Turbomachinery comprising first and second sets of rotors configured to operate on a working fluid. The machinery further comprises first and second sets of electric machines coupled to the respective first and second rotors, and a coupling arrangement arranged to couple adjacent rotors of the first and second rotor sets to provide for fixed ratio, contra-rotation of the first and second rotor sets.

The invention relates to a turbomachine for an aircraft, comprising: a first rotor comprising a first shaft, a second rotor comprising a second shaft, a mechanical reduction gearing having an epicyclic gear set comprising a sun gear connected to the second shaft, a ring gear connected to the first shaft, and planet gears located between the sun gear and the ring gear and borne by a planet carrier attached to a stator of the turbomachine, rolling element bearings for guiding said first shaft and second shaft in rotation, an annular gutter which extends around the ring gear of the reduction gearing and which is configured to recover oil for lubricating the reduction gearing that is sprayed by centrifugal action out from the ring gear during operation, and an annular bearing support which is attached, with the gutter, to a stator of the turbomachine and which supports at least one of said bearings, characterized in that it also comprises: at least one device for conveying oil recovered by said gutter, which device is borne by said annular support and extends as far as said at least one bearing in order to lubricate the latter.

An interdigitated turbine assembly for a gas turbine engine, the interdigitated turbine assembly including a first turbine rotor assembly interdigitated with a second turbine rotor assembly. A first static frame is positioned forward of the first turbine rotor assembly and the second turbine rotor assembly. The first turbine rotor assembly is operably coupled to an inner rotatable component of a gear assembly. The second turbine rotor assembly is operably coupled to an outer rotatable component of the gear assembly. The static structure is connected to the first static frame. A driveshaft is operably coupled to the outer rotatable component. A first bearing assembly is operably coupled to the driveshaft and the first static frame. A second bearing assembly is operably coupled to the first static frame and first turbine rotor assembly. A third bearing assembly is operably coupled to the first turbine rotor assembly and the second turbine rotor assembly.

In one aspect a propulsion system comprises an engine and a drive assembly coupled to the engine, comprising a first driveshaft rotatable in a first direction about a first axis, a first fan coupled to the first driveshaft to rotate in the first direction, and a clutch assembly to selectively disengage the first fan from the first driveshaft. Other aspects may be described.

A turbomachine engine according to aspects of the present disclosure is provided. The engine includes a fan assembly including a plurality of fan blades, and a core engine surrounded by an outer casing. The core engine includes a power output component operably connected to the fan assembly, a first input power source and a second input power source. The first input power source is counter-rotatable relative to the second input power source. The core engine includes a gear assembly operably connected to the power output component and configured to receive power from the first input power source and the second input power source.

A lubricant scavenging system for a turbine engine having a pair of concentric, counter-rotating shafts. The system comprises a lubricant sump housing having a radially inner surface, a pair of pedestal mounts each adapted to receive a bearing assembly from a respective shaft, a lubricant collection point axially disposed between the pedestal mounts, and a pair of axial channels adapted to guide lubricant toward the lubricant collection point.

The present disclosure is directed to a gas turbine engine including a first turbine frame defining one or more first struts extended along a radial direction and a turbine rotor assembly. The turbine rotor assembly defines a rotatable drum surrounding a reduction speed reduction assembly and coupled thereto. The turbine rotor assembly includes a first turbine rotor and a second turbine rotor each disposed on one or more bearing assemblies. The first turbine frame defines a first supply conduit through the first strut providing a flow of fluid to the speed reduction assembly and one or more of the bearing assemblies. The first turbine frame further defines a first scavenge conduit providing an egress of at least a portion of the flow of fluid from one or more of the bearing assemblies.

The present disclosure is directed to a gas turbine engine including a first turbine frame defining one or more first struts extended along a radial direction and a turbine rotor assembly. The turbine rotor assembly defines a rotatable drum surrounding a reduction speed reduction assembly and coupled thereto. The turbine rotor assembly includes a first turbine rotor and a second turbine rotor each disposed on one or more bearing assemblies. The first turbine frame defines a first supply conduit through the first strut providing a flow of fluid to the speed reduction assembly and one or more of the bearing assemblies. The first turbine frame further defines a first scavenge conduit providing an egress of at least a portion of the flow of fluid from one or more of the bearing assemblies.

A counter-rotating shaft assembly of a gas turbine engine includes an outer shaft rotatable in a first direction about a virtual rotational axis, an inner shaft counter-rotatable about the virtual rotational axis in a second direction that is opposite to the first direction, a differential bearing rotatably connecting the two shafts, a centering spring connecting the inner shaft to the differential bearing, and a squeeze film damper between the differential bearing and the inner shaft.

A gas turbine engine having an interdigitated turbine assembly including a first turbine rotor and a second turbine rotor, wherein a total number of stages at the interdigitated turbine assembly is between 3 and 8, and an average stage pressure ratio at the interdigitated turbine assembly is between 1.3 and 1.9. A gear assembly is configured to receive power from the interdigitated turbine assembly, and a fan assembly is configured to receive power from the gear assembly. The interdigitated turbine assembly and the gear assembly are together configured to allow the second turbine rotor to rotate at a second rotational speed greater than a first rotational speed at the first turbine rotor. The fan assembly and the gear assembly are together configured to allow the fan assembly to rotate at a third rotational speed less than the first rotational speed and the second rotational speed. The interdigitated turbine assembly, the gear assembly, and the fan assembly together have a maximum AN.sup.2 at the second turbine rotor between 30 and 90.