Abstract: An air blast fuel nozzle for a gas turbine engine includes a take apart head assembly having a large diameter air swirler for fuel flow from a pilot fuel distributor tube that is telescoped centrally within a take apart main fuel distributor and pilot nozzle element having means therein to form a thermal barrier air gap around the pilot fuel distributor tube and wherein the assembly further includes a main fuel distributor head having open ended axial fuel passages therethrough for supplying fuel to a main fuel distributing ring on the outboard end of the assembly immediately upstream of the air swirler.
Abstract: A regenerator seal assembly for use in a rotary regenerator includes a two-stage seal with a peripheral rim seal having a seal leaf turned inside out so that the free end of the leaf is of a smaller radius of curvature than the fixed end of the leaf and wherein the outer peripheral rim seal is made up of a plurality of straight leaf segments formed on chord lines along the outer circumference of the seal assembly with each straight leaf segment being joined by a mitered joint so that the free end of each such leaf segment is deflected without formation of waviness of wrinkles in the seal assembly.
Abstract: A method for manufacturing a hybrid, dual property turbine wheel assembly comprising the steps of preforming a blade element and separate support ring of a supperalloy material and locating the blades in support slots in the outer diameter of the support ring and radially outwardly of a preformed inner diameter underlying base tangs on each blade element; vacuum braze sealing each of the base tangs within a support slot and thereafter machining the inside diameter of the ring to expose the base tangs; thereafter joining the ring and undercut base tangs thereon to the outside diameter of a preformed disc element and vacuum braze sealing the hub disc and ring blade assemblies to produce a sealed interface region between the outside diameter of the hub element and the inside diameter of the ring and base tangs; and thereafter directly hot isostatically pressing the joined parts to form a direct diffusion bond between the tangs, ring and disc.
Abstract: An exhaust pipe of a front engine mounted transversely to roll about an axis transverse to the longitudinal axis of the vehicle is joined to a tailpipe by an improved high temperature resistant flexible coupling including a spherically surfaced ring seal supported between a tubular end segment of a first pipe and a free end spherical surface on a second pipe; the second pipe having a flange connected thereto and a pair of bolts are resiliently coupled to the flange fixed on the first pipe to bias the spherical lip against a high temperature lubricant surface on the seal to define a joint with minimal resistance to roll motion so that it readily accommodates substantial angular offset between the first and second pipe segments during high temperature exhaust conditions while maintaining a positively sealed surface at the joint.
June 6, 1977
Date of Patent:
June 27, 1978
General Motors Corporation
Daniel G. Crawford, Stanley E. James, Donald H. Nixon
Abstract: A gas turbine engine acoustic noise damping mount on a helicopter airframe includes a first outboard washer assembly with metallic inner and outer washers having a thin layer of elastomer bonded therebetween; an inboard bushing assembly has telescoped inner and outer metallic bushings with a thin layer of elastomer bonded therebetween; an engine trunnion is supported by the inner bushing; and flat inboard faces on the washer assembly and inboard bushing assembly are held against either side of an airframe strut by a nut threaded to the trunnion. The inboard bushing assembly includes a tubular extension pilot guided within an engine strut whereby the thin layers of elastomer serve to interrupt transmission of structure borne sound from engine to airframe.
Abstract: A regenerator assembly for a gas turbine engine includes a center driven rotatable matrix with a hub and drive shaft including a sprocket fixedly secured thereto with a roller chain driven thereacross by means of a cross shaft assembly including a first elongated tubular coupling telescoped with respect to a low rate torsion spring bar and wherein an input shaft connected to one end of the torsion spring bar is associated with damper means including first and second relatively movable parts connected in parallel to the torsion spring bar by the coupling and operative to damp oscillations in said matrix disc drive shaft during operation of the regenerator assembly.
