Patent Description:
Wing sections of fixed wing aircraft are moving toward thin sections (e.g., cross-sectional height) and the cross sectional area of loft is making more difficult to place a geared rotary actuator at the hinge line between an aft section of the thin wing and the aircraft control surface. Conventionally, aircraft control surfaces (e.g., flaps, etc.) are controlled using an actuator within the wing portion that is operably connected to such aircraft control surface. Drop hinges are typically used, but with thin wing configurations, such drop hinges have detrimental impact on drag and can offset the benefits of thin wing configurations. Accordingly, improved actuators for aircraft control surfaces may be desirable to improve flight efficiencies associated with thin wing craft.

<CIT> discloses an actuator system for a flap of an airfoil.

According to one aspect, actuator assemblies are provided. The assemblies include a first structure, a second structure configured to be moved relative to the first structure, and an actuator system arranged between the first structure and the second structure and configured to control relative movement between the first structure and the second structure. The actuator system includes a drive shaft, a first rotary actuator element operably coupled to the drive shaft and configured to be driven in a first direction about the drive shaft, a second rotary actuator element positioned adjacent the first rotary actuator element and operably coupled to the drive shaft and configured to be driven in a second direction about the drive shaft, the second direction being a counter-rotation relative to the first direction, a spar fixedly connected to the first structure, and a spar connection configured to pivotably connect the first rotary actuator element to the spar at a fixed coupler. The drive shaft, the first rotary actuator element, and the second rotary actuator element are housed within the second structure and rotation of the second rotary actuator element causes a translation motion of the drive shaft away from the first structure and rotation of the first rotary actuator element about the fixed coupler such that the second structure is translated and rotated relative to the first structure.

Embodiments of the assemblies may include that the first structure is a wing and the second structure is an aircraft flight control element.

Further embodiments of the assemblies may include that the aircraft flight control element is a flap attached to the wing by the actuator system.

Further embodiments of the assemblies may include a motor operably coupled to the drive shaft to drive rotation of the drive shaft.

Further embodiments of the assemblies may include an actuator controller operably coupled to the motor to control operation of the motor.

Further embodiments of the assemblies may include that each of the first rotary actuator element and the second rotary actuator element are compound gear rotary actuators.

Further embodiments of the assemblies may include that the second rotary actuator element comprises a linkage extension. The actuator system further includes a spar link pivotably connected to the linkage extension by a first pivot pin and the spar link is connected to the spar by a second pivot pin.

Further embodiments of the assemblies may include that the spar includes a pin, wherein the drive shaft is moveable from a first position to a second position by operation of the first and second rotary actuator elements.

Further embodiments of the assemblies may include that in the first position the drive shaft is separated from the pin of the spar by a first vertical distance and a first horizontal distance, and in the second position the drive shaft is separated from the pin of the spar by a second vertical distance and a second horizontal distance, wherein the first vertical distance is less than the second vertical distance and the first horizontal distance is greater than the second horizontal distance.

Further embodiments of the assemblies may include that in the second position an air gap is formed between the first structure and the second structure.

According to another aspect, aircraft are provided. The aircraft include a wing, an aircraft flight control element attached to the wing, and an actuator system arranged between the wing and the aircraft flight control element and configured to control relative movement of the aircraft flight control element relative to the wing. The actuator system includes a drive shaft, a first rotary actuator element operably coupled to the drive shaft and configured to be driven in a first direction about the drive shaft, a second rotary actuator element positioned adjacent the first rotary actuator element and operably coupled to the drive shaft and configured to be driven in a second direction about the drive shaft, the second direction being a counter-rotation relative to the first direction, a spar fixedly connected to the wing, and a spar connection configured to pivotably connect the first rotary actuator element to the spar at a fixed coupler. The drive shaft, the first rotary actuator element, and the second rotary actuator element are housed within the aircraft flight control element and wherein rotation of the second rotary actuator element causes a translation motion of the drive shaft away from the wing and rotation of the first rotary actuator element about the fixed coupler such that the aircraft flight control element is translated and rotated relative to the wing.

