Flap Actuation System for Aircraft

Abstract

The present invention relates to a flap actuation system for an aircraft, and a system for actuating a flap coupled to an aircraft wing in a downstream airflow direction is disclosed herein. The system includes a gear-type rotary actuator that includes a drive gear rotatable about a first axis of rotation. The system further includes a crankshaft that includes a driven gear in gear meshing engagement with the drive gear of the gear-type rotary actuator to cause the crankshaft to rotate about a second axis of rotation. The second axis of rotation is angled relative to the first axis of rotation. The system further includes a crank arm that is commonly rotatably coupled to the crankshaft and configured to be coupled to the flap. Rotation of the crankshaft about the second axis of rotation causes the crank arm to rotate in a direction perpendicular to the second axis of rotation.

Description

Technical Field

[0001] The present disclosure generally relates to aircraft, and more particularly to systems for actuating flaps coupled to the wings of an aircraft. Background Art

[0002] Flaps coupled to the wings of an aircraft are used to regulate the lift generated by the wings. For example, the flaps are extended to increase drag and lift during takeoff and landing and retracted at cruise speed. The flaps extend and retract along a set motion path. Actuating the flaps in an economically efficient, simple, and lightweight manner along the set motion path in the direction of the oncoming airflow can be difficult, especially in the case of the swept and relatively thin wings of today's commercial aircraft. Summary of the Invention

[0003] In response to the state of the art, and in particular to the disadvantages of conventional flap actuation systems and methods, the subject matter of the present application has been developed. The subject matter of the present application provides examples of flap actuation systems and corresponding methods for aircraft that overcome the above disadvantages of the prior art.

[0004] Disclosed herein is a system for actuating a flap coupled to a wing of an aircraft in the direction of the oncoming airflow. The system includes a gear-type rotary actuator that includes a drive gear rotatable about a first axis of rotation. The system further includes a crankshaft that includes a driven gear in gear meshing engagement with the drive gear of the gear-type rotary actuator to cause the crankshaft to rotate about a second axis of rotation. The second axis of rotation is angled relative to the first axis of rotation. The system further includes a crank arm rotatably coupled to the crankshaft and configured to be coupled to the flap. Rotation of the crankshaft about the second axis of rotation causes the crank arm to rotate in a direction perpendicular to the second axis of rotation. The foregoing subject matter of this paragraph characterizes Example 1 of the present disclosure.

[0005] When the second axis of rotation is perpendicular to the direction of the oncoming airflow, the first axis of rotation is parallel to the wingspan direction of the wing. The foregoing subject matter of this paragraph characterizes Example 2 of the present disclosure, where Example 2 further includes the subject matter described in Example 1 above.

[0006] The drive gear includes a bevel gear, and the driven gear includes a spool gear. The foregoing subject matter of this paragraph characterizes Example 3 of the present disclosure, where Example 3 further includes the subject matter described in any one of Examples 1-2 above. The crankshaft includes a central passage that is coaxial with the second axis of rotation and extends completely through the crankshaft. The diameter of the central passage varies along the second axis of rotation. The foregoing subject matter of this paragraph characterizes Example 4 of the present disclosure, where Example 4 further includes the subject matter described in any one of Examples 1-3 above.

[0007] The diameter of the central passage decreases and increases along the second axis of rotation. The foregoing subject matter of this paragraph characterizes Example 5 of the present disclosure, where Example 5 also includes the subject matter described in Example 4 above.

[0008] The crankshaft includes a central portion having a constant outer dimension along the second axis of rotation. The crankshaft further includes a first flared portion having an outer dimension that increases along the second axis of rotation away from the central portion. The crankshaft further includes a second flared portion that is spaced from the first flared portion by the central portion and has an increasing outer dimension along the second axis of rotation away from the central portion. The foregoing subject matter of this paragraph characterizes Example 6 of the present disclosure, where Example 6 also includes the subject matter described in any one of Examples 4-5 above.

[0009] The diameter of the central passage is constant within the central portion, increases away from the central portion within the first flared portion, and increases away from the central portion within the second flared portion. The foregoing subject matter of this paragraph characterizes Example 7 of the present disclosure, where Example 7 also includes the subject matter described in Example 6 above.

