Abstract: An annular support (22) accommodates differential thermal growth between first and second support rings (24, 26). The support (22) prevents relative axial, circumferential lateral and bending movement between the rings (24, 26), while allowing uniform differential radial expansion and contraction.

Abstract: A small gas turbine engine including a power turbine shaft and a gearbox input shaft co-axially aligned one with the other and mounted in three bearings. The power turbine shaft is provided with a male conical surface while the gearbox input shaft is hollow and includes a female conical surface adapted to mate with the male conical surface of the power turbine shaft. The power turbine shaft also includes an axial projection being threaded and inserted within the hollow portion of the gearbox input shaft. A nut having a shoulder is threaded onto the threaded projection of the power turbine shaft and engages a shoulder provided within the hollow gearbox input shaft such that torsion applied to the nut will force axial engagement of the conical surfaces. A complementary spline section may be provided, on the one hand, between the nut engaging shoulder and the female conical section on the gearbox input shaft. The complete coupling is within the diameter of the two co-axial shafts.

Abstract: A separating inlet duct (14) is provided with a reduced arm, bypass throat section (46) to restrict the bypass flow (18b) during periods of high speed aircraft flight. An ejector (34) ensures a minimum bypass flow (18b) during hover or low speed flight. An icing resistance baffle (40) having a rounded leading edge (42) defines the sized throat section (46).

Abstract: A ring gear (20) rotates circumferentially about a plain bearing (22) secured to the housing (10) of a centrifugal gas compressor. The ring gear (20) drives sector gears (18) for positioning variable guide vanes (14). A lever arm (32), actuator (36) and linkage (38, 40, 50) is provided for driving the ring gear (20).

Abstract: A method and fixture (10) for assembling compliant seals (30) includes an aligning member (12) having a grooved surface (14) for receiving a plurality of loose bristle elements (16). The bristle elements (16) are received within the grooves (26) and aligned thereby. First and second backing rings (20, 22) sandwich the aligned bristles (16) and are clamped by first and second clamping members (18, 24). The clamping rings (20, 22) and bristle elements (16) are then removed from the aligning member (12) and permanently secured together, forming the finished seal (30).

Abstract: A planetary gear transmission for use in gas turbine engines is provided which includes a gear case housing fixed to the engine housing, and a ring gear is fixed to the interior of the gear case housing in a cavity defined therein. A first stage planetary gear assembly is provided in the housing, including a first sun gear coupled to an output shaft of the engine, and a first planetary gear carrier is rotatably mounted in the housing. First planetary pinion gears are supported by the first carrier gears and mesh with the first sun gear and with the ring gear. A second stage planetary gear assembly is provided within the housing and comprises a second sun gear coupled to the first planetary carrier. The second stage planetary gear assembly includes a second planetary carrier coupled to a propeller shaft. The second carrier supports planetary pinion gears which mesh with the ring gear and the second gun gear.

Abstract: A method and apparatus for eliminating vortex whistle noise in a radial-to-axial compressor intake uses a plurality of flow fences (36) disposed along the radially inner gas passage boundary (10). The fences (36) disrupt a portion of the swirling gas flow (32) resulting from the position of a plurality of pivotal inlet guide vanes (28) disposed about the radially outward facing inlet (18).

Abstract: A gas turbine engine rotor (18) and shaft (28) are secured against radial loosening between the shaft (28) and axially spaced rotor spigots (24, 26) by annular spacer rings (42, 43) which are fabricated from a material having a thermal coefficient of expansion significantly higher or lower than the thermal coefficients of the shaft (28) or rotor (18). The ring (42, 43) is pre-assembled during production of the engine in an interference fit with either the rotor hub (22) or the shaft (28), being sized to remain tight with the pre-assembled member over a range of operating temperatures, and becoming more tightly fit with the other member due to differential thermal expansion therebetween.

Abstract: A method and system for providing training mode operation of a multiple engine aircraft simulates the failure of one engine and the simultaneous operation of at least one other engine in an elevated, emergency power condition. The engines (20, 22) are mechanically linked (24) and provide a single power output (26). A training power schedule (56a, 56b) is selected (60, 62) to limit the combined engine power output to a level equivalent to the combined output with one engine inoperative and another in an elevated, emergency power operating condition.

Abstract: An elongated conductive casing is filled with a dielectric material and has an opening at one end. The dielectric material forms a surface across the opening, and a plate member is disposed on the surface to form the sensitive arm of the capacitive probe. Formed within the casing are four capacitors, including the sensitive arm, which form a capacitive probe.

