Abstract: A gas turbine engine for an aircraft includes an engine core including a turbine, a compressor, and a core shaft connecting the turbine to the compressor, and a fan including a plurality of fan blades located upstream of the engine core. The fan has a fan diameter in the range from 240 cm to 280 cm. The turbine is the lowest pressure turbine of the engine and the compressor is the lowest pressure compressor of the engine. The turbine includes a total of three sets of turbine blades. The engine core further includes three bearings arranged to support the core shaft. The three bearings include a forward bearing and two rearward bearings located downstream of a leading edge of a lowest pressure turbine blade of the turbine at a root of the blade.

Abstract: Turbojet engine includes a fan, a compressor, a combustion chamber, and a turbine configured to rotatably drive the fan via a first reduction gear and the compressor via a second reduction gear, in which an outlet of the first reduction gear is rotatably coupled to an inlet of the second reduction gear by a reduction shaft, the reduction shaft being supported by a bearing arranged between the first reduction gear and the second reduction gear.

Abstract: A gas turbine engine has a fan drive turbine driving a gear reduction, the gear reduction, in turn, driving a fan rotor, the fan rotor delivering air into a bypass duct as bypass air and into a compressor section as core flow. A forward bearing is positioned between the gear reduction and the fan rotor and supports the gear reduction. A second bearing is positioned aft of the gear reduction and supports the gear reduction. The second bearing is a thrust bearing. A fan drive turbine drive shaft drives the gear reduction. The fan drive turbine drive shaft has a weakened link which is aft of the second bearing such that the fan drive turbine drive shaft will tend to fail at the weakened link, and at a location aft of the second bearing.

Abstract: There is provided a turbofan engine for an aircraft. The turbofan engine has a core with a fan cowl and a variable pitch fan (VPF) configured to only rotate in a first rotation direction. The VPF has a plurality of fan blades each configured to over-pitch to an over-pitch position relative to a feathered position. The turbofan engine has outer guide vanes (OGVs) axially disposed downstream of the VPF, and has a rotation control device to prevent the VPF from rotating in a second rotation direction opposite the first rotation direction, during an engine out (EO) condition of the turbofan engine. When the VPF is prevented from rotating during the EO condition, the fan blades are over-pitched to the over-pitch position relative to the feathered position, to achieve no or minimal air flow separation about the OGVs, and to reduce drag of the turbofan engine during the EO condition.

Abstract: A gas turbine engine is disclosed including a bifurcation fairing located in a bypass duct of the gas turbine engine and traversing the radial extent of the bypass duct. The bifurcation fairing has a delivery conduit inlet leading to a delivery conduit extending inside the bifurcation fairing, the delivery conduit being arranged in use for delivery of bypass air to one or more components of the gas turbine engine. A diverter conduit has a diverter conduit inlet from the delivery conduit upstream of the delivery conduit reaching the one or more components of the gas turbine engine. The diverter conduit has an outlet to a location other than the one or more components of the gas turbine engine.

Abstract: A borescope plug assembly includes a borescope plug having a shaft section and a tip section, a bushing engageable with the shaft section and a seal engageable with the tip section.

Abstract: A gas turbine engine includes a shaft defining an axis of rotation. An outer turbine rotor directly drives the shaft and includes an outer set of blades. An inner turbine rotor has an inner set of blades interspersed with the outer set of blades. The inner turbine rotor is configured to rotate in an opposite direction about the axis of rotation from the outer turbine rotor. A splitter gear system couples the inner turbine rotor to the shaft and is configured to rotate the inner set of blades at a faster speed than the outer set of blades.

Abstract: A gas turbine engine includes a shaft defining an axis of rotation. An outer rotor directly drives the shaft and includes an outer set of blades. An inner rotor has an inner set of blades interspersed with the outer set of blades. The inner rotor is configured to rotate in an opposite direction about the axis of rotation from the outer rotor. A gear system couples the inner rotor to the shaft and is configured to rotate the inner set of blades at a faster speed than the outer set of blades.