[0010] The central portion has a non-circular cross-sectional shape in a plane perpendicular to the second axis of rotation. The foregoing subject matter of this paragraph characterizes Example 8 of the present disclosure, where Example 8 also includes the subject matter described in any one of Examples 6-7 above.

[0011] The crank arm includes a first part and a second part attached together around the central portion of the crankshaft. The first part and the second part define a crank hole having a shape complementary to the non-circular cross-sectional shape of the central portion. The foregoing subject matter of this paragraph characterizes Example 9 of the present disclosure, where Example 9 also includes the subject matter described in Example 8 above.

[0012] The system further includes a torque shaft passing through the central passage of the gear-type rotary actuator and the crankshaft. The torque shaft is rotatably coupled to the drive gear to drive the drive gear to rotate about a first axis of rotation. The torque shaft passes through the central passage of the crankshaft without contacting the crankshaft. When the torque shaft passes through the central passage, the torque shaft is angled relative to the second axis of rotation. The foregoing subject matter of this paragraph characterizes Example 10 of the present disclosure, where Example 10 also includes the subject matter described in any one of Examples 4-9 above.

[0013] The torque shaft is rotatable about the first axis of rotation. The foregoing subject matter of this paragraph characterizes Example 11 of the present disclosure, where Example 11 also includes the subject matter described in Example 10 above.

[0014] The system further includes a torque tube that surrounds and is concentric with the torque axis. The torque tube is rotatably coupled with the torque axis. The torque tube is in direct gear meshing engagement with a gear-type rotary actuator to transfer torque from the torque axis to the gear-type rotary actuator. The foregoing subject matter of this paragraph characterizes Example 12 of the present disclosure, wherein Example 12 further includes the subject matter according to any one of Examples 10-11 above.

[0015] The gear-type rotary actuator includes a housing. The drive gear is at least partially located within the housing. At least a portion of the crankshaft is positioned to be within the housing. The foregoing subject matter of this paragraph characterizes Example 13 of the present disclosure, wherein Example 13 further includes the subject matter according to any one of Examples 1-12 above.

[0016] The system further includes a first support rib that is perpendicular to the second rotation axis and includes a mounting surface. The system further includes a second support rib that is parallel to and spaced apart from the first support rib. The crankshaft is between the first support rib and the second support rib. The gear-type rotary actuator is directly coupled to the second support rib. The foregoing subject matter of this paragraph characterizes Example 14 of the present disclosure, wherein Example 14 further includes the subject matter according to any one of Examples 1-13 above.

[0017] The crankshaft is hollow and has a spool shape. The foregoing subject matter of this paragraph characterizes Example 15 of the present disclosure, wherein Example 15 further includes the subject matter according to any one of Examples 1-14 above.

[0018] This document further discloses an aircraft including a fuselage. The aircraft further includes wings that are coupled to the fuselage and extend from the fuselage in the spanwise direction. The aircraft further includes flaps that are coupled to the wings and are extendable from the wings. The aircraft further includes a system coupled to the wings. The system includes a gear-type rotary actuator that includes a drive gear rotatable about a first rotation axis. The system further includes a crankshaft that includes a driven gear in gear meshing engagement with the drive gear of the gear-type rotary actuator to cause the crankshaft to rotate about a second rotation axis. The second rotation axis is angled relative to the first rotation axis. The system further includes a crank arm that is rotatably coupled to the crankshaft and is coupled to the flap. Rotation of the crankshaft about the second rotation axis causes the crank arm to rotate and causes the flap to move in a direction perpendicular to the second rotation axis. The foregoing subject matter of this paragraph characterizes Example 16 of the present disclosure.

[0019] The first rotation axis is parallel to the spanwise direction of the wing. The direction perpendicular to the second rotation axis is the airflow direction of the wing. The foregoing subject matter of this paragraph characterizes Example 17 of the present disclosure, wherein Example 17 further includes the subject matter according to Example 16 above.