Abstract: A capacitance to voltage conversion circuit for converting changes in capacitance of a capacitive bridge-type probe to voltage includes a detector for detecting changes in an excitation signal across a sensitive arm of the probe due to changes in capacitance of the sensitive arm. A variable gain amplifier having a gain control amplifies the output of the detector. The output of the amplifier is fed to a synchronous detector, and the output of the synchronous detector is fed to a comparator whose other input is fed from a source of reference voltage. An offset circuit provides a predetermined imbalance to the bridge, and a switching circuit are provided for switching the offset circuit in the sensitive arm. Both the synchronous detector and the offset circuit are clocked by a reference oscillator.

Abstract: A ceramic stator vane assembly for a gas turbine engine comprises a plurality of ceramic stator vane segments arranged in an annular array with each vane segment having integral concentric tip and root platform members. The tip and root platform members define continuous inner and outer surfaces for receiving inner and outer ceramic rings. Radial and axial housing members are provided for mounting the stator vane assembly within the engine, and thermal insulation means are provided between the ceramic vane assembly and the housing members.

Abstract: A firewall seal in accordance with the present invention comprises a one-piece sheet of flexible fireproof material folded to form at least a two-ply seal component. Aligned openings are provided in each ply. At least one opening in each ply of the sheet is provided for passing a pipe, and a slit extends from the opening to the edge of the respective ply of the sheet, to allow assembly of the folded sheet on the pipe. The slits are staggered from one play to the other. The seal is provided on one side of the firewall only, and the folded sheet-seal components are covered by a pair of metal plates with each plate having a staggered slot for assembly on the pipe, and fastening means are provided for mounting the plates and folded sheet to the firewall.

Abstract: A jet flap construction for the compressor of an aircraft gas turbine engine provided with a bleed for bleeding air interstage of the compressor and communicating with the hollowed-out struts in the airflow path to the compressor. The hollow struts are each provided with one or more rows of discrete openings extending from the shroud to the hub on the strut to form an aligned series of jets for discharging the pressurized bleed air and forming a jet flap, thereby providing pre-swirl at the compressor inlet.

Abstract: A manifold is provided surrounding the casing of a combustion chamber for a gas turbine engine, and the manifold is mounted in spaced aligned segments with couplings between the segments. Each coupling includes a removable tube connector extending between passageways forming the fuel line in the manifold. The tube connector is provided with a radial collar thereon, and a sleeve which is adapted to enclose the space between ends of respective manifold segments is also provided with a mating collar adapted to receive the radial collar on the tube connector. The sleeve is retractable over the ends of the manifold segments, and movement of the sleeve in one direction or the other will also move the tube connector by virtue of the interlocking collars. The manifold segments are provided with a second passageway for draining leaked fuel. The space defined by the sleeve is sealed, and fuel can communicate through to the second passageway for drainage outboard of the engine.

Abstract: An impeller shroud is mounted in a cantilever manner to a stator assembly in a compressor for a gas turbine engine, wherein the impeller has a radial component, the impeller shroud being adapted for deflection around its outer portion in correspondence with deflection which may occur in the outer portion of the impeller. The stator assembly includes a shroud surrounding the compressor gas path and is directly fixed to the casing of the engine and has a common datum with the rotor portion of the compressor through a thrust bearing.

Abstract: A compact torque measuring device for a gas turbine engine which has an output shaft. The torque measurement device includes a pair of tubular concentric shafts of elastic deformable material. The inner shaft is fixed to the output shaft and includes peripheral reference teeth fixed to the output shaft. The concentric shafts are fixed together at the other end in a cantilever manner. Peripheral teeth are mounted to the outer concentric shaft adjacent and interposed with the reference teeth. A magnetic electrical detector is provided to measure relative displacement between the teeth, and thus the torque magnitude can be determined.

Abstract: A free turbine, gas turbine engine provided with a pre-swirl arrangement in the compressor, based on bleeding air from the compressor and using the bleed air as a pre-swirl device upstream of the compressor to increase its rotational speed. A governor device, driven from the compressor rotor, controls the amount of pre-swirl bleed air to maintain a constant compressor speed from minimum to maximum power. Compressor rotor and gas inertia effects during acceleration are thus eliminated.

Abstract: A method of flank milling complex surfaces comprising the steps of analyzing the design surface to determine discrete areas in which straight lines can be drawn, determining straight lines in the discrete areas, transposing the coordinates of these straight lines and comparing them with the flank tool cutter positions, determining the tool positions to said straight lines, back generating the contact lines of said surface and comparing these with the design surface, determining the number of passes of said cutter tool and generating data for numerical control machining.

Abstract: A particle separator for a gas turbine engine is described having an inlet passage to the compressor of the gas turbine engine, with the inlet passageway being defined by an inner wall and an outer wall. The inner wall diverges outwardly to form a throat with a diverging outer wall and converges inwardly downstream thereof. A first bypass opening is provided immediately upstream of the diverging inner wall, whereby solid and liquid particles can be diverted and passed overboard. A splitter ring is provided in the inlet passageway downstream of the converging inner wall, such that the finer particles escaping from the first bypass openings would be separated by the splitter ring.