Abstract: A turbofan engine has an engine case and a gaspath through the engine case. A fan has a circumferential array of fan blades. The engine further has a compressor, a combustor, a gas generating turbine, and a low pressure turbine section. A speed reduction mechanism couples the low pressure turbine section to the fan. A bypass area ratio is greater than about 6.0. The low pressure turbine section airfoil count to bypass area ratio ratio is below about 170.

Abstract: A gas turbine engine includes a shaft defining an axis of rotation. An inner rotor directly drives the shaft and includes an inner set of blades. An outer rotor has an outer set of blades interspersed with the inner set of blades. The outer rotor is configured to rotate in an opposite direction about the axis of rotation from the inner rotor. A gear system couples the outer rotor to the shaft and is configured to rotate the inner set of blades at a lower speed than the outer set of blades.

Abstract: A gas turbine engine includes a first shaft defining an axis of rotation and a second shaft rotatable about the axis of rotation and spaced radially outwardly relative to the first shaft. A speed change mechanism is driven by the second shaft. A fan includes a fan rotor driven by the speed change mechanism such that the fan and the first shaft rotate at a slower speed than the second shaft. At least one inducer stage is positioned aft of the fan and is coupled for rotation with the fan rotor.

Abstract: A system of contra-rotating propellers for an aircraft turbomachine, including: a free power turbine including a first rotor; first and second propellers; and a mechanical transmission system including a planetary gear train fitted with a sun gear driven by the rotor, at least one planet gear driving the first propeller, and a ring driving the second propeller. The free power turbine also includes a second rotor that is contra-rotating relative to the first rotor, and rotating the ring.

Abstract: A turbofan engine is disclosed and includes a fan and a compressor in communication with the fan section, a combustor, a turbine and a speed reduction mechanism coupled to the fan and rotatable by the turbine. The turbine includes a first turbine section that includes three or more stages and a second turbine section that includes at least two stages. A ratio of airfoils in the first turbine section to a bypass area is less than about 170.

Abstract: A turbofan engine has an engine case and a gaspath through the engine case. A fan has a circumferential array of fan blades. The engine further has a compressor, a combustor, a gas generating turbine, and a low pressure turbine section. A speed reduction mechanism couples the low pressure turbine section to the fan. A bypass area ratio is greater than about 6.0. The low pressure turbine section airfoil count to bypass area ratio is below about 170.

Abstract: A gas turbine engine includes a fan section including a fan rotatable about an axis. A speed reduction device is connected to the fan. The speed reduction device includes a planetary fan drive gear system with a planet gear ratio of at least 2.5. A bypass ratio is greater than about 11.0.

Abstract: A gas turbine engine includes a fan section including a fan that is rotatable about an axis. A speed reduction device is connected to the fan. The speed reduction device includes a star drive gear system with a star gear ratio of at least 1.5. A bypass ratio is greater than about 11.0.

Abstract: A gas turbine engine according to an exemplary aspect of the present disclosure includes, among other things, a fan section including a fan rotatable about an axis and a speed reduction device in communication with the fan. The speed reduction device includes a star drive gear system with a star gear ratio of at least 1.5. A fan blade tip speed of the fan is less than 1400 fps.

Abstract: A turbofan engine includes a fan, a compressor section, a combustor in fluid communication with the compressor section, a turbine section in fluid communication with the combustor, a shaft configured to be driven by the turbine section and coupled to the compressor section through a first torque load path, and a speed reduction mechanism configured to be driven by the shaft through a second torque load path separate from the first load path for rotating the fan.

Abstract: A gas turbine engine according to an exemplary aspect of the present disclosure includes, among other things, a fan section including a fan rotatable about an axis and a speed reduction device in communication with the fan. The speed reduction device includes a planetary fan drive gear system with a planet gear ratio of at least 2.5. A fan blade tip speed of the fan is less than 1400 fps.

Abstract: A turbomachine comprises a flow duct with coaxially arranged radially inner and outer endwalls, first and second sets of axially spaced rotor stages arranged between the inner and outer endwalls, and a plurality of variable endwall segments arranged along the inner endwall. The first set of rotor stages rotates in a first direction, and the second set rotates in a second direction. The first and second sets alternate in axial series along the flow duct, such that axially adjacent rotor stages rotate in different directions. The variable endwall segments are radially positionable, in order to regulate loading on the first and second sets of rotor stages by changing a cross-sectional flow area between the inner and outer endwalls.