[0020] The crankshaft includes a central passage that is coaxial with a second axis of rotation and extends completely through the crankshaft. The diameter of the central passage varies along the second axis of rotation. The system further includes a torque shaft that passes through the central passage of the gear-type rotary actuator and the crankshaft. The system also includes a torque tube that is rotatably coupled to the torque shaft and rotatably coupled to the drive gear to drive the rotation of the drive gear about a first axis of rotation. The torque shaft passes through the central passage of the crankshaft without contacting the crankshaft. The torque shaft and the torque tube are rotatable about the first axis of rotation. The foregoing subject matter of this paragraph characterizes Example 18 of the present disclosure, where Example 18 further includes the subject matter according to any one of Examples 16-17 above.

[0021] The aircraft further includes a second flap that is coupled to the wing and is extendable from the wing. The aircraft further includes a second system that has the same characteristics as the system and is coupled to the wing. The crank arm of the second system is coupled to the second flap. The system also includes a second torque tube that is rotatably coupled to the torque shaft and rotatably coupled to the drive gear of the gear-type rotary actuator of the second system to drive the rotation of the drive gear of the gear-type rotary actuator of the second system about the first axis of rotation. The foregoing subject matter of this paragraph characterizes Example 19 of the present disclosure, where Example 19 further includes the subject matter according to Example 18 above.

[0022] Also disclosed herein is a method of actuating a flap coupled to an aircraft wing in a downstream flow direction relative to the wing. The method includes rotating a drive gear of a gear-type rotary actuator about a first axis of rotation parallel to the spanwise direction of the wing. The method further includes transmitting torque to a driven gear of the crankshaft to rotate the driven gear of the crankshaft about a second axis of rotation that is angled relative to the first axis of rotation and perpendicular to the downstream flow direction. The method further includes rotating a crank arm in the downstream flow direction in response to the rotation of the driven gear about the second axis of rotation. The method further includes translating the flap in the downstream flow direction in response to the movement of the crank arm in the downstream flow direction. The foregoing subject matter of this paragraph characterizes Example 20 of the present disclosure.

[0023] The features, structures, advantages, and / or characteristics described for the subject matter of the present disclosure may be combined in any suitable manner in one or more examples including embodiments and / or implementations. In the following description, numerous specific details are provided to afford a thorough understanding of examples of the subject matter of the present disclosure. Those skilled in the relevant art will recognize that the subject matter of the present disclosure may be practiced without one or more of the specific features, details, components, materials, and / or methods of a particular example, embodiment, or implementation. In other instances, additional features and advantages may be recognized that are not present in all examples, embodiments, or implementations. Further, in some instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of the subject matter of the present disclosure. The features and advantages of the subject matter of the present disclosure will become more fully apparent from the following description and the appended claims, or may be learned by practice of the subject matter as set forth below. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] To more readily understand the advantages of the present subject matter, the above-briefly-described subject matter will be described in more detail by reference to specific examples illustrated in the accompanying drawings. It is to be understood that these drawings depict only typical examples of the subject matter and are not to be considered limiting of its scope. The subject matter will be described and explained with additional features and details by use of the accompanying drawings, in which:

[0025] Figure 1 is a perspective view of an aircraft according to one or more examples of the present disclosure;

[0026] Figure 2 is a perspective view of an aircraft wing with a flap in a retracted position according to one or more examples of the present disclosure;

[0027] Figure 3 is a perspective view of a wing with a flap in an extended position according to one or more examples of the present disclosure Figure 2 of;

[0028] Figure 4 is a cross-sectional side view of an aircraft wing, flap, and flap actuation system according to one or more examples of the present disclosure;

[0029] Figure 5 is a perspective view of a flap actuation system as viewed from one side of the flap actuation system according to one or more examples of the present disclosure;

[0030] Figure 6 is a perspective view of a Figure 5 flap actuation system as viewed from the other side of the flap actuation system according to one or more examples of the present disclosure;

[0031] Figure 7A top plan view of two flap actuation systems coupled together by a common torque shaft according to one or more examples of the present disclosure;

[0032] Figure 8 A top plan view of a flap actuation system according to one or more examples of the present disclosure;