Embodiments of the aircraft may include that the actuator system comprises at least one additional first rotary actuator element and at least one additional second rotary actuator element coupled to the drive shaft and configured to control movement of the aircraft flight control element, wherein the at least one additional first and second rotary actuator elements are housed within the aircraft flight control element.

Further embodiments of the aircraft may include that the aircraft flight control element is a flap attached to the wing by the actuator system.

Further embodiments of the aircraft may include a motor operably coupled to the drive shaft to drive rotation of the drive shaft.

Further embodiments of the aircraft may include an actuator controller operably coupled to the motor to control operation of the motor.

Further embodiments of the aircraft may include that each of the first rotary actuator element and the second rotary actuator element are compound gear rotary actuators.

Further embodiments of the aircraft may include that the second rotary actuator element comprises a linkage extension. The actuator system further includes a spar link pivotably connected to the linkage extension by a first pivot pin and the spar link is connected to the spar by a second pivot pin.

Further embodiments of the aircraft may include that the spar includes a pin, wherein the drive shaft is moveable from a first position to a second position by operation of the first and second rotary actuator elements.

Further embodiments of the aircraft may include that in the first position the drive shaft is separated from the pin of the spar by a first vertical distance and a first horizontal distance, and in the second position the drive shaft is separated from the pin of the spar by a second vertical distance and a second horizontal distance, wherein the first vertical distance is less than the second vertical distance and the first horizontal distance is greater than the second horizontal distance.

Further embodiments of the aircraft may include that in the second position an air gap is formed between the wing and the aircraft flight control element.

<FIG> illustrates an example of an aircraft <NUM> having aircraft engines surrounded by (or otherwise carried in) nacelles <NUM>. The aircraft <NUM> includes wings <NUM> that extend from an aircraft fuselage <NUM>. Each wing <NUM> may include one or more slats <NUM> on a forward edge or leading edge and one or more flaps <NUM> on an aft, rear, or trailing edge thereof. The wings <NUM> may also include ailerons <NUM> on the trailing edges, as will be appreciated by those of skill in the art. The aircraft <NUM>, as shown, includes a tail structure <NUM> which can include various flaps, ailerons, slats, and the like, as will be appreciated by those of skill in the art. The flaps, slats, ailerons, and the like are generally referred to herein as "aircraft flight control elements" as they are movable under aircraft power systems and are configured to control flight and motion of the aircraft <NUM>. A flight control actuator system <NUM> may be connected to one or more of the aircraft flight control surfaces. For example, each wing <NUM> and the tail structure may include one or more flight control actuator systems <NUM>. The flight control actuator systems <NUM> may be operably connected to the various aircraft flight control elements and configured control the operation/position of the aircraft control surfaces to control flight of the aircraft <NUM>.

In order to reduce weight and increase flight efficiencies, aircraft are being designed with relatively thin wings (in a cross-sectional direction between pressure and suction sides). Conventionally, the actuators that connect to and control operation of the aircraft flight control elements are housed within the wing itself. However, with the reduced cross-sectional area of the wing (e.g., interior space) there is less room to install such actuators. For example, it has become more difficult to install a geared rotary actuator at a hinge line or aft spar of the wing due to space constraints. In view of this, embodiments of the present disclosure are directed to flight control actuator systems installed within or as part of the aircraft flight control element, with only a minimal connection or minimal components arranged within the aft portion of the wing. By installing the flight control actuator systems within the aircraft flight control element (e.g., flap, slat, aileron, etc.), volume in the wing area is made available for other components or purposes. For example, by moving the actuator system primarily into the aircraft flight control element, the wing may have more volume to contain fuel. In accordance with some embodiments, the flight control actuator systems may include a mechanism for transferring rotary motion into translational and rotary motion to produce an air gap slot and angle or move the aircraft flight control element. The operational components of such systems may be housed within the aircraft flight control elements.