Abstract: A rotor drive mechanism and pump apparatus according to the present invention may cause an external screw type rotor of a uniaxial eccentric screw pump to rotate and carry out a revolution movement. The rotor drive mechanism further comprises a shaft sealing structure configured such that a gap between an outer peripheral portion of an end portion of the revolution shaft is located on the external screw type rotor side and an inner peripheral portion of the casing in the pump apparatus is sealed. The rotor drive mechanism provides for a reduced amount of heat and vibrations to be generated when the rotor is rotated at high speed and further allows for lowering of contact pressure between an outer surface of the rotor and an inner surface of a stator inner hole.

Abstract: A gas turbine engine is provided that includes a low pressure spool, a high pressure spool, a stationary support frame, and at least one support arch. The low pressure spool extends between a low pressure compressor and a low pressure turbine. The high pressure spool extends between a high pressure compressor and a high pressure turbine. The spools are rotatable about a center axis of the engine. The support arch has a stationary support mount disposed between a low spool mount and a high spool mount. The support arch is disposed relative to the spools and the stationary support frame so that a load from each spool caused by the rotation of that spool can be transferred to the stationary support frame through the support arch. The support arch can freely rotate about the center axis of the engine relative to the spools and the stationary structural frame.

Abstract: A fan includes a fan frame, a front impeller and a rear impeller. The fan frame has a frame body and a plurality of connecting elements. The front impeller has a first bushing disposed at the central portion of the frame body. Two ends of each connecting element are respectively connected with the frame body and the first bushing. The rear impeller has a second bushing partially telescoped into the first bushing.

Abstract: A low pressure turbine for a gas turbine engine includes inner and outer counter-rotating rotor sets, with both said rotor sets driving a common shaft.

Abstract: A turboprop having at least one propeller formed by a set of variable pitch blades. Each blade is swivel-mounted on a rotary support and carries a gearwheel meshing with an actuator annulus rotating on the rotary support and coupled to a control annulus via an epicyclic mechanism.

Abstract: A counter-rotatable low pressure turbine includes counter-rotatable outer and inner drum rotors. The outer drum rotor is connected to a sole shaft for transmitting torque and power out of the low pressure turbine. Low pressure outer drum turbine blade rows extend radially inwardly from an outer shell of the outer drum rotor. Low pressure inner drum turbine blade rows extend radially outwardly from the low pressure inner drum rotor. The outer drum turbine blade rows are interdigitated with the inner drum turbine blade rows. The drum rotors are geared together through an epicyclic gearbox for transmitting all the torque and power produced by the drum rotors to the shaft. The gearbox may be located aft of the drum rotors. A differential thrust bearing is disposed between the drum rotors. A single stage fan section of an engine is connected to the turbine by the shaft.

Abstract: A gas turbine engine mid turbine frame having an inner case supporting at least one bearing and at least three spokes extending radially outwardly to an outer case, the mid turbine frame having an interturbine duct extending through the mid turbine frame, the interturbine duct spaced axially closer to an upstream turbine disc than a bearing supporting structure of the mid turbine frame and mounted axially slidingly relative to the bearing supporting structure to substantially isolate the bearing supporting structure from axial loads, for example such as disc loads incurred in the unlikely event a turbine disc shaft shears within the engine.

Abstract: A tip turbine engine (10) provides an axial compressor (22) having a compressor case (50) from which extend radially inwardly a plurality of outer compressor airfoils (54). The compressor case (50) is directly driven by the rotation of the turbine (32) and fan (28), while at least one gear (77) couples the rotation of the turbine (32) and fan (28) to an axial compressor rotor (46) having a plurality of inner compressor airfoils (52). In this manner, the axial compressor rotor (46) is driven in a direction opposite the direction of the outer compressor airfoils (54), thereby increasing the compression provided by the compressor without increasing the number of airfoils. The outer compressor airfoils (54) are formed on a plurality of outer airfoil assemblies (56) each having an arcuate substrate (58) from which the outer compressor airfoils (54) extend. Each of the outer compressor airfoil assemblies (56) includes more than one axially-spaced stage of outer compressor airfoils (54).