[0033] Figure 9 A cross-sectional top plan view of a flap actuation system according to one or more examples of the present disclosure;

[0034] Figure 10 A side view of a flap actuation system according to one or more examples of the present disclosure;

[0035] Figure 11 A perspective view of a geared rotary actuator and a crankshaft of a flap actuation system according to one or more examples of the present disclosure;

[0036] Figure 12 A perspective view of a geared rotary actuator and a crankshaft of a flap actuation system according to one or more examples of the present disclosure;

[0037] Figure 13 A perspective view of a crankshaft of a flap actuation system according to one or more examples of the present disclosure;

[0038] Figure 14 A perspective view of a shaft engagement portion of a crank arm of a flap actuation system according to one or more examples of the present disclosure; and

[0039] Figure 15 A method of actuating a flap coupled to an aircraft wing according to one or more examples of the present disclosure. Detailed Description

[0040] Throughout the specification, reference to "one example", "an example", or similar language means that a particular feature, structure, or characteristic described in connection with the example is included in at least one example of the present disclosure. Throughout the specification, the appearances of the phrases "in one example", "in an example", and similar language may, but do not necessarily, all refer to the same example. Similarly, the use of the term "embodiment" means an embodiment having a particular feature, structure, or characteristic described in connection with one or more examples of the present disclosure, however, an embodiment may be associated with one or more examples without indicating an explicit association.

[0041] The present disclosure relates to a system for actuating a flap coupled to an aircraft wing. The system allows for actuating the flap in the downstream direction by a gear-driven rotary actuator that is in line with a torque tube extending in the spanwise direction of the wing. The gear-driven rotary actuator facilitates actuating the flap in the downstream direction while providing a significant Fowler range of motion. Additionally, the compactness of the gear-driven rotary actuator allows it to be accommodated within the relatively thin wings of today's modern aircraft. Further, arranging the gear-driven rotary actuator in line with the torque tube helps to simplify the system, reduce weight, and effectively transfer power from the torque tube to the gear-driven rotary actuator and then to the flap.

[0042] Referring Figure 1 , an embodiment of an aircraft 100 is shown. The aircraft 100 can be any of a variety of types of aircraft, such as a commercial aircraft for transporting passengers, a military aircraft for military operations, a personal aircraft, etc. As shown, the aircraft 100 represents a passenger aircraft. The depicted aircraft 100 includes a fuselage 112 (e.g., a body), a pair of wings 114 coupled to and extending from the fuselage 112, a vertical stabilizer 116 coupled to the fuselage 112, and a pair of horizontal stabilizers 118 coupled to the fuselage 112 and / or the vertical stabilizer 116.

[0043] Referring Figure 4 , each wing 114 includes an outer upper surface 115 and an outer lower surface 117. The outer upper surface 115 is opposite the outer lower surface 117. Additionally, the outer upper surface 115 and the outer lower surface 117 converge at the leading edge 132 of the wing 114. The outer upper surface 115 and the outer lower surface 117 extend in the chordwise direction away from the leading edge 132 and terminate at a trailing edge location. Each wing 114 includes an internal cavity defined between the outer upper surface 115 and the outer lower surface 117. As Figure 4 shown, each wing 114 includes a rear spar 164 (e.g., the most rearward spar) within the internal cavity. The rear spar 164 extends between the upper skin of the wing 114 that defines the outer upper surface 115 and the lower skin of the wing 114 that defines the outer lower surface 117. Further, the rear spar 164 extends in the spanwise direction along the length or span of the wing 114. In other words, as defined herein, the spanwise direction 172 is the direction parallel to the rear spar 164, and in some examples, due to the sweep of the wing 114, the rear spar 164 is not perpendicular to the downstream direction 170 or the centerline of the fuselage 112 of the aircraft 100. Although not shown, the wing 114 can include other internal structures within the internal cavity, such as stringers, additional spars, and ribs, which stiffen the wing 114 and maintain its shape.

