Control surface actuator assembly, and aircraft comprising a control surface actuator assembly and an aircraft hydraulic system

Abstract

To provide control surface actuator assemblies, aircraft hydraulic systems including the same, and associated aircrafts and methods.SOLUTION: A control surface actuator assembly includes a control surface operatively coupled to a support structure, a torque-generating hydraulic actuator configured to apply a torque to pivot the control surface, and a variable horn radius (VHR) hydraulic actuator configured to vary a torque arm length for pivoting the control surface. In one example, an aircraft hydraulic system includes such control surface actuator assemblies, and an aircraft includes such aircraft hydraulic systems. In one example, a method of operating one or more control surfaces of an aircraft includes controlling a control surface by adjusting, with a VHR hydraulic actuator, an actuator moment arm length corresponding to the selected control surface and pivoting, with a torque-generating hydraulic actuator, the selected control surface.SELECTED DRAWING: None

Description

Technical Field

[0001] The present disclosure relates to a control surface actuator assembly, an aircraft hydraulic system including the control surface actuator assembly, and related aircraft and methods.

Background Art

[0002] Aircraft include one or more movable control surfaces (e.g., ailerons of the wings for roll control, elevators of the horizontal tail of the tail for pitch control, rudders of the vertical tail of the tail for yaw control, nose cones of missiles, and other movable control surfaces). The movement of the control surface is typically affected by one or more actuators mechanically coupled between a support member (such as a wing spar) and the control surface. In many aircraft, the actuator for the control surface is a hydraulic linear actuator driven by one or more hydraulic systems.

[0003] An aircraft hydraulic system can be designed to provide hydraulic fluid to a plurality of hydraulic actuators to move and position the control surfaces as needed during flight of the aircraft. Specifically, the hydraulic system may include a series of supply lines and return lines, and one or more hydraulic actuators are positioned along the supply line and the return line and further to the control surface. A pump moves the hydraulic fluid through the supply line to the actuator. The hydraulic fluid is then directed into various sections of the actuator to move the actuator and thus adjust the control surface.

[0004] During flight, various control surfaces can be subject to loads with changing intensities. As a result, in order to move the control surfaces, it is necessary for a force that varies according to such loads to be generated by a hydraulic actuator. The force applied by the hydraulic actuator is typically determined by the pressure of the hydraulic fluid utilized by the hydraulic actuator. In some examples, the hydraulic system operates at a certain fixed pressure and the flow rate of the hydraulic fluid is variable. However, in such examples, significant pressure losses can occur by metering the flow in the actuator. In other examples, the operating pressure of the hydraulic system is variable, but that pressure still needs to be set to correspond to the maximum load received by any of the actuators. In this method, the required peak hydraulic power of any of the actuators presents a sizing constraint for the entire hydraulic system. An increase in the demand for hydraulic power can limit the effective range or performance of the aircraft and / or can reduce the payload capacity of the aircraft. Therefore, there is a need for an aircraft having a hydraulic system that can operate the control surfaces against large and varying loads while reducing the demand for hydraulic power. Summary of the Invention

[0005] This book discloses a control surface actuator assembly, an aircraft hydraulic system including the control surface actuator assembly, and related aircraft and methods. A control surface actuator assembly for selectively pivoting a control surface relative to a support structure includes a support structure and a control surface operably coupled to the support structure such that the control surface is configured to pivot relative to the support structure about a control surface pivot axis. The control surface actuator assembly further includes a torque generating hydraulic actuator and a variable horn radius (VHR) hydraulic actuator pivotally coupled to the torque generating hydraulic actuator and operably coupled to the control surface. Each of the torque generating hydraulic actuator and the VHR hydraulic actuator includes a respective hydraulic actuator housing and a respective rod at least partially extending within the respective hydraulic actuator housing and configured to translate parallel to the respective hydraulic actuator housing along a respective actuator axis. Each of the torque generating hydraulic actuator and the VHR hydraulic actuator further includes a respective hydraulic valve that regulates the flow of hydraulic fluid to the respective hydraulic actuator housing to control the position of the respective rod relative to the respective hydraulic actuator housing. The torque generating hydraulic actuator and the VHR hydraulic actuator are configured to pivot relative to each other about an actuator coupling axis. The torque generating hydraulic actuator is configured to apply torque to the control surface to pivot the control surface relative to the support structure. The VHR hydraulic actuator is configured to selectively vary the actuator moment arm length measured between the control surface pivot axis and the actuator coupling axis to at least partially adjust the torque applied to the control surface by the torque generating hydraulic actuator.

[0006] In some examples, an aircraft hydraulic system for operating one or more flight control surfaces of an aircraft includes a fluid reservoir containing a fixed volume of hydraulic fluid, one or more hydraulic pumps configured to apply pressure to the hydraulic fluid, and a plurality of hydraulic actuators, one or more of which are configured to selectively pivot a corresponding one of the one or more flight control surfaces. Examples of aircraft hydraulic systems further include a plurality of hydraulic conduits configured to convey hydraulic fluid between components of the aircraft hydraulic system. In some such examples, at least one of the plurality of hydraulic actuators is a torque generating hydraulic actuator of a flight control surface actuator assembly, and at least one other hydraulic actuator of the plurality of hydraulic actuators is a VHR hydraulic actuator of the flight control surface actuator assembly.

[0007] In some examples, an aircraft includes one or more flight control surfaces, a flight control surface actuator assembly including a VHR hydraulic actuator and a torque generating hydraulic actuator, and an aircraft hydraulic system.

[0008] In some examples, a method of operating one or more flight control surfaces of an aircraft includes controlling a selected flight control surface using a flight control surface actuator assembly and an aircraft hydraulic system. In such examples, controlling the selected flight control surface includes adjusting an actuator moment arm length corresponding to the selected flight control surface using the VHR hydraulic actuator and pivoting the selected flight control surface relative to a support structure using the torque generating hydraulic actuator. BRIEF DESCRIPTION OF THE DRAWINGS

[0009]

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DETAILED DESCRIPTION OF THE INVENTION

[0010] Figures 1 through 16 provide exemplary and non-limiting examples of a control surface actuator assembly 100 according to the present disclosure, an aircraft hydraulic system 50 including the control surface actuator assembly 100, an aircraft 10 including the aircraft hydraulic system 50, and / or a method 400 for operating one or more control surfaces 20 of the aircraft 10. In each of Figures 1 through 16, elements that serve similar or at least substantially similar purposes are numbered similarly, and in this document, such elements may not be described in detail with reference to each of Figures 1 through 16. Similarly, although not all elements are numbered in each of Figures 1 through 16, in this document, reference numbers associated with elements may be used consistently. Elements, components, and / or features described herein with reference to one or more of Figures 1 through 16 may be included in and / or utilized in any of Figures 1 through 16 without departing from the scope of the present disclosure. Generally, in the figures, elements that are likely to be included in a given example are shown in solid lines, while elements that are optional in a given example are shown in dashed lines. However, elements shown in solid lines are not necessarily essential to all examples of the present disclosure, and elements shown in solid lines may be omitted from a particular example without departing from the scope of the present disclosure.

[0011] FIG. 1 shows an example of an aircraft 10 that may include an aircraft hydraulic system 50 and / or a control surface actuator assembly 100 according to the present disclosure. As shown in FIG. 1, the aircraft 10 may include one or more engines 11, a fuselage 12, one or more wings 14, a horizontal stabilizer 16, and / or a vertical stabilizer 18. The aircraft 10 generally includes one or more control surfaces 20 that are movably attached (e.g., to the wings 14, the horizontal stabilizer 16, and / or the vertical stabilizer 18) to various parts of the aircraft 10. More specifically, each control surface 20 may be pivotally coupled to a corresponding support structure 40 (e.g., a component of the wing 14, the horizontal stabilizer 16, and / or the vertical stabilizer 18). Examples of control surfaces 20 include ailerons, rudders, elevators, flaps, spoilers, and air brakes. As further shown in FIG. 1 and described in detail herein, the aircraft 10 further includes at least one control surface actuator assembly 100 for selectively pivoting the corresponding control surface 20 relative to the corresponding support structure 40. In some examples, as described in detail herein, the aircraft 10 further includes an aircraft hydraulic system 50 for operating the control surface actuator assembly 100.

[0012] In general, in the present disclosure, the control surface actuator assembly 100 is described from the perspective of the aircraft hydraulic system 50 including the control surface actuator assembly 100, but this is not essential, and it is also included in the scope of the present disclosure that the control surface actuator assembly 100 and / or any of its components can be utilized in any suitable situation. As an example, the control surface actuator assembly 100 and / or its components can be implemented without limitation in any type of open-loop or closed-loop control system used in any of a variety of different applications in any industry. In this regard, the control surface actuator assembly 100 and / or its components according to the present disclosure can be implemented in any vehicle-oriented or non-vehicle-oriented application. As an example, the control surface actuator assembly 100 and / or its components can be in any application in the ocean, on the ground, in the air, and / or in space that utilizes an actuator to operate a movable device, and also in any vehicle-oriented or non-vehicle-oriented system, subsystem, assembly, subassembly, structure, building, machine, or application.

[0013] Figures 2 through 3 schematically illustrate an example of a control surface actuator assembly 100 according to the present disclosure. As schematically shown in Figures 2 through 3, the control surface actuator assembly 100 includes a support structure 40 and a control surface 20 operably coupled to the support structure 40 so as to pivot relative to the support structure 40 about a control surface pivot axis 22 (see Figure 3). As further schematically shown in Figures 2 through 3, the control surface actuator assembly 100 further includes a torque generating hydraulic actuator 2110 and a variable horn radius (VHR) hydraulic actuator 1110 pivotally coupled to the torque generating hydraulic actuator 2110. Specifically, as schematically shown in Figure 3, the VHR hydraulic actuator 1110 and the torque generating hydraulic actuator 2110 are configured to pivot relative to each other about an actuator coupling axis 28.

[0014] The torque generating hydraulic actuator 2110 and the VHR hydraulic actuator 1110 collectively operate to pivot the control surface 20 relative to the support structure 40. More specifically, as detailed herein, the torque generating hydraulic actuator 2110 is configured to apply torque to the control surface 20 via the VHR hydraulic actuator 1110 to pivot the control surface 20 relative to the support structure 40. In other words, at least a portion of the control surface 20 and the VHR hydraulic actuator 1110 are at least substantially interlocked to pivot about the control surface pivot axis 22, and the application of torque by the torque generating hydraulic actuator 2110 to the VHR hydraulic actuator 1110 acts to pivot the control surface 20 about the control surface pivot axis 22 such that the VHR hydraulic actuator 1110 is coupled to the control surface 20.

[0015] In this approach, the VHR hydraulic actuator 1110 can be described as representing a bell crank and / or control horn for pivoting the control surface 20 and / or operating as such a bell crank and / or control horn. However, in contrast to conventional control horn structures, as detailed herein, the VHR hydraulic actuator 1110 is configured to selectively transition between multiple configurations in order to selectively vary the lever arm that pivots the control surface 20. More specifically, referring to FIG. 3, the VHR hydraulic actuator 1110 is configured to selectively vary the actuator moment arm length 30 measured between the control surface pivot axis 22 and the actuator connection axis 28 to at least partially regulate the torque applied to the control surface 20 by the torque generating hydraulic actuator 2110. Specifically, for a given force applied to the VHR hydraulic actuator 1110 by the torque generating hydraulic actuator 2110, operating the VHR hydraulic actuator 1110 to shorten the actuator moment arm length 30 acts to reduce the torque applied to the control surface 20, while operating the VHR hydraulic actuator 1110 to lengthen the actuator moment arm length 30 acts to increase the torque applied to the control surface 20. In this approach, as described herein, the torque applied to the control surface 20 by the torque generating hydraulic actuator 2110 can be selectively and dynamically changed to adapt to the varying load demands generated by the control surface 20 without substantially reconfiguring the torque generating hydraulic actuator 2110 and / or aspects of the corresponding hydraulic system (e.g., the pressure of the hydraulic system).

[0016] Continuing to refer to FIGS. 2-3, the control surface actuator assembly 100 can be described from the perspective of the aircraft hydraulic system 50 and / or as a component of the aircraft hydraulic system 50. For example, as schematically shown in FIG. 1, an aircraft hydraulic system 50 according to the present disclosure for operating one or more control surfaces 20 includes a fluid reservoir 60 containing a fixed volume of hydraulic fluid 81, one or more hydraulic pumps 52, a plurality of hydraulic actuators 110, and a plurality of hydraulic conduits 80. As further schematically shown in FIG. 3, the aircraft hydraulic system 50 and / or the control surface actuator assembly 100 can further include a controller 90 for controlling the movement and pressure of the hydraulic fluid 81 through the aircraft hydraulic system 50.

[0017] As detailed herein, each hydraulic pump 52 is configured to apply pressure to hydraulic fluid 81 for operational use by a plurality of hydraulic actuators 110, and each hydraulic conduit 80 is configured to convey hydraulic fluid 81 between components of the aircraft hydraulic system 50. Each hydraulic pump 52 may be configured to apply pressure to the hydraulic fluid 81 to any suitable pressure. In some examples, as schematically shown in FIG. 2 and detailed herein, at least one hydraulic pump 52 is a central pump 54 configured to apply pressure to the hydraulic fluid 81 to a reference pressure, and at least one other hydraulic pump 52 is a boost pump 56 configured to apply pressure to the hydraulic fluid 81 to a boost pressure above the reference pressure. In some examples, additionally or alternatively, the reference pressure may be referred to as a static pressure, while the boost pressure may be referred to as a variable pressure. As used herein, the pressure of the hydraulic fluid 81 generated by the central pump 54 and / or the boost pump 56 may be described as the operating pressure of the aircraft hydraulic system 50 and / or its components (e.g., hydraulic actuator 110). The reference pressure and the boost pressure may each have any suitable value. By way of example, the reference pressure and / or the boost pressure may each be at least 800 pounds per square inch (psi), at least 1000 psi, at least 1300 psi, at least 1500 psi, at least 2000 psi, at least 2500 psi, at least 3000 psi, at least 5000 psi, at least 10000 psi, up to 12000 psi, up to 7000 psi, up to 2700 psi, up to 2200 psi, up to 1700 psi, up to 1200 psi, and / or up to 900 psi. As a more specific example, the reference pressure generated by the central pump 54 may be about 1200 psi, and the boost pressure generated by the boost pump 56 may be about 3000 psi. The central pump 54 and / or the boost pump 56 may include any suitable hydraulic pump (e.g., an engine-driven hydraulic pump and / or an electric motor-driven hydraulic pump), and / or may be any such suitable hydraulic pump.

