Abstract: The rotor assembly can have a first disc having a first body extending circumferentially and radially around the axis, a first set of circumferentially distributed blades protruding radially from the first disc, and a male spline extending axially relative the first body, the male spline extending around and along the axis, and a second disc having a second body extending circumferentially and radially around the axis, a second set of circumferentially distributed blades protruding radially from the second disc, and a female spline extending around and along the axis, the female spline receiving the male spline in a spline engagement.

Abstract: A rotor assembly for a gas turbine engine includes a turbine shaft disposed about a longitudinal axis, a first rotor and a second rotor configured for rotation about the longitudinal axis, and an intermediate shaft positioned radially between the turbine shaft and the second rotor. The second rotor is mounted to and axially adjacent the first rotor. The intermediate shaft is mounted to the turbine shaft on an inner radial side of the intermediate shaft. The intermediate shaft is mounted to the second rotor on an outer radial side of the intermediate shaft.

Abstract: The gas turbine engine includes a casing assembly located proximate a turbine section of the gas turbine engine, and a tangential on-board injector (TOBI) having a body defining a plurality of air passages extending in a radial direction, the plurality of air passages circumferentially distributed and directing cooling air toward a turbine rotor of the turbine section of the gas turbine engine. An interference fit is provided between a face of the body and a face of a member of the casing assembly, the interference fit defining a fastener-free engagement between the bearing housing and the TOBI to prevent relative movement between the member of the casing and the TOBI.

Abstract: A rotor assembly for a gas turbine engine includes a turbine shaft disposed about a longitudinal axis, a first rotor and a second rotor configured for rotation about the longitudinal axis, and an intermediate shaft positioned radially between the turbine shaft and the second rotor. The second rotor is mounted to and axially adjacent the first rotor. The intermediate shaft is mounted to the turbine shaft on an inner radial side of the intermediate shaft. The intermediate shaft is mounted to the second rotor on an outer radial side of the intermediate shaft.

Abstract: A rotor assembly comprises a rotor having annular flange including a plurality of protrusions axisymmetrically disposed about the annular flange, each protrusion having a mounting aperture for selectively receiving a balancing feature, and a plurality of slots axisymmetrically disposed about the circumference of the annular flange between adjacent protrusions. Each slot has a pair of converging flat portions extending axially inwardly from an adjacent protrusion end, an inner flat portion at an inner end of each slot, and a pair of curved portions respectively joining each converging flat portion to the inner flat portion in each slot. Each slot has a depth at least as great as an adjacent mounting aperture depth extending normally from the adjacent protrusion end to a far end of the corresponding mounting aperture.

Abstract: A retention assembly for interconnecting first and second rotating components in a gas turbine engine. The second component includes an engagement portion defining protrusions circumferentially spaced apart and extending axially therefrom. A threaded fastener axially retains the second rotating component to the first and has key-receiving slots and a circumferentially-extending groove. A key washer is mounted to the fastener and defines first and second axial surfaces. The key washer has a first set of keys extending radially inwardly from a radially inner surface and received within the key-receiving slots and a second set of keys extending from the second axial surface. A retaining ring is disposed within the groove, is radially retained by the protrusions extending axially from the second component, axially retained between the second set of keys and the second axial surface, and radially spaced apart from the second set of keys to define a radial gap therebetween.

Abstract: An ejector comprises a primary nozzle having an annular wall forming part of an outer boundary of an exhaust portion of a primary flow path of a gas turbine engine. The annular wall has a downstream end defining a plurality of circumferentially distributed lobes. The ejector further comprises a secondary nozzle having an annular wall disposed about the primary nozzle, the primary nozzle and the secondary nozzle defining a secondary flow passage therebetween for channeling a secondary flow. The secondary nozzle defines a mixing zone downstream of an exit of the primary nozzle. A flow guide ring is mounted to the primary nozzle lobes. The ring has an aerodynamic surface extending from a leading edge to a trailing edge respectively disposed upstream and downstream of the exit of the primary nozzle. The aerodynamic surface of the ring is oriented to guide the high velocity primary flow into the mixing zone.

Abstract: The rotor assembly can have a first disc having a first body extending circumferentially and radially around the axis, a first set of circumferentially distributed blades protruding radially from the first disc, and a male spline extending axially relative the first body, the male spline extending around and along the axis, and a second disc having a second body extending circumferentially and radially around the axis, a second set of circumferentially distributed blades protruding radially from the second disc, and a female spline extending around and along the axis, the female spline receiving the male spline in a spline engagement.

Abstract: The gas turbine engine includes a casing assembly located proximate a turbine section of the gas turbine engine, and a tangential on-board injector (TOBI) having a body defining a plurality of air passages extending in a radial direction, the plurality of air passages circumferentially distributed and directing cooling air toward a turbine rotor of the turbine section of the gas turbine engine. An interference fit is provided between a face of the body and a face of a member of the casing assembly, the interference fit defining a fastener-free engagement between the bearing housing and the TOBI to prevent relative movement between the member of the casing and the TOBI.

