Patent Description:
Wing sections of fixed wing aircraft may include geared rotary actuator(s) at a hinge line between an aft section of a wing and the aerostructure (e.g., flaps, slats, etc.). Conventionally, aerostructures are controlled using an actuator within the wing that is operably connected to such aerostructure(s). Aerostructures may be prone to damage if a load exceeds an aircraft limit load. For example, during high load events, a drive shaft or the like associated with the actuator system may cause damage to the aerostructure by applying to great of a torque. <CIT> relates to a friction drive for force transmission, in particular for a transport conveying device, by which a transmission torque from a drive element to an output element is able to be set. The object of the disclosure of this document is to propose a friction drive for force transmission which works in a virtually wear-free manner. <CIT> relates generally to gear systems. More specifically, the document is a wedge clutch assembly for insertion in rotary power devices to prevent damage to a gear or other drive system upon excessive stress.

According to appended claim <NUM>, an aerostructure actuator system is provided. The aerostructure actuator system includes a first shaft portion having a first mandrel, a second shaft portion having a second mandrel, and a clutch assembly arranged within the first mandrel and configured to operably connect the first shaft portion to the second shaft portion. The clutch assembly includes a post fixedly connected to the second mandrel, the post having a post extension extending therefrom, a first bearing installed on the post extension, a portion of the first bearing frictionally engaging with a portion of the post, a second bearing installed on the post, a spacer arranged between the first bearing and the second bearing, wherein the spacer is configured to fixedly attach to the first mandrel, and a load setting nut configured to threadedly engage with the post extension and apply a compressive force to the first bearing, spacer, and the second bearing against the post, wherein the compressive force defines a coupling limit between the first shaft portion and the second shaft portion. The clutch assembly is configured to rotationally decouple the first shaft portion from the second shaft portion if a relative rotational speed between the first shaft portion and the second shaft portion exceeds the coupling limit.

In addition to one or more of the features described herein, further embodiments of the aerostructure actuator systems may include that the first shaft portion and the second shaft portion form a part of a drive shaft of the aerostructure actuator system.

In addition to one or more of the features described herein, further embodiments of the aerostructure actuator systems may include that the drive shaft is operably coupled to a drive mechanism that is configured to rotationally drive the drive shaft.

In addition to one or more of the features described herein, further embodiments of the aerostructure actuator systems may include that the drive mechanism is a motor.

In addition to one or more of the features described herein, further embodiments of the aerostructure actuator systems may include an aerostructure actuator operably coupled to one of the first shaft portion and the second shaft portion.

In addition to one or more of the features described herein, further embodiments of the aerostructure actuator systems may include an aerostructure operably coupled to the aerostructure actuator.

In addition to one or more of the features described herein, further embodiments of the aerostructure actuator systems may include that the aerostructure is a slat or flap of an aircraft.

In addition to one or more of the features described herein, further embodiments of the aerostructure actuator systems may include that each of the first bearing and the second bearing comprise an inner race, an outer race, and one or more bearing elements arranged therebetween.

In addition to one or more of the features described herein, further embodiments of the aerostructure actuator systems may include that the first mandrel has an outer diameter and an inner diameter and the clutch assembly has an outer diameter that is less than the inner diameter of the first mandrel.

In addition to one or more of the features described herein, further embodiments of the aerostructure actuator systems may include that the first shaft portion has as first diameter and the clutch assembly has an outer diameter that is equal to or greater than the first diameter.

In addition to one or more of the features described herein, further embodiments of the aerostructure actuator systems may include that the outer diameter of the clutch assembly is between <NUM>% and <NUM>% larger than the first diameter.

In addition to one or more of the features described herein, further embodiments of the aerostructure actuator systems may include that the second shaft portion has a second diameter that is equal to the first diameter.

In addition to one or more of the features described herein, further embodiments of the aerostructure actuator systems may include that the clutch assembly further comprises a washer arranged between the load setting nut and the second bearing.

In addition to one or more of the features described herein, further embodiments of the aerostructure actuator systems may include that a portion of the post fits within the second mandrel.

In addition to one or more of the features described herein, further embodiments of the aerostructure actuator systems may include that the post comprises a stop and the first bearing frictionally engages with the stop.

According to some embodiments, an aircraft as in claim <NUM> is provided.