[0018] FIG. 2 schematically illustrates aircraft hydraulic system 50 as including a single central pump 54 and a single boost pump 56, although it is within the scope of the present disclosure for aircraft hydraulic system 50 to include more than one central pump 54 and / or more than one boost pump 56. In some examples, aircraft 10 and / or aircraft hydraulic system 50 includes an equal number of boost pumps 56 as the number of hydraulic actuators 110 dealing with a common load and / or as the number of hydraulic actuators 110 used in aircraft hydraulic system 50.

[0019] As further schematically shown in FIG. 2, the plurality of hydraulic conduits 80 can include one or more supply conduits 82 configured to convey hydraulic fluid 81 at a reference pressure, one or more boost conduits 84 configured to convey hydraulic fluid 81 at a boosted pressure, and / or one or more return conduits 86 configured to convey hydraulic fluid 81 at a pressure below the reference pressure. Return conduit 86 can convey hydraulic fluid 81 to fluid reservoir 60, where hydraulic fluid 81 can be stored and cooled before being resupplied to hydraulic pump 52. If the amount of hydraulic fluid 81 available for use in boost pump 56 becomes insufficient, the returning hydraulic fluid 81 can be supplied to boost pump 56 before moving to fluid reservoir 60 along return conduit 86. In some examples, as further schematically shown in FIG. 2, aircraft hydraulic system 50 further includes one or more accumulators 70 for maintaining the pressure of hydraulic fluid 81 within hydraulic conduit 80. As schematically shown in FIG. 2, accumulator 70 can be connected to supply conduit 82 downstream of central pump 54 and / or can be connected to return conduit 86 upstream of fluid reservoir 60 to supply additional hydraulic fluid 81 for use in aircraft hydraulic system 50. Accumulator 70 can supply hydraulic fluid 81 in certain situations (such as, but not limited to, when the volume of hydraulic fluid 81 moving along supply conduit 82 drops below a predetermined level or when the pressure of hydraulic fluid 81 within supply conduit 82 falls below a predetermined level).

[0020] The boost pump 56, if present, is positioned remotely along the aircraft hydraulic system 50 from the central pump 54. This distributed architecture may be for improving responsiveness when hydraulic fluid 81 at boost pressure can be supplied to the hydraulic actuator 110 in a short time. The distributed architecture also enables the hydraulic fluid 81 from the hydraulic actuator 110 to be diverted around a portion of the return line 86 and directed to the boost pump 56. This feature reduces the energy loss due to the pressure drop in the return line 86 that routes the hydraulic fluid 81 back to the central pump 54, thereby reducing the peak power demand.

[0021] Typically, each hydraulic pump 52 (e.g., the central pump 54 and / or the boost pump 56) can be configured to apply pressure to the hydraulic fluid 81 up to a variable pressure. In this manner, an example of an aircraft hydraulic system 50 that includes the central pump 54 but not the boost pump 56 can potentially satisfy the varying operating demands of each hydraulic actuator 110 through changes in the operating pressure. For example, such an aircraft hydraulic system 50 can generate a pressure of the hydraulic fluid 81 that varies according to the flight phase (e.g., takeoff phase, cruise phase, or landing phase) in which the aircraft 10 operates. However, in an example where the aircraft hydraulic system 50 does not have a boost pump 56, the central pump 54 generally needs to operate at a pressure high enough to be suitable for the pressure requirements of a single hydraulic actuator 110 that experiences the maximum aerodynamic load among a plurality of hydraulic actuators 110 at a given point in time. In contrast, as described herein, by utilizing the central pump 54 in combination with one or more boost pumps 56 (e.g., up to a number equal to the number of sets of hydraulic actuators 110 that handle a common load and / or the number of hydraulic actuators 110 used in the hydraulic system and including such number), it can be possible to selectively vary the operating pressure of each of the plurality of hydraulic actuators 110 at a given point in time. By utilizing such techniques (e.g., variable pressure and / or distributed architecture that utilizes the boost pump 56) in combination with the VHR hydraulic actuator 1110, the peak power demand of the aircraft hydraulic system 50 can be further limited. More specifically, in such an example, each of the VHR hydraulic actuators 1110 can be utilized to set the corresponding actuator moment arm length 30 to a value that enables the corresponding torque-generating hydraulic actuator 2110 to operate at a pressure of the hydraulic fluid 81 that is at least substantially equal to the pressure of the hydraulic fluid 81 that is sent by a given boost pump 56 to one or more other hydraulic actuators 110. In this manner, such a configuration can facilitate a reduction in pressure loss by metering the flow in one or more hydraulic actuators 110.This minimizes the peak power demand, along with the number of boost pumps 56 in the aircraft hydraulic system 50, while simultaneously meeting the dynamic (and dynamically varying) requirements of the corresponding control surfaces 20. Additionally, as described herein, by utilizing the VHR hydraulic actuator 1110 in combination with technologies such as, for example, variable pressure and / or distributed architectures, it may be facilitated and / or such reduction may result in a reduction in the peak power demand of one or more hydraulic actuators 110 (such as torque generating hydraulic actuator 2110). This relaxes the overall sizing constraints on the aircraft hydraulic system 50.

[0022] The aircraft 10 may include a plurality of aircraft hydraulic systems 50 to control the movement of the control surfaces 20. For example, the aircraft 10 may include a first aircraft hydraulic system 50 that extends along a first portion of the aircraft (such as the starboard side). The first aircraft hydraulic system 50 includes a central pump 54 driven by a first engine 11 (such as the starboard engine 11). A second aircraft hydraulic system 50 may be positioned on a second portion of the aircraft (such as the port side) and include a separate central pump 54 driven by a separate engine 11 (such as the port engine 11). The number of engines 11 and / or the number of aircraft hydraulic systems 50 in the aircraft 10 may vary. By way of example, the aircraft 10 may include one engine 11, two engines 11, three engines 11, four engines 11, or more than four engines 11. Further, each engine 11 may drive any suitable number of central pumps 54. For example, the aircraft 10 may include four main engines 11, namely, two left main engines 11 and two right main engines 11. In some examples, each of the main engines 11 drives two central pumps 54 respectively. In such some examples, the aircraft 10 includes two aircraft hydraulic systems 50 such that four central pumps 54 associated with the left main engine 11 generate hydraulic power for the left aircraft hydraulic system 50 and four central pumps 54 associated with the right main engine 11 generate hydraulic power for the right aircraft hydraulic system 50.

[0023] As schematically shown in FIGS. 2 to 3, in an example where the aircraft hydraulic system 50 includes the control surface actuator assembly 100, at least one of the plurality of hydraulic actuators 110 is the torque generating hydraulic actuator 2110, and at least one other of the plurality of hydraulic actuators 110 is the VHR hydraulic actuator 1110. Each of the VHR hydraulic actuator 1110 and the torque generating hydraulic actuator 2110 can have any suitable configuration (which may be known in the technical field of hydraulic actuators, for example). For example, as schematically shown in FIGS. 2 to 3, each of the VHR hydraulic actuator 1110 and the torque generating hydraulic actuator 2110 includes a corresponding hydraulic actuator housing 120 (such as a hydraulic cylinder) and a corresponding rod 140 that at least partially extends within the corresponding hydraulic actuator housing 120. The corresponding rod 140 is configured to translate axially parallel to the corresponding hydraulic actuator housing 120 along the corresponding actuator shaft 122 (see FIG. 3). In this way, each of the VHR hydraulic actuator 1110 and the torque generating hydraulic actuator 2110 can be described as including a hydraulic linear actuator that utilizes a hydraulic cylinder.

[0024] Each of the VHR hydraulic actuator 1110 and the torque generating hydraulic actuator 2110 further includes a corresponding hydraulic valve 200 that regulates the flow of hydraulic fluid 81 to the corresponding hydraulic actuator housing 120 to control the position of the corresponding rod 140 relative to the corresponding hydraulic actuator housing 120. Referring to FIG. 3, it can be described that the actuator shaft 122 corresponding to the VHR hydraulic actuator 1110 is the VHR actuator shaft 1122, and the actuator shaft 122 corresponding to the torque generating hydraulic actuator 2110 is the torque generating actuator shaft 2122. In this way, it can be described that the VHR hydraulic actuator 1110 is configured to selectively translate the corresponding rod 140 of the VHR hydraulic actuator 1110 along the VHR actuator shaft 1122 to change the actuator moment arm length 30.

[0025] During the operational use of the control surface actuator assembly 100, the VHR hydraulic actuator 1110 and the torque generating hydraulic actuator 2110 can have any suitable relative orientation and / or range of motion. For example, as shown in FIG. 3, the configuration of the control surface actuator assembly 100 can be characterized by a control surface torque angle 26 measured between the torque generating actuator axis 2122 and the VHR actuator axis 1122. The control surface torque angle 26 generally has a value greater than 0 degrees and less than 180 degrees, and can have any suitable value during the operational use of the control surface actuator assembly 100. As a more specific example, during the operational use of the control surface actuator assembly 100, the control surface torque angle 26 can be at least 30 degrees, at least 50 degrees, at least 70 degrees, at least 90 degrees, at least 110 degrees, at least 130 degrees, at least 150 degrees, up to 160 degrees, up to 140 degrees, up to 120 degrees, up to 100 degrees, up to 80 degrees, up to 60 degrees, and / or up to 40 degrees.

[0026] As another example, as further schematically shown in FIG. 3, the configuration of the control surface actuator assembly 100 can be characterized by a control surface deflection angle 24 of the control surface 20 with respect to the support structure 40, measured in a plane perpendicular to the control surface pivot axis 22. As a more specific example, the control surface actuator assembly 100 can be configured to selectively vary the control surface deflection angle 24 over a range of motion angles that are at least 5 degrees, at least 10 degrees, at least 20 degrees, at least 40 degrees, at least 60 degrees, at least 80 degrees, up to 90 degrees, up to 70 degrees, up to 50 degrees, up to 30 degrees, up to 15 degrees, and / or up to 7 degrees.

[0027] As yet another example, the control surface actuator assembly 100 can be characterized in terms of the axial range of motion of the VHR hydraulic actuator 1110. Specifically, the VHR hydraulic actuator 1110 can be described as varying the actuator moment arm length 30 within a range of values defined between a minimum actuator moment arm length 30 and a maximum actuator moment arm length 30, and including the minimum actuator moment arm length 30 and the maximum actuator moment arm length 30. As a more specific example, the VHR hydraulic actuator 1110 can be configured such that the maximum actuator moment arm length 30 is at least 1.1 times the minimum actuator moment arm length 30, at least 1.3 times the minimum actuator moment arm length 30, at least 1.5 times the minimum actuator moment arm length 30, at least 2 times the minimum actuator moment arm length 30, at least 2.5 times the minimum actuator moment arm length 30, up to 3 times the minimum actuator moment arm length 30, up to 2.2 times the minimum actuator moment arm length 30, up to 1.7 times the minimum actuator moment arm length 30, and / or up to 1.2 times the minimum actuator moment arm length 30.

[0028] In some examples, as shown in FIG. 3, the hydraulic actuator housing 120 of the torque generating hydraulic actuator 2110 is pivotally coupled to the support structure 40, and the rod 140 of the torque generating hydraulic actuator 2110 is pivotally coupled to the VHR hydraulic actuator 1110. However, this is not essential in all examples of the control surface actuator assembly 100, and the torque generating hydraulic actuator 2110 can be configured such that the corresponding hydraulic actuator housing 120 is pivotally coupled to the VHR hydraulic actuator 1110 and the corresponding rod 140 is pivotally coupled to the support structure 40, which is also within the scope of the present disclosure.

[0029] In some examples, as shown in FIG. 3, the hydraulic actuator housing 120 of the VHR hydraulic actuator 1110 is pivotally connected to the torque generating hydraulic actuator 2110, and the rod 140 of the VHR hydraulic actuator 1110 is pivotally connected to the control surface 20. However, this is not essential in all examples of the control surface actuator assembly 100, and the VHR hydraulic actuator 1110 may be configured such that the corresponding hydraulic actuator housing 120 is operably connected to the control surface 20 and the corresponding rod 140 is pivotally connected to the torque generating hydraulic actuator 2110, which is also within the scope of the present disclosure.

[0030] As described, each of the hydraulic actuators 110 (e.g., VHR hydraulic actuator 1110 and / or torque generating hydraulic actuator 2110) can include any suitable structure (e.g., the structure of a conventional hydraulic cylinder). In some examples, as schematically shown in FIGS. 2 through 3, each of the VHR hydraulic actuator 1110 and the torque generating hydraulic actuator 2110 includes a corresponding piston 142, and the corresponding piston 142 extends into the corresponding hydraulic actuator housing 120 and defines a corresponding first chamber 124 and a corresponding second chamber 128 on both sides of the piston 142 within the hydraulic actuator housing 120. In such examples, each rod 140 extends from the corresponding piston 142 and extends out of the corresponding hydraulic actuator housing 120. Thus, in such examples, the hydraulic pressure difference of the hydraulic fluid 81 in each of the corresponding first chamber 124 and the corresponding second chamber 128 acts to move the corresponding piston 142 within the corresponding hydraulic actuator housing 120 and translate the corresponding rod 140 along the corresponding actuator shaft 122. In such examples, as further schematically shown in FIG. 3, each of the hydraulic actuator housings 120 includes a corresponding first chamber port 126 for allowing the hydraulic fluid 81 to flow into and out of the corresponding first chamber 124, and a corresponding second chamber port 130 for allowing the hydraulic fluid 81 to flow into and out of the corresponding second chamber 128. In some examples, as shown in FIG. 3, the torque generating hydraulic actuator 2110 and / or the VHR hydraulic actuator 1110 further includes a support rod 141 (shown in FIG. 3 as a component of the VHR hydraulic actuator 1110), and the support rod 141 extends from the corresponding piston 142 to the opposite side of the corresponding rod 140 and is operably connected to the corresponding hydraulic actuator housing 120. In such examples, the support rod 141 can act to strengthen the rigidity of the corresponding hydraulic actuator 110.

