Abstract: A porous, laminated metal fabrication includes first and second porous walls, each having laminae therein with a free edge portion across at least one end thereof; each of the first and second walls including an outer lamina with a first preformed hole pattern therein, each of the first and second walls further including an inner lamina having a second preformed hole pattern therein combined to form a tortuous air flow path through the first and second walls for cooling the metal therein; and each of the lamina in the laminae including a solid metal annulus therein of uniform density for welding; the annulus being located between the hole patterns and the free edge portions to define a weldable region between the first and second walls having an axial width limited to the axial width of the solid metal annulus whereby air flow through the first and second walls will flow freely throughout the full extent of all the performed hole patterns therein so as to maintain full coolant flow from exteriorly of the poro
Abstract: A unitary ceramic gas turbine wheel for use in gas turbine engines having turbine inlet temperatures in excess of 2000.degree. F. includes an outer rim of reduced axial length that is merged with scallops in the upstream face of the turbine wheel to reduce leading edge stresses in integral turbine wheel blades of airfoil configuration and wherein the fairing of the airfoil into the rim is configured to produce a reduction in the polar moment of inertia of the turbine wheel to improve engine acceleration characteristics.
Abstract: A propeller shaft nut lock assembly for retention of a propeller shaft bearing assembly includes an externally threaded shaft surface threadably receiving a thrust nut that includes an outboard undercut groove therein to receive a cup lock that is shifted to locate an eccentric segment on the cup lock into interlocking engagement with the undercut groove when a thrust nut lock centers the cup lock on the assembly, and wherein the cup lock includes a plurality of axially extending bendable tangs to indicate that the thrust nut lock assembly is seated in load transfer relationship with the bearing assembly.
November 16, 1979
Date of Patent:
September 29, 1981
General Motors Corporation
Bryce R. Baldwin, Laurence M. Brady, Warren N. Holcomb
Abstract: A method for manufacturing a hot side regenerator cross arm seal assembly having a thermally stablilized wear coating with a substantially flat wear surface thereon to seal between low pressure and high pressure passages to and from the hot inboard side of a rotary regenerator matrix includes the steps of forming a flat cross arm substrate member of high nickel alloy steel; fixedly securing the side edges of the substrate member to a holding fixture with a concave surface thereacross to maintain the substrate member to a slightly bent configuration on the fixture surface between the opposite ends of the substrate member to produce prestress therein; applying coating layers on the substrate member including a wear coating of plasma sprayed nickel oxide/calcium flouride material to define a wear surface of slightly concave form across the restrained substrate member between the free ends thereon; and thereafter subjecting the substrate member and the coating thereon to a heat treatment of 1600.degree. F.
November 23, 1979
Date of Patent:
August 18, 1981
General Motors Corporation
Leonard C. Davis, Theodore Pacala, George R. Sippel
Abstract: A flexible coupling for use in engine exhaust systems includes a pair of flanges maintained at a fixed distance with respect to one another by a pair of spaced shouldered bolt components and wherein one of the fixed flanges has a free end directed therefrom supportingly receiving a ring seal with a spherical surface thereon; and wherein the other of the flanges includes an edge portion thereon bent over to form a spring seat and to define a pipe opening to receive a spherically flared end of a downstream pipe and supportingly receiving one end of a coil spring that surrounds the downstream pipe, the coil spring having the opposite end thereof supported by one of the spaced flanges and a movable retainer ring on an outer spherical surface of the spherically flared end whereby a resilient force is maintained continuously around the outer surface of the flared end of the downstream pipe to bias it into sealing engagement with the ring seal and to force the ring seal into a sealed shouldered relationship with the
Abstract: A method for manufacturing a turbine rotor assembly from dissimilar materials to produce a hybrid composite rotor including the steps of: preforming a hub disc of a controlled outer diameter and prefabricating a ring of airfoils including a machine slotted fixture ring of mild steel slotted to receive airfoils inserted therein; and wherein the method further includes the steps of grinding the internal diameter of the mild steel ring to expose the airfoil bases to locate them at a radius line which will correspond to the outer diameter of the hub disc rim to maintain a pressure fit relationship therebetween when the ring of airfoils is pressed or shrunk on the outer diameter of the disc and thereafter sealing exterior joint lines between the mild steel fixture ring, airfoils and hub disc to form a pressure sealed surface on the exterior of the joined parts; subjecting the full outer planar extent of the pressure sealed configuration to an elevated pressure while maintaining it under an elevated temperature to