<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 "aerostructures" as they are movable under aircraft power systems and are configured to control flight and motion of the aircraft <NUM>. An aerostructure actuator system <NUM> may be connected to one or more of the aerostructures. For example, each wing <NUM> and the tail structure <NUM> may include one or more aerostructure actuator systems <NUM>. The aerostructure actuator systems <NUM> may be operably connected to the various aerostructures and configured control the operation/position of the aerostructures to control flight of the aircraft <NUM>.

Aircraft and associated components and systems may be limited by load applications, such that aircraft load limits are imposed to prevent damage to the aircraft, components of the aircraft, or negatively impact slight of the aircraft. For example, secondary flight control systems may self-damage the aerostructure if a load exceeds an aircraft limit load. In view of this potential self-imposed damage, embodiments of the present disclosure are directed to systems for preventing over torque and other excess loads that could damage aerostructures. To achieve this, a driveline of the actuator system is provided with an integrated driveline slip-clutch that is configured to protect key aerostructures by slipping a load prior to reaching a limit load of the aircraft.

Referring now to <FIG>, a schematic illustration of a portion of an aircraft <NUM> that may incorporate embodiments of the present disclosure is shown. The aircraft <NUM> includes a wing <NUM> that includes aerostructures <NUM>, <NUM>. Leading edge aerostructures <NUM> may be slats or the like and trailing edge aerostructures <NUM> may be flaps or the like. The leading edge aerostructures <NUM> may be controlled or operated by a first aerostructure actuator system <NUM> and the trailing edge aerostructures <NUM> may be controlled or operated by a second aerostructure actuator system <NUM>.

The first aerostructure actuator system <NUM> includes a drive mechanism <NUM>, such as a motor and associated components. The drive mechanism <NUM> is operably coupled to, and configured to drive rotation of, a drive shaft <NUM>. The drive shaft <NUM> may be a segmented drive shaft that coupled to one or more aerostructure actuators <NUM> that may be operably driven by the drive shaft <NUM>. Each of the leading edge aerostructures <NUM> may be coupled to one or more of the aerostructure actuators <NUM>. Actuation of the aerostructure actuators <NUM> causes a rotational and/or translational movement of a leading edge aerostructure <NUM> to which the aerostructure actuator(s) <NUM> is connected.

The second aerostructure actuator system <NUM> includes a drive mechanism <NUM>, such as a motor and associated components. The drive mechanism <NUM> is operably coupled to, and configured to drive rotation of, a drive shaft <NUM>. The drive shaft <NUM> may be a segmented drive shaft that coupled to one or more aerostructure actuators <NUM> that may be operably driven by the drive shaft <NUM>. Each of the trailing edge aerostructures <NUM> may be coupled to one or more of the aerostructure actuators <NUM>. Actuation of the aerostructure actuators <NUM> causes a rotational and/or translational movement of a trailing edge aerostructure <NUM> to which the aerostructure actuator(s) <NUM> is connected.

The drive shafts <NUM>, <NUM> may be formed from a series of torque tubes that are arranged with the aerostructure actuators <NUM>, <NUM> (or portions thereof) arranged between such torque tubes. When the drive shafts <NUM>, <NUM> are rotated to drive actuation of the aerostructure actuators <NUM>, <NUM>, at times, the rotation must be stopped. During such events, the drive shaft <NUM>, <NUM> will have inertia due to the rotational spinning and cannot stop immediately, and thus may continue to rotate after a commanded stop. Such stop may be initiated by a pilot or other aircraft operator commanding a flight operation. In other situations, the stop may be initiated by the aerostructure actuator systems <NUM>, <NUM> itself. In such configurations, the aerostructure actuator systems <NUM>, <NUM> may include sensors that are configured to monitor operation and loads of the aerostructures <NUM>, <NUM> (e.g., skew sensors, disconnect sensors, torque sensors, etc.). In accordance with embodiments of the present disclosure, the drive shafts <NUM>, <NUM> may be configured with one or more slip-clutches that are arranged to decouple a portion of the drive shaft <NUM>, <NUM> and thus prevent high loads to be imparted to the aerostructures.

Referring now to <FIG>, schematic illustrations of a portion of a drive shaft <NUM> for an aerostructure actuator system in accordance with an embodiment of the present disclosure are shown. The drive shaft <NUM> may be representative of two segments or portions of a drive shaft assembly that operably connects a drive mechanism (e.g., motor) to one or more aerostructure actuators, as will be appreciated by those of skill in the art.

