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.

A control system for an engine operatively coupled with a propeller and methods for controlling an engine operatively coupled with a propeller are provided. In one example aspect, the control system includes a controller and an electric propeller governor. The electric propeller governor includes a motor operatively coupled with a flyweight governor spring. The motor is communicatively coupled with the controller. The controller is operable to receive data indicative of the speed of the propeller, determine if the measured speed exceeds a propeller speed threshold, and if the threshold is exceeded, the controller is configured to change a propeller speed set point. Particularly, the controller can cause the motor to change the preload on the flyweight governor spring, which in turn causes adjustment of the propeller speed set point. In this way, propeller speed overshoot is prevented during fast acceleration of the engine.

A locking device for use in a rotor blade, said locking device comprising: a locking member that is arranged to be movable from an unlocked position to a locking position upon experiencing sufficiently fast rotation; and a selectively engagable retaining device arranged when engaged to retain the locking member in the unlocked position. The locking device will typically default to an unlocked position during normal rotation and will only be locked so as to prevent movement when the retaining device is de-activated. A method of locking an actuator is also disclosed. The locking device has applications in helicopter rotor blades and wind turbine blades amongst others.

Systems and methods related to passive variable pitch propellers are described. For example, an aerial vehicle may include one or more passive variable pitch propellers, and such propellers may include one or more passively movable propeller blades having respective hinges, flexible joints, or torsionally flexible joints. Based at least in part on current flight configurations, required thrust, and/or desired advance ratios, the passively movable propeller blades may modify their coning angles and/or pitches, such that the passive variable pitch propellers may operate with improved efficiency in two or more flight configurations. For example, in a VTOL flight configuration, the passive variable pitch propellers may have increased coning angles and decreased pitches, whereas in a horizontal flight configuration, the passive variable pitch propellers may have decreased coning angles and increased pitches.

A device for automatic control of an angular position of turbine blades of a propeller device, in which the turbine blades are rotatable about a rotational axis and are pivotally displaceable about their respective pivot axes. The device includes a set of control blades kinematically connected with the turbine blades, said control blades are pivotally displaceable about respective pivot axes once the propeller device is exposed to a flow of fluid. The device further includes a transmission unit configured for transmitting pivotal displacement of the control blades to the turbine blades such that the turbine blades could be pivoted by the control blades. Pivoting of the turbine blades takes place simultaneously with the pivoting of the control blades. The angular disposition of the turbine blades is automatically set and remains invariant irrespective of direction of the flow of fluid.

A control system for an engine operatively coupled with a propeller and methods for controlling an engine operatively coupled with a propeller are provided. In one example aspect, the control system includes a controller and an electric propeller governor. The electric propeller governor includes a motor operatively coupled with a flyweight governor spring. The motor is communicatively coupled with the controller. The controller is operable to receive data indicative of the speed of the propeller, determine if the measured speed exceeds a propeller speed threshold, and if the threshold is exceeded, the controller is configured to change a propeller speed set point. Particularly, the controller can cause the motor to change the preload on the flyweight governor spring, which in turn causes adjustment of the propeller speed set point. In this way, propeller speed overshoot is prevented during fast acceleration of the engine.

An assembly for a propeller of a turbine engine of an aircraft is provided. The assembly includes a variable-pitch vane having a blade connected to a root, the vane having a longitudinal axis aligned with a vane pitch axis which passes through the root, a base rigidly connected to the vane to rotate together with the vane about the axis and connected to a portion of a toothed wheel extending around the axis, and a counterweight device having a shaft which can rotate about an axis substantially perpendicular to the axis, the shaft being connected to at least one flyweight and to a pinion meshed with the toothed wheel portion. The toothed wheel portion can be attached to the base by at least one shear pin.

One example includes a passive rotor pitch control system. The system includes a counterweights that are each associated with one of a respective plurality of rotors and can be arranged to have a center of mass configured to provide a pitch torque about a pitch axis associated with the respective one of the rotors in response to rotation of the rotors about a rotation axis. The system also includes a spring forcer comprising a pitch rod and a spring configured to provide a spring force on the pitch rod. The system further includes a pitch change assembly coupled to the counterweights and the pitch rod. The pitch change assembly can be configured to rotate a pitch of each of the rotors from a first pitch state to a second pitch state in response to a sum of pitch torques associated with the counterweights being greater than the spring force.

The present invention relates to a rotor for a turbomotor impeller, with variable-pitch blades, comprising blade roots capable of rotating in a blade supporting structure and a device for feathering the blades. Said feathering device comprises at least one flyweight secured to a crank connected by a gear set to at least one of said blade roots.

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.