A turbomachinery engine can include a fan assembly with a plurality of variable pitch fan blades. The fan blades are configured such that they define a first VPF parameter and a second VPF parameter. The first VPF parameter is defined as the hub-to-tip radius ratio divided by the fan pressure ratio. The second VPF parameter is defined as the bearing spanwise force divided by the fan area. In some instances, the first VPF parameter is within a range of 0.1 to 0.25, and the second VPF parameter is within a range of 2-30 lbf/in.sup.2. In other instances, the first VPF parameter is within a range of 0.1 to 0.4 and the second VPF parameter is within a range of 5.25-30 lbf/in.sup.2. In certain examples, the turbomachinery engine further includes a pitch change mechanism, a vane assembly, a core engine, and a gearbox.

A turbomachinery engine can include a fan assembly with a plurality of variable pitch fan blades. The fan blades are configured such that they define a first VPF parameter and a second VPF parameter. The first VPF parameter is defined as the hub-to-tip radius ratio divided by the fan pressure ratio. The second VPF parameter is defined as the bearing spanwise force divided by the fan area. In some instances, the first VPF parameter is within a range of 0.1 to 0.25, and the second VPF parameter is within a range of 2-30 lbf/in.sup.2. In other instances, the first VPF parameter is within a range of 0.1 to 0.4 and the second VPF parameter is within a range of 5.25-30 lbf/in.sup.2. In certain examples, the turbomachinery engine further includes a pitch change mechanism, a vane assembly, a core engine, and a gearbox.

A feedback device for use in a gas turbine engine, and methods and systems for controlling a pitch for an aircraft-bladed rotor, are provided. The feedback device is composed of a circular disk and a plurality of position markers. The circular disk is coupled to rotate with a rotor of the gas turbine engine, to move along a longitudinal axis of the rotor, and has first and second opposing faces defining a root surface that extends between and circumscribes the first and second faces. The plurality of position markers extend radially from the root surface and are circumferentially spaced around the circular disk. The position markers have a top surface elevated with respect to the root surface and opposing first and second side surfaces. The side surfaces of the position markers have a curved concave profile extending toward the root surface.

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.

A ducted fan module with variable-pitch blades for a turbo engine includes a rotor carrying a plurality of blades, a stationary casing, and a blade pitch changing and control system. The rotor includes a central shaft and a surrounding blade support ring. A front end of the blade support ring is connected to a front end of the central shaft, creating a rearward-opening annular space between the blade support ring and the central shaft. A tubular part is connected to the stationary casing and extends into the annular space.

A system is described that includes a turbine engine including an engine fan including one or more variable-pitch blades driven by a shaft, which rotates at a rotational speed which depends on a pitch of the one or more variable-pitch blades of the engine fan. The system further includes a generator configured to produce alternating-current (AC) electricity at a particular frequency relative to the rotational speed of the shaft. The system also includes a propulsor, which includes a propulsor motor and a propulsor fan. The propulsor motor is configured to drive, based on the AC electricity produced by the generator, the propulsor fan. The system includes a controller configured to control the particular frequency of the AC electricity by at least controlling the pitch of the one or more variable-pitch blades of the engine fan and thereby the rotational speed of the generator.

Methods, apparatus, systems, and articles of manufacture are disclosed for a slot to accommodate a blade of an engine. An example blade apparatus includes: a collet including a slot to receive an end of a blade; and a plurality of retainers including a first retainer positioned on a first end of the collet and a second retainer positioned on a second end of the collet to provide axial retention for the blade in the slot.

There is provided a blade angle feedback system for an aircraft-bladed rotor rotatable about a longitudinal axis and having an adjustable blade pitch angle. A feedback device is coupled to rotate with the rotor and to move along the axis with adjustment of the blade pitch angle. The feedback device comprises a body having position marker(s) embedded therein, the body made of a first material having a first magnetic permeability and the position marker(s) comprising a second material having a second magnetic permeability greater than the first. Sensor(s) are positioned adjacent the feedback device and configured for producing, as the feedback device rotates about the axis, sensor signal(s) in response to detecting passage of the position marker(s). A control unit is communicatively coupled to the sensor(s) and configured to generate a feedback signal indicative of the blade pitch angle in response to the sensor signal(s) received from the sensor(s).

Methods, apparatus, systems, and articles of manufacture are disclosed for a slot to accommodate a blade of an engine. An example blade apparatus includes: a collet including a slot to receive an end of a blade; and a plurality of retainers including a first retainer positioned on a first end of the collet and a second retainer positioned on a second end of the collet to provide axial retention for the blade in the slot.

Methods, apparatus, systems, and articles of manufacture are disclosed for a slot to accommodate a blade of an engine. An example apparatus includes: a socket to receive an end of a blade; and a retaining device to interact with the socket and the blade for retention of the end of the blade in the socket. The example retaining device includes: a spacer to be positioned in the socket with the end of the blade; a wedge positioned inside the spacer; and a spring to tighten to pull the wedge to expand the spacer.