For example, referring now to <FIG>, a schematic illustration of a wing <NUM> having an aircraft flight control element <NUM> installed at an aft end thereof is shown. In this embodiment, the aircraft flight control element <NUM> is a flap that is moveable (e.g., rotatable or pivotable) relative to the wing <NUM> to control an airflow across the wing <NUM> to aid in flight control (e.g., lift). The aircraft flight control element <NUM> is operably connected to the wing by a flight control actuator system <NUM>. The wing <NUM> is shown in cross-section, having a leading edge <NUM>, a trailing edge <NUM>, a pressure side surface <NUM>, and a suction side surface <NUM>. The flight control actuator system <NUM> is arranged to couple the aircraft flight control element <NUM> to the wing <NUM> at the trailing edge <NUM> thereof.

At the trailing edge <NUM> of the wing <NUM>, the wing <NUM> has a cross-sectional thickness <NUM>. With conventional or prior wing configurations, the cross-sectional thickness <NUM> of the wing may be <NUM>-<NUM> inches (<NUM> - <NUM>). This cross-sectional thickness of the conventional wings provided sufficient space (volume) for installation of components such as a flight control actuator system. However, in accordance with some embodiments of the present disclosure, thin wing configurations are employed, where the wing <NUM> may have a cross-sectional thickness <NUM> at the trailing edge <NUM> of <NUM> inches (<NUM>) or less. This reduction in cross-sectional thickness as compared to conventional wings has required adjustment of the flight control actuator systems. For example, rather than having the primary components of the flight control actuator system <NUM> installed within the wing <NUM>, in accordance with embodiments of the present disclosure, the flight control actuator system <NUM> is primarily installed within and part of the aircraft flight control element <NUM>. In some embodiments, the flight control actuator system <NUM> may include one or more linkages that connect to an aft spar of the wing <NUM>, and the operational components (e.g., drive shaft, motor, geared actuator, etc.) may be housed within the aircraft flight control element <NUM>. It is noted that although thin wings are described herein for implementation of embodiments of the present disclosure, it will be appreciated that the flight control actuator systems described herein may be employed with conventional (e.g., thick) wings, doors, or other surfaces and/or systems that require rotation or pivoting of one component relative to another. As such, the present disclosure is not intended to be limited to thin wing applications, but rather such description is provided merely for informative purposes.

Turning now to <FIG>, a schematic illustration of a wing <NUM> having an aircraft flight control element <NUM> installed at an aft end thereof is shown. In this embodiment, the aircraft flight control element <NUM> is a flap that is moveable (e.g., rotatable or pivotable) relative to the wing <NUM> to control an airflow across the wing <NUM> to aid in flight control (e.g., lift). The aircraft flight control element <NUM> is operably connected to the wing by a flight control actuator system <NUM>.

The flight control actuator system <NUM> is primarily installed and housed within the aircraft flight control element <NUM>. In this embodiment, the flight control actuator system <NUM> includes a motor <NUM>, an actuator controller <NUM>, a drive shaft <NUM>, and a plurality of actuators <NUM>. The actuator controller <NUM> is an electronic or electrical component configurated to control operation of the motor <NUM>, such as in response to commands received from a command system <NUM> that may be controlled by a pilot, operator, or autonomous system that controls operation of an aircraft to which the wing <NUM> is part of. The command system <NUM> is configured send and receive electrical signals to/from the actuator controller <NUM> through command connection <NUM> (e.g., wired, or wireless). The motor <NUM> is configured to rotationally drive the drive shaft <NUM>. As the drive shaft <NUM> is rotated by the motor <NUM>, the actuators <NUM> will be actuated or otherwise operated to cause movement (e.g., rotation, pivot, translation, etc.) of the aircraft flight control element <NUM>.

Each actuator <NUM> is arranged and housed within the aircraft flight control element <NUM> and is connected to the wing <NUM> by one or more respective wing spars <NUM>. The wing spars <NUM> are structural elements arranged at an aft end or side of the wing <NUM> and provide structural connection between the wing <NUM> and the aircraft flight control element <NUM>. As such, the only portion of the flight control actuator system <NUM> that is housed within the wing <NUM> is the connection to the wing spars <NUM> at the actuators <NUM>, and the remainder of the components of the flight control actuator system <NUM> are housed within the aircraft flight control element <NUM> (e.g., actuator controller <NUM>, motor <NUM>, drive shaft <NUM>, and actuators <NUM>).