Abstract: A drive system for a multiple gas turbine engine system includes power output shafts from first and second gas turbine engines, each power shaft connected to drive a load and each engine including a load sharing cross-over shaft for power transfer from one of the engines to the other engine;a right angle gear box assembly connects each of the power output shafts to the cross-over shaft and each of the right angle gear box assemblies includes first and second load sharing gear paths including tooth geometry in an input bevel gear configured to produce a thrust reversal so that for normal direction torque transfer the input bevel gear thrust is in a direction to load mesh points in both gear paths and for a reversal of torque direction from input to output gears the input gear thrust is reversed so that the input gear will be directed into a tighter mesh to take out normal backlash in the system so that reverse meshed torque paths will be maintained in each of the first and second gear paths to maintain a shari
Abstract: An automotive gas turbine engine includes a gasifier spool having variable iris control means for regulating air flow to a compressor supplying a primary burner that is operative to produce motive fluid for driving the gasifier turbine and to supply a thermally insulated pressure accumulator located upstream of a secondary burner that exhausts to a variably controlled power turbine nozzle of a power turbine and wherein control means are operative upon engine start to open the variable iris to the gasifier spool and to direct fuel to the primary burner until the gasifier turbine produces a desired pressure in the accumulator and wherein means are provided to sense the pressure within the accumulator and operative following attainment of the desired pressure to close the iris and reduce primary burner fuel flow to a predetermined minimum to maintain gasifier spool speed at between 85% to 95% of full design speed thereof; the control means further including a manual control to the variable power turbine nozzle t
Abstract: A transpiration air cooled combustor assembly for a gas turbine engine includes an annular liner of laminated metal with an inner sheet and an outer sheet having a plurality of mechanically formed holes therein on either side of a mechanically pressed waffle patterned core sheet with offset depressings and dimples on either face thereof; the dimples have raised lands bonded to the inner and outer sheets; small cross passages are drilled in the core sheet so that the margins of the cross passages are located in spaced relationship to the land surfaces thereby to prevent burr formation disruption of the bond joints; the core sheet has a total metal mass equivalent to the orginal metal mass prior to press displacement of metal to form the depressions and dimples therein except for the metal removed by formation of the cross passages which communicate offset depressions on opposite sides of the core sheet to form a tortuous intercommunicating flow path through said annular liner between holes in the inner and out
Abstract: A gas turbine engine having variable geometry flow controllers therein for controlling mass flow in accordance with engine operation includes a rotor with a wide variation in thrust forces thereon during different phases of engine operation countered by a variable axial load integrating device having a rotating hydraulic thrust compensating piston mounted forwardly of the rotor in association with a rotor thrust bearing and further including means for generating a centrifugal head in accordance with engine speed and wherein improved oil distribution panels are included to evenly distribute oil between the rotating piston and a nonrotating counterpiston to form a uniform depth of rotating oil automatically regulated by an integral, flow regulator having flow area therethrough varied in accordance with axial position of a thrust bearing carriage that has the variable rotor thrust loading imposed thereon.
Abstract: A combustion apparatus for gas turbine engines particularly adapted to reduce emissions to meet automotive requirements. The fuel is laid on the wall of a cylindrical prechamber and evaporated from the wall by combustion air which is introduced through a swirler at the upstream end of the prechamber. The inner surface of the prechamber is artificially roughened by a grid of grooves to improve fuel evaporation. The fuel is laid on the wall from an annular manifold extending around the upstream end of the prechamber through tangential orifices leading from the manifold into the interior of the prechamber. More air enters through entrance ports distributed around the prechamber toward its downstream end. The resulting lean fuel-air mixture is delivered past an annular flow dam at the outlet of the prechamber into a domed combustor wall forming a combustion or reaction zone which is abruptly enlarged from the prechamber.
Abstract: A regenerator cross arm seal structure for a rotary regenerator of a gas turbine engine includes a cross arm seal extending diametrically of a matrix of the rotating regenerator which includes a center bore therein for a drive bushing and spindle; the seal having a leaf spring on one surface thereof that is engageable with an engine block support platform to seal between the engine block and one surface of a seal platform that supports a cross arm wear face with a hub section cooled by leakage of air through the center bore and the seal wear face including a material with low friction and good wear characteristics when operating at elevated temperatures between 1000.degree. F. to 1500.degree. F. (523.degree. C. to 800.degree. C.
