Abstract: A method of adhering a ceramic facing material to an underlying substrate is disclosed. Substrates to which the concepts apply include unsupported low modulus, porous wire pads as well as low modulus, porous wire pads backed by a solid metallic form. The ceramic application techniques employed are centered around the impregnation of the regions of the pad to be ceramic coated with an underlayment coating, such as MCrAlY material, wherein the designation "M" stands for at least one of the elements from the iron cobalt and nickel group. Deep penetration of the underlayment material into the pad is achieved with a high velocity, spraying process. Ceramic material is applied over the underlayment material by conventional spraying techniques.Articles of manufacture which are suited to fabrication in accordance with the concepts disclosed herein include, but are not limited to, outer air seals, combustion chambers, and airfoils of gas turbine engines.

Abstract: Apparatus for mounting a workpiece to be coated in a cathode sputtering device is disclosed. Various construction details enable effective masking or shielding of a portion of the workpiece from coating deposition. In detailed form a box-like member circumscribes the platform of a blade or vane to be coated and encases the attachment section of the blade or vane.

Abstract: A compressor structure for a gas turbine engine capable of enhanced active clearance control within the compressor is disclosed. Various construction details which enable the discharge of cooling air against the compressor case and which minimize thermal distortion of the case are developed. The concepts are applied to a longitudinally split compressor case and include an external bleed manifold of circular cross section which extends across the longitudinal split in the case. Cooling air is dischargeable beneath the manifold to cool the case structure. Heat shields are provided in access ports to the manifold to inhibit heat transfer to the compressor case at the local regions of the ports.

Abstract: The present invention provides methods and apparatus improving the dimensional accuracy of forged components. Uniformity of like component details is sought and a specific object is to provide a die package for forming closely toleranced appendages integrally with a central disk structure from which the appendages extend.In one effective embodiment incorporating concepts of the present invention, the forging dies include a stationary die and a movable die comprising at least two separately movable elements which are mounted on a common axis with the stationary die. A plurality of arcuate die segments are adjacently placed in cylindrical array about the stationary and movable dies. The arcuate die segments form cavities of the inverse geometry of the appendages to be formed and in at least one embodiment are interlocked to prevent tilting of the segments in the die package.

Abstract: A gas turbine engine has a rotor including a rotor shaft which is journaled within an external structural engine casing. Stator elements are mounted within the external casing about the rotor, and in order to maintain a precise radial clearance between the rotor and stator elements, a stator support assembly is positioned within the engine casing and supports the stator elements relative to the rotor. The support assembly is comprised by an internal casing having one portion that is free to move by a limited amount in radial directions relative to the external casing, and a casing support disc extending generally radially outward to the internal casing from a bearing on the rotor shaft. The casing support disc holds the internal casing radially fixed relative to the shaft and, thus, references the movable portion of the internal casing relative to the rotor and rotor shaft rather than the external engine casing.

Abstract: A gas turbine engine has an engine casing surrounding the turbine section and an internal chamber or jacket which separates the casing from blade tip seals supported by the casing. To maintain an adequate clearance between the turbine blades and the seals during engine startup and acceleration, a portion of the hot combustion gases passing through the turbine blades is bled through the chamber in heat exchange relationship with the casing. The hot gases expand the casing at a faster rate than otherwise to approximate the thermal growth rate of the turbine rotor and maintain a adequate clearance between the turbine blade tips and seals. During steady-state operation relatively cool air bled from the compressor is ducted through the chamber to cool the engine casing and hold the proper clearance between the blades and the seals.

Abstract: A plasma spray method capable of directing plasticized powders against a substrate for deposition of a protective coating thereon is disclosed. Various structural details of the apparatus described enable the attainment of high particle velocities without melting the particles. The technical concepts employed are directed to normalizing the temperature of the plasma stream at a reduced value prior to the injection of coating particles. A general reduction in temperature and substantial elimination of a thermal spike at the core of the stream are achieved. Coating particles are injected into the plasma stream only after the plasma is first cooled and then preferably accelerated. In detailed embodiments, a nozzle extension assembly having a plasma cooling zone, a plasma acceleration zone, a powder injection zone and a plasma/powder discharge zone is affixed to the downstream end of a conventional plasma generator.