The drive shaft <NUM> includes a first shaft portion <NUM> coupled to a second shaft portion <NUM> by a clutch assembly <NUM>. The first and second shaft portions <NUM>, <NUM> may be torque tubes or other structural elements, as will be appreciated by those of skill in the art. The clutch assembly <NUM> is arranged as a slip-clutch that is configured to disengage or decouple the rotation of the first shaft portion <NUM> from the second shaft portion <NUM>.

The first shaft portion <NUM> includes a first mandrel <NUM> that is sized to receive, at least, parts of the clutch assembly <NUM> and a second mandrel <NUM> of the second shaft portion <NUM>. The clutch assembly <NUM> includes the first mandrel <NUM> and the second mandrel <NUM>. The first mandrel <NUM>, in this specific illustrative embodiment, defines a housing for the other components of the clutch assembly <NUM> to fit within. The clutch assembly <NUM> includes a post <NUM>, a first bearing <NUM>, a spacer <NUM>, a second bearing <NUM>, a washer <NUM>, and a load setting nut <NUM>.

In this configuration, the first mandrel <NUM> is configured to fixedly connect to the spacer <NUM>. The spacer <NUM> is arranged between the first bearing <NUM> and the second bearing <NUM>. The spacer <NUM> is secured or fixedly connected to the first mandrel by one or more fasteners <NUM>. The spacer <NUM>, when assembled within the clutch assembly <NUM>, is positioned to engage or connect with bearing outer races of the first and second bearings <NUM>, <NUM>. The post <NUM> includes a post extension <NUM> about which the bearings <NUM>, <NUM>, the spacer <NUM>, the washer <NUM>, and the load setting nut <NUM> may be installed. In this configuration, the load setting nut <NUM> may threadedly attach to an end of the post extension <NUM>, and the other components (e.g., the washer <NUM>, the bearings <NUM>, <NUM>, and the spacer <NUM> may be configured to not directly attach to the post <NUM> or post extension <NUM>).

As noted, the outer race of the bearings <NUM>, <NUM> are configured to engage with the spacer <NUM> which is fixedly attached to the first mandrel <NUM> of the first shaft portion <NUM>. The inner race of the bearings <NUM>, <NUM> are configured to engage with the post extension <NUM>. The post extension <NUM> is an extension of the post <NUM>, and the post <NUM> is configured to fixed attach to the second shaft portion <NUM> at the second mandrel <NUM>. In this illustrative embodiment, the post <NUM> is configured to be installed within an interior of the second mandrel <NUM> and may be fixedly attached thereto by one or more fasteners <NUM>, as will be appreciated by those of skill in the art and illustratively shown in <FIG>.

In normal operation, when the first shaft portion <NUM> is rotated, the first mandrel <NUM> will rotate and the rotation may be conveyed through the spacer <NUM> and other elements of the clutch assembly <NUM> to cause rotation of the post <NUM>, which in turn will cause rotation of the second mandrel <NUM> and thus rotation of the second shaft portion <NUM>. This transmission of rotational energy from the first shaft portion <NUM> to the second shaft portion <NUM> may be achieve because during normal operation the two bearings <NUM>, <NUM> are fixedly connected through the spacer <NUM> (e.g., by friction forces). The amount of friction between the bearings <NUM>, <NUM> and the spacer <NUM> is controlled by the load setting nut <NUM>. This selective frictional contact enables load setting and resetting of the clutch assembly <NUM> if such a reset of the components is necessary.

The load setting nut is configured to threadedly engage with the post extension and apply a compressive force to the first bearing <NUM>, the spacer <NUM>, and the second bearing <NUM> against the post <NUM>. This compressive force defines a coupling limit between the first shaft portion <NUM> and the second shaft portion <NUM> such that if a relative rotational speed between the first shaft portion <NUM> and the second shaft portion <NUM> exceeds a predefined limit (defined by the compressive force), the two shaft portions <NUM>, <NUM> will rotationally decouple and prevent transmission of torque from one shaft portion to the other and thus limit the amount of load carried by the shaft portions.

