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.

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.

Low latency pitch adjustable rotors are disclosed. A disclosed example rotor includes a rotor hub to rotate about a rotational axis, rotor blades coupled to the rotor hub, the rotor blades being pitch adjustable and having corresponding pitch angles, and a reaction hinge operatively coupled between the rotor hub and the rotor blades, the reaction hinge to move relative to the rotor hub in response to an angular acceleration or deceleration of the rotor hub to adjust the pitch angles.

An offset blade of a propeller varies the blade pitch according to in-flight conditions in order to maximize the performance and efficiency of the propeller. As the propeller begins to rotate, upward thrust forces and lateral centrifugal forces are generated on the blade. The balance between the thrust and centrifugal forces determines the blade pitch. At rest, the blade pitch is minimized whereas when in-flight, the blade pitch of the propeller blade is maximized. The blade is coupled with a rotor hub through a connector that determines the maximum and minimum blade pitches of the blade. Furthermore, the connector reduces blade pitch oscillations that often occur in flight.

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.

An exemplary continuous variable pitch rotor system includes a blade extending radially from a hub along a longitudinal axis, the blade rotationally coupled to the hub to permit limited rotation of the blade about the longitudinal axis in response to a change in a rotational speed of the hub. In some embodiments, the blade is held in a radially fixed position relative to the hub. In some embodiments, the blade is permitted to translate radially.

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.

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.

A counterweight for use in a variable-pitch propeller system (includes a weighted element having walls forming a sealed chamber). The sealed chamber contains a weighting material, and an arm. The counterweight is configured to be coupled to a propeller blade the walls of the weighted element and the arm comprise a single piece, and are an additively manufactured single piece. The weighting material may comprise a powder element. The sealed chamber may have been sealed during the additive manufacturing process, or after the additive manufacturing process has been completed.

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.