[0031] In some examples, the respective corresponding pistons 142 of the torque generating hydraulic actuator 2110 and the VHR hydraulic actuator 1110 can be characterized by the surface area thereof facing each of the corresponding first chamber 124 and the corresponding second chamber 128. As an example, as shown in FIG. 3, the respective corresponding pistons 142 of the torque generating hydraulic actuator 2110 and the VHR hydraulic actuator 1110 can be described as including a corresponding first piston surface 144 having a corresponding first piston surface area that partially defines the corresponding first chamber 124, and a corresponding second piston surface 146 having a corresponding second piston surface area that partially defines the corresponding second chamber 128. In such an example, the corresponding first piston surface area and the corresponding second piston surface area of one or both of the VHR hydraulic actuator 1110 and the torque generating hydraulic actuator 2110 may or may not be at least substantially equal. In some examples, the first piston surface area and / or the second piston surface area are at least partially defined by the respective dimensions of the corresponding rod 140 and / or the corresponding support rod 141 (if any). As an example, FIG. 3 shows a configuration in which the VHR hydraulic actuator 1110 includes a rod 140 extending from the first piston surface 144 within the first chamber 124 and a support rod 141 extending from the second piston surface 146 within the second chamber 128. In the example of FIG. 3, since the rod 140 has a diameter larger than the diameter of the support rod 141, the second piston surface area is larger than the first piston surface area. Thus, in such an example, the total force exerted by the hydraulic fluid 81 at a given pressure within the first chamber 124 on the piston 142 is smaller compared to the hydraulic fluid 81 at the same given pressure within the second chamber 128.

[0032] In some examples, the operation of the control surface actuator assembly 100 includes, for example, using the VHR hydraulic actuator 1110 to reduce the torque applied to the control surface 20 at a given operating pressure of the torque generating hydraulic actuator 2110 (and thus the given force applied to the VHR hydraulic actuator 1110 by the rod 140 of the torque generating hydraulic actuator 2110), in order to reduce the actuator moment arm length 30. However, in some cases, reducing the actuator moment arm length 30 can introduce an undesirably high flutter sensitivity or flutter response into the control surface 20 during flight. In other words, the control surface 20 may be characterized by resonance conditions under which flutter can occur, and reducing the actuator moment arm length 30 can overlap the operating bandwidth of the control surface actuator assembly 100 with such resonance conditions. In such examples, the flutter of the control surface 20 can be reduced and / or minimized by utilizing a mechanism for damping the vibration of the control surface 20. Thus, in some examples, as further schematically shown in FIGS. 2-3, the control surface actuator assembly 100 further includes one or more inertias 300 for damping the movement of one or more components of the control surface actuator assembly 100. More specifically, as schematically shown in FIGS. 2-3, each inertia 300 includes a corresponding first terminal 302 and a corresponding second terminal 304, and the corresponding first terminal 302 and the corresponding second terminal 304 are configured to translate parallel to each other along a corresponding inertia axis 306 (see FIG. 3), and each inertia 300 is configured to resist the acceleration of the corresponding first terminal 302 relative to the corresponding second terminal 304. Thus, in such examples, the inertia 300 can act to provide damping of the vibration of the control surface 20, and thus an expansion of the actual operating bandwidth of the control surface actuator assembly 100, which is important because it includes a smaller value of the actuator moment arm length 30 and reduces the peak power demand of the aircraft hydraulic system 50.

[0033] As schematically shown in FIG. 2, the inertor 300 may be a component of the hydraulic actuator 110 and / or may be incorporated into the hydraulic actuator 110 (e.g., into the corresponding hydraulic actuator housing 120 of the torque generating hydraulic actuator 2110 and / or the VHR hydraulic actuator 1110), and / or may be a separate unit. Specifically, FIG. 2 schematically shows, with a dashed line, an example in which the torque generating hydraulic actuator 2110 includes the inertor 300, and an example in which the inertor 300 is positioned in parallel with the hydraulic actuator housing 120 of the torque generating hydraulic actuator 2110. FIG. 3 shows more specifically an example in which the torque generating hydraulic actuator 2110 includes the inertor 300. FIG. 4 is a more specific diagram of an example of the inertor 300 incorporated into the hydraulic actuator housing 120 of an example of the hydraulic actuator 110, while FIG. 5 is a more specific diagram of a part of another example of the inertor 300. As schematically shown from FIG. 2 to FIG. 3 and more specifically shown from FIG. 4 to FIG. 5, each inertor 300 may include a corresponding inertor housing 301 (see FIGS. 2 to 4), a corresponding threaded shaft 322 that is connected to a corresponding first terminal portion 302 and terminates at a corresponding shaft free end portion 324 (numbered in FIGS. 3 to 4), and a corresponding inertor rod 308 that is connected to a corresponding second terminal portion 304. In this manner, the inertor rod 308 and the second terminal portion 304 are configured to move in parallel with respect to the first terminal portion 302 along the corresponding inertor shaft 306 in an interlocking manner. Each of the inertor rod 308 and the threaded shaft 322 extends at least partially into the corresponding inertor housing 301.

[0034] The inertia rod 308 and the threaded shaft 322 can have any suitable respective configuration and / or relative configuration. In some examples, as shown in FIGS. 3 to 4, the inertia rod 308 and / or the threaded shaft 322 extend at least substantially parallel to the inertia axis 306. In some examples, as shown in FIGS. 3 to 5, the inertia rod 308 is hollow and defines an inertia rod hole 310. In such some examples, as further shown in FIGS. 3 to 5, the shaft free end 324 (numbered in FIGS. 3 to 4) of the threaded shaft 322 is received within the inertia rod hole 310. Additionally or alternatively, as shown in FIG. 5, the threaded shaft 322 may be hollow and may define a corresponding shaft hole 323 that opens to the shaft free end 324 (not visible in FIG. 5). In such some examples, as shown in FIG. 5, the threaded shaft 322 is one or more radial passages 325 that extend radially from the shaft hole 323 to the outer surface of the threaded shaft 322 to allow fluid (e.g., hydraulic fluid 81) to flow between the shaft hole 323 and the outer surface of the threaded shaft 322. In an example where the inertia 300 is incorporated into the hydraulic actuator 110, such a configuration may be advantageous.

[0035] Each inertial 300 can be configured to resist relative acceleration between a corresponding first terminal portion 302 and a corresponding second terminal portion 304 in any suitable manner. In some examples, as shown in FIGS. 2 to 5, each inertial 300 is a corresponding flywheel 314 having a corresponding flywheel ring 318 (see FIGS. 4 to 5) connected to one or both of a corresponding inertial rod 308 and a corresponding threaded shaft 322. In such examples, the flywheel 314 is configured to rotate relative to the threaded shaft 322 at a rotational speed proportional to the linear speed at which the corresponding inertial rod 308 translates parallel to the corresponding threaded shaft 322. More specifically, as most clearly visible in FIG. 5, the flywheel 314 can be threadedly coupled to the threaded shaft 322 such that a force is applied to the flywheel 314 to rotate relative to the threaded shaft 322 by translating the flywheel 314 (and / or vice versa) parallel to the threaded shaft 322 along the inertial axis 306. In this manner, in such examples, the rotational inertia of the flywheel 314 acts to resist angular acceleration of the flywheel 314, and thus the linear acceleration of the threaded shaft 322 (and the first terminal portion 302) relative to the inertial rod 308 (and the second terminal portion 304) is resisted.

[0036] The flywheel 314 can be operably coupled to one or more other components of the inertial 300 in any suitable manner. By way of example, the flywheel ring 318 can be operably coupled to the inertial rod 308, to the threaded shaft 322, and / or to the inertial housing 301. Additionally or alternatively, as shown in FIGS. 4 to 5, the flywheel 314 can include a flywheel bearing 328 at the flywheel ring 318 to rotatably couple the flywheel 314 to at least one other component of the inertial 300. In some such examples, the flywheel bearing 328 is configured to allow the flywheel 314 to translate axially in parallel with the inertial rod 308 as the flywheel 314 rotates relative to the threaded shaft 322.

[0037] As described, one or both of the torque generating hydraulic actuator 2110 and the VHR hydraulic actuator 1110 may include a corresponding inerter 300. In such an example, as shown in FIGS. 3 to 4, the corresponding hydraulic actuator housing 120 of the torque generating hydraulic actuator 2110 and / or the VHR hydraulic actuator 1110 may include the inerter housing 301 of the corresponding inerter 300 and / or may be such an inerter housing 301. Similarly, in such an example, as shown in FIGS. 3 to 4, the corresponding rod 140 of the torque generating hydraulic actuator 2110 and / or the VHR hydraulic actuator 1110 may include the inerter rod 308 of the corresponding inerter 300 and / or may be such an inerter rod 308. In some such examples, as shown in FIG. 4, the flywheel 314 of the corresponding inerter 300 is rotatably coupled to the corresponding piston 142 of the torque generating hydraulic actuator 2110 and / or the VHR hydraulic actuator 1110, for example via the flywheel bearing 328 of the corresponding flywheel 314.

[0038] FIG. 6 shows another inertia 300 that includes a dual rack - pinion structure having a circular pinion that engages two linear gear racks. The rotational motion applied to the pinion moves the racks relative to each other and relative to the pinion, and thus converts the rotational motion of the pinion into linear motion. Specifically, in the example of FIG. 6, the inertia 300 includes a flexible retaining structure 330 and a dual rack - pinion assembly 332 that is held or clamped between the flexible retaining structures 330 by the flexible retaining structure 330. The dual rack - pinion assembly 332 includes dual racks 334 that are positioned to face each other, and the dual racks 334 are at least substantially housed within the flexible retaining structure 330 and are held or clamped by the flexible retaining structure 330. These racks 334 include a first rack 334 and a second rack 334, each having a plurality of teeth. The dual rack - pinion assembly 332 also includes a pinion 336, in the form of, for example, a pinion gear, that engages the first and second racks between the first rack 334 and the second rack 334. The pinion 336 has a plurality of gear teeth configured to engage the teeth of the first and second racks 334. In some examples, the first terminal portion 302 of the inertia 300 is connected to the first rack 334, and the second terminal portion 304 of the inertia 300 is connected to the second rack 334.

[0039] An example of an inerter 300 that includes a dual rack and pinion assembly 332 further includes a pair of inertia wheels 340. Each inertia wheel 340 is positioned adjacent to both outer surfaces of the flexible retaining structure 330. A mandrel element 342 extends through the first inertia wheel 340, the flexible retaining structure 330, the pinion 336, and the second inertia wheel 340. In such an example, the movement of the first terminal 302 relative to the second terminal 304 (e.g., due to the relative movement of the control surface 20, the VHR hydraulic actuator 1110, the torque generating hydraulic actuator 2110, and / or the support structure 40) causes a translation of the first rack 334 relative to the second rack 334 along the inerter axis 306, and in turn, causes a rotational movement of the pinion 336 and the pair of inertia wheels 340. Thereby, the rotational movement of the pinion 336 is resisted by the pair of inertia wheels 340, and no incidental motion occurs. This results in damping of the movement of the control surface 20 by the dual rack and pinion assembly 332.

[0040] As the movement of the pinion 336 is resisted by the inertia wheel 340, a resistance force against the rotation of the first terminal 302 connected to the control surface 20 is induced, so that the change in the orientation of the rack 334 is only related to the inerter axis 306. This resistance force is resisted by the inertia wheel 340. By damping the movement of the control surface 20, an improvement in flutter suppression is brought about, and in turn, an improvement in the stability of hydraulic application and an improvement in the efficiency of activation of flight control by the control surface actuator assembly 100 may be brought about.

[0041] Further examples of inerters 300 and / or their features and components that may be used in conjunction with the control surface actuator assembly 100 according to the present disclosure are disclosed in U.S. Patent No. 10,088,006, U.S. Patent Application Publication No. 2019 / 0048959, U.S. Patent No. 10,107,347, and U.S. Patent No. 10,352,389, the entire disclosures of which are incorporated herein by reference for all purposes.

[0042] As described, each of the hydraulic actuators 110 (e.g., VHR hydraulic actuator 1110 and / or torque generating hydraulic actuator 2110) acts to regulate the movement of the corresponding piston 142 and the corresponding rod 140 relative to the corresponding hydraulic actuator housing 120 by causing hydraulic fluid 81 to flow into the corresponding first chamber 124 and the corresponding second chamber 128 and out of the corresponding first chamber 124 and the corresponding second chamber 128, by utilizing the corresponding hydraulic valve 200. Each hydraulic valve 200 can have any suitable structure and / or function (e.g., known in the art of hydraulic systems). FIGS. 2 through 3 schematically show an example of the hydraulic valve 200, while FIGS. 7 through 9 present a more detailed schematic of the hydraulic valve 200.

[0043] In some examples, as schematically shown in FIGS. 2 through 3 and FIGS. 7 through 9, the corresponding hydraulic valve 200 of the torque generating hydraulic actuator 2110 and / or the VHR hydraulic actuator 1110 includes a fluid input 242 configured to receive a high pressure hydraulic fluid flow and a fluid return 246 configured to discharge a low pressure hydraulic fluid flow. The hydraulic valve 200 further includes a first outlet 250 fluidly connected to the first chamber 124 of the corresponding hydraulic actuator housing 120 and a second outlet 252 fluidly connected to the second chamber 128 of the corresponding hydraulic actuator housing 120.