Abstract: An engine for powering a vehicle, such as a military aircraft or a commercial aircraft, is provided. The engine broadly comprises a main core with a plurality of spools with each spool having a plurality of compressor blades and a plurality of turbine blades attached thereto. One of the spools has a first set of fan blades attached thereto. The engine further has a variable bypass turbine fan formed by a second set of fan blades. The second set of fan blades is arranged outboard of the main core. The second set of fan blades may be decoupled from the first set of fan blades.

Abstract: A counter-rotating blade stage in lieu of a stator stage may compensate for relatively low rotational speed of a gas turbine engine spool. A first spool may have at least two compressor blade stage and at least two turbine blade stage. A combustor is located between the at least two compressor blade stage and the at least two turbine blade stage along a core flowpath. The at least two counter-rotating compressor blade stage is interspersed with the first spool at least two compressor blade stage. A transmission couples the at least two additional compressor blade stage to the first spool for counter-rotation about the engine axis.

Abstract: A gas turbine engine mid turbine frame having an inner case supporting at least one bearing and at least three spokes extending radially outwardly to an outer case, the mid turbine frame having an interturbine duct extending through the mid turbine frame, the interturbine duct spaced axially closer to an upstream turbine disc than a bearing supporting structure of the mid turbine frame and mounted axially slidingly relative to the bearing supporting structure to substantially isolate the bearing supporting structure from axial loads, for example such as disc loads incurred in the unlikely event a turbine disc shaft shears within the engine.

Abstract: The invention provides a fuel cell compressor system that comprises a motor, including a motor shaft driven by the motor; a drive housing at least partially surrounding the motor shaft; a first gear set driven by the motor shaft; a carrier torque tube driven by the first gear set; and an impeller. The impeller includes an impeller shaft driven by the second gear set, so that the impeller shaft is configured to rotate at a speed greater than motor speed. Embodiments of the invention may also be used with a multi-stage compressor that allows, for example, first and second impellers to rotate at different speeds. Embodiments of the invention may also include removal of a gear set driving the carrier torque tube or the impeller shaft, so that the impeller shaft speed is divided between one or more bearings supporting the carrier torque tube and one or more bearings supporting the impeller shaft.

Abstract: This turbine engine compressor comprises a separating nose extended by inner and outer annular walls defining in cooperation an annular volume (V) of separation of a primary flow (F1) and a secondary flow (F2). This volume (V) comprises a plurality of annular segments in the form of cells separated in pairs by blades of a first fan, these blades passing through both the primary flow (F1) and the secondary flow (F2). These cells are fixed to an upstream annular collar and a downstream annular collar driven rotationally by the aforementioned blades.

Abstract: A turbocharger, having an axial compressor wheel and an axial turbine wheel mounted on a first shaft supported by a housing, and a radial compressor wheel and a radial turbine wheel mounted on a second shaft, the second shaft concentrically extending around the first shaft and being supported by the housing. The housing defines a first duct extending axially from the exducer of the axial compressor to the inducer of the radial compressor, and a second duct extending axially from the exducer of the radial turbine to the inducer of the axial turbine. A plurality of controllable compressor guide vanes extend through the first duct, and a plurality of controllable turbine stator vanes extend through the second duct. The housing is provided with variable diffuser vanes at the exducer of the radial compressor, and with variable turbine vanes at the inducer of the radial turbine.

Abstract: A twin spool rotor shaft having an inner rotor shaft and an outer rotor shaft concentric to the inner rotor shaft, an outer shaft seal assembly formed between the outer rotor shaft and a stationary casing, and an inner shaft seal assembly formed between the outer shaft and the inner shaft. The two seal assemblies include a purge cavity and two drain cavities formed on the sides of the purge cavity. A purge fluid is supplied to the outer purge cavity, and drain passages in the stationary housing drain the two outer drain cavities without mixing the two fluids. The outer purge cavity is fluidly connected to the inner purge cavity through a radial passage in the outer rotor shaft in one embodiment, or through a bore tube passing within the inner rotor shaft in a second embodiment.

