Abstract: A gas turbine engine mid turbine frame apparatus includes a an inner case supporting a bearing, an outer case to which the inner case is mounted, and an apparatus for radially positioning one relative to the other, the apparatus including a plurality of radial locators extending outwardly of the outer case and an associated locking apparatus. The locking apparatus is mounted adjacent to but independent of the locators and provides for anti-rotation of the radial locators once installed.

Abstract: A method for centering an engine structure such as a bearing housing is provided which may be used, for example, during assembly of a mid turbine frame or other engine case structure. In one aspect, the method includes using spacers with respective radial spokes which connect inner and outer portions of the case. In another aspect, centring may be provided by machining selected contacting surfaces of selected components.

Abstract: A seal arrangement for segmented turbine components comprises a sealing strip and a resilient cord element compressed against the strip to provide positive loading of the strip against the segment sealing faces. The sealing strip and the resilient cord element are engaged in confronting cavities defined in the end faces of adjacent segments. The resilient cord element is commonly held by both segments in a compressed state against the sealing strip.

Abstract: A split ring seal assembly includes a metal seal ring having two ends defining a circumferential gap therebetween. At least a first spring element is mounted to the two ends to bias the two ends circumferentially towards each other to reduce the diameter of a circumferential inner sealing surface of the metal seal ring.

Abstract: A gas turbine engine has an engine casing component, such as a mid turbine frame system, which may includes an outer case surrounding a spoke or strut casing. Load transfer spokes of the spoke casing extend between the outer case and an inner case of the spoke casing. A bearing housing supported by the engine casing may include a fuse arrangement for isolating bearing seizure loads from the engine casing. A seal arrangement may be provided to centralize the rotors after the fuse fails. The mid turbine frame may be provided to have a desired flexibility through the configuration of the casing and bearings in design.

Abstract: A split ring seal assembly includes a metal seal ring having two ends defining a circumferential gap therebetween. At least a first spring element is mounted to the two ends to bias the two ends circumferentially towards each other to reduce the diameter of a circumferential inner sealing surface of the metal seal ring.

Abstract: An arrangement for sealing a turbine shroud gas path duct interface of a turbine engine comprises a static shroud surrounding a rotatable airfoil array and an annular duct downstream of the shroud with respect to a gas flow passing through the gas path. The shroud and the duct define a portion of the gas path for directing the gas flow, having an axially extending interface gap between the shroud and duct. An annular seal in use engages both the shroud and the duct, thereby sealing the annular gap.

Abstract: A gas turbine engine has a casing component, such as a mid turbine frame system, which includes an outer case surrounding a spoke or strut casing. Load transfer spokes of the spoke casing are detachably connected to the outer case and radially extend between the outer case and an inner case of the spoke casing. A bearing housing is supported by the inner case of the spoke casing. An arrangement for radially centring the bearing within the outer case is provided, the arrangement including at least three radial locators mounted to the outer case.

Abstract: A mid turbine frame of a gas turbine engine includes an outer case which supports a spoke casing co-axially positioned therein. The spoke casing has load transfer spokes extending radially from an inner case and secured to the outer case. A load transfer device is provided to transfer load from the spokes to the outer case in addition to load transfer through a first group of fasteners securing the spokes to the outer case, thereby forming a secondary load transfer path from the spokes. The load transfer device includes an opening of the outer case into which at least some of the spokes are inserted.

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 vane assembly for a gas turbine engine comprising an axial loading element disposed between a mounting element of the vane ring and a cooperating portion of the supporting structure, such as to generate a load force therebetween in an axial direction. The axial load force limits unwanted relative movement between the vane ring and the supporting structure during operation of the gas turbine engine.

Abstract: A seal housing is provided to substantially cover at least one duct wall of vane array duct of a gas turbine engine, and one example arrangement is employed in a mid-turbine frame. The arrangement provides improved sealing of the vane array duct through the provision of a plurality of cavities extending along the duct wall. The arrangement may also include insulation tubes to assist in sealing around load transfer spokes passing through the vane array.

Abstract: A method for centering an engine structure such as a bearing housing is provided which may be used, for example, during assembly of a mid turbine frame or other engine case structure. In one aspect, the method includes using spacers with respective radial spokes which connect inner and outer portions of the case. In another aspect, centring may be provided by machining selected contacting surfaces of selected components.

Abstract: A split ring seal assembly includes a metal seal ring having two ends defining a circumferential gap therebetween. At least a first spring element is mounted to the two ends to bias the two ends circumferentially towards each other to reduce the diameter of a circumferential inner sealing surface of the metal seal ring.

Abstract: A mid turbine frame with an annular interturbine duct may be assembled by placing an mid turbine frame inner case of into the interturbine duct, inserting a plurality of mid turbine frame spokes radially through respective hollow radial struts of the interturbine duct to be connected to the mid turbine frame inner case to form a mid turbine frame spoke casing. A mid turbine frame outer case is also connected to the spokes, to provide an assembled mid turbine frame.

Abstract: A gas turbine engine has a casing component, such as a mid turbine frame system, which includes an outer case surrounding a spoke or strut casing. Load transfer spokes of the spoke casing are detachably connected to the outer case and radially extend between the outer case and an inner case of the spoke casing. A bearing housing is supported by the inner case of the spoke casing. An arrangement for radially centring the bearing within the outer case is provided, the arrangement including at least three radial locators mounted to the outer case.

Abstract: A gas turbine engine mid turbine frame apparatus includes a an inner case supporting a bearing, an outer case to which the inner case is mounted, and an apparatus for radially positioning one relative to the other, the apparatus including a plurality of radial locators extending outwardly of the outer case and an associated locking apparatus. The locking apparatus is mounted adjacent to but independent of the locators and provides for anti-rotation of the radial locators once installed.

Abstract: A gas turbine engine has a mid turbine frame system which includes an outer case surrounding a spoke casing. Spokes of the spoke casing are detachably connected to the outer case and radially extend through hollow struts of a segmented interturbine duct which is disposed between the outer case and an inner case of the spoke casing. A bearing housing is supported by the inner case of the spoke casing. The mid turbine frame is assembly by inserting the interturbine duct segments over the spokes and then inserting the spoke casing into the outer case.

Abstract: A gas turbine engine mid turbine frame having an annular interturbine duct and vane ring assembly includes a duct having outer and inner duct walls of sheet metal interconnected by radial hollow struts of sheet metal and a vane ring is connected to the duct to provide the assembly. The interturbine duct and vane ring assembly may be provided within a mid turbine frame in a manner which is independent of a bearing load path through the mid turbine frame.

Abstract: A gas turbine engine has an engine casing component, such as a mid turbine frame system, which may includes an outer case surrounding a spoke or strut casing. Load transfer spokes of the spoke casing extend between the outer case and an inner case of the spoke casing. A bearing housing supported by the engine casing may include a fuse arrangement for isolating bearing seizure loads from the engine casing. A seal arrangement may be provided to centralize the rotors after the fuse fails. The mid turbine frame may be provided to have a desired flexibility through the configuration of the casing and bearings in design.