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.

The invention relates to a bypass turbomachine (2) for an aircraft, comprising a gas generator (5) and a ducted fan (4) comprising variable pitch blades (18) configured to take a reverse thrust position driving a reverse flow (24) of air within a secondary duct (16), the gas generator (5) being connected to a fan casing (3) by a stator blade assembly (40) that passes through the secondary duct, first openings (28) for letting in air from the reverse flow being located on an outer casing (17) at least partially internally delimiting the outer duct, and second openings (29) for letting said air out being located on an inner casing (14) at least partially externally delimiting an inner duct (12). The first openings are located within a plane that is perpendicular to a longitudinal axis (C) of the turbomachine and passes substantially through the middle of the blade assembly.

The invention relates to a bypass turbomachine (2) for an aircraft, comprising a gas generator (5) and a ducted fan (4) comprising variable pitch blades (18) configured to take a reverse thrust position driving a reverse flow (24) of air within a secondary duct (16), the gas generator (5) being connected to a fan casing (3) by a stator blade assembly (40) that passes through the secondary duct, first openings (28) for letting in air from the reverse flow being located on an outer casing (17) at least partially internally delimiting the outer duct, and second openings (29) for letting said air out being located on an inner casing (14) at least partially externally delimiting an inner duct (12). The first openings are located within a plane that is perpendicular to a longitudinal axis (C) of the turbomachine and passes substantially through the middle of the blade assembly.

The present invention concerns a turbomachine hub, intended to be mounted so as to be able to rotate about a longitudinal axis (X) of the turbomachine, the hub comprising a main body (1) arranged around the longitudinal axis (X), an outer surface of which has a plurality of recesses; a plurality of platforms (3) comprising an outer surface delimited by a circular outer edge of radius r, each platform (3) being arranged in a corresponding recess of the plurality of recesses of the main body (1), and intended to receive a variable pitch blade (2), the pitch of which is variable according to a pitch change axis (Z), the platform (3) being centred and able to rotate about the pitch change axis (Z); characterised in that, for each platform, at least one part of the outer surface of the platform (3) and the main body (1) of the hub comprises a curvature defined by a same sphere portion of radius R and centre C, the at least one part being situated at the outer edge of the platform (3), in a junction zone between the platform (3) and the main body of the hub (1), the centre C of the sphere being situated on the pitch change axis (Z) outside a hemispherical zone delimited between the longitudinal axis (X) and the outer surface of the platform (3).

A gas turbine engine defining a centerline and a circumferential direction, the gas turbine engine including: a turbomachine comprising a compressor section, a combustion section, and a turbine section arranged in serial flow order, the turbomachine defining a working gas flowpath and a fan duct flowpath; a primary fan driven by the turbomachine defining a primary fan tip radius R.sub.1 and a primary fan hub radius R.sub.2; a secondary fan located downstream of the primary fan and driven by the turbomachine, at least a portion of an airflow from the primary fan configured to bypass the secondary fan, the secondary fan defining a secondary fan tip radius R.sub.3 and a secondary fan hub radius R.sub.4, wherein the secondary fan is configured to provide a fan duct airflow through the fan duct flowpath during operation to generate a fan duct thrust, wherein the fan duct thrust is equal to %Fn.sub.3S of a total engine thrust during operation of the gas turbine engine at a rated speed during standard day operating conditions; wherein a ratio of R.sub.1 to R.sub.3 equals

[00001]$\sqrt{\left(EFP\right)\frac{\left(1-Rq{R}_{sec.-Fan}{}^2\right)}{\left(1-Rq{R}_{Prim.-Fan}{}^2\right)}\left(\frac{1}{\%F{n}_{3s}}-1\right)};$

wherein EFP is between 1.5 and 11, wherein RqRp.sub.rim.-Fan is a ratio of R.sub.1 to R.sub.2, and wherein RqR.sub.Sec.-Fan is a ratio of R.sub.3 to R.sub.4.

Flow control system systems and techniques are described. A flow control system, such as a thruster, includes an annular rotor within an annular housing. The annular rotor rotates about a central axis relative to the annular housing. The flow control system includes rotor blades with respective bases that are coupled to the annular rotor, and with respective tips directed toward the central axis. The flow control system includes a first actuator that rotates the annular rotor about the central axis relative to the annular housing, thus also rotating the rotor blades about the central axis relative to the annular housing. The flow control system includes a second actuator that rotates the rotor blades relative to the annular rotor. Actuation of the second actuator rotates a rotor blade about a rotor blade axis that extends from a base of the rotor blade toward the central axis.

Flow control system systems and techniques are described. A flow control system, such as a thruster, includes an annular rotor within an annular housing. The annular rotor rotates about a central axis relative to the annular housing. The flow control system includes rotor blades with respective bases that are coupled to the annular rotor, and with respective tips directed toward the central axis. The flow control system includes a first actuator that rotates the annular rotor about the central axis relative to the annular housing, thus also rotating the rotor blades about the central axis relative to the annular housing. The flow control system includes a second actuator that rotates the rotor blades relative to the annular rotor. Actuation of the second actuator rotates a rotor blade about a rotor blade axis that extends from a base of the rotor blade toward the central axis.

A fan module including variable-pitch blades, a fan rotor bearing the blades of the fan, each mounted to pivot about a pitch axis; a fan shaft extending along a longitudinal axis X inside the fan rotor and driving the fan rotor in rotation. A power shaft drives the fan shaft with a planetary gear speed reducer At least a first and a second bearing guide the rotation of the fan rotor, housed inside a lubrication chamber. A system varies the pitch of the fan blades, including a connecting mechanism connected to the blades of the fan and a controller acting on the connecting mechanism. The first bearing is disposed upstream of the speed reducer and the second bearing is disposed downstream of the speed reducer. The fan rotor is connected to the fan shaft by an annular trunnion extending at least along an upstream portion of the lubrication chamber.

A fan module including variable-pitch blades, a fan rotor bearing the blades of the fan, each mounted to pivot about a pitch axis; a fan shaft extending along a longitudinal axis X inside the fan rotor and driving the fan rotor in rotation. A power shaft drives the fan shaft with a planetary gear speed reducer At least a first and a second bearing guide the rotation of the fan rotor, housed inside a lubrication chamber. A system varies the pitch of the fan blades, including a connecting mechanism connected to the blades of the fan and a controller acting on the connecting mechanism. The first bearing is disposed upstream of the speed reducer and the second bearing is disposed downstream of the speed reducer. The fan rotor is connected to the fan shaft by an annular trunnion extending at least along an upstream portion of the lubrication chamber.

A propulsion system (100) comprises: a generator (30) driven by a shaft (22) of a thermal engine (20) and configured to generate electrical power; an induction motor (60) that is electrically coupled to the output of the generator (30) and is configured to generate a rotational output in response to electrical power provided by the generator (30); a generator control unit (40) that is configured to control an output voltage of the generator (30) to limit a current supplied to the induction motor (60) during start-up of the propulsion system (100); and a switch (50) that is electrically coupled between the generator (30) and the induction motor (60), wherein the switch (50) is controllable by the generator control unit (40).