Abstract: A water propulsion unit having an intake housing, a pump housing and an outlet with two spaced apart counter rotating impellers being located in the pump housing. The impeller blades on one impeller have an opposite pitch to the blades of the second impeller. The impellers are configured so that one of the impellers will impart less energy to the water as it passes the blades of the impeller than the second impeller.

Abstract: A device for effecting heat transfer to rotating equipment, in particular gas turbines, is provided. A gas turbine (10) comprises a first rotating unit (11), i.e. an internal shaft and a second fixed unit (16), i.e. a housing. A third rotating unit (14, 17), i.e. rotor blades and plates connected to the rotor blades are disposed between the first unit (11) and the second unit (16). The first (11) and third (14, 17) units are rotatable around a common axis (12) and with respect to each other. At least one device (21) for improving heat transfer by convection is assigned to the first rotating unit (11), i.e. the internal shaft.

Abstract: A method for assembling a gas turbine engine that includes providing a low-pressure turbine inner rotor that includes a first plurality of rows of turbine blades configured to rotate in a first rotational direction, providing a low-pressure turbine outer rotor that includes a second plurality of rows of turbine blades configured to rotate in a rotational direction that is opposite the first rotational direction, and coupling a support structure between the outer rotor and a turbine mid-frame such that the support structure supports a forward end of the outer rotor, and wherein the support structure includes a first portion that has a first coefficient of thermal expansion and a second portion that has a second coefficient of thermal expansion that is different than the first coefficient of thermal expansion.

Abstract: A method for assembling a gas turbine engine that includes providing a low-pressure turbine inner rotor that includes a first plurality of turbine blade rows configured to rotate in a first direction, providing a low-pressure turbine outer rotor that includes a second plurality of turbine blade rows configured to rotate in a second direction that is opposite the first direction, coupling a turbine mid-frame assembly including a plurality of spokes within the engine such that the spokes are spaced axially forward of the inner rotor, coupling a bearing between the turbine mid-frame assembly and the inner rotor such that the inner rotor is rotatably coupled to the turbine mid-frame, and adjusting the plurality of spokes to align the bearing in a radial direction.

Abstract: A method for assembling a gas turbine engine that includes providing a low-pressure turbine inner rotor configured to rotate in a first direction, providing a low-pressure turbine outer rotor configured to rotate in a second direction that is opposite the first rotational direction, and coupling at least one foil bearing to at least one of the inner and outer rotors to facilitate improving clearance control between a first rotating component and at least one of a second rotating component and a non-rotating component.

Abstract: A method for assembling a gas turbine engine includes providing a low-pressure turbine inner rotor that includes at least a first pair of adjacent rows of turbine blades that are configured to rotate in a first direction providing a low-pressure turbine outer rotor that includes a forward end, an aft end, and at least one row of turbine blades that is rotatably coupled between the first pair of inner rotor turbine blades, wherein the at least one row of outer rotor turbine blades is configured to rotate in a second direction that is opposite the first direction, and coupling a support assembly between the first pair of inner rotor turbine blades such that the support assembly supports the outer rotor forward end.

Abstract: A spigot arrangement for split impeller (inducer and exducer) includes a recess of the exducer and means for reducing exducer blade root stresses and localized contact stresses between inducer and exducer.

Abstract: The present invention relates to vacuum pumps and a method for creating and maintaining a high vacuum. A vacuum pump includes a regenerative section and a turbo-molecular section. A common first rotor carries forward-rotating elements of both the regenerative section and the turbo-molecular section. Additionally, a second rotor carries counter-rotating elements of the turbo-molecular section. A first drive rotates the first rotor in a forward rotational direction while a second drive rotates the second rotor in a counter-rotational direction. The drives may be controlled to drive the common first rotor on start-up, and to later drive the second rotor.