Turning now to <FIG>, a schematic illustration of a clutch assembly <NUM> in accordance with an embodiment of the present disclosure is shown. The clutch assembly <NUM> may be integrated into an aerostructure actuator system for use onboard an aircraft and for controlling aerostructures of the aircraft. More particularly, as described above, the clutch assembly <NUM> may be part of a drive shaft of such aerostructure actuator system and may be arranged and provided to prevent over-torque or over-load events that can damage the drive shaft or other parts of the aerostructure actuator system.

Similar to the embodiment of <FIG>, the clutch assembly <NUM> is a slip-clutch configuration that is adjustable to slip given a specific amount of force applied thereto. The clutch assembly <NUM> a post <NUM>, a first bearing <NUM>, a spacer <NUM>, a second bearing <NUM>, a washer <NUM>, and a load setting nut <NUM>. The post <NUM> comprises a post extension <NUM>, a stop <NUM>, and a shaft connector <NUM>. The shaft connector <NUM> is configured to fixedly connect to a shaft or tube of a drive shaft. The stop <NUM> provides an end surface upon which components (e.g., the first bearing) can contact and engage with to impart rotational movement (e.g., through frictional contact). The post extension <NUM> includes a threaded portion <NUM> that is configured to receive and threadedly connect with the load setting nut <NUM>. In some configurations, the post extension <NUM> may not include threading between the threaded portion <NUM> and the stop <NUM>. This non-threaded portion allows for components to rotate freely about the post extension <NUM>.

The load setting nut <NUM> is configured to threadedly engage and connect to the post extension <NUM> at the threaded portion <NUM> thereof. Between the load setting nut <NUM> and the stop <NUM> of the post <NUM> are positioned the first bearing <NUM>, the spacer <NUM>, the second bearing <NUM>, and the washer <NUM>. The first bearing <NUM> includes an inner race <NUM>, one or more bearing elements <NUM>, and an outer race <NUM>. The inner race <NUM>, the bearing elements <NUM>, and the outer race <NUM> form a concentric or annular arrangement about a central aperture <NUM> through which the post extension <NUM> may pass. The inner race <NUM> of the first bearing <NUM> is configured to frictionally engage with the stop <NUM>. The outer race <NUM> of the first bearing <NUM> is configured to frictionally engage with the spacer <NUM>. The bearing elements <NUM> are configured to be stationary relative to both the inner race <NUM> and the outer race <NUM> during normal operation. The inner and outer races <NUM>, <NUM> have angled or wedged surfaces such that a compression of the two races <NUM>, <NUM> determines the frictional engagement of the bearing elements <NUM> therebetween. If a predetermined torque is applied to one or both of the races <NUM>, <NUM>, the frictional engagement with the bearing elements <NUM> may be overcome, thus permitting relative rotation of the races <NUM>, <NUM> and the components operably connected thereto. That is, the engagement between the inner and outer races <NUM>, <NUM> may be decoupled upon a predetermined torque applied thereto.

The spacer <NUM> is configured to be fixedly secured to a mandrel of a drive shaft, and thus is configured to be in locked communication with such structure. Such attachment may be by fastener, adhesives, welding, and the like, as will be appreciated by those of skill in the art. On the opposite side of the spacer <NUM> from the first bearing <NUM> is the second bearing <NUM>. The second bearing <NUM> is similarly arranged and constructed as the first bearing <NUM>. The second bearing <NUM> includes an inner race <NUM>, one or more bearing elements <NUM>, and an outer race <NUM>. The second bearing <NUM> is a circumferential or annular structure with a central aperture <NUM> provided therein for installation of the second bearing <NUM> on the post extension <NUM> of the post <NUM>. Similar to the first bearing <NUM>, the outer race <NUM> of the second bearing <NUM> is configured to frictionally engage with the spacer <NUM>. The inner race <NUM> of the second bearing <NUM> is configured to frictionally engage with the load setting nut <NUM> or a washer <NUM> that may be provided between the load setting nut <NUM> and the inner race <NUM> of the second bearing <NUM>.

