A propulsion system includes a drive shaft movable about an axis of rotation, a fan, a fan shaft that drives the fan, and a reduction device coupling the drive shaft and the fan shaft. The reduction device has first and second reduction stages and includes a sun gear, centered on the axis and driven by the drive shaft, a ring gear that is coaxial with the sun gear and that drives the fan shaft about the axis, and planet gears distributed circumferentially about the axis between the sun gear and the ring gear. Each planet gear includes a first portion meshed with the sun gear and a second portion meshed with the ring gear. A diameter of the first portion is different from a diameter of the second portion, and the first portion of the planet gears extend between the second portion of the planet gears and the fan.

A propulsion system includes a drive shaft, a fan, a fan shaft, and a reduction device coupling the drive and fan shafts. The reduction device includes a first reduction stage and a second reduction state, and include a sun gear, centered on an axis of rotation of the drive and fan shafts and driven in rotation by the drive shaft, a ring gear, coaxial with the sun gear and that drives the fan shaft in rotation about the axis, and planet gears distributed circumferentially about the axis between the sun and ring gears, each planet gear including a first portion which is meshed with the sun gear and a second portion which is meshed with the ring gear, a diameter of the first portion being different from a diameter of the second portion, and an oil transfer bearing positioned between the fan and the reduction device.

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.

Methods and systems for filtering pressurized air used to control a compressor bleed valve of a gas turbine engine are provided. One method comprises receiving the pressurized air in a conduit via an inlet of the conduit, releasing a first portion of the pressurized air out of the conduit via an outlet of the conduit, releasing a second portion of the pressurized air from the conduit via a port disposed between the inlet and the outlet of the conduit, directing the second portion of the pressurized air from the port to a filter along an upward flow path, filtering the second portion of the pressurized air using the filter, and directing the second portion of the pressurized air from the filter toward the compressor bleed valve.

A propeller control unit (PCU) has: a pitch angle actuator; a valve operable to selectively fluidly connect the pitch angle actuator with a source of oil for controlling pitch angles of blades of a propeller and with a drain line for draining oil out of the pitch angle actuator for feathering the blades; and a bypass line having an inlet hydraulically between the valve and an inlet of the drain line, the bypass line having an outlet hydraulically between the inlet of the drain line and an outlet of the drain line.

A morphing airfoil includes a dynamic flexible skin system that is capable of carrying high level aerodynamic (or fluid) pressure loads over a structural surface. The structural surface can morph and bend in response to control inputs to change a lift force without separate movable control surfaces. A plurality of standoff mounts are attached to an inner surface of anisotropic skin. The standoff mounts include through apertures for receiving a flexible stringer. The anisotropic skin is attached to underlying structure through the flexible stringers. The flexible stringers interface with actuated position control ribs and passive compliant support ribs. A control system causes the underlying support structure to move to a desired location which in turn causes the skin to bend and/or flex without exceeding a stress threshold and thus vary the lift and drag distributions along a span of the airfoil without separate control surfaces.

The present disclosure is directed to a turbine engine (10) defining an axial direction and a radial direction. The turbine engine includes a fan or propeller assembly (14) comprising a gearbox; an engine core (20) comprising one or more rotors, wherein at least one of the rotors defines an axially extended annular hub; and a flexible coupling shaft (100) defining a first end and a second end along the axial direction, wherein the first end is connected to the engine core and the second end is connected to the gearbox, and further wherein the flexible coupling shaft extends from the one or more rotors to the gearbox in the axial direction and inward of the hub in the radial direction.

An apparatus is provided for a turbine engine. This turbine engine apparatus includes a journal bearing extending axially along and circumferentially about an axis. The journal bearing extends radially between an inner side and an outer side. The journal bearing includes a bore, a passage and a groove. The bore extends axially within the journal bearing and is formed by the inner side. The passage extends radially within the journal bearing and is fluidly coupled with the bore and the groove. The groove is arranged at the outer side. The groove extends longitudinally within the journal bearing between a first end and a second end. The groove extends axially within the journal bearing between a first side and a second side. An axial distance between the first side and the second side changes as the groove extends longitudinally between the first end and the second end.

An orifice pack is provided for delivering pressurized air to a compressor bleed valve of a gas turbine engine. The orifice pack has a diffusion chamber in serial flow communication with a tapering passage and a first outlet passage for venting a first portion of the pressurized air from the diffusion chamber. A second outlet passage branches off from the diffusion chamber at an axial location between the inlet and the tapering passage. The second outlet passage is fluidly connected to the compressor bleed valve for directing a second portion of the pressurized air from the diffusion chamber to the compressor bleed valve.

A turbomachine module with a longitudinal axis comprising an unducted propeller rotated about the longitudinal axis and at least one straightener. The module includes a plurality of unducted variable-pitch stator blades extending along a radial axis, perpendicular to the longitudinal axis, from a fixed casing. The module includes a first stator blade pitch-changing system. The pitch-changing system includes at least one first control that includes a first fixed body connected to the fixed casing and a first body which is axially mobile in relation to the first fixed body and at least one first joining mechanism joining each stator blade to the first mobile body of the first control. The first joining mechanism includes: a joining ring centered on the longitudinal axis, joined to the feet of each stator blade and at least one lever joined, on one hand, to the joining ring and, on the other hand, to the first mobile body of the first control.