Abstract: Successive outer stator shroud rings of a gas turbine confront each other at the downstream edge of one and the upstream edge of the other, with a gap between them. To seal against leakage through this gap, edges of the shrouds have grooves aligned to define an annular cavity of generally rectangular cross section in the shrouds. A thin flexible coiled metal strip of about 720.degree. extent is disposed in the cavity, with the strip overlapping itself to form a double layer. Layers of the strip are slidable relative to each other to allow the strip to expand and contract with the shrouds and abut outer or inner walls of the cavity to provide the seal.
Abstract: An integrally cast turbine blade and wheel assembly has a plurality of circumferentially spaced radially outwardly directed blades on a peripheral rim that is connected by a wheel web to a central hub having a bore therethrough. The assembly includes a plurality of circumferentially spaced, pairs of grooves to define a plurality of weakened sections in the wheel rim and web that will selectively crack in shear to relieve stresses during either a tensile or compressive phase of wheel assembly operation produced during thermal cycling of an associated engine; and wherein resultant stress relief cracks define a labyrinth seal path to control gas bypass across the blade row.
Abstract: A matrix disc for a rotary regenerator heat exchange apparatus includes a pair of spirally wound sheets, a first sheet having a continuously formed sinusoidal corrugation having a pitch dimension that accomodates thermal expansion in the strip. The first sheet is juxtaposed against a second corrugated sheet having a plurality of axial spaced corrugated segments therein having a pitch to accomodate thermal expansion and wherein each segment is interconnected by a plurality of elements including flat side wall segments having an axial length greater than the pitch dimension of abutting corrugation of the adjacent first strip and including a diagonally directed segment therebetween to space the corrugated segments of the second strip away from the first strip to define a plurality of generally rectangularly configured air form fluid flow paths in the matrix disc.
Abstract: A quick response gasifier spool for an automotive gas turbine engine has a shaft with a turbine wheel connected on one end thereof with a row of turbine blades driven by motive fluid from an engine combustor and further has a low inertia centrifugal compressor impeller with a low mass hub secured to the opposite end of the shaft. The impeller has a plurality of separate, free formed blades each having a root segment integrally formed with the hub; the blades including spaced apart radial tip portions joined by a continuous ring of span splitter elements located on the radial extent of each of the blades to prevent flutter between adjacent free blade radial tips and wherein each element of the continuous ring includes a leading edge and a trailing edge joined by a curved segment located along a flow streamline path between each of the individual blades.
Abstract: A multi-shaft gas turbine has an inner shaft rotatably supported at opposite ends thereof with one end adapted to be connected to a load and the other end to a turbine wheel with a tubular section that receives a balance tube removably mounted within the shaft and accessible from the aft end of the engine by removal of an inner exhaust cone and a bearing pump cover. The balance tube includes front, rear and intermediate circumferentially arranged splined lands that bear balance weights angularly positioned on the tube prior to insertion thereof into the shaft, each of the weights having a peripheral surface thereon for locating the longitudinal axis of the balance tube colinearly of the longitudinal axis of the inner shaft.
Abstract: A nonglare rear view mirror assembly includes a combination diaphragm and bellows and a front transparent lens on the bellows defining a variable volume chamber of opaque liquid rearwardly of the transparent lens. A light reflective mirror is connected to a plurality of bosses on the diaphragm to define a liquid pump chamber in communication with the variable volume chamber. The diaphragm is associated with a rigid cover to define a variable pressure space selectively connected to a source of power fluid to flex the diaphragm to direct opaque liquid from the pump chamber into the variable volume chamber behind the lens for producing a nonglare light reflection under night operation and operative under daylight conditions to flex the diaphragm to draw liquid from between the lens and mirror to locate the mirror adjacent the lens for producing greater light reflectivity.
Abstract: A variable cycle air breathing gas turbine engine includes a core engine having a combustor, a high pressure turbine stage and a low pressure stage and wherein the high pressure stage drives a compressor for the core engine and the low pressure stage drives a bypass fan for the engine. The low pressure turbine stage includes a row of tip mounted blades located in a first bypass duct and the engine includes auxiliary inlets and crossover valve means for directing air through the first bypass duct during a first mode of engine operation to cause the tip blades on the low pressure turbine stage to operate as an auxiliary bypass fan while the primary fan is driven during the first mode to produce a bypass ratio in a second bypass duct.