[0044] In one example, as shown in FIGS. 7-9, the hydraulic valve 200 includes a spool manifold 204 that is selectively fluidly connected to two or more of a fluid input 242, a fluid return 246, a first outlet 250, and a second outlet 252, and a spool 210 that is at least substantially positioned within the spool manifold 204. In such an example, the spool 210 includes a spool shaft 212 and one or more spool blocks 214 attached to the spool shaft 212, and further includes a spool actuator 216 configured to selectively translate the spool 210 parallel to the spool manifold 204. More specifically, in such an example, selectively translating the spool 210 parallel to the spool manifold 204 serves to selectively and mutually fluidly connect the fluid input 242, the fluid return 246, the first outlet 250, and the second outlet 252, and to regulate the flow of hydraulic fluid 81 between the fluid input 242, the fluid return 246, the first outlet 250, and the second outlet 252. In this manner, translating the spool 210 parallel to the spool manifold 204 serves to vary the pressures of the hydraulic fluid 81 in the first chamber 124 and the second chamber 128, respectively, and to selectively translate the piston 142 and the rod 140 within the hydraulic actuator housing 120.

[0045] The spool actuator 216 can be configured to selectively translate the spool 210 relative to the spool manifold 204 in any suitable manner. For example, in some examples, as shown in FIGS. 7 through 9, the spool actuator 216 includes and / or is a solenoid 218 that is selectively energized to selectively translate the spool 210. In some examples, the solenoid 218 is controlled by the controller 90 and is for positioning the spool 210 within the spool manifold 204. Additionally or alternatively, the hydraulic valve 200 may include and / or be a servo valve that includes a servo feedback system 230. In some such examples, as shown in FIGS. 7 through 9, the control surface actuator assembly 100 and / or the hydraulic valve 200 includes a piston position sensor 148 configured to generate a piston position measurement representative of the position of the piston 142 relative to the hydraulic actuator housing 120. In such examples, the hydraulic valve 200 is configured to regulate the flow of hydraulic fluid 81 based at least in part on the piston position measurement, for example, by control of the solenoid 218 via the servo feedback system 230.

[0046] The hydraulic valve 200 can have any suitable configuration and / or functionality (which may be known in the field of hydraulic systems, for example). For example, FIG. 7 shows an example where the hydraulic valve 200 is a 4-way 3-position hydraulic valve 200 having a single spool 210. However, this is not essential, and it is also within the scope of the present disclosure that the hydraulic valve 200 is a dual spool hydraulic valve 202 including two individual spools 210. In some examples, as detailed herein, the dual spool hydraulic valve 202 further includes a fluid boost input portion 244 configured to receive the flow of the boosted pressure hydraulic fluid 81. As detailed herein, by utilizing the dual spool hydraulic valve 202, energy regeneration within the hydraulic valve 200 may be possible in certain operating situations. This reduces the peak power demand of the aircraft hydraulic system 50 compared to an example where each hydraulic valve 200 includes only a single spool 210.

[0047] Figures 8 through 9 illustrate an example of the dual spool hydraulic valve 202. As shown in Figures 8 through 9, in the example where the hydraulic valve 200 is the dual spool hydraulic valve 202, the spool manifold 204 is the first spool manifold 204, and the spool 210 of the dual spool hydraulic valve 202 is the first spool 210 having the first spool shaft 212 and one or more first spool blocks 214, and the spool actuator 216 is the first spool actuator 216 configured to selectively translate the first spool 210 relative to the first spool manifold 204. In contrast to the single spool hydraulic valve 200, as shown in Figures 8 through 9, the dual spool hydraulic valve 202 further includes a second spool manifold 206 and a second spool 220 positioned at least substantially within the second spool manifold 206. In such an example, the second spool 220 includes the second spool shaft 222 and one or more second spool blocks 224 attached to the second spool shaft 222, and the dual spool hydraulic valve 202 further includes a second spool actuator 226 configured to selectively translate the second spool 220 relative to the second spool manifold 206 independently of the first spool 210. That is, each of the first spool 210 and the second spool 220 is controllable individually and can be positioned regardless of the position of the other spool. In such an example, the dual spool hydraulic valve 202 is configured to act to regulate the flow of the hydraulic fluid 81 between the fluid input 242, the fluid return 246, the first outlet 250, and the second outlet 252 such that translating each of the first spool 210 and the second spool 220 changes the pressure of the hydraulic fluid 81 in the first chamber 124 and the second chamber 128 of the hydraulic actuator housing 120 respectively to selectively translate the piston 142 and the rod 140 within the hydraulic actuator housing 120. The first spool 210 and the second spool 220 may include the same or different shapes and / or sizes. In some examples, the first spool 210 and the second spool 220 have at least substantially the same shape and size.

[0048] Each of the first spool manifold 204 and the second spool manifold 206 can be selectively fluidly connected to two or more of a fluid input portion 242, a fluid boost input portion 244, a fluid return portion 246, a first outlet 250, and a second outlet 252. Specifically, each of the first spool manifold 204 and the second spool manifold 206 can be described as "selectively" fluidly connecting two or more components when the corresponding first spool 210 or the corresponding second spool 220 is positioned so as not to restrict such fluid connection. As an example, FIGS. 8 to 9 show an example in which the first spool manifold 204 is selectively fluidly connected to the first chamber 124 via the first outlet 250, and the second spool manifold 206 is selectively fluidly connected to the second chamber 128 via the second outlet 252. In addition, FIG. 8 shows an example in which each of the first spool manifold 204 and the second spool manifold 206 is fluidly connected to each of the fluid input portion 242 and the fluid return portion 246, while FIG. 9 shows an example in which each of the first spool manifold 204 and the second spool manifold 206 is fluidly connected to each of the boost input portion 244 and the fluid return portion 246.

[0049] In some examples, the dual spool hydraulic valve 202 is configured such that even if the first spool actuator 216 or the second spool actuator 226 becomes inoperative, the dual spool hydraulic valve 202 continues to function to operably translate the corresponding rod 140 relative to the corresponding hydraulic actuator housing 120. In this way, by using the dual spool hydraulic valve 202, a level of redundancy is provided that can increase the overall reliability and / or robustness of the dual spool hydraulic valve 202 and / or the control surface actuator assembly 100.

[0050] As described and as shown in FIGS. 8 to 9, the dual spool hydraulic valve 202 is configured to selectively enable fluid communication between the fluid input portion 242 and one of the first outlet 250 and the second outlet 252, and to enable fluid communication between the fluid return portion 246 and the other of the first outlet 250 and the second outlet 252. However, in contrast to the single spool hydraulic valve 200, some examples of the dual spool hydraulic valve 202 are configured to selectively enable fluid communication between the first outlet 250 and the second outlet 252, as detailed below.

[0051] As described, a portion of the example aircraft hydraulic system 50 includes a boost pump 56 configured to apply pressure to hydraulic fluid 81 up to a boosted pressure that exceeds the reference pressure provided by the central pump 54. In some such examples, as schematically shown in FIGS. 2-3 and more specifically shown in FIG. 9, the dual spool hydraulic valve 202 further includes a fluid boost input 244 configured to receive the flow of hydraulic fluid 81 at the boosted pressure. In some such examples, as schematically shown in FIG. 2, the boost pump 56 supplies a flow of hydraulic fluid to the fluid boost input 244 while the central pump 54 supplies a flow of hydraulic fluid to the fluid input 242. In some examples, as further shown in FIGS. 3 and 9, the hydraulic actuator 110 and / or the hydraulic actuator housing 120 includes a pressure sensor 160 positioned within the first chamber 124 and / or the second chamber 128, each configured to generate a pressure signal indicative of the pressure of the hydraulic fluid 81 within the corresponding chamber of the hydraulic actuator housing 120. Each pressure sensor 160 may include any suitable sensor (such as a pressure transducer) and / or may be any such suitable sensor. In such examples, the dual spool hydraulic valve 202 is configured to selectively fluidly connect the fluid boost input 244 to the first outlet 250 and / or the second outlet 252, at least in part based on the pressure signal. In some such examples, as shown in FIG. 9, one or both of the first spool shaft 212 and the second spool shaft 222 define a shaft opening 213 through which the hydraulic fluid 81 can flow. Specifically, in such examples, each shaft opening 213 can enable a direct fluid connection between the fluid input 242 and the first chamber 124 or the second chamber 128 if the corresponding spool shaft is appropriately positioned.

[0052] FIG. 10 shows a diagram of the forces acting on piston 142 that is operably and / or dynamically coupled to control surface 20 and affects the required movement of hydraulic fluid 81 through aircraft hydraulic system 50. Specifically, in FIG. 10, the first axis (i.e., the x-axis) represents the rate of movement of piston 142 and thus of control surface 20. As shown in FIG. 10, this rate can be either positive (e.g., when piston 142 and / or control surface 20 moves in a first direction) or negative (e.g., when piston 142 and / or control surface 20 moves in a second direction opposite to the first direction). The second axis (i.e., the y-axis) represents the load applied to piston 142 through control surface 20. As shown in FIG. 10, this load can be either positive (e.g., when applied in a first direction to piston 142 and / or control surface 20) or negative (e.g., when applied in a second direction opposite to the first direction to piston 142 and / or control surface 20). The diagram of FIG. 10 includes four quadrants numbered Q1, Q2, Q3, and Q4, corresponding to four combinations of the directionality of speed and load.

[0053] FIG. 11 shows an example of a hydraulic actuator 110 having a dual spool hydraulic valve 202, showing an example within the first quadrant Q1 where a positive load is applied to piston 142 at a positive speed. In the first quadrant Q1, the speed is controlled by the flow of hydraulic fluid 81 entering the first chamber 124 through fluid pressure boosting input 244. As shown, the first spool 210 is positioned in a second position relative to the first spool manifold 204 such that hydraulic fluid 81 from fluid input 242 enters the first chamber 124. The second spool 220 is positioned relative to the second spool manifold 206 in a position that maximizes the flow accumulation and allows hydraulic fluid 81 to flow out of the second chamber 128 and to fluid return 246.

[0054] FIG. 12 is an example of a hydraulic actuator 110 having a dual spool hydraulic valve 202, showing an example within the second quadrant Q2 where a positive load is applied to the piston 142 at a negative velocity. In the second quadrant Q2, the velocity is controlled by the flow of hydraulic fluid 81 exiting the first chamber 124. Instead of the hydraulic fluid 81 being output from the first chamber 124 to the fluid return section 246, the hydraulic fluid 81 exiting the first chamber 124 is directed to the second chamber 128. By regenerating the hydraulic fluid 81 from the first chamber 124 to the second chamber 128, the number of pressure cycles that would be required to introduce the hydraulic fluid 81 from the fluid input section 242 to the second chamber 128 of the hydraulic actuator 110 and pass through the fluid return section 246 (if not regenerated) is reduced. In the configuration shown in FIG. 12, the first spool 210 and the second spool 220 are positioned such that the hydraulic fluid 81 from the first chamber 124 can move to the second chamber 128. The second spool 220 is positioned relative to the second spool manifold 206 at a position that maximizes the flow accumulation. The movement of the piston 142 towards the first chamber 124 can cause a pressure drop in the second chamber 128, which can cause the hydraulic fluid 81 to move to the second chamber 128.

[0055] FIG. 13 is an example of a hydraulic actuator 110 having a dual spool hydraulic valve 202, showing an example within the third quadrant Q3 where a negative load is applied to the piston 142 at a negative velocity. In the third quadrant Q3, the velocity is controlled by the flow of hydraulic fluid 81 entering the second chamber 128 from the fluid input section 242. In the example of FIG. 13, the second spool 220 is positioned relative to the second spool manifold 206 such that the hydraulic fluid 81 from the fluid input section 242 can enter the second chamber 128, and the first spool 210 is positioned relative to the first spool manifold 204 at a position that maximizes the flow accumulation and allows the hydraulic fluid 81 to flow out of the first chamber 124 and to the fluid return section 246.

[0056] FIG. 14 is an example of a hydraulic actuator 110 having a dual spool hydraulic valve 202, showing an example within the fourth quadrant Q4 where a negative load is applied to the piston 142 at a positive speed. In the fourth quadrant Q4, the speed is controlled by the flow of hydraulic fluid 81 exiting the second chamber 128. In the example of FIG. 14, the second spool 220 is positioned relative to the second spool manifold 206 to allow hydraulic fluid 81 to flow out of the second chamber 128, and the first spool 210 is positioned relative to the first spool manifold 204 to allow hydraulic fluid 81 to enter the first chamber 124. Similar to the example of FIG. 12, this configuration regenerates the hydraulic fluid 81 already within the hydraulic actuator 110, and thus reduces the number of pressure cycles necessary to introduce hydraulic fluid 81 into the hydraulic actuator 110 through the fluid input 242 and exit the hydraulic actuator 110 through the fluid return 246. In the configuration shown in FIG. 12, the first spool 210 and the second spool 220 are positioned to allow the hydraulic fluid 81 from the second chamber 128 to move into the first chamber 124. The first spool 210 is positioned relative to the first spool manifold 204 at a position that maximizes the flow accumulation. The pressure drop within the first chamber 124 due to the movement of the piston 142 towards the second chamber 128 can cause the movement of the hydraulic fluid 81 into the first chamber 124.

[0057] The dual spool hydraulic valve 202 is provided such that the controller 90 is operable to control an example of a hydraulic actuator 110 including the dual spool hydraulic valve 202 in all four operating quadrants. Specifically, the controller 90 controls the solenoid 218 to provide control by appropriately positioning the first spool 210 and the second spool 220. In some examples, a pressure boost is provided by the hydraulic fluid 81 entering through the fluid input 242. In the following description, P represents the pressure of the hydraulic fluid 81 entering through the fluid input 242, T represents the pressure of the hydraulic fluid 81 exiting through the fluid return 246, A represents the pressure of the hydraulic fluid 81 within the first chamber 124, and B represents the pressure of the hydraulic fluid 81 within the second chamber 128.