[0044] The aircraft 100 also includes a plurality of adjustable elements, which may be adjustable aerodynamic surfaces that are adjustable to change the characteristics of the airflow above, around, and trailing edge of the surface. For example, each wing 114 has ailerons 124, flaps 126, spoilers 128, and slats 130 coupled thereto. Additionally, the vertical stabilizer 116 includes a rudder 122, and each horizontal stabilizer 118 includes an elevator 120. In the responsive control of the flight of the aircraft 100, the relative positions of the adjustable aerodynamic surfaces of the aircraft (such as Figure 1 those shown) should be capable of being precisely adjusted.

[0045] The flap 126 is coupled to the wing 114 and is selectively actuatable relative to the wing 114 to facilitate the desired flight characteristics of the aircraft 100. Specifically, each flap 126 can extend away from the respective wing 114 in the downstream airflow direction 170 (e.g., see Figure 4 and Figure 7 ) to an extended position and retract towards the respective wing 114 in the downstream airflow direction 170 to a retracted position. In the retracted position (e.g., flap up position), as Figure 2 and Figure 4 shown, the combined camber of the wing 114 and the flap 126 is minimized, which reduces lift and drag. Thus, when the aircraft 100 is cruising at high altitude, the flaps 126 are typically in the retracted position. In the extended position as Figure 3 shown (e.g., flap down position), the combined camber of the wing 114 and the flap 126 is a certain camber greater than the minimum value (e.g., the maximum value), which increases lift and drag. Thus, when the aircraft 100 is flying at a lower speed, such as during approach, takeoff, and landing, the flaps 126 are typically in the extended position. To further increase lift and reduce drag, the spoilers 128 can be raised as Figure 3 shown.

[0046] Referring to Figure 3 , each flap 126 includes an inner end 127 and an outer end 129. The outer end 129 is opposite the inner end 127. In some embodiments, the flap 126 is an elongated structure having an aerodynamic profile. For example, the flap 126 can be elongated in the longitudinal direction extending from the inner end 127 to the outer end 129. The cross-sectional shape or aerodynamic profile of the flap 126 is based on the cross-sectional shape or aerodynamic profile of the wing 114. Generally, the flap 126 serves as a chordwise extension of the wing 114. More specifically, the wing 114 includes a flap slot in which the flap 126 is stored in the retracted position. As Figure 4As shown, the profile of the flap 126 is configured such that in the retracted position, the outer surface of the flap 126 is substantially flush with the outer surface of the wing 114. In particular, when retracted, the flap 126 abuts the trailing end of the outer lower surface 117 of the wing 114 to form an almost seamless transition between the outer lower surface 117 and the flap 126. Similarly, with the flap 126 retracted and the spoiler 128 lowered, the flap 126 abuts the spoiler 128, the spoiler hinge being coupled to the trailing end of the outer upper surface 115 to form an almost seamless transition between the outer upper surface 115, the spoiler 128 and the flap 126. Thus, as Figure 2 shown, when the flap 126 is in the retracted position and the spoiler 128 is lowered, the combined cross-sectional profile of the wing 114, the spoiler 128 and the flap 126 defines a conventional airfoil shape. In this way, as Figure 4 shown, the trailing edge 134 of the flap 126 effectively acts as the trailing edge of the wing 114 opposite the leading edge 132 of the wing 114.

[0047] Referring Figure 4 , the flap 126 includes a main axis 176 about which the flap 126 is rotatable. The main axis 176 defines a main axis of rotation about which the flap 126 rotates when actuated by the flap actuation system 140, as described below. In some embodiments, the main axis 176 is defined by a continuous rod or pin or coaxial aligned rod or pin segments that are translationally fixed relative to the leading edge 132 of the wing 115. The leading edge 133 of the flap 126 is opposite the trailing edge 134 of the flap 126. The main axis 176 is indirectly coupled to the flap 126 via a linkage and a mounting bracket 163 fixed to the flap 126. The main axis 176 extends through aligned holes in the support ribs of the flap actuation system 140 and facilitates rotation of the flap 126 relative to the wing 115 when the flap 126 is actuated by the actuator arm 166 of the flap actuation system 140. In other words, the actuation system 140 facilitates rotatably coupling the flap 126 and the wing 114 together at the main axis 176. The actuation system 140 may extend below the nominal wing surface of the wing 114 into a space defined by a fairing 119 coupled to the wing 114.

