A propeller control system for controlling a blade pitch angle including: a propeller blade extending from a blade base, the propeller blade being configured to rotate around a longitudinal axis to generate thrust for the propeller blade and rotate around a pitch change axis to adjust the blade pitch angle, wherein the pitch change axis extends through a center point of the blade base; a trunnion pin operably connected to the blade base at a location offset from the center point; a yoke plate operably connected to the trunnion pin; an actuator configured to move the yoke plate linearly along the longitudinal axis to rotate the trunnion pin and the propeller blade around the pitch change axis; and a transfer tube operably connected to the yoke plate, the transfer tube being free to rotate around the longitudinal axis as the actuator moves the yoke plate linearly along the longitudinal axis.

Rotor hubs having pitch control systems and related methods are disclosed herein. An example apparatus includes a housing including a first housing arm to support a first blade grip and a first blade spindle and a second housing arm to support a second blade grip and a second blade spindle. The example apparatus includes a first pitch link and a second pitch link. The example apparatus includes a first pitch arm coupled to the first pitch link and one of the first blade grip or the first blade spindle and a second pitch arm coupled to the second pitch link and one of the second blade grip or the second blade spindle. The second pitch arm is to extend past the first housing arm to couple with the one of the second blade grip or the second blade spindle.

Rotor hubs having pitch control systems and related methods are disclosed herein. An example apparatus includes a housing including a first housing arm to support a first blade grip and a first blade spindle and a second housing arm to support a second blade grip and a second blade spindle. The example apparatus includes a first pitch link and a second pitch link. The example apparatus includes a first pitch arm coupled to the first pitch link and one of the first blade grip or the first blade spindle and a second pitch arm coupled to the second pitch link and one of the second blade grip or the second blade spindle. The second pitch arm is to extend past the first housing arm to couple with the one of the second blade grip or the second blade spindle.

A pitch change actuation system for varying a propeller blade pitch includes: an actuator body defining an interior volume; and a chamber separator located within the interior volume of the actuator body and dividing the interior volume into a first chamber and a second chamber, the two chambers being fluidly separated by the chamber separator. The first and second chambers are configured to receive hydraulic fluid. The actuator body is configured to translate relative to the chamber separator in response to a difference in hydraulic pressure between the first chamber and second chamber; and the translation of the actuator body is configured to effect a change in propeller blade pitch.

A pitch change actuation system for varying a propeller blade pitch includes: an actuator body defining an interior volume; and a chamber separator located within the interior volume of the actuator body and dividing the interior volume into a first chamber and a second chamber, the two chambers being fluidly separated by the chamber separator. The first and second chambers are configured to receive hydraulic fluid. The actuator body is configured to translate relative to the chamber separator in response to a difference in hydraulic pressure between the first chamber and second chamber; and the translation of the actuator body is configured to effect a change in propeller blade pitch.

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 variable pitch propeller assembly operatively coupled with an engine and methods for controlling the pitch of a plurality of propeller blades thereof is provided. In one example aspect, the variable pitch propeller assembly includes features for combining overspeed, feathering, and reverse functionality in a single secondary control valve. The secondary control valve is operable to selectively allow a controlled amount of hydraulic fluid to flow to or from a pitch actuation assembly such that the pitch of the propeller blades can be adjusted to operate the variable pitch propeller assembly in one of a constant speed mode, a feather mode, and a reverse mode.

A variable pitch propeller assembly operatively coupled with an engine and methods for controlling the pitch of a plurality of propeller blades thereof is provided. In one example aspect, the variable pitch propeller assembly includes features for combining overspeed, feathering, and reverse functionality in a single secondary control valve. The secondary control valve is operable to selectively allow a controlled amount of hydraulic fluid to flow to or from a pitch actuation assembly such that the pitch of the propeller blades can be adjusted to operate the variable pitch propeller assembly in one of a constant speed mode, a feather mode, and a reverse mode.

A turbo engine includes a system for changing a pitch of blades of a propeller, the system including an annular fluid cylinder with a linear drive and a link mechanism linking the cylinder to the blades of the propeller to change an orientation of the propeller. The annular cylinder of the system can be rigidly mounted on a fixed housing supporting the propeller and internal to the propeller, unlike the blades mounted in an external rotating hub of the propeller, and the link mechanism includes a displacement transfer bearing fixed, on one side, to the mobile part of the cylinder and cooperating, on the other side, with a mechanism linking to the blades of the rotating hub of the propeller.