Turning now to <FIG>, schematic illustrations of a flight control actuator system <NUM> in accordance with an embodiment of the present disclosure are shown. <FIG> illustrates a side elevation view of the flight control actuator system <NUM> (without wing or aircraft flight control element shown), <FIG> illustrates the flight control actuator system <NUM> as mounted to a wing <NUM> and supporting and controlling movement of an aircraft flight control element <NUM> in a first position, and <FIG> illustrates the flight control actuator system <NUM> in a second position. The flight control actuator system <NUM> may be part of a fixed-wing aircraft (e.g., airplane), as shown, but may be employed to allow relative movement between any two structures (e.g., to replace a hinge in a door or hatchway).

Referring to <FIG>, the flight control actuator system <NUM> includes a first rotary actuator element <NUM>, a second rotary actuator element <NUM>, and a drive shaft <NUM>. The drive shaft <NUM> may be operably coupled to a motor (e.g., motor <NUM> shown in <FIG>) and may be rotationally driven by the motor. The drive shaft <NUM> passes through apertures <NUM> of the first and second rotary actuator elements <NUM>, <NUM>. <FIG> illustrates the drive shaft <NUM> and <FIG> illustrates the apertures <NUM> without the drive shaft <NUM> passing therethrough, for clarity of illustration. Each of the first and second rotary actuator elements <NUM>, <NUM> are operably coupled to the drive shaft <NUM> such that rotation of the drive shaft <NUM> causes rotation of the respective first and second rotary actuator elements <NUM>, <NUM>. In accordance with embodiments of the present disclosure, the first rotary actuator element <NUM> is configured to be rotationally driving in a direction opposite to the second rotary actuator element <NUM>. Such counter rotation may be achieved, for example, by using a compound gear or compound gearing or threaded drive shaft that interacts with threading on each of the first and second rotary actuator elements. It will be appreciated that other connection configurations may be employed without departing from the scope of the present disclosure. For example, in some embodiments, a geared connection or compound geared connection may be employed. In some embodiments, the first and second rotary actuator elements <NUM>, <NUM> may be compound gear rotary actuators.

In this illustrative configuration, the flight control actuator system <NUM> includes two first rotary actuator elements <NUM> with a single second rotary actuator element <NUM> arranged between the two first rotary actuator elements <NUM>. Each of the first rotary actuator elements <NUM> are substantially cylindrical in shape and the second rotary actuator element <NUM> is substantially cylindrical in shape and includes a linkage extension <NUM>. The linkage extension <NUM> of the second rotary actuator element <NUM> is configured to pivotably connect to a spar link <NUM> at a first pivot pin <NUM>. The first pivot pin <NUM> is coupled to the spar link <NUM> at a first end of the spar link <NUM> and the spar link <NUM> is coupled to a wing spar <NUM> at a second end thereof by a second pivot pin <NUM>. The wing spar <NUM> is a structural part of the wing <NUM> (e.g., at an aft or trailing end of the wing <NUM>). The spar link <NUM> is moveable relative to both the first pivot pin <NUM> at the first end thereof and the second pivot pin <NUM> at the second end thereof (opposite the first end). In other configurations of the present disclosure, the wing spar <NUM> may be attached to a rear spar of the wing.

The first rotary actuator elements <NUM> are movably coupled to the wing spar <NUM> by a first spar connection <NUM> and a second spar connection <NUM>. <FIG> illustrates the flight control actuator system <NUM> without one set of the spar connections <NUM>, <NUM> for clarity purposes. The first and second spar connections <NUM>, <NUM> are fixed connections that do not move. As such, in some embodiments, the first and second spar connections <NUM>, <NUM> and the wing spar <NUM> may be formed as a single, integral, or unitary structure, and such separate element configuration as shown is not to be limiting. As shown, the first and second spar connections <NUM>, <NUM> couple to the first rotary actuator elements at a fixed coupler <NUM>. The fixed coupler <NUM> defines a point about which the first rotary actuator elements <NUM> may rotate, causing a rotation and translation of the aircraft flight control element <NUM> (illustratively shown between a first position in <FIG> and a second position in <FIG>).