[0048] Referring again to Figure 3, the aircraft 100 may additionally include at least one auxiliary support system 151. However, it is recognized that the flap actuation system 140 of the present disclosure can operate with or without the auxiliary support system 151. Generally, the flap actuation system 140 initiates and drives the actuation of the flap 126 relative to the wing 114, and if present, the auxiliary support system 151 mechanically supports the flap 126 at an auxiliary position of the flap 126 when the flap 126 is actuated. In other words, the auxiliary support system 151 is configured to limit the deflection and bending of the flap 126 during flight at an auxiliary position of the flap 126 where the auxiliary support system 151 is coupled to the flap 126 when the flap 126 is extended and during positive extension and positive retraction. The auxiliary position of the flap 126 is a position on the flap 126 that is spaced apart from the flap actuation system 140 along the length of the flap 126. For example, the flap actuation system 140 and the auxiliary support system 151 are spaced apart along the spanwise direction 172 of the wing 114.

[0049] The flap actuation system 140 is selectively operable to extend the flap 126 from the wing 114 along an extension path and retract the flap 126 toward the wing 114 along the same extension path. The extension path represents the translational movement of the flap 126 when the flap actuation system 140 actuates the flap 126. Accordingly, the flap actuation system 140 includes a linkage that includes an actuating arm 166 configured to move the leading edge 133 of the flap 126 along the extension path when the flap actuation system 140 actuates the flap 126. The flap actuation system 140 actuates in a first manner (e.g., the crankshaft 144 rotates in one direction) to extend the flap 126 from a retracted position (e.g., see Figure 2 ) to an extended position (e.g., see Figure 3 ) along the extension path away from the wing 114 in the extension direction. Similarly, the actuator 141 actuates in a second manner (e.g., the crankshaft 144 rotates in the opposite direction) to retract the flap 126 from the extended position to the retracted position along the extension path toward the wing 114 in a retraction direction opposite to the extension direction. In one embodiment, the extension path includes a linear portion (e.g., Fowler motion) and a curved portion (e.g., curvilinear motion).

[0050] In some embodiments, the linkage of the flap actuation system 140 is further configured to rotate the flap 126 about a main axis 176 as the flap 126 undergoes translational movement along the extension path. In this way, the flap 126 can undergo translational and rotational movement when the flap 126 is extended and retracted by the flap actuation system 140.

[0051] Referring to Figure 6 and Figure 7, according to one example, the flap actuation system 140 includes a gear-type rotary actuator 142 and a crankshaft 144. The gear-type rotary actuator 142 includes a drive gear 160 rotatable about a first axis of rotation 168 (see Figure 8 ). The gear-type rotary actuator 142 also includes a housing 143 that houses one or more planetary gear sets and at least partially houses the drive gear 160. The drive gear 160 is coupled to the planetary gear set, and the planetary gear set drives the drive gear 160. Thus, the drive gear 160 serves as the output of the gear-type rotary actuator 142. The input to the gear-type rotary actuator 142 is provided by a torque tube 150. In other words, the torque tube 150 is coupled to the planetary gear set of the gear-type rotary actuator 142 to transfer torque from the torque tube 150 to the planetary gear set. The planetary gear set is configured to reduce the rotational speed of the drive gear 160 and increase the torque with respect to the rotational speed and torque of the torque tube 150.

[0052] The flap actuation system 140 further includes a torque shaft 152. The torque tube 150 is rotatably coupled to the torque shaft 152 in common, for example, by a splined engagement with the torque shaft 152. The torque tube 150 surrounds and is concentric with an end of the torque shaft 152. In other words, the torque tube 150 is hollow, and an end of the torque shaft 152 enters an end of the hollow central passage of the torque tube 150. In one example, the torque shaft 152 includes external splines that engage complementary internal splines of the torque tube 150 to facilitate co-rotation between the torque shaft 152 and the torque tube 150. According to some examples, the torque shaft 152 is made of a first material, and the torque tube 150 is made of a second material different from the first material. In one example, the first material (e.g., steel) is stronger than the second material (e.g., aluminum).