[0058] In the operation in the first quadrant Q1 (see FIG. 11), the control is performed through the hydraulic fluid 81 that enters the first chamber 124 through the fluid pressure boosting input section 244. This includes the movement of the hydraulic fluid 81 from the fluid input section 242 to the first chamber 124 (due to the pressure difference P - A), and the movement of the hydraulic fluid 81 from the second chamber 128 to the fluid return section 246 (due to the pressure difference B - T). When the pressure in the fluid input section 242 is lower than the pressure in the first chamber 124 plus the margin (i.e., when P ≧ A + δP), a pressure boost is applied. The margin δP is provided to cope with the application of a load that exceeds the pressure required to handle various forces on the hydraulic fluid 81 (such as surface friction and surface-inertia acceleration). The pressure of the hydraulic fluid 81 in the second chamber 128 contributes to the required margin δP and the peak power demand. In one example, the system pressure is 1200 psi and the margin δP is 300 psi.

[0059] In the operation in the second quadrant Q2, no pressure boost by the hydraulic fluid 81 entering through the fluid input section 242 is required because the pressure A in the first chamber 124 is equal to or higher than the pressure B in the second chamber 128 (i.e., A ≧ B). The control in the second quadrant Q2 is performed through the hydraulic fluid 81 that exits the first chamber 124 and enters the second chamber 128 (due to the pressure difference A - B minimized by minimizing the flow accumulation entering the second chamber 128).

[0060] In the operation in the third quadrant Q3, the control is performed through the movement of the hydraulic fluid 81 from the fluid input section 242 to the second chamber 128 due to the pressure difference (P - B), and the movement of the hydraulic fluid 81 from the first chamber 124 to the fluid return section 246 (due to the pressure difference A - T). When the pressure in the fluid input section 242 is lower than the pressure in the second chamber 128 plus the margin (i.e., when P ≧ B + δP), a pressure boost is applied. The pressure of the hydraulic fluid 81 in the first chamber 124 contributes to the required margin δP.

[0061] In the operation in the fourth quadrant Q4, no boosting of the hydraulic fluid 81 entering through the fluid input portion 242 is required. This is because the pressure B in the second chamber 128 becomes equal to or higher than the pressure A in the first chamber 124 (i.e., B≧A). The control in the fourth quadrant Q4 is performed through the hydraulic fluid 81 that exits the second chamber 128 and enters the first chamber 124 (by the pressure difference B - A minimized by minimizing the flow accumulation entering the first chamber 124).

[0062] In each of the quadrants, as shown in FIGS. 11 to 14, the first spool shaft 212 of the first spool 210 and the second spool shaft 222 of the second spool 220 prevent the first chamber 124 and the second chamber 128 from being fluidly connected to the fluid input portion 242 on the right side. However, in some examples, the shaft openings 213 of the first spool shaft 212 and / or the second spool shaft 222 may be aligned with the corresponding hydraulic conduits 80 to enable such fluid communication.

[0063] In some examples, when a defect is detected in the dual spool hydraulic valve 202, the controller 90 may return to the non - differential control mode of the dual spool hydraulic valve 202. In such some examples, this includes operating the boost pump 56 at an intermediate pressure of 5000 psi (which may be well below the peak capacity of the boost pump 56, for example, 8000 to 9000 psi). In such examples, the central pump 54 may be operated at 3000 psi rather than 1200 psi.

[0064] In an example where a problem occurs with the second spool actuator 226 in the dual spool hydraulic valve 202, the second spool 220 assumes a third position relative to the second spool manifold 206. In the second spool manifold 206, the shaft opening 213 of the second spool shaft 222 is aligned with the corresponding hydraulic conduit 80. This positioning enables the flow of hydraulic fluid 81 to enter and exit the second chamber 128 through the shaft opening 213. In some examples, the second spool 220 is biased toward the third position. Thus, in such an example, if a problem related to the second spool 220 occurs, the second spool actuator 226 (e.g., the associated solenoid 218) is de-energized, allowing the second spool 220 to assume the third position. The third position may also include the second spool 220 being positioned to fluidly isolate the second chamber 128 from the fluid boost input 244 and / or the fluid return 246. In such an example, the first spool 210 can continue to operate to control the flow of hydraulic fluid 81 entering and exiting the first chamber 124.

[0065] Further examples of the dual spool hydraulic valve 202 that can be used in conjunction with the aircraft hydraulic system 50 according to the present disclosure and / or the aircraft hydraulic system 50 and / or the control surface actuator assembly 100 are disclosed in U.S. Patent Application Publication No. 2019 / 0315456, U.S. Patent Application Publication No. 2019 / 0316606, and U.S. Patent Application Publication No. 2019 / 0316607, the entire disclosures of which are incorporated herein by reference for all purposes.

[0066] In some examples, the operation of the control surface actuator assembly 100 includes using a hydraulic actuator 110 that includes a dual spool hydraulic valve 202 to reduce the peak power demand of the aircraft hydraulic system 50 (e.g., by reducing the pressure loss by metering the flow in and out of the first chamber 124 and the second chamber 128 of the hydraulic actuator 110 at maximum flow rate to achieve a minimum margin δP for a chamber port whose flow rate in a given quadrant is not being controlled). However, in some cases, increasing the port area of the dual spool hydraulic valve 202 can introduce an undesirably high flutter sensitivity or flutter response to the control surface 20 during flight. In other words, the control surface 20 may be characterized by resonance conditions under which flutter can occur, and metering the flow in and out of the first chamber 124 and the second chamber 128 of the hydraulic actuator 110 at maximum flow rate to achieve a minimum margin δP can cause an overlap between the operating bandwidth of the control surface actuator assembly 100 and such resonance conditions. In such examples, the flutter of the control surface 20 can be reduced and / or minimized by utilizing a mechanism for damping the vibration of the control surface 20. Thus, in some examples, as described above with reference to FIGS. 2 - 6, the control surface actuator assembly 100 further includes one or more inertias 300 for damping the movement of one or more components of the control surface actuator assembly 100. In such examples, as described, each inertia 300 is configured to resist the acceleration of a corresponding first terminal 302 relative to a corresponding second terminal 304. Thus, in such examples, the inertia 300 can act to provide an essential damping of the vibration of the control surface 20 and thus an expansion of the actual operating bandwidth of the control surface actuator assembly 100, since it includes achieving a minimum margin δP and reducing the peak power demand of the aircraft hydraulic system 50 by metering the flow in and out of the first chamber 124 and the second chamber 128 of the hydraulic actuator 110 at maximum flow rate.

[0067] FIG. 15 is a schematic diagram of an example of a controller 90 for controlling one or more aspects of the aircraft hydraulic system 50 and / or the control surface actuator assembly 100. As shown in FIG. 15, in some examples, the controller 90 can include one or more processing circuits (illustrated as processing circuit 91), which can include one or more microprocessors, application specific integrated circuits (ASICs), etc., configured with appropriate software and / or firmware. A computer-readable storage medium (illustrated as memory circuit 92) stores data and computer-readable program code that configures the processing circuit 91 to implement the techniques described above. The memory circuit 92 is a non-transitory computer-readable medium and can include various memory devices (random access memory, read-only memory, flash memory, etc.).

[0068] The controller 90 can receive signals from sensors (such as piston position sensor 148 and / or pressure sensor 160) associated with the aircraft hydraulic system 50 and / or the control surface actuator assembly 100. In some examples, the controller 90 can communicate with a flight control system 99 that controls one or more functions of the aircraft 10. In such examples, the flight control system 99 can provide the controller 90 with various data (such as, but not limited to, commanded motion of the control surface 20). In some examples, the controller 90 further controls the movement of hydraulic fluid 81 through the aircraft hydraulic system 50 to position the control surface 20 at its commanded position. In such examples, the controller 90 utilizes inputs from the piston position sensor(s) 148 and / or the pressure sensor(s) 160 to control the boost pump 56 and / or the accumulator 70 to supply the required hydraulic fluid 81.

[0069] The controller 90 can be any suitable one or more devices configured to perform the functions of the controller described in this document. For example, the controller can include one or more of an electronic controller, a dedicated controller, an application-specific controller, a personal computer, an application-specific computer, a display device, a logic device, a memory device, and / or a memory device having a non-transitory computer-readable medium suitable for storing computer-executable instructions for implementing aspects of the systems and / or methods according to the present disclosure.

[0070] FIG. 16 is a flow diagram showing a method 400 according to the present disclosure for operating one or more control surfaces of an aircraft (e.g., the control surface(s) 20 of the aircraft 10). Specifically, method 400 relates to a method that utilizes a control surface actuator assembly (e.g., control surface actuator assembly 100) that includes a VHR hydraulic actuator (e.g., VHR hydraulic actuator 1110) coupled to the control surface and a torque generating hydraulic actuator (e.g., torque generating hydraulic actuator 2110) pivotally coupled to the VHR hydraulic actuator, where the actuator moment arm length (e.g., actuator moment arm length 30) of the VHR hydraulic actuator can be selectively varied as described in this document. Method 400 further relates to a method that utilizes an aircraft hydraulic system (e.g., aircraft hydraulic system 50) that includes the control surface actuator assembly.

[0071] As shown in FIG. 16, method 400 includes, at 420, controlling a selected control surface of one or more control surfaces using a control surface actuator assembly and an aircraft hydraulic system. Specifically, as shown in FIG. 16, controlling the selected control surface at 420 includes, at 422, adjusting an actuator moment arm length corresponding to the selected control surface using a VHR hydraulic actuator, and, at 426, pivoting the selected control surface relative to a support structure using a torque generating hydraulic actuator. In some examples, adjusting the actuator moment arm length at 422 is performed prior to pivoting the selected control surface at 426.

[0072] In some examples, method 400 includes adjusting the pressure of hydraulic fluid (e.g., hydraulic fluid 81) within one or more components of the control surface actuator assembly. For example, as shown in FIG. 16, some examples of method 400 include, at 430, measuring a measured load pressure of the hydraulic fluid within a hydraulic actuator housing (e.g., corresponding hydraulic actuator housing 120 of VHR hydraulic actuator 1110 and / or torque generating hydraulic actuator 2110). More specifically, in such examples, measuring the measured load pressure at 430 includes using a pressure sensor (e.g., pressure sensor 160) to measure the load pressure within a first chamber (e.g., first chamber 124) and / or a second chamber (e.g., second chamber 128) of the hydraulic actuator housing. In some such examples, as further shown in FIG. 16, method 400 further includes, at 440, using a hydraulic valve (e.g., corresponding hydraulic valve 200 of VHR hydraulic actuator 1110 and / or torque generating hydraulic actuator 2110) to adjust the operating pressure of the hydraulic fluid within the corresponding hydraulic actuator housing. Specifically, in such examples, adjusting the operating pressure of the hydraulic fluid at 440 is at least partially based on the measured load pressure measured in measuring the measured load pressure at 430. Adjusting the operating pressure of the hydraulic fluid at 440 can be implemented in any suitable manner described herein, for example, by selectively varying the pressure of the hydraulic fluid supplied to the first chamber and / or the second chamber of the hydraulic actuator housing of the VHR hydraulic actuator and / or the torque generating hydraulic actuator using a dual spool hydraulic valve (e.g., dual spool hydraulic valve 202) in combination with a central pump (e.g., central pump 54) and / or a boost pump (e.g., boost pump 56).

[0073] Adjusting the actuator moment arm length at 422 can be based on any suitable factor and / or consideration. For example, adjusting the actuator moment arm length at 422 can be performed selectively and / or dynamically to accommodate predicted and / or calculated load and / or torque requirements. In some examples, as shown in FIG. 16, prior to adjusting the actuator moment arm length at 422, method 400 further includes, at 410, determining a target actuator moment arm length using a controller (e.g., controller 90). In such examples, adjusting the actuator moment arm length at 422 includes, at 424, setting the selected control surface's actuator moment arm length to the target actuator moment arm length after determining the target actuator moment arm length at 410. In such examples, determining the target actuator moment arm length at 410 can be based on any suitable consideration and / or calculation. As an example, determining the target actuator moment arm length at 410 can be at least partially based on a machine learning algorithm. As a more specific example, determining the target actuator moment arm length at 410 can include training a machine learning algorithm with the hydraulic pressure and / or power requirements of the hydraulic system and the associated actual values of the moment arm length (e.g., those commanded during flight operation), and developing an algorithm that optimizes the determination of the target moment arm length based on one or more predetermined figures of merit using such training with machine learning techniques. In such examples, training, developing, and / or operating the machine learning algorithm can include utilizing any suitable method and / or technique known in the field of machine learning computations.

[0074] Additionally or alternatively, in some examples, determining the target actuator moment arm length at 410 is at least partially based on a predicted aircraft maneuver. As a more specific example, method 400 may be performed while the aircraft is performing a known and / or defined maneuver (e.g., a banked turn, altitude change, pitch angle adjustment, roll angle adjustment, yaw adjustment, etc.) that may be selected, for example, to minimize the peak power demand of a hydraulic system, and for which a corresponding known target actuator moment arm length is associated. Thus, in such examples, determining the target actuator moment arm length at 410 may include identifying the predicted maneuver and, thus, identifying the corresponding known target actuator moment arm length.

[0075] In some examples, determining the target actuator moment arm length at 410 is additionally or alternatively at least partially based on measuring the measured load pressure at 430. Similarly, in some examples, determining the target actuator moment arm length at 410 includes determining a value of the target actuator moment arm length that at least substantially sets the load pressure of the hydraulic fluid within the corresponding hydraulic actuator housing to a target load pressure. In such some examples, the target load pressure may be based on or substantially equal to the load pressure corresponding to one or more other control surfaces of the aircraft. More specifically, in some examples, the aircraft includes a plurality of control surfaces and corresponding plurality of control surface actuator assemblies, and the target load pressure corresponds to the measured load pressure of the hydraulic fluid within the torque generating hydraulic actuator and / or VHR hydraulic actuator of at least one other control surface actuator assembly (i.e., corresponding to one control surface other than the selected control surface).