When the aircraft flight control element <NUM> is transitioned from the first position (<FIG>) to the second position (<FIG>) the aircraft flight control element <NUM> may be positioned to increase lift or provide other flight control. Further, when the aircraft flight control element <NUM> is in the second position (<FIG>) an air gap <NUM> is formed between the aft end of the wing <NUM> and the aircraft flight control element <NUM>. This air gap <NUM> permits airflow therethrough when the aircraft flight control element <NUM> is in the second position.

In operation, when the drive shaft <NUM> is rotationally driven by a motor, the drive shaft <NUM> will cause the first rotary actuator elements <NUM> and the second rotary actuator element <NUM> to counter-rotate relative to each other. As the rotary actuator elements <NUM>, <NUM> counter-rotate, the first rotary actuator elements <NUM> will rotate about the fixed coupler <NUM> causing the entire assembly (rotary actuator elements <NUM>, <NUM> and drive shaft <NUM>) to move (e.g., from the first position toward the second position). During this movement, the linkage extension <NUM> and the spar link <NUM> will pivot relative to each other about the first pivot pin <NUM> providing an extension or translation motion to extend the aircraft flight control element <NUM> outward and away from the wing <NUM>.

Turning now to <FIG>, schematic illustrations of a flight control actuator system <NUM> operably coupled between a wing <NUM> and an aircraft flight control element <NUM> are shown. <FIG> is separated into a sequential series of images in matrix form representing operation of the components of a system in accordance with an embodiment of the present disclosure. The grid of <FIG> includes three rows: first row (i), second row (ii), and third row (ii); and four columns: first column (a), second column (b), third column (c), and fourth column (d). The first row (i) illustrates the operation of the flight control actuator system <NUM> in isolation, the second row (ii) illustrates the operation of the flight control actuator system <NUM> with the wing <NUM> and aircraft flight control element <NUM> shown, and the third row (iii) illustrates the relative movement of the aircraft flight control element <NUM> relative to the wing <NUM> with the flight control actuator system <NUM> illustratively removed. First column (a) illustrates a side view of the flight control actuator system <NUM>, the wing <NUM>, and the aircraft flight control element <NUM> in a first position and the second column (b) is the same illustration but with certain features omitted for clarity. The fourth column (d) illustrates a side view of the flight control actuator system <NUM>, the wing <NUM>, and the aircraft flight control element <NUM> in a second position. The third column (c) illustrates a side view of the flight control actuator system <NUM>, the wing <NUM>, and the aircraft flight control element <NUM> in a transition state between the first position and the second position.

The flight control actuator system <NUM> may be substantially similar to that shown and described above with respect to <FIG>. The flight control actuator system <NUM> includes at least two rotary actuator elements <NUM> that are configured to counter-rotate relative to each other in response to a rotation of a drive shaft. A first rotary actuator element is attached to a wing spar <NUM> at a fixed coupler that defines a rotational or pivot point, as described above. A second rotary actuator element, configured to counter-rotate relative to the first rotary actuator element, is connected to the wing spar through a linkage extension and a spar link that are joined by a first pivot pin. This configuration enables a rotation and translational movement of the aircraft flight control element <NUM> relative to the wing <NUM> during actuation of the flight control actuator system <NUM>. As shown in <FIG>, as the rotary actuator elements are rotated (from the first position to the second position), the rotary actuator elements <NUM> will translate away and downward relative to the wing spar <NUM>.

The movement provided actuation of a flight control actuator system <NUM> is illustratively shown in <FIG> illustrates the flight control actuator system <NUM> in a first position and <FIG> illustrates the fight control actuator system <NUM> in a second position. The flight control actuator system <NUM> is similar in construction as that shown and described above with respect to <FIG>. The flight control actuator system <NUM> includes a first rotary actuator element <NUM> and a second rotary actuator element <NUM>. The rotary actuator elements <NUM>, <NUM> are each operably coupled to a drive shaft <NUM>. Rotation of the drive shaft <NUM> causes counter-rotation of the rotary actuator elements <NUM>, <NUM>, which causes actuation or movement of the flight control actuator system <NUM>. The second rotary actuator element <NUM> is coupled to a spar link <NUM> by a first pivot pin <NUM>. The spar link <NUM> is pivotably coupled to a wing spar <NUM> by a second pivot pin <NUM>. The first rotary actuator element <NUM> is rotatably coupled to the wing spar <NUM> by at least one spar connection <NUM> at a respective fixed coupler <NUM>.