[0053] The torque for driving the flap actuation system 140 is provided directly from a torque source of the aircraft 100 to a torque tube 150. A torque shaft 152 passes through a gear-type rotary actuator 142 and a crankshaft 144 and reconnects to another segment of the torque tube 150, as described below. In this way, the torque shaft 152 facilitates the transfer of torque from one segment of the torque tube 150 through the gear-type rotary actuator 142 and the crankshaft 144 to another segment of the torque tube 150. In some examples, the torque source is located inside the wing 114, or in other examples within the wing, and can be any of a variety of devices or systems configured to generate torque, such as a motor, a power take-off device, etc. The torque source rotates the torque tube 150 about a first axis of rotation 168. Thus, the torque shaft 152 of the gear-type rotary actuator 142, the torque tube 150, and the drive gear 160 are concentric or rotate about the same axis. In this way, the gear-type rotary actuator 142 is in line with the torque shaft 152 and the torque tube 150. This in-line arrangement allows the torque tube 150 to be directly coupled to the gear-type rotary actuator 142 without an intermediate shaft and an angled gearbox, which would be necessary to redirect torque from the torque tube 150 to the gear-type rotary actuator 142 if the torque tube 150 were not in line with the gear-type rotary actuator 142.

[0054] The crankshaft 144 of the flap actuation system 140 is rotated by a drive gear 160 of the gear-type rotary actuator 142. More specifically, the drive gear 160 rotates the crankshaft 144 about a second axis of rotation 174 (e.g., see Figure 8 ). The second axis of rotation 174 is angled relative to the first axis of rotation 168. In other words, an angle θ is defined between the first axis of rotation 168 and the second axis of rotation 174. In some examples, the angle θ is less than 90 degrees. According to certain examples, the angle θ depends on the sweep of the wing 114 or the angle defined between the spanwise direction 172 of the wing 114 and the airframe 112 of the aircraft 100. The greater the sweep of the wing 114, or the greater the angle between the spanwise direction 172 and the airframe 112, the greater the angle θ. Additionally, the second axis of rotation 174 is perpendicular to the airflow direction 170, which facilitates the translational movement of the flap 126 in the airflow direction 170. The first axis of rotation 168 is angled greater than or less than 90 degrees relative to the airflow direction 170. Thus, to ensure that the second axis of rotation 174 is perpendicular to the airflow direction 170, the second axis of rotation 174 is angled relative to the first axis of rotation 168 by the angle θ.

[0055] The crankshaft 144 includes a driven gear 162 that is in gear meshing engagement with a drive gear 160 of a gear-type rotary actuator 142. The drive gear 160 rotates the crankshaft 144 through gear meshing engagement with the driven gear 162. The driven gear 162 rotates about a second axis of rotation 174. Since the driven gear 162 rotates about an axis that is angled relative to the axis about which the drive gear 160 rotates, the driven gear 162 and the drive gear 160 are configured to facilitate the transfer of rotation about one axis to rotation about another angled axis. Thus, in some examples, at least one of the drive gear 160 or the driven gear 162 includes beveled teeth. In one example, the drive gear 160 is beveled teeth and the driven gear 162 is a spur gear.

[0056] Referring Figure 11 and Figure 12 , the driven gear 162 is formed in at least one of two end portions 159 of the crankshaft 144. More specifically, the driven gear 162 includes an annular array of teeth formed in an inner surface of at least one of the two end portions 159. The crankshaft 144 further includes a central portion 184 inserted between the two end portions 159. The crankshaft 144 further includes two flared portions 158 inserted between the two end portions 159. Additionally, the central portion 184 is interposed between the two flared portions 158. In some examples, the central portion 184 has a constant outer dimension along the second axis of rotation 174, while each flared portion 158 has an increasing outer dimension away from the central portion 184. In certain examples, the outer dimension of the flared portion 158 is a diameter. The end portions 159 have a constant outer dimension along the second axis of rotation 174. The outer dimension of the flared portion 158 is greater than the outer dimension of the central portion 184. Additionally, the outer dimension of the end portion 159 is greater than the outer dimension of the flared portion 158. Thus, the crankshaft 144 has a spool shape (e.g., a narrow middle tapering to wider ends). The spool shape of the crankshaft 144 facilitates the central passage 154 of the crankshaft 144, which is also of a spool shape.

