A fixing device fixes a relative position in a rotational direction of an outer member and an inner member of a stationary body of the rotary machine, and includes: a radial pin that is inserted into a through hole passing through the outer member in a radial direction of a rotary machine and having a stepped portion formed therein to have a larger diameter at a portion on an outer side in the radial direction of the rotary machine than at a portion on an inner side in the radial direction, that has a part on the inner side in the radial direction of the rotary machine to be inserted into a concave portion of the inner member, and that has a flange portion on the outer side in the radial direction of the rotary machine.

A fixing device fixes a relative position in a rotational direction of an outer member and an inner member of a stationary body of the rotary machine, and includes: a radial pin that is inserted into a through hole passing through the outer member in a radial direction of a rotary machine and having a stepped portion formed therein to have a larger diameter at a portion on an outer side in the radial direction of the rotary machine than at a portion on an inner side in the radial direction, that has a part on the inner side in the radial direction of the rotary machine to be inserted into a concave portion of the inner member, and that has a flange portion on the outer side in the radial direction of the rotary machine.

Methods and systems for governing an aircraft propeller of an engine are described. The method comprises obtaining a fluid flow command for speed control of the propeller, determining pulse parameters of a pulse width modulated valve control signal for actuating a two-position solenoid valve in accordance with the fluid flow command based on an average fluid flow through the solenoid valve and an opening and closing time of the solenoid valve, generating the valve control signal with the pulse parameters as determined, and transmitting the valve control signal to the solenoid valve for actuating the solenoid valve, thereby controlling the speed of the propeller.

A ram air turbine has turbine blades connected to rotate a transmission shaft. The transmission shaft is connected to drive a first gear which is engaged to drive a second gear. The second gear is connected to rotate an output shaft extending through a strut away from the transmission shaft. A governor arrangement is configured to change a pitch angle of the blades in response to speed, and includes counterweights acting on a spring in the governor arrangement. The governor spring is positioned on an opposed side of the strut relative to the turbine.

A ram air turbine has turbine blades connected to rotate a transmission shaft. The transmission shaft is connected to drive a first gear which is engaged to drive a second gear. The second gear is connected to rotate an output shaft extending through a strut away from the transmission shaft. A governor arrangement is configured to change a pitch angle of the blades in response to speed, and includes counterweights acting on a spring in the governor arrangement. The governor spring is positioned on an opposed side of the strut relative to the turbine.

Aerial vehicles may be equipped with propellers having pivotable blades that are configured to rotate or fold when the propellers are not rotating under power. A pivotable blade may rotate about an axis of a propeller with respect to a hub in the presence of wind flow until the pivotable blade is coaligned with a fixed blade, in a direction opposite to the wind flow. A pivotable blade may also fold over a hub of a propeller in the presence of wind flow, with the pivotable blade and a fixed blade being oriented in directions opposite to the wind flow. A center of mass of the pivotable blade may be caused to be on the same side of an axis as a center of mass of a fixed blade, even where the axis is not normal to the wind flow, thereby reducing an amount of drag generated by the propeller.

Aerial vehicles may be equipped with propellers having pivotable blades that are configured to rotate or fold when the propellers are not rotating under power. A pivotable blade may rotate about an axis of a propeller with respect to a hub in the presence of wind flow until the pivotable blade is coaligned with a fixed blade, in a direction opposite to the wind flow. A pivotable blade may also fold over a hub of a propeller in the presence of wind flow, with the pivotable blade and a fixed blade being oriented in directions opposite to the wind flow. A center of mass of the pivotable blade may be caused to be on the same side of an axis as a center of mass of a fixed blade, even where the axis is not normal to the wind flow, thereby reducing an amount of drag generated by the propeller.

There is described a casing assembly for a gas turbine engine, the casing assembly comprising: an annular casing having a longitudinal axis; a unison ring assembly configured for rotation about the longitudinal axis; a plurality of vanes rotatably coupled to the annular casing; and a plurality of linkages, wherein each of the plurality of vanes is coupled to the unison ring assembly by a respective one of the plurality of linkages. Each linkage comprises: a first link coupled to the respective vane; and a second link rotatably coupled to the first link and rotatably coupled to the unison ring assembly, such that rotation of the unison ring assembly about the longitudinal axis effects rotation of the respective vane.

There is described a casing assembly for a gas turbine engine, the casing assembly comprising: an annular casing having a longitudinal axis; a unison ring assembly configured for rotation about the longitudinal axis; a plurality of vanes rotatably coupled to the annular casing; and a plurality of linkages, wherein each of the plurality of vanes is coupled to the unison ring assembly by a respective one of the plurality of linkages. Each linkage comprises: a first link coupled to the respective vane; and a second link rotatably coupled to the first link and rotatably coupled to the unison ring assembly, such that rotation of the unison ring assembly about the longitudinal axis effects rotation of the respective vane.

A pitch actuation system for a turbine engine propeller, comprising an actuator, a movable part of which is designed to be connected to blades of the propeller so as to rotate said blades relative to blade pitch-setting axes, wherein the actuator is an electromechanical actuator and comprises at least two electric motors for driving a common rotor, and a transmission screw rotated by the common rotor, and in that the system further comprises a nut, through which the transmission screw passes and which is designed to cooperate with the blades so as to move them.