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 blade pivot of adjustable orientation for a turbomachine fan hub includes: a block having a retaining device configured to retain a fan blade root and a coupling device for the transmission of a torque; a ball type rolling bearing for taking up centrifugal forces having an inner ring; a clamping nut screwed onto an external thread of the block in order to clamp the inner ring of the ball type rolling bearing for taking up centrifugal forces to the block; a rolling bearing for taking up transverse forces; a pitch setting transmission ring positioned inside the inner radial end of the block and equipped with a coupling device cooperating with the coupling device of the block, and a device for locking the pitch setting transmission ring on the block.

A fan wheel with a hub is centrally supported with respect to a drive and coaxially rotatable with the hub between stops relative to the hub. The fan wheel having fan blades extending radially from the hub are rotatable about their axes in a range delimited by the stops. Overlaying the rotational support between the stops of the hub, a rotational support between the hub and the drive is provided including a planetary drive in operative arrangement with an adjustment control ring of the driven hub. The fan blades are rotatable in the hub about their blade axes, and adjustment of the blade angles of the fan blades via drive connections to the adjustment control ring, which connections operate in a manner superimposed on one another starting from the drive of the fan wheel.

The present invention relates to a blade comprising: - a structure made of composite material; - a blade root attachment part comprising a wall delimiting a cavity, a first opening formed in the wall and a second opening located under the blade root portion, the structure made of composite material extending through the first opening; - two locking parts configured to axially abut against a shoulder of the attachment part and to bear against the blade root portion; and - a cover for compressing the blade root portion against the locking parts.

A fan assembly for a gas turbine engine includes a fan disk, a trunnion, a fan blade, and a counterweight assembly. The fan disk is configured to rotate about an axial centerline of the gas turbine engine when installed in the gas turbine engine. The trunnion is mounted to the fan disk and defines a slot extending through a portion of the trunnion. The fan blade defines a pitch axis and is rotatably attached to the fan disk about its pitch axis through the trunnion. The counterweight assembly includes a link arm extending to the trunnion and an engagement device mounted to the link arm that is disposed to move through the slot of the trunnion.

Methods, apparatus, systems, and articles of manufacture are disclosed to adjust a pitch axis of a blade of an engine. An example blade apparatus includes: a hub to facilitate movement of blades in an engine, the engine having a radial center line; and a trunnion connected to the hub. The example trunnion includes a slot to accommodate a first blade, and at least one of the trunnion or the first blade is positioned with at least one of a tilt or a lean with respect to the radial center line to form a pitch axis offset from the radial center line such that the pitch axis is not parallel to or co-linear with the radial center line. The example hub is to rotate the first blade about the pitch axis.

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 variable-pitch bladed disc including a plurality of blades, each at a variable pitch in relation to a rotation axis of the blade and each having a root, the plurality of blades including at least one first blade and at least one second blade, a plurality of rotor connecting shafts, each having a root and a tip, each root being mounted at the tip of a corresponding rotor connecting shaft by way of a pivot so as to allow each blade to rotate about the blade rotation axis, the first blade having a first blade inclination, such that the first blade is inclined in a fixed manner with respect to the blade rotation axis of the first blade, and the second blade having a second blade inclination different from the first blade inclination.

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.

A variable pitch fan assembly includes a plurality of rotating trunnion assemblies, a plurality of counterweight assemblies, a first unison ring gear engaged with the trunnion assemblies, and a second unison ring member that restricts out of synch movement of the counterweights relative to each other.