The load setting nut <NUM> may be tightened on the threaded portion <NUM> of the post extension <NUM> to compress the washer <NUM>, the first and second bearings <NUM>, <NUM>, and the spacer <NUM> between the load setting nut <NUM> and the stop <NUM> of the post <NUM>. This compression applied by the load setting nut <NUM> enables tailoring of the torque or other forces that can overcome the frictional engagement of the components of the clutch assembly <NUM> and thus allow for relative rotational movement between the various components. That is, the setting of the compression using the load setting nut <NUM> enables setting of a load limit that if exceeded the components of the clutch assembly <NUM> will decouple such that excessive inertia is not transferred from one side (e.g., from the first shaft portion <NUM> to the second shaft portion <NUM> shown in <FIG>). This decoupling ensures that excessive loads and forces are not conveyed through the drive shaft, and thus damage to components thereof may be reduced or eliminated.

As illustratively shown and described herein, the majority of the clutch assembly components in accordance with embodiments of the present disclosure are housed within a portion of the drive shaft. This small profile or package for the clutch assembly provides advantages over prior configuration which may be relatively large. In such prior configurations, a drive shaft portion would be attached to the clutch on either side and the clutch would sit between such shaft portions. Because of the size and weight of the clutch in such configurations, a high or large inertia would be present during a transition from a rotational state to a change to no rotation or a change in direction (e.g., reverse of the rotation) during flight maneuvers. This high inertia results in continued rotation after a commanded change, and such continued rotation may cause damage to components that are commanded to operate differently from a prior state of operation. Advantageously, the clutch assemblies of the present disclosure have low inertia due to a low/small profile, which reduces risk of damage to components of the clutch assembly, drive shaft, aerostructure actuator system, aerostructures, and/or associated components.

The low profile or small packaging of a clutch assembly in accordance with an embodiment of the present disclosure is shown in <FIG> illustrates a portion of a drive shaft <NUM> for an aerostructure actuator system in accordance with an embodiment of the present disclosure having a clutch assembly <NUM> installed within/relative to shaft portions <NUM>, <NUM> of the drive shaft <NUM> of an aerostructure actuator system. <FIG> illustrates the clutch assembly <NUM> in isolation for explanatory and clarity purposes.

As shown in <FIG>, the first shaft portion <NUM> has a first diameter D<NUM> and the second shaft portion <NUM> had a second diameter D<NUM>. In some configurations the first diameter D<NUM> is equal to the second diameter D<NUM>. The first shaft portion <NUM> includes a respective first mandrel <NUM> and the second shaft portion <NUM> includes a respective second mandrel <NUM>. In this illustrative embodiment, the second mandrel <NUM> of the second shaft portion <NUM> is substantially the same or equal in diameter as the second shaft portion <NUM> (i.e., the second mandrel has a diameter equal to the second diameter D<NUM> of the second shaft portion <NUM>). The first mandrel <NUM> of the first shaft portion <NUM> has an enlarged outer diameter Dmo as compared to the diameter (first diameter D<NUM>) of the first shaft portion <NUM>. That is, the outer diameter Dmo of the first mandrel <NUM> is enlarged as compared to the first diameter D<NUM> of the first shaft portion <NUM>. Such increased size of the first mandrel <NUM> allows accommodation or installation of the clutch assembly <NUM> within the first mandrel <NUM>, as shown in <FIG>. The first mandrel <NUM> is a hollow body housing to receive the clutch assembly <NUM> therein. The first mandrel <NUM> has an inner diameter Dmi that is sized to receive the clutch assembly <NUM> and allow connection between the first mandrel <NUM> and a spacer <NUM> of the clutch assembly <NUM>. For example, as shown and described above, fasteners or the like may be passed through the first mandrel <NUM> and fasten or engage with the spacer <NUM> to fixedly connect the spacer to the first mandrel <NUM> and thus to the first shaft portion <NUM>.