Abstract: A low-pressure turbine of a turbomachine, the turbomachine comprising a high-pressure turbine disposed upstream from the low-pressure turbine, and an exhaust casing disposed downstream from the low-pressure turbine, the low-pressure turbine comprising a rotor secured on a low-pressure trunnion, a low-pressure shaft, a first rolling bearing disposed on said low-pressure shaft and supporting a high-pressure trunnion having fastened thereon a rotor of the high-pressure turbine, a second rolling bearing disposed on said low-pressure trunnion downstream from said first rolling bearing and enabling said low-pressure trunnion to be centered relative to said exhaust casing, and a system of fluting for enabling said low-pressure trunnion to drive said low-pressure shaft, said system of fluting being disposed between said first and second rolling bearings.

Abstract: A rotor system for a gas turbine engine is provided having an outer rotor which includes an annular outer spool that comprises at least one ring portion of increased thickness with respect to the remainder of the outer spool, attached to a relatively thinner, axially extending arm portion. A plurality of outer turbine blades are attached to the ring portion of the outer spool and extend radially inwardly into a working gas flowpath of the engine. A casing surrounds the outer spool and defines an annular cavity between the casing and the outer spool, which is sealed by forward and aft brush seals at the forward and aft ends thereof. At least one inlet port is formed through the casing for admitting a flow of cooling air to the annular cavity. Means are provided for directing this cooling air flow to the ring portion of the outer spool.

Abstract: A dual rotor wind turbine according to the present invention includes a rotatable drive shaft, a first rotor assembly connected to the drive shaft, a second independently-rotating rotor assembly coupled to the drive shaft rearward of the first rotor assembly, a first stage generator coupled to the drive shaft, a second stage generator operatively connected to the second rotor assembly, a housing wherein the generators are situated, a rotary base, and a tail. In use, the rotary base allows the tail to optimally position the rotors for collecting wind. Wind rotates the first rotor assembly, causing the drive shaft to rotate and operate the first stage generator. Wind passing through and directed off the first rotor assembly rotates the second rotor assembly, independent of the first rotor assembly, operating the second stage generator. The two stage generators are any combination of AC or DC electrical generators, pumps, and compressors.

Abstract: A gas turbine engine turbine assembly includes a high pressure spool having a high pressure turbine drivingly connected to a high pressure compressor by a high pressure shaft which is rotatable about an engine centerline. A low pressure turbine has counter rotatable low pressure inner and outer shaft turbines with a row of low pressure variable vanes disposed therebetween and drivingly connected to coaxial low pressure inner and outer shafts respectively which are located radially inwardly of the high pressure spool. The low pressure inner and outer shaft turbines are drivingly connected to a forward and aft fan blade rows by the low pressure inner and outer shafts. A single direction of rotation booster is drivenly connected to the low pressure outer shaft and axially located aft and downstream of the aft fan blade row.

Abstract: A counterrotatable booster compressor assembly for a gas turbine engine having a counterrotatable fan section with a first fan blade row connected to a first drive shaft and a second fan blade row axially spaced from the first fan blade row and connected to a second drive shaft. The counterrotatable booster compressor assembly includes a first compressor blade row connected to the first drive shaft, a plurality of fan shaft extensions connected to the second drive shaft for driving the second fan blade row, and at least one compressor blade integral with each fan shaft extension so as to form a second compressor blade row interdigitated with the first compressor blade row.

Abstract: A gas turbine engine comprising a combustion chamber section, a turbine section, and a compressor section. The turbine section surrounds the combustion chamber and the compressor section surrounds the turbine section.

Abstract: A fluid flow controller and method of operation thereof are presented. The fluid flow controller may include a casing having a casing blade. The fluid flow controller may also include a rotor having a first rotor blade and a second rotor blade radially spaced from the first rotor blade. The rotor may be configured to rotate relative to, and preferably within, the casing such that the casing blade passes between the first and second rotor blades during use. Compared to conventional pumps or compressors, the present fluid flow controller may have an enhanced ability to accelerate (and possibly to subsequently pressurize) fluid flow. Thus, the need to use multiple stages may be reduced or eliminated.