Abstract: A variable flow air controller for a gas turbine engine combustor has a rotatable band including a first plurality of slots formed therein that overlie a plurality of primary air admission slots in the combustor wall circumferentially therearound and directed radially into a primary combustion zone. The slots are arranged to form an open junction therebetween which shifts axially along the combustor assembly upon rotation of the band thereby to control the point of admission of primary air into a combustion apparatus for completing combustion at preselected positions downstream of a liner dome in accordance with engine operation.
Abstract: A current switching device for use in printed circuit board application includes a terminal contact board sandwiched with respect to a foamed spring pad that supportingly receives a pivotal contactor plate in juxtaposed relationship therewith and wherein the switch includes a rotatable rocker engageable with the contactor plate and pivotal to cause the contactor plate to be shifted into electrical bridging engagement with the terminal board and wherein the foamed pad yields in both compression and shear to produce a bias on the contactor plate for return thereof to a spaced relationship with the terminal board when the rocker is in a neutral position.
Abstract: A combustor for a gas turbine engine has a prevaporization chamber wall having a plurality of air passages therethrough and wherein a variable geometry air flow control element is located in overlying relationship with the air passages to control air flow therethrough. A fuel injector is located concentrically within the chamber for supplying fuel for combustion with air supplied thereto and a hydraulic control actuator is located in surrounding relationship with the injector immediately outboard of the chamber including the hydraulic actuator having pressure supplied thereto from the fuel flow through the nozzle and including means for coupling the actuator directly to the control element for increasing primary air flow in accordance with increased fuel flow to the prevaporization chamber.
Abstract: A stagnation sensing control for determining when a gas turbine engine has stagnated during a start phase of operation includes means for sampling the engine speed at a first predetermined point in time and means to hold the sampled speed in memory and further including means operative following a period of time to compare engine speed at the later point in time with the speed in memory and means operative if the speed increase is less than an established amount greater than the sampled speed in memory to produce an engine shutdown signal to operate engine starter and shut down circuits for terminating engine operation.
Abstract: A gas coupled or free turbine type gas turbine engine of the type having two or more independently rotatable turbines has a set of hydraulic (oil cooled) clutches for coupling a gasifier turbine to a power turbine and wherein the turbine engine includes a combustor for supplying motive fluid to both of the turbines and having an operating characteristic that produces an abrupt fall in the motive fluid temperature at the turbine inlets upon synchronous operation of the independently rotatable turbines.
Abstract: A method of bonding a laminated porous sheath to a cast strut includes the step of performing a compressible pad to have a plurality of closely spaced grooves on one surface thereon and a plurality of spaced apart lands on the opposite face thereof; locating a preformed porous laminate sheath over the outer surface of a cast strut and laser welding it thereto and thereafter assembling the preformed compressible pad to locate the plurality of grooves thereon in overlying relationship to a plurality of airflow openings in the porous laminated sheath and with ribs on either side of the grooves being located in juxtaposed relationship with the outer surface of the porous laminated sheath for uniformly distributing a load thereto; locating the preassembled casting, sheath and compressible pad within a contoured opening formed by a three piece pressure block fixture and applying a predetermined pressure to the assembled parts while subjecting them to a predetermined bond temperature while applying a vacuum.
Abstract: A vehicular gas turbine engine includes a first electronic controller responsive to a plurality of engine operating parameters and associated with a power relay box to control operation of engine functions and further includes a manual controller that allows open loop operation of the engine to start and run it at a speed and power level independent of the electronic controller and associated signals of engine parameters. The manual controller includes a timer set to shut the engine down after a preselected time period of manual operation to prevent excessive use of the open loop control thereby to minimize possibility of engine damage.