To allow for the fastening connection between the first mandrel <NUM> and the spacer <NUM> of the clutch assembly <NUM>, the spacer <NUM> has an outer diameter Dc that defines the largest outer diameter of the clutch assembly <NUM>. By having the outer diameter Dc of the clutch assembly <NUM> being smaller but substantially equal to the inner diameter Dmi of the first mandrel <NUM> allows for installation of the clutch assembly <NUM> within the first mandrel <NUM> and for a fastener to fixedly connect the spacer <NUM> to the first mandrel <NUM>. In some non-limiting embodiments, the outer diameter Dc of the clutch assembly <NUM> may be about the same dimension of the first and second diameters D<NUM>, D<NUM> of the shaft potions <NUM>, <NUM> or only slightly larger than the first and second diameters D<NUM>, D<NUM>. In some non-limiting embodiments, the outer diameter Dc of the clutch assembly <NUM> may be between <NUM>% and <NUM>% larger than the first and second diameters D<NUM>, D<NUM> of the shaft potions <NUM>, <NUM>. In some non-limiting embodiments, the outer diameter Dc of the clutch assembly <NUM> may be less than the first and second diameters D<NUM>, D<NUM> of the shaft potions <NUM>, <NUM>. In some non-limiting embodiments, the outer diameter Dmo of the first mandrel <NUM> may be between <NUM>% and <NUM>% larger than the first and second diameters D<NUM>, D<NUM> of the shaft potions <NUM>, <NUM>. From this perspective, the total maximum diameter may be defined by the outer diameter Dmo of the first mandrel <NUM> that is configured to house the clutch assembly <NUM>. This is in contrast to prior clutch assembly configurations where the clutch assembly may be positioned between (not in or around) two shaft portions and may have a sizing with an equivalent diameter being at least twice that of the shaft itself. This larger size is part of why such prior clutch assemblies had high inertia and could cause damage or other issues associated with operation of aerostructure actuator systems.

It will be appreciated that one or more of the clutch assemblies described herein may be implemented within a drive shaft of an aerostructure actuator system. In some embodiments, a single clutch assembly as described herein may be arranged between a drive mechanism (e.g., motor or the like) and a drive shaft that may be operably connected to one or more aerostructure actuators. In other embodiments, multiple such clutch assemblies may be distributed along the length of a drive shaft, and thus allow for multiple different points of decoupling at the respective clutch, based on torque loads and/or the load setting of the load setting nuts of the clutch assemblies. In such multi-assembly systems, each clutch assembly may be configured with a different threshold based on location and total loads at the specific location of the clutch assembly. As such, a clutch assembly close to a drive mechanism may have a different load threshold (based on setting of the load setting nut) than a clutch assembly at the distal end of a drive shaft (e.g., proximate a tip or end of a wing).

Advantageously, embodiments of the present disclosure provide for improved aerostructure actuator systems for use on aircraft. In accordance with some embodiments, low profile, low inertia clutch systems are provided within aerostructure actuator systems to reduce potential for damage or other risks associated with high inertia situations. The total package of the clutch assembly is significantly smaller than prior clutch assemblies, thus providing improved weight and operation benefits. Secondary flight control systems may self-damage the aerostructure if a load exceeds an aircraft limit load. The integrated driveline slip-clutches described herein can protect key aerostructures by slipping the load prior to reaching the limit load of the aircraft. In accordance with some embodiments of the present disclosure, the slip-clutch assemblies are integrated into the drive line of the high lift system. The compression of the bearing within the slip-clutch to the plate or spacer determines the setting of the slip load. The slip is resettable when the load is reduced below the set slip load or when the rotation stops. Advantageously, the clutch assemblies described herein may be light weight and compact in design (e.g., fitting within a mandrel of a portion of a drive shaft), thus providing weight, volume, and operational benefits, as described herein.

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, and the endpoints are independently combinable with each other. 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 aerostructure actuator system comprising:
a first shaft portion (<NUM>) having a first mandrel (<NUM>);
a second shaft portion (<NUM>) having a second mandrel (<NUM>); and
a clutch assembly (<NUM>) arranged within the first mandrel (<NUM>) and configured to operably connect the first shaft portion (<NUM>) to the second shaft portion (<NUM>), wherein the clutch assembly (<NUM>) comprises:
a post (<NUM>) fixedly connected to the second mandrel (<NUM>), the post (<NUM>) having a post extension (<NUM>) extending therefrom;
a first bearing (<NUM>) installed on the post extension, a portion of the first bearing frictionally engaging with a portion of the post;
a second bearing (<NUM>) installed on the post;
a spacer (<NUM>) arranged between the first bearing and the second bearing, wherein the spacer is configured to be fixedly attached to the first mandrel; and
a load setting nut (<NUM>) configured to threadedly engage with the post extension and apply a compressive force to the first bearing, spacer, and the second bearing against the post, wherein the compressive force defines a coupling limit between the first shaft portion and the second shaft portion,
wherein the clutch assembly (<NUM>) is configured to rotationally decouple the first shaft portion from the second shaft portion if a relative rotational speed between the first shaft portion and the second shaft portion exceeds the coupling limit.