[0076] Exemplary and non-exclusive examples of the inventive subject matter according to the present disclosure are set forth in the clauses listed below.

[0077] A control surface actuator assembly (100) for selectively pivoting a control surface (20) relative to a support structure (40), comprising: a support structure (40); a control surface (20) operatively coupled to the support structure (40) and configured to pivot relative to the support structure (40) about a control surface pivot axis (22); a torque generating hydraulic actuator (2110); a variable horn radius (VHR) hydraulic actuator (1110) pivotally coupled to the torque generating hydraulic actuator (2110) and operatively coupled to the control surface (20); each of the torque generating hydraulic actuator (2110) and the VHR hydraulic actuator (1110) includes: a corresponding hydraulic actuator housing (120) and a corresponding rod (140) extending at least partially within the corresponding hydraulic actuator housing (120), the corresponding rod (140) being configured to translate parallel to the corresponding hydraulic actuator housing (120) along a corresponding actuator axis (122); a corresponding hydraulic valve (200) for regulating the flow of hydraulic fluid (81) to the corresponding hydraulic actuator housing (120) to control the position of the corresponding rod (140) relative to the corresponding hydraulic actuator housing (120). The torque generating hydraulic actuator (2110) and the VHR hydraulic actuator (1110) are configured to pivot relative to each other about the actuator connection shaft (28). The torque generating hydraulic actuator (2110) is configured to apply torque to the control surface (20) to pivot the control surface (20) relative to the support structure (40). The VHR hydraulic actuator (1110) is configured to selectively vary the actuator moment arm length (30) measured between the control surface pivot axis (22) and the actuator connection shaft (28) in order to at least partially adjust the torque applied to the control surface (20) by the torque generating hydraulic actuator (2110). Control surface actuator assembly (100).

[0078] A2. The corresponding actuator shaft (122) of the corresponding hydraulic actuator housing (120) of the torque generating hydraulic actuator (2110) is the torque generating actuator shaft (2122). The corresponding actuator shaft (122) of the corresponding hydraulic actuator housing (120) of the VHR hydraulic actuator (1110) is the VHR actuator shaft (1122). The VHR hydraulic actuator (1110) is configured to selectively translate the corresponding rod (140) of the VHR hydraulic actuator (1110) along the VHR actuator shaft (1122) to vary the actuator moment arm length (30). The control surface actuator assembly (100) according to clause A1.

[0079] A3. The control surface torque angle (26) measured between the torque generating actuator shaft (2122) and the VHR actuator shaft (1122) is configured to be greater than 0 degrees and less than 180 degrees. The control surface actuator assembly (100) according to clause A1 or A2.

[0080] A4. During the operation of the control surface actuator assembly (100), the control surface torque angle (26) is one or more of at least 30 degrees, at least 50 degrees, at least 70 degrees, at least 90 degrees, at least 110 degrees, at least 130 degrees, at least 150 degrees, up to 160 degrees, up to 140 degrees, up to 120 degrees, up to 100 degrees, up to 80 degrees, up to 60 degrees, and up to 40 degrees, the control surface actuator assembly (100) according to clause A3.

[0081] A5. The control surface actuator assembly (100) according to any one of clauses A1 to A4, configured to selectively vary the control surface turning angle (24) of the control surface (20) with respect to the support structure (40) over a range of motion angles that is one or more of at least 5 degrees, at least 10 degrees, at least 20 degrees, at least 40 degrees, at least 60 degrees, at least 80 degrees, up to 90 degrees, up to 70 degrees, up to 50 degrees, up to 30 degrees, up to 15 degrees, and up to 7 degrees, measured in a plane perpendicular to the control surface pivot axis (22).

[0082] A6. The VHR hydraulic actuator (1110) is defined between a minimum actuator moment arm length (30) and a maximum actuator moment arm length (30), and is configured to selectively vary the actuator moment arm length (30) within a range of values including the minimum actuator moment arm length (30) and the maximum actuator moment arm length (30), the maximum actuator moment arm length (30) being at least 1.1 times the minimum actuator moment arm length (30), at least 1.3 times the minimum actuator moment arm length (30), at least 1.5 times the minimum actuator moment arm length (30), at least 2 times the minimum actuator moment arm length (30), at least 2.5 times the minimum actuator moment arm length (30), up to 3 times the minimum actuator moment arm length (30), up to 2.2 times the minimum actuator moment arm length (30), up to 1.7 times the minimum actuator moment arm length (30), and up to 1.2 times the minimum actuator moment arm length (30), one or more of which, the control surface actuator assembly (100) according to any one of clauses A1 to A5.

[0083] A7. The control surface actuator assembly (100) according to any one of clauses A1 to A6, wherein the corresponding hydraulic actuator housing (120) of one or both of the torque generating hydraulic actuator (2110) and the VHR hydraulic actuator (1110) is a hydraulic cylinder.

[0084] A8. Each of the torque generating hydraulic actuator (2110) and the VHR hydraulic actuator (1110) further includes a corresponding piston (142), and the corresponding piston (142) extends into the corresponding hydraulic actuator housing (120), and within the corresponding hydraulic actuator housing (120), on both sides of the corresponding piston 142, a corresponding first chamber '(124) and a corresponding second chamber (128) are defined, and the corresponding rod (140) extends from the corresponding piston (142) and extends out of the corresponding hydraulic actuator housing (120), and the hydraulic pressure difference of the hydraulic fluid (81) in each of the corresponding first chamber (124) and the corresponding second chamber (128) moves the corresponding piston (142) within the corresponding hydraulic actuator housing (120) to act to translate the corresponding rod (140) along the corresponding actuator shaft (122), the control surface actuator assembly (100) according to any one of clauses A1 to A7.

[0085] A9. One or both of the torque generating hydraulic actuator (2110) and the VHR hydraulic actuator (1110) further includes a corresponding support rod (141), and the corresponding support rod (141) extends from the corresponding piston (142) to the opposite side of the corresponding rod (140) and is operably connected to the corresponding hydraulic actuator housing (120), the control surface actuator assembly (100) according to clause A8.

[0086] A10. Each corresponding hydraulic actuator housing (120) of the torque generating hydraulic actuator (2110) and the VHR hydraulic actuator (1110) includes a corresponding first chamber port (126) for allowing the hydraulic fluid (81) to flow into and out of the corresponding first chamber (124), and a corresponding second chamber port (130) for allowing the hydraulic fluid (81) to flow into and out of the corresponding second chamber (128), the control surface actuator assembly (100) according to clause A8 or A9.

[0087] A11. The corresponding hydraulic actuator housing (120) of the torque generating hydraulic actuator (2110) is pivotally connected to the support structure (40), and the corresponding rod (140) of the torque generating hydraulic actuator (2110) is pivotally connected to the VHR hydraulic actuator (1110). The control surface actuator assembly (100) according to any one of clauses A1 to A10.

[0088] A12. The corresponding hydraulic actuator housing (120) of the torque generating hydraulic actuator (2110) is pivotally connected to the VHR hydraulic actuator (1110), and the corresponding rod (140) of the torque generating hydraulic actuator (2110) is pivotally connected to the support structure (40). The control surface actuator assembly (100) according to any one of clauses A1 to A10.

[0089] A13. The corresponding hydraulic actuator housing (120) of the VHR hydraulic actuator (1110) is pivotally connected to the torque generating hydraulic actuator (2110), and the corresponding rod (140) of the VHR hydraulic actuator (1110) is operably connected to the control surface (20). The control surface actuator assembly (100) according to any one of clauses A1 to A12.

[0090] A14. The corresponding hydraulic actuator housing (120) of the VHR hydraulic actuator (1110) is operably connected to the control surface (20), and the corresponding rod (140) of the VHR hydraulic actuator (1110) is pivotally connected to the torque generating hydraulic actuator (2110). The control surface actuator assembly (100) according to any one of clauses A1 to A12.

[0091] A15. The control surface actuator assembly (100) according to any one of clauses A8 to A14, wherein corresponding pistons (142) of the torque generating hydraulic actuator (2110) and the VHR hydraulic actuator (1110) each include a corresponding first piston surface (144) having a corresponding first piston surface area that partially defines a corresponding first chamber (124), and a corresponding second piston surface (146) having a corresponding second piston surface area that partially defines a corresponding second chamber (128).

[0092] A16. The control surface actuator assembly (100) according to clause A15, wherein the corresponding first piston surface area and the corresponding second piston surface area of one or both of the torque generating hydraulic actuator (2110) and the VHR hydraulic actuator (1110) are at least substantially equal.

[0093] A17. The control surface actuator assembly (100) according to clause A15 or A16, wherein the corresponding first piston surface area and the corresponding second piston surface area of the corresponding piston (142) of the corresponding hydraulic actuator housing (120) of one or both of the torque generating hydraulic actuator (2110) and the VHR hydraulic actuator (1110) are not equal.

[0094] A18. The control surface actuator assembly (100) according to any one of clauses A1 to A17, further comprising one or more inertias (300), each inertia (300) of the one or more inertias (300) including a corresponding first terminal portion (302) and a corresponding second terminal portion (304), the corresponding first terminal portion (302) and the corresponding second terminal portion (304) being configured to translate parallel to each other along a corresponding inertia axis (306), and each inertia (300) of the one or more inertias (300) being configured to resist acceleration of the corresponding first terminal portion (302) with respect to the corresponding second terminal portion (304).

[0095] A19. Each of the one or more inertias (300) The corresponding inert housing (301), The corresponding threaded shaft (322) that is connected to the corresponding first terminal part (302) and terminates at the corresponding free end of the shaft (324), The corresponding inert rod (308), and the corresponding inert rod (308) is connected to the corresponding second terminal part (304) such that the corresponding inert rod (308) and the corresponding second terminal part (304) are configured to move in parallel with respect to the corresponding first terminal part (302) along the corresponding inert shaft (306) in an interlocking manner, Each of the corresponding inert rod (308) and the corresponding threaded shaft (322) at least partially extends into the corresponding inert housing (301), the control surface actuator assembly (100) according to clause A18.

[0096] A20. The control surface actuator assembly (100) according to clause A19, wherein one or both of the corresponding inert rod (308) and the corresponding threaded shaft (322) extend at least substantially parallel to the inert shaft (306).

[0097] A21. The control surface actuator assembly (100) according to clause A19 or A20, wherein the corresponding inert rod (308) is hollow and defines a corresponding inert rod hole (310).

[0098] A22. The control surface actuator assembly (100) according to clause A21, wherein the corresponding free end of the shaft (324) is received within the corresponding inert rod hole (310).

[0099] A23. The control surface actuator assembly (100) according to any one of clauses A19 to A22, wherein the corresponding threaded shaft (322) is hollow and defines a corresponding shaft hole (323) that opens at the corresponding free end of the shaft (324) of the corresponding threaded shaft (322).

[0100] A24. The corresponding threaded shaft (322) includes one or more corresponding radial passages (325) that extend radially from the corresponding shaft hole (323) to the outer surface of the corresponding threaded shaft (322) to enable fluid flow between the outer surface of the corresponding threaded shaft (322) and the corresponding shaft hole (323). The control surface actuator assembly (100) according to clause A23.

[0101] A25. Each of the one or more inertias (300) further includes a corresponding flywheel (314) having a corresponding flywheel ring (318) connected to one or both of the corresponding inertia rod (308) and the corresponding threaded shaft (322). The corresponding flywheel (314) is configured to rotate relative to the corresponding threaded shaft (322) at a rotational speed proportional to the linear speed at which the corresponding inertia rod (308) translates parallel to the corresponding threaded shaft (322). The control surface actuator assembly (100) according to any one of clauses A19 to A24.

[0102] A26. The control surface actuator assembly (100) according to clause A25, wherein the corresponding flywheel ring (318) is operably connected to one or more of the corresponding inertia rod (308), the corresponding threaded shaft (322), and the corresponding inertia housing (301).

[0103] A27. The control surface actuator assembly (100) according to clause A25 or A26, wherein the corresponding flywheel (314) includes a corresponding flywheel bearing (328) at the corresponding flywheel ring (318) to rotatably connect the corresponding flywheel (314) to at least one other component of the corresponding inertia (300).

[0104] A28. The corresponding flywheel bearing (328) is configured to allow the corresponding flywheel (314) to translate axially together with the corresponding inertor rod (308) when the corresponding flywheel (314) rotates relative to the corresponding threaded shaft (322), for the control surface actuator assembly (100) according to clause A27.

[0105] A29. The control surface actuator assembly (100) according to any one of clauses A19 to A28, wherein one or both of the torque generating hydraulic actuator (2110) and the VHR hydraulic actuator (1110) includes the corresponding inertor (300) among one or more inertors (300).

[0106] A30. The control surface actuator assembly (100) according to clause A29, wherein the corresponding hydraulic actuator housing (120) of one or both of the torque generating hydraulic actuator (2110) and the VHR hydraulic actuator (1110) includes the inertor housing (301) of the corresponding inertor (300), and optionally is such an inertor housing (301).

[0107] A31. The control surface actuator assembly (100) according to clause A29 or A30, wherein the corresponding rod (140) of one or both of the torque generating hydraulic actuator (2110) and the VHR hydraulic actuator (1110) includes the inertor rod (308) of the corresponding inertor (300), and optionally is such an inertor rod (308).

[0108] A32. The control surface actuator assembly (100) according to any one of clauses A29 to A31, wherein the corresponding flywheel (314) is rotatably connected to the corresponding piston (142) of one or both of the torque generating hydraulic actuator (2110) and the VHR hydraulic actuator (1110).