<FIG> are illustratively shown with the second pivot pin <NUM> aligned between the two schematics such that the relative movement of components of the flight control actuator system <NUM> may be shown. The wing spar <NUM>, the second pivot pin <NUM>, the spar connection <NUM>, and the fixed coupler <NUM> do not change position between the first position (<FIG>) and the second position (<FIG>) of the flight control actuator system <NUM>.

In the first position (<FIG>), the drive shaft <NUM>, representative of the movement imparted to an aircraft flight control element, has a first vertical separation distance Dv1 from the second pivot pin <NUM>. In the second position (<FIG>), the drive shaft <NUM> has a second vertical separation distance Dv2 from the second pivot pin <NUM>. As illustrated, the first vertical separation distance Dv1 is greater than the second vertical separation distance Dv2. This decrease in the vertical separation distance illustrates the movement of an aircraft flight control element moving downward.

Similarly, in the first position (<FIG>), the drive shaft <NUM>, representative of the movement imparted to an aircraft flight control element, has a first horizontal separation distance Dh<NUM> from the second pivot pin <NUM>. In the second position (<FIG>), the drive shaft <NUM> has a second horizontal separation distance Dh2 from the second pivot pin <NUM>. As illustrated, the first horizontal separation distance Dh1 is less than the second horizontal separation distance Dh2. This increase in the horizontal separation distance illustrates the movement of an aircraft flight control element moving downward.

Because of the fixed connection at the fixed coupler <NUM>, when the two translational movement occur (vertical and horizontal), the drive shaft <NUM> and rotary actuator elements <NUM>, <NUM> and the attached aircraft flight control element will translate and rotate. Such translation and rotation will position the attached aircraft flight control element in a desired position (e.g., second position) where an air gap is formed, and the attached aircraft flight control element may be positioned to generate more lift to an aircraft. As described above, and in accordance with embodiments of the present disclosure, the drive shaft <NUM> and rotary actuator elements <NUM>, <NUM> may be housed within the aircraft flight control element, with only the wing spar <NUM> and spar connection <NUM> being part of the wing of the aircraft.

Turning now to <FIG>, schematic illustrations of a flight control actuator system <NUM> in accordance with an embodiment of the present disclosure are shown. <FIG> illustrates a side elevation view of the flight control actuator system <NUM> coupled between a wing <NUM> and an aircraft flight control element <NUM> and <FIG> illustrates the flight control actuator system <NUM>, wing <NUM>, and aircraft flight control element <NUM> in a series of illustrations showing a transition from a first position (column (a)) to a second position (column (f)).

The flight control actuator system <NUM> includes a first rotary actuator element <NUM>, a second rotary actuator element <NUM>, and a drive shaft <NUM> about which the two rotary actuator elements <NUM>, <NUM> may counter-rotate, as described above. In this configuration, as in the above described embodiments, the first rotary actuator element <NUM>, the second rotary actuator element <NUM>, and the drive shaft <NUM> are housed within the aircraft flight control element <NUM>. The wing <NUM> includes a wing spar <NUM> that is positioned in fixed relation to the wing <NUM>. In this embodiment, a spar connection <NUM> connects the first rotary actuator element <NUM> to the wing spar <NUM> to permit rotation and translation similar to that described above, with the pivot point of the first rotary actuator element <NUM> being at a fixed coupler <NUM>. In this embodiment, the second rotary actuator element <NUM> includes a slot <NUM> which enables the second rotary actuator element <NUM> to translate relative to a spar pin <NUM>. As the rotary actuator elements <NUM>, <NUM> rotate relative to each other, as driven by the drive shaft <NUM>, the second rotary actuator element <NUM> will translate, and the first rotary actuator element <NUM> will pivot about the fixed coupler <NUM>, thus causing the aircraft flight control element <NUM> to translate and rotate or pivot.

