In accordance with at least one aspect of this disclosure, there is provided a drive shaft system. In embodiments, the drive shaft system includes a generator shaft extending along a longitudinal axis with a longitudinal bore defined through the generator shaft. A thru shaft extends through the longitudinal bore of the generator shaft. In embodiments, the thru shaft includes, a front coupler mount at a first end operative to receive torque input, and a rear coupler mount at a second end opposite the first end.

The gas turbine engine assembly can include a first component having a male fit perimeter, a second component having a female fit perimeter forming an interference fit with the male fit perimeter, one of the first component and the second component having a pulling lip spanning transversally and further spanning peripherally, and a structure holding the pulling lip transversally offset from the interference fit, the structure having a bending portion extending at least partially transversally.

An assembly for a turbine engine extending along an axis, includes a stator, a low-pressure compressor shaft, a low-pressure compressor comprising a rotor comprising a drum rotatably coupled to the shaft of the low-pressure compressor, and a fan comprising a disk rotatably coupled to the shaft of the low-pressure compressor. The drum has a radially internal part rotatably coupled to the shaft of the low-pressure compressor and a radially external part fixed to the radially internal part by means of detachable fixing means. A first axial retention means is configured to axially and detachably retain the disk of the fan relative to the shaft of the low-pressure compressor. A second axial retention means is configured to axially and detachably retain the radially internal part of the drum relative to the shaft of the low-pressure compressor.

An air starter for an engine, such as a turbine engine, that includes a turbine for rotatably extracting mechanical power from a flow of fluid. The turbine includes a drive shaft that can be coupled to an output shaft to provide a rotational output. The interface between the drive shaft and the output shaft can be offset and include piloted portions.

A gas turbine engine includes a low speed spool mechanically interconnecting a low pressure turbine and at least one of a fan and a prop, a high speed spool mechanically interconnecting a high pressure turbine and a high pressure compressor, and an epicyclic gear system mechanically coupled to the high speed spool. The gas turbine engine also includes a low pressure compressor mechanically coupled to the high speed spool via the epicyclic gear system. The low pressure compressor may be mechanically independent of the low speed spool. The gas turbine engine may include a plurality of motor-generators for transferring power between the high speed spool and the low pressure compressor.

An engine assembly defining an axial direction (A) and including a gearbox, an engine core including at least one rotor, and a flexible coupling shaft having a first end and a second end along the axial direction (A). The first end of the flexible coupling shaft is connected to the engine core and the second end of the flexible coupling shaft is connected to the gearbox. A damper system is positioned at the second end of the flexible coupling shaft. The damper system is configured to reduce vibrations to the flexible coupling shaft during operation of the engine assembly.

A gas turbine engine rotor assembly comprises a torque tube, turbine stage and stiffening mass. The torque tube comprises a shaft extending from a forward location to an aft end, and a shaft fastening flange disposed at the aft end. The turbine stage comprises a disc, a disc adapter extending forward from the disc, and a disc fastening flange extending from the disc adapter and couplable to the shaft fastening flange at an interface. The stiffening mass is positioned proximate the interface to reduce operational stress in the torque tube. A method of reducing operational stress in a rotor assembly comprises de-stacking a rotor stack, separating a first stage rotor disc adapter from a torque tube, attaching a stiffening mass to an inner diameter of one or both of the disc adapter and the torque tube, attaching the disc adapter to the torque tube, and re-stacking the rotor stack.

The invention relates to an assembly for a turbine engine, comprising a radially inner shaft (3) and a radially outer shaft (7), said shafts (7, 8) being coaxial and extending along an axis (X), means (11, 15) for coupling said inner and outer shafts (7, 8) in rotation, means (22) for axially holding the inner shaft (8) relative to the outer shaft (7), means for centring the inner shaft (8) relative to the outer shaft (7), characterised in that the centring means comprise a shim (14) for radial centring and for axial positioning, this shim being frustoconical and interposed between a frustoconical centring surface (13) of the inner shaft (8) and a corresponding frustoconical centring surface (10) of the outer shaft (7).

A tool for installing segments of a coupling having male and female couplers drivingly engaged to one another by the segments, the tool has: a coupler-engaging section engageable to the a female coupler of the couplers for radially supporting the tool relative to the female coupler about a rotation axis of the coupling; and a peripheral wall secured to the coupler-engaging section and extending circumferentially around the rotation axis, a diameter (D2) of the peripheral wall selected to allow insertion of the segments between the female coupler and the peripheral wall, the peripheral wall defining an abutting surface against which radially inner ends of the segments abut during insertion of the segments between the female coupler and the peripheral wall.

A rotor assembly includes a plurality of wheels and a tie bolt that extends through the plurality of wheels and applies a compressive force to the plurality of wheels. The tie bolt includes a first segment with a first stiffness and a second segment with a second stiffness to allow for thermal growth of the plurality of wheels.