A device for controlling the pitch of fan blades in a turbine engine having an unducted fan including at least one set of adjustable pitch fan blades, each fan blade being coupled, for pitch adjustment purposes, to a radial control shaft constrained to rotate with the set of fan blades and suitable for pivoting about a radial pitch axis of the fan blade, the device including a stationary actuator centered on a longitudinal axis of the turbine engine and driving an outer ring of a load transfer bearing in translation, the outer ring of the load transfer bearing being coupled directly to a lever arm of each control shaft via a respective ball joint connection in order to adjust its pivoting.

This patent discloses improvements over a mechanism to modulate the pitch of the blades of a fan, turbine or propeller driven by a rotating shaft bearing a helical thread onto which a nut made of a ferromagnetic material was threaded; this nut was spun by electromagnets disposed about it on the stator system and its resultant axial motion manipulated the blades' pitch. This patent discloses refinement of control of the electromagnets employed to spin the axial modulator by embedding a plurality of ferrous protuberances in this nut—the rotational position of which is determined via metallic edge detection sensors whose logic levels are used to selectively energize electromagnets that apply a force onto the protuberances in order to induce rotation and axial motion on the nut. This additional degree of rotational freedom is controlled by this reluctance-motor like configuration while a second motor is used to spin the blades.

Propulsion assembly comprising: an inner casing (13); an outer casing (3); an inter-duct casing (15) delimiting a primary duct (12) between the inner casing (13) and an outer wall (14), and a secondary duct (16) between the outer casing (3) and an outer wall (17); a fan capable of generating an air flow (24) circulating from downstream to upstream in the secondary duct (16); the assembly further comprising: at least one duct (27) for bleeding air from said flow (24), this bleed duct (27) comprising an inlet port (28) in the outer wall (17) and an outlet port (29) in the inner wall (14); an outer flap (30) movable between an open position and a closed position of the inlet port (28); an inner flap (31) movable between an open position and a closed position of the outlet port (29).

An air cleaning element comprises a generally rectangular frame comprising a first two opposing sides and a second two opposing sides; a plurality of rods supported on and extending between the first two opposing sides, wherein each rod is offset from its two adjacent rods; and a wire mesh sheet that is generally rectangular and corrugated around the plurality of rods. The sheet extends to and between the two opposing sides.

A fan control system for a variable pitch fan of a work vehicle includes a first sensor that measures a parameter of a cooling system and a blade pitch module that adjust a pitch of a plurality of blades of the variable pitch fan to generate airflow in a first direction. A reversing module selectively commands a fan reversal that includes instructing the blade pitch module to temporarily adjust the pitch of the plurality of blades to generate airflow in a second direction. A first timer module, in response to the reversing module commanding the fan reversal, resets and increments a first timer and compares the first timer to a first threshold. A first reversal prevention module, in response to the first timer being less than the first threshold, prevents the reversing module from commanding a fan reversal by indicating that a first type of fan reversal is not permitted.

A system and method for providing feedback for an aircraft-bladed rotor about a longitudinal axis and having an adjustable blade pitch angle. At least one position marker is provided at the rotor, extends along an axial direction, from a first end to a second end, and has varying magnetic permeability from the first end to the second end. At least one sensor is coupled to the rotor and configured for producing, as the rotor rotates about the longitudinal axis, at least one sensor signal in response to detecting passage of the at least one position marker. A control unit is communicatively coupled to the at least one sensor and configured to generate a feedback signal indicative of the blade pitch angle in response to the at least one sensor signal received from the at least one sensor.

A variable pitch bladed disc including a plurality of blades, each being of variable pitch about a blade axis of rotation and 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 shaft having a root and a tip, the root of each blade being mounted on the tip of a corresponding rotor connecting shaft via a pivot so as to allow each blade to be rotated about the blade axis of rotation, the first blade having a first rotation axis inclination such that the rotation axis thereof is inclined in a fixed manner with respect to a radial axis passing through the root of the corresponding shaft, and the second blade has a second rotation axis inclination different from the first rotation axis inclination.

Methods and apparatus to retain a rotor blade are disclosed herein. An example apparatus includes a rotor blade coupled to a rotatable hub of an engine system. The rotor blade includes a root, a flange and a blade. The root and the flange are disposed inside a cowling, and the blade is disposed outside of the cowling. The example apparatus also includes a retainer disposed inside the cowling adjacent the flange. The flange is to engage the retainer to retain the rotor blade with the engine system.

The variable pitch propeller assembly includes a hub. The variable pitch propeller assembly also includes a plurality of propeller blade assemblies spaced circumferentially about the hub. Each of the plurality of propeller blade assemblies configured to rotate a respective propeller blade. The variable pitch propeller assembly also includes a hydraulic fluid port assembly integrally formed and including at least three hydraulic fluid ports configured to receive respective flows of hydraulic fluid from a stationary hydraulic fluid transfer sleeve. The variable pitch propeller assembly also includes a pitch actuator assembly coupled in flow communication with at least three hydraulic fluid ports through respective hydraulic fluid transfer tubes. The pitch actuator coupled to the plurality of propeller blade assemblies to selectively control a pitch of the propeller blades. The pitch actuator assembly includes a travel stop configured to limit a rotation of at least one of the pitch actuator assemblies.

An actuation system is provided for varying the pitch of the blades of a variable pitch fan or propeller. The actuation system includes a first actuator and a second actuator. The actuation system further includes a first linkage which operably connects the first actuator to the blades such that operation of the first actuator varies the pitch of the blades via the first linkage. The actuation system further includes a second linkage which operably connects the second actuator to the first actuator such that operation of the second actuator varies the pitch of the blades by series connection of the second linkage to the first linkage.