both axial and circumferential directions; the downstream inner passive ring including a first leg and a second leg forming the U-shape, the first leg being firmly tightened to one of the first and second struts of the inner platform with a split taper socket and a threaded fastener, the split taper socket having a collar at one end and a smooth area at an opposite end which is slidingly fitted into holes of the second leg and the other of the first and second struts for expansion/contraction compensation in the axial direction.