Abstract: A rotor assembly comprises a rotor having annular flange including a plurality of protrusions axisymmetrically disposed about the annular flange, each protrusion having a mounting aperture for selectively receiving a balancing feature, and a plurality of slots axisymmetrically disposed about the circumference of the annular flange between adjacent protrusions. Each slot has a pair of converging flat portions extending axially inwardly from an adjacent protrusion end, an inner flat portion at an inner end of each slot, and a pair of curved portions respectively joining each converging flat portion to the inner flat portion in each slot. Each slot has a depth at least as great as an adjacent mounting aperture depth extending normally from the adjacent protrusion end to a far end of the corresponding mounting aperture.

Abstract: Turbine and other bladed disc assemblies and associated methods are disclosed. In an embodiment, a turbine assembly includes a rotor and a turbine disc secured to the rotor via a nut and a deformable retainer. The nut is threadably engaged with the rotor to secure the turbine disc to the rotor. The retainer is deformed to co-operatingly engage with a periphery of the nut and configured to hinder rotation of the nut relative to the rotor.

Abstract: There is disclosed a vane segment for a gas turbine engine. The vane segment includes vanes extending radially from inner ends to outer ends. The vanes have leading edges, trailing edges, and chords extending from the leading edges to the trailing edges. A platform circumferentially extends around the central axis. The platform has an inner face facing the central axis and an opposed outer face. The inner face of the platform is connected to the outer ends of the vanes. Ribs protrude away from the outer face and have lengths extending along the outer face.

Abstract: Turbine and other bladed disc assemblies and associated methods are disclosed. In an embodiment, a turbine assembly includes a rotor and a turbine disc secured to the rotor via a nut and a deformable retainer. The nut is threadably engaged with the rotor to secure the turbine disc to the rotor. The retainer is deformed to co-operatingly engage with a periphery of the nut and configured to hinder rotation of the nut relative to the rotor.

Abstract: A rim seal between a stator and a rotor in a gas turbine engine is described. The seal includes an axial overlap between platform rims of the stator and the rotor. The axial length of the platform rim of one of the stator and the rotor is accommodated within a radially aligned trench defined in the other of the stator and the rotor.

Abstract: A rim seal located between a stator and a rotor in a gas turbine engine includes an axial overlap between platform rims of the stator and the rotor. The axial length of the platform rim of one of the stator and the rotor is accommodated within a radially aligned trench defined in the other of the stator and the rotor.

Abstract: An ejector/mixer for a gas turbine engine includes an annular wall having upstream end adapted to be fastened to an engine case and a downstream end forming a plurality of lobes. A support member interconnects the lobes, and includes an annular blade located radially inwardly of the bight of the lobes. The lobes extend radially inwardly downstream relative to the annular wall and the support member includes an annular blade and has spaced apart joint surfaces spaced apart to coincide with the joint surfaces of a respective lobes. The spaced-apart joint surfaces of the support member being profiled to mate with the corresponding joint surface of the lobes.

Abstract: There is disclosed a vane segment for a gas turbine engine. The vane segment includes vanes extending radially from inner ends to outer ends. The vanes have leading edges, trailing edges, and chords extending from the leading edges to the trailing edges. A platform circumferentially extends around the central axis. The platform has an inner face facing the central axis and an opposed outer face. The inner face of the platform is connected to the outer ends of the vanes. Ribs protrude away from the outer face and have lengths extending along the outer face.

Abstract: An ejector comprises a primary nozzle having an annular wall forming part of an outer boundary of an exhaust portion of a primary flow path of a gas turbine engine. The annular wall has a downstream end defining a plurality of circumferentially distributed lobes. The ejector further comprises a secondary nozzle having an annular wall disposed about the primary nozzle, the primary nozzle and the secondary nozzle defining a secondary flow passage therebetween for channeling a secondary flow. The secondary nozzle defines a mixing zone downstream of an exit of the primary nozzle. A flow guide ring is mounted to the primary nozzle lobes. The ring has an aerodynamic surface extending from a leading edge to a trailing edge respectively disposed upstream and downstream of the exit of the primary nozzle. The aerodynamic surface of the ring is oriented to guide the high velocity primary flow into the mixing zone.

Abstract: An ejector comprises a primary nozzle having an annular wall forming part of an outer boundary of an exhaust portion of a primary flow path of a gas turbine engine. The annular wall has a downstream end defining a plurality of circumferentially distributed lobes. The ejector further comprises a secondary nozzle having an annular wall disposed about the primary nozzle, the primary nozzle and the secondary nozzle defining a secondary flow passage therebetween for channeling a secondary flow. The secondary nozzle defines a mixing zone downstream of an exit of the primary nozzle. A flow guide ring is mounted to the primary nozzle lobes. The ring has an aerodynamic surface extending from a leading edge to a trailing edge respectively disposed upstream and downstream of the exit of the primary nozzle. The aerodynamic surface of the ring is oriented to guide the high velocity primary flow into the mixing zone.

Abstract: A turbine shroud segment forms part of a circumferentially segmented shroud assembly surrounding a circumferential array of turbine blades of a gas turbine engine. The turbine shroud segment has a platform extending axially from an upstream end portion to a downstream end portion relative to a flow of gas through the gas turbine engine. A heat shield extension projects radially inwardly and in an upstream direction from the upstream end portion of the platform.