Electromechanical linear actuator for in blade rotor control
AssigneeClaverham Limited
InventorsPaul R. Brewer, Suat Bekircan
Life of this patent
Estimating the term…
Abstract
A rotor blade assembly includes a rotor blade and a movable trim tab located along a span of the rotor blade. A linear positioner is located inside the rotor blade and operably connected to the trim tab to move the trim tab thereby reducing rotor blade vibration. A method for reducing vibration of a rotor assembly includes energizing a linear positioner located inside a rotor blade of the rotor assembly and moving an output piston of the linear positioner. A trim tab located at the rotor blade is moved to a selected trim tab angle relative to the rotor blade by the output piston, and the linear positioner is deenergized thereby locking the trim tab at the selected trim tab angle.
Claims12
A rotor blade assembly comprising:
- a rotor blade;
- a movable trim tab disposed along a span of the rotor blade;
- and
- a linear positioner disposed inside the rotor blade and operably connected to the trim tab to move the trim tab thereby reducing rotor blade vibration, the linear positioner including:
- a brushless DC motor having a motor shaft;
- and
- an output piston extending transversely to the motor shaft;
- and
- a planetary roller nut operably connected to the motor via a non back driving reduction gear;
- the output piston operably connected to the planetary roller nut via a screw shaft to transform rotary motion of the roller nut into linear motion on the output piston;
- and
- a plurality of rolling elements disposed in the linear positioner between the screw shaft and the planetary roller nut.
A rotary-winged aircraft comprising:
- an airframe;
- and
- a main rotor assembly operably connected to the airframe including a plurality of rotor blade assemblies rotatable about a rotor assembly axis, at least one rotor blade assembly of the plurality of rotor blade assemblies including:
- a rotor blade;
- a movable trim tab disposed along a span of the rotor blade;
- and
- a linear positioner disposed inside the rotor blade and operably connected to the trim tab to move the trim tab thereby reducing rotor blade vibration, the linear positioner including:
- a brushless DC motor having a motor shaft;
- and
- an output piston extending transversely to the motor shaft;
- and
- a planetary roller nut operably connected to the motor via a non back driving reduction gear;
- the output piston operably connected to the planetary roller nut via a screw shaft to transform rotary motion of the roller nut into linear motion on the output piston;
- and
- a plurality of rolling elements disposed in the linear positioner between the screw shaft and the planetary roller nut.
A method for reducing vibration of a rotor assembly comprising:
- energizing a linear positioner disposed inside a rotor blade of the rotor assembly;
- moving an output piston of the linear positioner;
- moving a trim tab disposed at the rotor blade to a selected trim tab angle relative to the rotor blade by the output piston motion;
- and
- deenergizing the linear positioner thereby locking the trim tab at the selected trim tab angle;
- wherein moving the output piston of the linear positioner includes:
- rotating a motor shaft of a brushless DC motor, the motor shaft positioned transversely to the output piston;
- transferring rotational energy from the motor shaft to a planetary roller nut via a reduction gear;
- and
- transforming rotational motion of the planetary roller nut into linear motion of the output piston via a screw shaft operably connected to the planetary roller nut and the output piston.
Dependencies are inferred from the claim text.