This rotation and translation of the aircraft flight control element <NUM> is schematically shown in grid form in <FIG> (e.g., similar to that shown in <FIG>). The grid of <FIG> includes three rows: first row (i), second row (ii), and third row (ii); and six columns: first column (a), second column (b), third column (c), fourth column (d), fifth column (d), and sixth column (e). The first row (i) illustrates the operation of the flight control actuator system <NUM> in isolation, the second row (ii) illustrates the operation of the flight control actuator system <NUM> with the wing <NUM> and aircraft flight control element <NUM> shown, and the third row (iii) illustrates the relative movement of the aircraft flight control element <NUM> relative to the wing <NUM> with the flight control actuator system <NUM> illustratively removed. First column (a) illustrates a side view of the flight control actuator system <NUM>, the wing <NUM>, and the aircraft flight control element <NUM> in a first position. Second column (b) illustrates schematic directions arrows indicating the translation and rotation of the various components, still in the first position. The third (c), forth (d), and fifth (e) columns illustrate the movement or transition from the first position (first column (a)) to the second position (sixth column (f)) of the flight control actuator system <NUM>, the wing <NUM>, and the aircraft flight control element <NUM>. The sixth column (f) illustrates a side view of the flight control actuator system <NUM>, the wing <NUM>, and the aircraft flight control element <NUM> in the second position.

Advantageously, embodiments of the present disclosure provide for improved aerodynamics for thin wing aircraft configurations. In accordance with some embodiments, various components of a flight control actuator system installed and housed within an aircraft flight control element. This differs from prior configurations that housed the same components within the wing of the aircraft. By moving such components into the aircraft flight control element, drop hinges may be eliminated for operation of the aircraft flight control elements. Advantageously, this can improve the aerodynamics of the aircraft (e.g., reduction in drag). Additionally, weight savings may be realized by embodiments of the present disclosure by eliminated complex hinging mechanisms. Furthermore, by moving various components of the flight control actuator systems into the aircraft flight control element, space savings may be realized within the wing, enabling a lighter wing and/or ability to provide other functionality to the wing (e.g., increased fuel storage capacity).

The use of the terms "a", "an", "the", and similar references in the context of description (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or specifically contradicted by context. The modifier "about" used in connection with a quantity is inclusive of the stated value and has the meaning dictated by the context (e.g., it includes the degree of error associated with measurement of the particular quantity). All ranges disclosed herein are inclusive of the endpoints. As used herein, the terms "about" and "substantially" are intended to include the degree of error associated with measurement of the particular quantity based upon the equipment available at the time of filing the application. For example, the terms may include a range of ± <NUM>%, or <NUM>%, or <NUM>% of a given value or other percentage change as will be appreciated by those of skill in the art for the particular measurement and/or dimensions referred to herein. It should be appreciated that relative positional terms such as "forward," "aft," "upper," "lower," "above," "below," and the like are with reference to normal operational attitude and should not be considered otherwise limiting.

Claim 1:
An assembly comprising:
a first structure (<NUM>);
a second structure (<NUM>) configured to be moved relative to the first structure; and
an actuator system (<NUM>) arranged between the first structure and the second structure and configured to control relative movement between the first structure and the second structure, wherein the actuator system comprises:
a drive shaft (<NUM>);
a first rotary actuator element (<NUM>) operably coupled to the drive shaft and configured to be driven in a first direction about the drive shaft;
a second rotary actuator element (<NUM>) positioned adjacent the first rotary actuator element and operably coupled to the drive shaft and configured to be driven in a second direction about the drive shaft, the second direction being a counter-rotation relative to the first direction;
a spar (<NUM>) fixedly connected to the first structure; and
a spar connection (<NUM>, <NUM>) configured to pivotably connect the first rotary actuator element to the spar at a fixed coupler;
wherein the drive shaft, the first rotary actuator element, and the second rotary actuator element are housed within the second structure, and
wherein rotation of the second rotary actuator element causes a translation motion of the drive shaft away from the first structure and rotation of the first rotary actuator element about the fixed coupler such that the second structure is translated and rotated relative to the first structure.