Abstract: The present invention provides a technique for improving the dimensional accuracy of forged components. Uniformity of like component details is sought and a specific object is to provide a die package for forming closely toleranced appendages integrally with a central disk structure from which the appendages extend.In one effective embodiment incorporating concepts of the present invention, the forging dies include a stationary die 26 and a moveable die 28 which are mounted on a common axis and a plurality of arcuate die segments 30 which are adjacently placed in cylindrical array about the stationary and moveable dies. The arcuate die segments form cavities of the inverse geometry of the appendages to be formed and are interlocked to prevent tilting of the segments in the die package. A collar 40 extends from the stationary die to interlocking engagement with a channel 46 in the inwardly facing surface of each arcuate die segment.

Abstract: A blade tip shroud structure for a compression stage of a gas turbine engine is disclosed. Various concepts relating to shroud designs and their influence on blade performance are discussed. In accordance with the teaching contained herein, one shroud geometry includes a circumferentially extending recess in the wall of a case which circumscribes the tips of the blades. A surface at the bottom of the recess has discontinuities therein. The tips of the blades run line on line with the respective wall at the design operating condition of the engine in which the shroud structure is incorporated. In one embodiment axially skewed grooves and circumferentially extending grooves form the surface discontinuities.

Abstract: A fiber optic encoding device capable of long term reliable operation in hostile environments is disclosed. Various construction details which contribute to a compact device with high mechanical reliability are discussed. An encoder formed to a cylindrical geometry including a correspondingly shaped code plate is shown in detail. The code plate has a multiplicity of apertures arranged in rows to produce an encoded position signal of the type suitable for use in digital intelligence processing equipment.

Abstract: An airfoil tip seal structure for an axial flow rotary machine is disclosed. Various concepts relating to seal designs and their influence on tip sealing effectiveness are discussed. In accordance with the teaching contained herein, one seal geometry includes a circumferentially extending groove in the stator which circumscribes the tips of the blades of a corresponding rotor stage. Another seal geometry applicable to machines having cantilevered stator vanes includes a circumferentially extending groove in the rotor which circumscribes the tips of the vanes of a corresponding stator stage. The tips of the blades and the tips of the cantilevered stator vanes run over the corresponding groove in line on line relationship with the adjacent flow path wall at the design operating condition of the machine in which the seal structure is incorporated.

Abstract: A thermal spray method capable of directing plasticized powders against a substrate for deposition of a protective coating thereon is disclosed. Various structural details of the apparatus described enable the attainment of high particle velocities without melting the particles. The method is built around the concept of reducing the temperature of a hot plasma stream after the hot plasma stream is generated. Coating particles are injected into the hot plasma stream only after the medium is cooled. In detailed embodiments, a generated plasma is cooled by the addition of a diluent gas or by passing the generated plasma through an elongated heat exchanger upstream of the point at which the powders are to be injected. The plasma is accelerated after the plasma is cooled to recover velocity lost in the cooling step.

Abstract: Thermal spray apparatus capable of directing plasticized powders against a substrate for deposition of a protective coating thereon is disclosed. Various structural details of the apparatus of the present invention enable the attainment of high particle velocities without melting the particles. The apparatus is built around the concept of reducing the temperature of a hot plasma stream after the hot plasma stream is generated. Particles are injectedinto the hot plasma stream only after the medium is cooled. In detailed embodiments, a generated plasma is cooled by the addition of a diluent gas or by passing the generated plasma through an elongated heat exchanger upstream of the point at which the powders are to be injected.