[0109] At least one of the one or more inertias (300) includes a flexible retaining structure (330) and a dual rack and pinion assembly (332) operably supported by the flexible retaining structure (330), and the dual rack and pinion assembly (332) (i) a pair of racks (334) including a first rack (334) and a second rack (334) positioned opposite to each other and operably supported by the flexible retaining structure (330), each rack (334) having a plurality of teeth, and (ii) a pinion (336) disposed between the first rack (334) and the second rack (334) and engaging with the first rack (334) and the second rack (334), The pinion (336) has a plurality of gear teeth that engage with the teeth of the first rack (334) and the second rack (334). The control surface actuator assembly (100) according to any one of clauses A19 to A32.

[0110] For the control surface actuator assembly (100) according to clause A33, the first terminal portion (302) is connected to the first rack (334), and the second terminal portion (304) is connected to the second rack (334).

[0111] For the control surface actuator assembly (100) according to clause A33 or A34, at least one of the one or more inertias (300) includes a pair of inertia wheels (340) respectively positioned adjacent to both outer surfaces of the flexible retaining structure (330).

[0112] For the control surface actuator assembly (100) according to clause A35, at least one of the one or more inertias (300) further includes a mandrel element (342) extending through the first inertia wheel (340) of the pair of inertia wheels (340), the flexible retaining structure (330), the pinion (336), and the second inertia wheel (340) of the pair of inertia wheels (340).

[0113] A37. The relative movement of the first terminal part (302) and the second terminal part (304) causes a translation of the first rack (334) relative to the second rack (334) along the inertia axis (306), and thereby causes a rotational movement of the pair of the pinion (336) and the inertia wheel (340), wherein the rotational movement of the pinion (336) is resisted by the pair of the inertia wheels (340), the control surface actuator assembly (100) according to clause A35 or A36.

[0114] A38. Each corresponding hydraulic valve (200) of the torque generating hydraulic actuator (2110) and the VHR hydraulic actuator (1110) has a fluid input part (242) configured to receive a flow of high-pressure hydraulic fluid, and has a fluid return part (246) configured to discharge a flow of low-pressure hydraulic fluid, and has a first outlet (250) fluidly connected to the first chamber (124) of the corresponding hydraulic actuator housing (120), and has a second outlet (252) fluidly connected to the second chamber (128) of the corresponding hydraulic actuator housing (120), and has a spool manifold (204) selectively fluidly connected to two or more of the fluid input part (242), the fluid return part (246), the first outlet (250), and the second outlet (252), and has a spool (210) positioned at least substantially within the spool manifold (204), the spool (210) including a spool shaft (212) and one or more spool blocks (214) mounted on the spool shaft (212), and has a spool actuator (216) configured to selectively translate the spool (210) relative to the spool manifold (204). The corresponding hydraulic valve (200) is configured to selectively translate the spool (210) relative to the spool manifold (204) to vary the pressure of the hydraulic fluid (81) in each of the first chamber (124) and the second chamber (128) of the corresponding hydraulic actuator housing (120) to translate the corresponding rod (140) relative to the corresponding hydraulic actuator housing (120), and to act to regulate the flow of the hydraulic fluid (81) between the fluid inlet (242), the fluid return (246), the first outlet (250), and the second outlet (252), the control surface actuator assembly (100) according to any one of clauses A1 to A37.

[0115] A39. The control surface actuator assembly (100) according to clause A38, wherein the spool actuator (216) includes at least one solenoid (218).

[0116] A40. The control surface actuator assembly (100) according to clause A38 or A39, wherein the corresponding hydraulic valve (200) of one or both of the torque generating hydraulic actuator (2110) and the VHR hydraulic actuator (1110) is a servo valve including a servo feedback system (230).

[0117] A41. One or both of the torque generating hydraulic actuator (2110) and the VHR hydraulic actuator (1110) includes a corresponding piston position sensor (148) configured to generate a piston position measurement representing the position of the corresponding piston (142) relative to the hydraulic actuator housing (120), and the corresponding hydraulic valve (200) is configured to regulate the flow of the hydraulic fluid (81) based at least in part on the piston position measurement, the control surface actuator assembly (100) according to any one of clauses A38 to A40.

[0118] The control surface actuator assembly (100) according to any one of clauses A38 to A41, wherein the corresponding hydraulic valve (200) of one or both of the torque generating hydraulic actuator (2110) and the VHR hydraulic actuator (1110) is a four-way three-position hydraulic valve (200).

[0119] A43. The control surface actuator assembly (100) according to any one of clauses A38 to A42, wherein the corresponding hydraulic valve (200) of one or both of the torque generating hydraulic actuator (2110) and the VHR hydraulic actuator (1110) is a dual spool hydraulic valve (202).

[0120] A44. The spool manifold (204) is a first spool manifold (204), and the spool (210) of the dual spool hydraulic valve (202) is a first spool (210) that is at least substantially positioned within the first spool manifold (204) and has a corresponding first spool shaft (212) and a corresponding one or more first spool blocks (214). The spool actuator (216) of the dual spool hydraulic valve (202) is a first spool actuator (216) configured to selectively translate the first spool (210). The dual spool hydraulic valve (202) is selectively fluidly connected to two or more of a fluid input portion (242), a fluid return portion (246), a first outlet (250), and a second outlet (252), a second spool manifold (206), a second spool (220) that is at least substantially positioned within the second spool manifold (206) and includes a corresponding second spool shaft (222) and a corresponding one or more second spool blocks (224) attached to the second spool shaft (222), and further includes a second spool actuator (226) configured to selectively translate the second spool (220) independently of the first spool (210) relative to the second spool manifold (206). The dual spool hydraulic valve (202) is configured to adjust the flow of hydraulic fluid (81) between a fluid input section (242), a fluid return section (246), a first outlet (250), and a second outlet (252) so that moving the first spool (210) relative to the first spool manifold (204) and moving the second spool (220) relative to the second spool manifold (206) vary the pressure of the hydraulic fluid (81) in each of a first chamber (124) and a second chamber (128) of the corresponding hydraulic actuator housing (120) to move the corresponding rod (140) relative to the corresponding hydraulic actuator housing (120), the control surface actuator assembly (100) according to clause A43.

[0121] A45. The dual spool hydraulic valve (202) is configured to allow fluid communication between the first outlet (250) and the second outlet (252), the control surface actuator assembly (100) according to clause A43 or A44.

[0122] A46. The dual spool hydraulic valve (202) is configured to continue to function to operably move the corresponding rod (140) relative to the corresponding hydraulic actuator housing (120) even if one of the first spool actuator (216) and the second spool actuator (226) becomes inoperative, the control surface actuator assembly (100) according to clause A44 or A45.

[0123] A47. The dual spool hydraulic valve (202) further includes a fluid boost input section (244) configured to receive a flow of hydraulic fluid at a boost pressure higher than the pressure of the flow of high-pressure hydraulic fluid, the control surface actuator assembly (100) according to any one of clauses A44 to A46.

[0124] The control surface actuator assembly (100) according to clause A47, wherein one or both of the first spool manifold (204) and the second spool manifold (206) are selectively fluidly connected to the fluid pressure input section (244).

[0125] The control surface actuator assembly (100) according to clause A47 or A48, wherein a corresponding hydraulic actuator housing (120) includes at least one pressure sensor (160) positioned in one or both of the first chamber (124) and the second chamber (128), each pressure sensor (160) being configured to generate a pressure signal indicative of the pressure of the hydraulic fluid (81), and the dual spool hydraulic valve (202) being configured to selectively fluidly connect the fluid pressure input section (244) to one or both of the first outlet (250) and the second outlet (252) based at least in part on the pressure signal.

[0126] The control surface actuator assembly (100) according to any one of clauses A44 to A49, wherein one or both of the first spool shaft (212) and the second spool shaft (222) define a shaft opening (213) through which the hydraulic fluid (81) can flow.

[0127] The control surface actuator assembly (100) according to any one of clauses A1 to A50, wherein the control surface (20) is one or more of an auxiliary wing, a rudder, an elevator, a flap, a spoiler, and an air brake.

[0128] The control surface actuator assembly (100) according to any one of clauses A1 to A51, wherein the support structure (40) is one or more components of a wing, a horizontal stabilizer, and a vertical stabilizer.

[0129] An aircraft hydraulic system (50) for operating one or more control surfaces (20) of an aircraft (10), a fluid reservoir (60) containing a fixed volume of hydraulic fluid (81), One or more hydraulic pumps (52), each configured to apply pressure to a hydraulic fluid (81), A plurality of hydraulic actuators (110), wherein one or more of the hydraulic actuators (110) are configured to selectively pivot a corresponding control surface (20) among one or more control surfaces (20), A plurality of hydraulic conduits (80) configured to convey the hydraulic fluid (81) between components of the aircraft hydraulic system (50), At least one hydraulic actuator (110) of the plurality of hydraulic actuators (110) is the torque generating hydraulic actuator (2110) of the control surface actuator assembly (100) according to any one of clauses A1 to A52, and at least one other hydraulic actuator (110) of the plurality of hydraulic actuators (110) is the VHR hydraulic actuator (1110) of the control surface actuator assembly (100) according to any one of clauses A1 to A52, An aircraft hydraulic system (50).

[0130] The aircraft hydraulic system (50) according to clause B1, further comprising one or more accumulators (70) for maintaining the pressure of the hydraulic fluid (81).

[0131] B3. One or more hydraulic pumps (52) are A central pump (54) configured to apply pressure to the hydraulic fluid (81) up to a reference pressure, A boost pump (56) configured to apply pressure to the hydraulic fluid (81) up to a boost pressure above the reference pressure, and the aircraft hydraulic system (50) according to clause B1 or B2.

[0132] B4. The aircraft hydraulic system (50) according to any one of clauses B1 to B3, wherein one or both of the reference pressure and the boost pressure are one or more of at least 800 pounds per square inch (psi), at least 1000 psi, at least 1300 psi, at least 1500 psi, at least 2000 psi, at least 2500 psi, at least 3000 psi, at least 5000 psi, at least 10000 psi, at least 12000 psi, up to 7000 psi, up to 2700 psi, up to 2200 psi, up to 1700 psi, up to 1200 psi, and up to 900 psi.

[0133] B5. The aircraft hydraulic system (50) according to clause B3 or B4, comprising a plurality of hydraulic conduits (80) including: (i) one or more supply conduits (82) configured to convey hydraulic fluid (81) at a reference pressure; (ii) one or more boost conduits (84) configured to convey hydraulic fluid (81) at a boost pressure; and (iii) one or more return conduits (86) configured to convey hydraulic fluid (81) at a pressure below the reference pressure.

[0134] B6. The aircraft hydraulic system (50) according to any one of clauses B3 to B5, wherein a boost pump (56) supplies a flow of hydraulic fluid to a fluid boost input (244) of a dual spool hydraulic valve (202).

[0135] C1. An aircraft (10) comprising: one or more control surfaces (20); a control surface actuator assembly (100) according to any one of clauses A1 to A52 for pivoting at least one of the one or more control surfaces (20); and an aircraft hydraulic system (50) according to any one of clauses B1 to B6 for operating the control surface actuator assembly (100). Aircraft (10).

[0136] A method (400) of operating one or more control surfaces (20) of an aircraft (10) as recited in clause C1, comprising: Controlling (420) a selected one of the one or more control surfaces (20) using a control surface actuator assembly (100) and an aircraft hydraulic system (50), wherein controlling the selected control surface (20) comprises: Adjusting (422) an actuator moment arm length (30) corresponding to the selected control surface (20) using a VHR hydraulic actuator (1110), and Pivoting (426) the selected control surface (20) relative to a support structure (40) using a torque generating hydraulic actuator (2110). A method.

[0137] The method (400) as recited in clause D1, wherein adjusting (422) the actuator moment arm length (30) is performed prior to pivoting (426) the selected control surface (20).

[0138] The method (400) as recited in clause D1 or D2, further comprising measuring (430) a measured load pressure of a hydraulic fluid (81) within a corresponding hydraulic actuator housing (120) using a pressure sensor (160) positioned in one or both of a first chamber (124) and a second chamber (128) of the corresponding hydraulic actuator housing (120) of one or both of the torque generating hydraulic actuator (2110) and the VHR hydraulic actuator (1110).

[0139] Adjusting the operating pressure of the hydraulic fluid (81) within the corresponding hydraulic actuator housing (120) of one or both of the VHR hydraulic actuator (1110) and the torque generating hydraulic actuator (2110) using one or both of the corresponding hydraulic actuator valves (200) of the D4.VHR hydraulic actuator (1110) and the torque generating hydraulic actuator (2110), the method (400) according to clause D3 further comprising adjusting the operating pressure (440) based at least in part on the measured load pressure.

[0140] D5. Prior to adjusting the actuator moment arm length (30) (422), further comprising determining a target actuator moment arm length (30) (410) using a controller (90), and adjusting the actuator moment arm length (30) (422) includes, after determining the target actuator moment arm length (30) (410), setting the actuator moment arm length (30) of the selected control surface (20) to the target actuator moment arm length (30) (424), the method (400) according to any one of clauses D1 to D4.

[0141] D6. The method (400) according to clause D5, wherein determining the target actuator moment arm length (30) (410) is based at least in part on a machine learning algorithm.

[0142] D7. The method (400) according to clause D5 or D6, wherein determining the target actuator moment arm length (30) (410) is based at least in part on the predicted operation of the aircraft (10).

[0143] D8. The method (400) according to any one of clauses D5 to D7 when dependent on clause D3, wherein determining the target actuator moment arm length (30) (410) is based at least in part on measuring the measured load pressure (430).

[0144] D9. Determining (410) a target actuator moment arm length (30) includes determining a value of the target actuator moment arm length (30) such that a load pressure of a hydraulic fluid (81) within a corresponding hydraulic actuator housing (120) is at least substantially a target load pressure, the method (400) according to any one of clauses D5 to D8.