Abstract: A gas turbine engine control for regulating bleed from a compressor which has an engine performance map that is compressor stall stable when the ambient inlet air temperature of the engine exceeds a predetermined level and including a compressor bleed valve having a servo controlled pressure diaphragm operated poppet valve therein that is operative to bleed valve from the compressor in accordance with compressor discharge pressure conditions to extend the stall limits of operation of the compressor during engine start and low power or ground idle operation and wherein the bleed valve is associated with a thermally responsive solenoid valve controlled by a thermal switch responsive to ambient inlet air and supported on the inlet of the compressor at a point beyond the influence of engine generated heat for imposing an override pressure on the bleed valve to hold it in a closed position to prevent engine compressor bleed thereby to avoid engine power depreciation at ambient inlet air temperatures above the pred
Abstract: A turbine rotor shroud is mounted by means for rigidly supporting it on an internal bearing for turbine and shaft components of a gas turbine engine and a low rate flexible seal member extends between the outer case of the gas turbine engine and an outer gas flow path wall for maintaining continuity of gas and air stream pass through the gas turbine engine during different modes of engine operation thereby to maintain a closely controlled clearance between blade tips of a row of turbine blades on a rotor connected to the gas turbine engine drive shaft and the rotor shroud to maintain close clearance under mechanical (static or dynamic) loads wherein the deflected rotor or engine casing systems move but the motion is accommodated by the flexible seal member and prevented by a rigid nozzle to turbine bearing support structure.
Abstract: A centrifugal compressor for a gas turbine turbo-shaft engine includes a stationary shroud cover over the inducer section of an impeller in the centrifugal compressor including a plurality of raised reinforcing bridges at the leading edge of the outer surface of the cover and having an annular control slot formed inboard of the bridges to communicate the inner surface of the shroud cover with surrounding gas and wherein the shroud surrounds an impeller which produces a variable cover static pressure at the point of the control slot so it serves combined functions of causing an inflow of gas from exteriorly of the cover into the impeller to add to the inlet flow to the impeller under high speed conditions of compressor operation and wherein the same slots serve to bleed gas flow from the impeller to a point exteriorly of the compressor at part speeds of rotation of the impeller thereby to flow stabilize the impeller at part speed phases of operation thereof.
Abstract: A turbine blade tip seal assembly for controlling the blade tip clearance between a flexible outer shroud and the tips of a thermally expansible row of turbine blades on a turbine rotor includes a fixed outer shroud with a pressure deflectable wall portion thereon located in surrounding, radially outwardly relationship with blade tips on the blades of a turbine rotor and wherein an excessive blade tip to shroud wall spacing is maintained when the engine is at cold start conditions; said turbine blades of the turbine rotor expanding in response to increases in operating temperature within the engine during turbine engine operation to partially close the excessive blade tip to shroud clearance and further including pressurizable means responsive to turbine operation to produce pressure bias on the deflectable wall to cause it to be deflected raidally inwardly to further reduce the excessive blade tip clearance so as to produce a resultant operative clearance between the tip of the turbine rotor and the shroud t
Abstract: A gas turbine engine power turbine support structural nozzle includes a nozzle ring with an annular outer shroud and an inboard blade platform having a plurality of cast nozzle vanes therebetween located at circumferentially spaced points for directing motive fluids through the turbine; the support includes bearing oil and air coolant annuli.
Abstract: A method for manufacturing a composite sheet of material having a controlled porous characteristic and made up of two or more metal lamina bonded together, including the steps of forming first and second sheets of porous material with a first and second array of openings therein offset with respect to one another; stacking the first and second sheets together to form a peripheral joint line therebetween having end edges indexed to align the first and second array of openings to form a coolant flow pattern through the stacked sheets; welding indexed end edges to fixedly connect the first and second sheets together; stretch-forming the stacked sheets by bending them under tension across a predetermined curvature on a form die to cause the first and second sheets to exceed their yield point to effect an intimate fit across juxtaposed surfaces thereon; thereafter further bending and restraining the welded end edges of the first and second sheets to produce a bond pressure between the sheets at the juxtaposed surf
Abstract: A gas turbine engine has a compressor and power turbine driven by gas flow across a nozzle arrangement that includes a partial admission gate valve therein movable into and out of overlying relationship with a limited number of vanes of the nozzle in order to control power output therefrom during part load operation of the engine.
Abstract: A combustor assembly for a gas turbine engine includes a tubular, multi-layered porous metal wall with pores and cavities for distribution of compressor discharge air into a combustion chamber and wherein a rigid combustor support ring connects one end of the porous wall to fixed support components of the gas turbine engine; the combustor assembly further including a porous metal transition member for joining the tubular porous metal wall to a downstream nozzle plate; the transition member including free formed side walls and top and bottom walls without substantial reduction in permeability due to forming and each of the transition walls further including a sharp radius bend at the side edge thereof defining a compressed porous metal section for connection to an adjacent sharp radius bend by means of a longitudinal seam weld along the length thereof to maximize the flow of secondary cooling air into the hot combustion gases passing from the outlet of the combustion chamber of the apparatus.