Abstract: An improved combustor for a gas turbine engine is disclosed. Techniques for reducing the level of noxious pollutants emitted by the combustor are developed. In one embodiment, a combination of serpentine geometried, fuel-mixing tubes discharging to the radially outward area of the combustor and an axially oriented, fuel-mixing tube near the center of the combustor are adapted to generate a strong centrifugal force field within the combustor. The force field promotes rapid mixing and combustion within the chamber to reduce both the magnitude of the combustor temperature and the period of exposure of the medium gases to that temperature. In accordance with the method taught, the fuel air ratio in the serpentine mixing tubes is maintained within the range of 0.035 to 0.05 and the fuel air ratio in the axial mixing tube is maintained at a value less than 0.05.

Abstract: An improved combustor for a gas turbine engine is disclosed. Techniques for reducing the level of noxious pollutants emitted by the combustor are developed. In one embodiment, a combination of serpentine geometried, fuel-mixing tubes discharging to the radially outward area of the combustor and an axially oriented, fuel-mixing tube near the center of the combustor are adapted to generate a strong centrifugal force field within the combustor by swirling the fuel/air mixtures flowing therethrough. The force field promotes rapid mixing and combustion within the chamber to reduce both the magnitude of the combustor temperature and the period of exposure of the medium gases to that temperature. The tube at the center of the combustor is adapted to swirl the medium flowing therefrom in a circumferential direction counter to the direction in which the medium from the serpentine geometried tubes is swirled.

Abstract: Apparatus for impeding the leakage of a gaseous medium between the rotating and stationary components of a machine is disclosed. Various construction details which are specifically adapted for use in gas turbine engines are developed. Wide channel type sealing techniques are discussed in combination with honeycomb facing materials.

Abstract: An improved combustor for a gas turbine engine is disclosed. Techniques for reducing the level of noxious pollutants emitted by the combustor are developed. In one embodiment, a combination of serpentine geometried, fuel-mixing tubes discharging to the radially outward area of the combustor and an axially oriented, fuel-mixing tube near the center of the combustor are adapted to generate a strong centrifugal force field within the combustor. The tube near the center of the combustor has a convergent section at the upstream end thereof and a divergent section at the downstream end thereof. Fuel supply means is adapted to discharge fuel into the convergent section of the tube. Vaporization of the fuel in the tube is aided by maintaining a differential axial velocity over the length of the tube. The force field promotes rapid mixing and combustion within the chamber to reduce both the magnitude of the combustor temperature and the period of exposure of the medium gases to that temperature.

Abstract: A bearing support structure capable of reliable operation in a rotary machine is disclosed. Various construction details which enable the damping of vibratory energy are discussed. Fluid damping and spring damping apparatus are combined in forming an effective structure for damping synchronous and non-synchronous vibratory energy. The system is built around a plurality of arcuate beams which effect spring damping, and which collaterally form chambers for the containment of a fluid damping medium.

Abstract: A rotary liquid metal atomizer is positioned to receive a stream of molten metal on the top thereof. The atomizer is formed as a hollow disc means having a concave top surface and mounted for rotation at high R. P. M.'s on the top of a hollow drive shaft. A circular coolant baffle is located in the hollow disc means, for cooling fluid to flow around, and is mounted on the top of an inlet cooling tube located within the drive shaft. Cooling fluid is directed through the inlet cooling tube to the top of the water baffle where it flows through a hole in the center thereof and around the space between the baffle and the interior of the hollow disc means and down between the inlet cooling tube and drive shaft. The top of the disc means over the coolant baffle is formed of copper. A metal rim is placed around the upper outer periphery of the copper disc forming a recessed center portion. A ceramic coating is placed in the recessed portion with its outer edge against the inside of the rim.

Abstract: A coolable disk structure which is capable of extended use in the turbine section of a gas turbine engine is disclosed. Various construction details which improve the service life of the disk are developed. Techniques which provide positive control of the heating and cooling rates in turbine disks are incorporated in the structure to increase the low cycle fatigue life of the disk by optimizing the disk thermal profile.