摘要 |
A blade clearance control apparatus (46) for a gas turbine engine (10) comprises a series of segments (42) which define a casing in the rotor path of high pressure shroudless turbine blades (30). The segments (42) are attached to plates (78) having surfaces co-operating with chordal lengths (74) of a number of pressure tubes (68) which are located in a frame (46). The application and release of pressure to the pressure tubes (68) causes the segments (42) to move between inner and outer positions in order to control clearance X between the tips of blades (30) and the segments (42).
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