United Technologies Corporation

Richard J Tiernan, Jr

Joseph C Burge

William E Dixon

Bruce V Lyon

Lee E Hensen

The segmented inner case supporting the stator vanes of the compressor is tied to an axially split outer case of a gas turbine engine by utilizing a segmented ring-like element forming a rail with bosses at either end and intermediate the ends and having a relatively thin resilient body between bosses capable of flexing in response to thermal loads. Bolts extending through the outer case are threaded into the bosses. This arrangement facilitates the assembly and disassembly of the compressor section.

Case tying means for gas turbine engine

Rotating machinery construction employing one or more split balance rings within a rotating element the circumferential position of a ring being adjustable through associated casing structure without disassembly of the machinery to permit rebalancing or trim balancing of the rotor element.

Rotor trim balancing

A 'dog bone' in cross section shaped seal mounted in adjacent grooves of segmented stator vanes span the axial extent covering a single casted three rows of vanes. The outer diameter shroud of the stator vane defines a portion of an enclosed cavity subjected to leakage flow in and out of the gas path where the flow reverses at some axial extent of the seal such that the forces acting at different locations on the seal reverses. In a preferred embodiment, the bulbous ends of the 'dog bone' are solid coated metallic material.

Segmented stator vane seal

The thermal environment to which the engine's compressor case is subjected is controlled and the coefficient of expansion selected for the stator and rotor components are suitably matched to improve engine performance by reducing radial clearances during part power engine operations. A thermal barrier around the engine case by virtue of a heat shield attached to the customary case flanges and the coaxially mounted spaced stator vanes forming an inner case defining cavities sandwiching the engine case and holds the metal temperature at a value higher than would otherwise be provided. The thermal barrier serves to isolate the outer case from the engine's fan discharge air and the engine's core gas path.

Compressor case with controlled thermal environment

Two shafts 12, 14 are secured axially with bolts 58 through flanges 22 and 32. Coupling 42 is splined to the shafts and resists bending by interaction of bearing surfaces 46, 44, 48 and 50. Threads 66 on one end of the shaft and an inwardly extending flange 68 on the coupling provide a means for removing a shaft without placing axial loading on bearing 18. Either shaft may be removed while leaving the coupling 42 in place to protect the bearing compartment. Axial loading is taken by bolts 58, torque loading by splines 30, 40 and bending moment taken by the interacting surfaces.

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Hobe Sound, FL, United States of America

Richard J Tiernan, Jr