Avco Corporation

Zoltan L Libertini

Edward O Hartel

Theodore Ivanko

Joseph C Manente, Jr

Steven D White

Alan R Duly

Donald E Wilson

James Martinelli

A ceramic nozzle assembly for a gas turbine engine is provided. The assembly includes ceramic inner and outer shroud rings dimensioned to be concentrically disposed relative to one another. Recesses are provided in the outer circumferential surface of the inner shroud ring and apertures extend through the outer shroud ring in register with the recesses. Vanes extend through the apertures in the outer shroud ring and are engaged by the recesses in the inner shroud ring. A ceramic outer support ring slides over the outer shroud ring to securely retain the vanes. Slots or recesses are provided in both the inner and outer shroud ring to prevent rotation of the nozzle in the engine.

Ceramic nozzle assembly for gas turbine engine

A combination air and oil cooled seal housing is provided which also utilizes trapped stagnant air as an insulator. The combination prevents coking of the oil supplied as a lubricant to the bearings and seals in the hot section of a turbine engine. Pressurized air is introduced from the compressor into the inner structure support housing by means of hollow passages. The pressurized air absorbs heat as it traverses the passages in the structure. The oil supplied is connected to an annular shape cavity allowing the oil to be circulated therein and cool the seal support structure. Additional insulation is provided by cylindrically shaped trapped air shields surrounding the bearing package. Oil flowing through the structure can then properly lubricate the seals and bearings which support the turbine rotor stages within the housing assembly.

Air and oil cooled bearing package

A combination air and oil cooled seal housing is provided which also utilizes trapped stagnant air as an insulator. The combination prevents coking of the oil supplied as a lubricant to the bearings and seals in the hot section of a turbine engine. Pressurized air is introduced from the compressor into the inner structure support housing by means of hollow passages. The pressurized air absorbs heat as it traverses the passages in the structure. The oil supply is connected to an annular shape cavity allowing the oil to be circulated therein and cool the seal support structure. Additional insulation is provided by cylindrically shaped trapped air shields surrounding the bearing package. Oil flowing through the structure can then properly lubricate the seals and bearings which support the turbine rotor stages within the housing assembly.

A cylinder of a gas turbine engine is formed of a multilayered construction including a radially inner ceramic ring, the inner surface of which is juxtaposed to the tips of a turbine rotor, an intermediate arrangement of two annular ceramic rings that are substantially L-shaped in cross-section and are disposed in mirror image so as to entrap the radially inner ceramic ring, and a radially outer metallic support means which envelopes the intermediate ceramic rings for maintaining the composite ceramic structure during different operating modes of the turbine engine. The composite ceramic portion of the cylinder enables the engine to operate at higher temperatures, and offers the potential for improved turbine tip clearance control, since the ceramic material is less sensitive to thermal distortion.

Composite ceramic/metal cylinder for gas turbine engine

In a dynamically balanced turbine wheel wherein a plurality of turbine blades are secured to a turbine disc by conventional fir tree mounting arrangements, a retaining assembly is provided to positively restrain movement of the turbine blades in an axial direction forward or aft of the wheel. A tang is machined in the leading edge of the root of each blade and bears against the forward face of the disc to prevent axial movement of the blade in the aft direction. To restrain each blade from axial movement in the forward axial direction, a radial groove is machined into the aft side of the disc and the trailing edge of the root of each blade for accommodating a wire-type retainer which is held in place by a generally cylindrical plate. The latter is piloted on the disc and secured by means of a split retainer ring which is accommodated in opposed continuous slots provided in the plate and the disc. The split retainer ring includes enlarged projections which are accommodated in enlarged portions of the opposed continuous slots, with the projections being symmetrically arranged about the periphery of the split retainer ring. The resulting assembly is dynamically balanced, and prevents relative rotation between the plate and the disc, while preventing axial movement of the blades in the cooperating channels provided in the periphery of the turbine disc.

Boltless blade retainer for a turbine wheel

A probe is constructed for placement in the hot turbine section of a gas turbine engine. A housing containing two electrodes extends through the turbine shroud into the tip clearance area of the turbine rotor. A voltage impressed across the electrodes will generate an electric field in the vicinity of the turbine blades which will be distorted as the blades pass, thereby generating a charge pulse at the output of the probe. The electrode conductors are imbedded in pins which are retained by insulating rings brazed in place. The electrodes extend slightly outward from the surrounding insulating surfaces to create an air gap around each electrode. This air gap provides additional insulation and prevents contamination.

Electrode structure for a high temperature capacitance probe for sensing

The shroud or stationary housing for the impeller of a centrifugal compressor includes inherent means for selectively controlling the displacement thereof during operation of the centrifugal compressor, and in a manner to substantially maintain uniform spacing or clearance between the shroud and the blade tips of the rotating impeller in order to achieve improved performance at both part and full power operating conditions. The shroud is preferably formed of a unitary member including an annular, concave disc portion substantially corresponding to the configuration of the tips of the blades of the impeller, with the annular concave disc portion being rigid and connected to a fixed flange support portion by a flexible, annular diaphragm which extends generally perpendicular to the shaft of the impeller. The annular diaphragm is sufficiently flexible such that during operation of the centrifugal compressor, the differential thermal and pressure forces generated along the length of the blades within the compressor cause deformation of the flexible diaphragm and a substantially linear movement of the rigid, concave disc portion relative to the flange support portion. The movement of the annular concave disc portion substantially corresponds to the change in configuration of the blades, thereby minimizing blade tip losses.

Impeller shroud of a centrifugal compressor

A centrifugal oil filter for removing contaminant particles from a pressurized fluid medium includes a cylindrical drum concentric with and fixedly secured to a rotational shaft, with an annular disc being disposed within and rotatable with the drum. The disc is centered within the drum and spaced from the internal circumferential surface of the drum so as to partition the drum into two radial passageways interconnected at said internal circumferential surface. The latter is of irregular configuration to define an annular collection zone for collecting contaminant particles centerfuged outwardly by rotation of said drum. Pressurized fluid medium is provided to one radial passageway, flows past the annular collection zone where the contaminant particles are centerfuged and entrapped in the irregular internal circumferential surface of the drum, after which the pressurized fluid medium is forced radially inwardly through the other radial passageway and out of the centrifugal oil filter.

Centrifugal oil filter

A support strut for gas turbine engines is disclosed which includes an internal wall employed as a lubricating oil duct and which is separated from the outer wall to form an insulating chamber which is closed at one end and which is sealed at the other end by means of a sliding seal member which bridges the open end of the chamber. The sliding seal preferably is secured to the outer strut wall and includes a sleeve portion in telescoping engagement with the interior wall of the oil duct.

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Stamford, CT, United States of America

Zoltan L Libertini