[0145] D10. An aircraft (10) includes a plurality of control surfaces (20), a control surface actuator assembly (100) is one of the corresponding plurality of control surface actuator assemblies (100), and a target load pressure corresponds to a measured load pressure of the hydraulic fluid (81) within a corresponding hydraulic actuator housing (120) of one or both of a corresponding torque generating hydraulic actuator (2110) and a corresponding VHR hydraulic actuator (1110) of at least one other control surface actuator assembly (100) of the plurality of control surface actuator assemblies (100), the method (400) according to clause D9.

[0146] As used herein, the expression "at least substantially" when modifying a degree or relationship does not mean including only the stated "substantial" degree or relationship, but includes the full extent of the stated degree or relationship. A substantial amount of the stated degree or relationship can include at least 75% of the stated degree or relationship. For example, a first direction that is at least substantially parallel to a second direction includes a first direction within a range of angular displacement of 22.5° with respect to the second direction, and further includes a first direction that is the same as the second direction.

[0147] In this book, the terms "selective" and "selectively" when modifying the operation, movement, configuration, or other activity of one or more components or characteristics of a device mean that a particular operation, movement, configuration, or other activity is a direct or indirect result of one or more dynamic processes described in this book. Thus, the terms "selective" and "selectively" can characterize an activity that is a direct or indirect result of user operation of an aspect of the device or of one or more components of the device, or can characterize a process that occurs automatically (e.g., via mechanisms disclosed in this book).

[0148] In this book, the terms "adapted" and "configured" mean that an element, component, or other object is designed and / or intended to perform a given function. Thus, the use of the terms "adapted" and "configured" should not be construed to mean simply that a given element, component, or other object is "capable of" performing a given function, but rather should be construed to mean that these elements, components, and / or other objects are specifically selected, created, implemented, utilized, programmed, and / or designed for the purpose of performing that function. It is within the scope of this disclosure that an element, component, and / or other object described as adapted to perform a particular function can additionally or alternatively be described as configured to perform that function, and vice versa. Similarly, an object described as configured to perform a particular function can additionally or alternatively be described as operable to perform that function.

[0149] As used herein, the term "and / or" placed between a first entity and a second entity means one of (1) the first entity, (2) the second entity, and (3) the first entity and the second entity. A plurality of entities listed using "and / or" should be construed in a similar manner, i.e., as "one or more" of the entities so conjoined. There may optionally be other entities in addition to (regardless of whether or not they are related to such specifically identified entities) the entities specifically identified by the phrase "and / or". Thus, by way of non-limiting example, a reference to "A and / or B" may, when used in conjunction with an open-ended term (such as "comprising"), in one instance refer to only A (optionally including entities other than B), in another instance refer to only B (optionally including entities other than A), and in yet another instance refer to both A and B (optionally including other entities). Such entities may refer to elements, acts, structures, steps, processes, values, etc.

[0150] As used herein, the phrase "at least one" in reference to the listing of one or more entities means at least one entity selected from any one or more of the entities in the listing of entities, but does not necessarily include at least one of every entity specifically listed in the listing of entities, and is to be understood not to exclude any combination of entities in the listing of entities. Further, by this definition, entities other than the specifically identified entities in the listing of entities referred to by the phrase "at least one" may optionally be present (whether or not related to such specifically identified entities). Thus, by way of non-limiting example, "at least one of A and B" (or equivalently "at least one of A or B", or equivalently "at least one of A and / or B") may, in one embodiment, refer to at least one, optionally two or more, of A and no B (and, optionally, include entities other than B), in another embodiment, refer to at least one, optionally two or more, of B and no A (and, optionally, include entities other than A), and in yet another embodiment, refer to at least one, optionally two or more, of A and at least one, optionally two or more, of B (and, optionally, include other entities). In other words, the phrases "at least one", "one or more", and "and / or" are open-ended expressions that are both conjunctive and disjunctive in their operation. For example, the expressions "at least one of A, B, and C", "at least one of A, B, or C", "one or more of A, B, and C", "one or more of A, B, or C", and "A, B, and / or C" may each mean only A, only B, only C, A and B together, A and C together, B and C together, A, B, and C together, and optionally, in combination with at least one other entity of any of the foregoing.

[0151] In this book, the expressions "for example", "as an example", and / or simply the word "example" are used in connection with one or more components, features, details, structures, embodiments, and / or methods according to the present disclosure. When used in this context, it is intended to convey that the aforementioned components, features, details, structures, embodiments, and / or methods are exemplary and non-limiting examples of the components, features, details, structures, embodiments, and / or methods according to the present disclosure. Therefore, the aforementioned components, features, details, structures, embodiments, and / or methods are not intended to be limiting, necessary, or exhaustive, and other components, features, details, structures, embodiments, and / or methods that are structurally and / or functionally similar and / or equivalent are also included within the scope of the present disclosure.

[0152] Any patent, patent application, or other reference is incorporated herein by reference, and if there is any conflict between any part of this disclosure that is not incorporated by reference and any other reference that is incorporated, (1) the terms are defined in a consistent manner, and / or (2) if not (1), and if they are consistent, the part of this disclosure that is not incorporated by reference is a reference that defines the terms and / or cross-references the reference in which the disclosed matter that is incorporated originally existed, and the terms in this disclosure or the part of the disclosure that is incorporated by reference only cross-reference such reference.

[0153] In this disclosure, some exemplary and non-limiting examples have been described and / or presented with reference to flow diagrams. In such flow diagrams, a method is illustrated and described as a series of blocks (or steps). Unless specifically stated otherwise in the relevant description, the order of the blocks can vary from the order illustrated in the flow diagram (including two or more of the blocks (or steps) being performed in a different order, simultaneously, and / or repeatedly). The fact that a block (or step) can be implemented as logic (which can also be described as implementing the block (or step) as logic) is also within the scope of this disclosure. In some applications, a block (or step) can represent multiple representations and / or operations to be performed by multiple functionally equivalent circuits or other logic devices. The illustrated blocks can represent executable instructions that cause a computer, a processor, and / or other logic device to respond, perform an operation, change a state, generate an output or display, and / or make a determination, but it is not necessary to represent such executable instructions.

[0154] The various disclosed elements of the apparatus and system, as well as the steps of the methods disclosed herein, are not necessarily essential to all of the apparatuses, systems, and methods according to this disclosure. This disclosure includes all novel and inventive combinations and sub-combinations of the various elements and steps disclosed herein. Further, one or more of the various elements and steps disclosed herein can define a separate and independent inventive subject matter separate from the overall disclosed apparatus, system, or method. Accordingly, such inventive subject matter need not be associated with the specific apparatuses, systems, and methods explicitly disclosed herein, and such inventive subject matter may find utility in apparatuses, systems, and / or methods not explicitly disclosed herein.

Claims

Claim 1 A control surface actuator assembly (100) for selectively pivoting a control surface (20) relative to a support structure (40), comprising: a support structure (40); a control surface (20) operatively coupled to the support structure (40) and configured to pivot relative to the support structure (40) about a control surface pivot axis (22); a torque generating hydraulic actuator (2110); a control horn hydraulic actuator (1110) pivotally coupled to the torque generating hydraulic actuator (2110) and operatively coupled to the control surface (20); each of the torque generating hydraulic actuator (2110) and the control horn hydraulic actuator (1110) comprising: a corresponding hydraulic actuator housing (120) and a corresponding rod (140) at least partially extending within the corresponding hydraulic actuator housing (120), the corresponding rod (140) being configured to translate parallel to the corresponding hydraulic actuator housing (120) along a corresponding actuator axis (122); a corresponding hydraulic valve (200) for regulating the flow of hydraulic fluid (81) to the corresponding hydraulic actuator housing (120) to control the position of the corresponding rod (140) relative to the corresponding hydraulic actuator housing (120). The torque generating hydraulic actuator (2110) and the control horn hydraulic actuator (1110) are configured to pivot relative to each other about an actuator connecting shaft (28). The torque generating hydraulic actuator (2110) is configured to apply torque to the control surface (20) via the control horn hydraulic actuator (1110) in order to pivot the control surface (20) relative to the support structure (40). The control horn hydraulic actuator (1110) is configured to selectively vary the moment arm length (30) of the control horn hydraulic actuator (1110) measured between the control surface pivot axis (22) and the actuator connecting shaft (28) in order to at least partially adjust the torque applied to the control surface (20) by the torque generating hydraulic actuator (2110). The corresponding hydraulic actuator housings (120) of both the torque generating hydraulic actuator (2110) and the control horn hydraulic actuator (1110) include an inertia (300). The inertia (300) is configured to resist the acceleration of the corresponding rod (140) relative to the corresponding hydraulic actuator housing (120). Each of the torque generating hydraulic actuator (2110) and the control horn hydraulic actuator (1110) further includes a corresponding piston (142). The corresponding piston (142) extends into the corresponding hydraulic actuator housing (120) and defines a corresponding first chamber (124) and a corresponding second chamber (128) on both sides of the corresponding piston (142) within the corresponding hydraulic actuator housing (120). The corresponding rod (140) extends from the corresponding piston (142) and extends out of the corresponding hydraulic actuator housing (120). The hydraulic pressure difference of the hydraulic fluid (81) in each of the corresponding first chamber (124) and the corresponding second chamber (128) acts to move the corresponding piston (142) within the corresponding hydraulic actuator housing (120) and translate the corresponding rod (140) along the corresponding actuator shaft (122). One or both of the torque generating hydraulic actuator (2110) and the control horn hydraulic actuator (1110) further includes a corresponding support rod (141), and the corresponding support rod (141) extends from the corresponding piston (142) to the opposite side of the corresponding rod (140) and is operably connected to the corresponding hydraulic actuator housing (120). Flight control surface actuator assembly (100). [

2. ] The control horn hydraulic actuator (1110) is configured to selectively change the moment arm length (30) within a range of values defined between the minimum moment arm length (30) and the maximum moment arm length (30) of the control horn hydraulic actuator (1110) and including the minimum moment arm length (30) and the maximum moment arm length (30), and the maximum moment arm length (30) is at least 1.5 times the minimum moment arm length (30). The flight control surface actuator assembly (100) according to claim 1. [

3. ] The corresponding hydraulic valve (200) of one or both of the torque generating hydraulic actuator (2110) and the control horn hydraulic actuator (1110) is a 4-way 3-position hydraulic valve (200). The flight control surface actuator assembly (100) according to claim 1 or 2. [

4. ] The corresponding hydraulic valve (200) of one or both of the torque generating hydraulic actuator (2110) and the control horn hydraulic actuator (1110) is a dual spool hydraulic valve (202). The flight control surface actuator assembly (100) according to any one of claims 1 to 3. [

5. ] The dual spool hydraulic valve (202) has A fluid input portion (242) configured to receive a flow of high-pressure hydraulic fluid; A fluid boost input portion (244) configured to receive a flow of hydraulic fluid at a boost pressure higher than the pressure of the flow of high-pressure hydraulic fluid; A fluid return portion (246) configured to discharge a flow of low-pressure hydraulic fluid; A first outlet (250) fluidly connected to the first chamber (124) of the corresponding hydraulic actuator housing (120); A second outlet (252) fluidly connected to the second chamber (128) of the corresponding hydraulic actuator housing (120). A first spool manifold (204) that is selectively fluidly connected to two or more of the fluid input section (242), the fluid boost input section (244), the fluid return section (246), the first outlet (250), and the second outlet (252); A second spool manifold (206) that is selectively fluidly connected to two or more of the fluid input section (242), the fluid boost input section (244), the fluid return section (246), the first outlet (250), and the second outlet (252); A first spool (210) positioned at least substantially within the first spool manifold (204), the first spool (210) including a corresponding first spool shaft (212) and one or more corresponding first spool blocks (214) mounted on the first spool shaft (212); A second spool (220) positioned at least substantially within the second spool manifold (206), the second spool (220) including a corresponding second spool shaft (222) and one or more corresponding second spool blocks (224) mounted on the second spool shaft (222); A first spool actuator (216) configured to selectively translate the first spool (210) parallel to the first spool manifold (204); A second spool actuator (226) configured to selectively translate the second spool (220) parallel to the second spool manifold (206) independently of the first spool (210). Translating the first spool (210) relative to the first spool manifold (204) and translating the second spool (220) relative to the second spool manifold (206) changes the pressure of the hydraulic fluid (81) in each of the first chamber (124) and the second chamber (128) of the corresponding hydraulic actuator housing (120) to translate the corresponding rod (140) relative to the corresponding hydraulic actuator housing (120). The hydraulic valve (200) corresponding to the fluid inlet (242), the fluid boost inlet (244), the fluid return (246), the first outlet (250), and the second outlet (252) is configured to act to regulate the flow of the hydraulic fluid (81) therebetween. The control surface actuator assembly (100) according to claim 4.

6. The dual spool hydraulic valve (202) of the control surface actuator assembly (100) according to claim 5 is configured to enable fluid communication between the first outlet (250) and the second outlet (252).

7. The corresponding hydraulic actuator housing (120) includes at least one pressure sensor (160) positioned in one or both of the first chamber (124) and the second chamber (128). Each pressure sensor (160) is configured to generate a pressure signal indicative of the pressure of the hydraulic fluid (81). The dual spool hydraulic valve (202) is configured to selectively fluidly connect the fluid boost inlet (244) to one or both of the first outlet (250) and the second outlet (252) based at least in part on the pressure signal. The control surface actuator assembly (100) according to claim 5 or 6.

8. The control surface (20) of the control surface actuator assembly (100) according to any one of claims 1 to 7 is one or more of an aileron, a rudder, an elevator, a flap, a spoiler, and an air brake.

9. The support structure (40) of the control surface actuator assembly (100) according to any one of claims 1 to 8 includes one or more of a wing, a horizontal stabilizer, and a vertical stabilizer.

10. An aircraft (10) comprising: One or more control surfaces (20); The control surface actuator assembly (100) according to any one of claims 1 to 9 for pivoting at least one of the one or more control surfaces (20), and an aircraft hydraulic system (50) for operating the control surface actuator assembly (100). An aircraft (10).

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