An assembly includes a variable area inlet and an inlet duct. The variable area inlet includes an inlet structure and a center body structure. The inlet structure extends circumferentially about the center body structure with an outer inlet passage radially between the center body structure and the inlet structure. The center body structure includes an outer body and an inner body. The outer body extends circumferentially about the inner body with an inner inlet passage radially between the inner and outer bodies. The inner body is configured to move along a centerline relative to the outer body between a first position and a second position. The inlet duct is fluidly coupled with the outer inlet passage when the inner body is in the first position. The inlet duct is fluidly coupled with the outer inlet passage and the inner inlet passage when the inner body is in the second position.

A coupling has: a first coupler rotatable about an axis and defining first connections distributed about the axis; a second coupler defining second connections distributed about the axis, the second connections offset from the first connections; and segments distributed about the axis and extending radially from the first connections to the second connections, a segment of the segments having a first end engaging a first connection of the first connections and a second end engaging a second connection of the second connections, the first end circumferentially offset from the second end, a face of the segment abutting against a face of the first coupler when the segment is inserted into the first connection in a first orientation such that a penetration depth of the segment into the first connection in the first orientation is less than the penetration depth in a second orientation opposite the first orientation.

An internal retaining ring for placement in a bore of an outer component of a rotating assembly comprises a semi-annular body having an outer circumferential surface with a curvature defined about a first center of curvature and radially outward protruding anti-rotation tabs operable for engagement with a corresponding anti-rotation feature of the outer component. An inner circumferential surface of the semi-annular body has radially inward protruding tabs circumferentially spaced apart around the inner circumferential surface. The radially inward protruding tabs have radially inner surfaces concentric with the outer circumferential surface, and recessed portions between the radially inward protruding tabs and having curvatures defined about a second center of curvature, the second center of curvature different from the first center of curvature.

A mechanical reduction gear of a turbomachine, in particular of an aircraft. The reduction gear includes a sun gear, a ring gear surrounded by a ring gear carrier, and planet gears meshed with the sun gear and the ring gear. The ring gear carrier includes an axial abutment on which the ring gear is configured to bear, and helical external splines which are engaged in complementary internal splines of the ring gear carrier and which are configured to cooperate by sliding with the internal splines so as to force the ring gear to be held against the abutment in operation.

There is provided a compact turbine-compressor assembly 25. The turbine-compressor assembly 25 includes a turbine wheel 39 with one or more turbine blades 41 and a compressor wheel 47 that includes one or more compressor blades 49. The compressor wheel 47 is concentric with the turbine wheel 39. Furthermore, the compressor wheel 47 and the turbine wheel 39 are not located at opposite ends of a common axle with a medial portion of the axle distancing them apart, as is the case with prior art turbine-compressor assemblies that are known. In contrast, the turbine wheel 39 and the compressor wheel 47 are located adjacent to each other and in one embodiment they axially overlap each other so that one nests within the other to thereby provide a compact arrangement. The turbine-compressor assembly 25 includes a first fluid path 67 which is configured to convey fluid, which will typically be air, through the turbine blades 41. The turbine-compressor assembly 25 also includes a second fluid path 77 which is configured to convey fluid, which will typically be air, through the compressor blades. The turbine-compressor assembly 25 is arranged so that the first fluid path 67 is distinct from the second fluid path 77 and vice-versa.

An assembly is provided for a turbine engine. This turbine engine assembly includes a turbine engine shaft, a gearbox and a coupler. The turbine engine shaft is configured to rotate about a rotational axis. The gearbox includes a gear configured to rotate about the rotational axis. The coupler is coupled to the turbine engine shaft by a coupler-shaft connection. The coupler-shaft connection is configured as or otherwise includes a crowned spline connection. The coupler is coupled to the gear by a coupler-gear connection. The coupler-gear connection is configured as or otherwise includes a crowned spline connection.

An assembly is provided for a turbine engine. This turbine engine assembly includes a rotating structure, a stationary structure and an electric machine. The rotating structure is configured to rotate about a rotational axis. The stationary structure circumscribes the rotating structure. The electric machine includes a rotor and a stator. The rotor circumscribes the rotating structure and is coupled to the rotating structure through a spline connection. The stator is connected to the stationary structure.

An air turbine starter that includes a housing. The housing can circumscribe a turbine coupled that is coupled to a gear train in a gear box via a drive shaft. The gear train can couple to an output shaft via at least a carrier. The air turbine starter can include at least a first bearing assembly and a second bearing assembly to rotatably support one or more of the drive shaft, the carrier, or the output shaft.

A turbopump includes: a main shaft rotatably supported; a pump section including an impeller attached to one end of the main shaft; and a turbine section including: a disk attached to the other end of the main shaft, rotor blades provided on an outer periphery of the disk, and nozzles provided inclined to an entrance plane of a blade cascade constituted of the rotor blades, the nozzles having axisymmetric cross sections and arranged in at least two rows along a circumferential direction of the main shaft in a plane orthogonal to the main shaft.

Aircraft turbomachine comprising a casing, a fan, a compressor and a turbine and an epicyclic gear train comprising an input driven in rotation by the turbine, a first output stage configured to drive in rotation the compressor and a second output stage coupled to the first output stage and configured to drive in rotation the fan, the compressor being driven in rotation by the ring gear of the first output stage.