[0057] The central passage 154 of the crankshaft 144 extends through the crankshaft 144 from one end portion 159 to the opposite end portion 159. Accordingly, the crankshaft 144 is hollow. Further, the central passage 154 is coaxial with the second rotational axis 174. The diameter (e.g., internal dimension) of the central passage 154 varies along the second rotational axis 174. More specifically, in some examples, from one end portion 159 to the other end portion 159, the diameter of the central passage 154 decreases and increases along the second rotational axis 174. In one example, the diameter of the central passage 154 is constant (e.g., a first diameter (d1)) within the central portion 184, is constant (e.g., a second diameter (d2)) within the end portions 159, and increases continuously from the central portion 184 to a respective one of the end portions 159 within the flared portion 158. Accordingly, the second diameter (d2) of the central passage 154 within the flared portion 158 is greater than the first diameter (d1) of the central passage 154 within the central portion 184. See Figure 9 , the varying diameter of the central passage 154 (e.g., a diameter that continuously increases away from the central portion 184) allows the torque shaft 152 to pass through the central passage 154 at an angle relative to the second rotational axis 174 without contacting or interfering with the rotation of the crankshaft 144. The ratio of the first diameter (d1) to the second diameter (d2) depends on the angle θ and the distance D between the first support rib 146A and the second support rib 146B (e.g., see Figure 9 ). For example, the greater the angle θ and / or the greater the distance D, the smaller the ratio of the first diameter (d1) to the second diameter (d2).

[0058] The various portions of the crankshaft 144 are rotatable together such that rotation of the driven gear 162 formed in one of the two end portions 159 causes rotation of the other end portion 159, the flared portion 158, and the central portion 184. According to one example, the central portion 184, the flared portion 158, and the end portions 159 form a one-piece integral seamless configuration.

[0059] Referring to Figure 11 and Figure 12 , the housing 143 of the gear-type rotary actuator 142 is sized to allow at least a portion of the crankshaft 144 to be located within the housing 143. In the example shown, a portion of the end portion 159 (including the driven gear 162) is located within the housing 143. This configuration contributes to the compactness of the flap actuation system 140, which is desirable when space within the internal cavity of the wing 114 is limited.

[0060] As Figure 9As shown, the torque shaft 152 passes completely through the central passage 154 of the gear-type rotary actuator 142 and the crankshaft 144. Thus, gear reduction relative to the torque shaft 152 is facilitated by the gear-type rotary actuator 142, allowing the crankshaft 144 to rotate independently. This allows the torque shaft 152 to distribute torque to the torque tube 150, which leads to other flap actuator systems 140 to actuate other flaps. For example, as Figure 7 shown and from right to left, the first section of the torque tube 150 is directly coupled to the first gear-type rotary actuator 142 to drive the first gear-type rotary actuator 142. The first torque shaft 152 extends completely through the central passage 154 of the first gear-type rotary actuator 142 and the first crankshaft 144 and is rotatably coupled to the second section of the torque tube 150 on the opposite side of the crankshaft 144. The second section of the torque tube 150 extends away from the first gear-type rotary actuator 142 and is directly coupled to the second gear-type rotary actuator 142 to drive the second gear-type rotary actuator 142. Another torque shaft 152 rotatably coupled to the second section of the torque tube 150 extends completely through the central passage 154 of the second gear-type rotary actuator 142 and the second crankshaft 144 and is rotatably coupled to the third portion of the torque tube 150 on the opposite side of the second crankshaft 144. The third portion of the torque tube 150 may extend to a third gear-type rotary actuator (not shown) to drive the third gear-type rotary actuator, or it may extend to another driven system.

[0061] Before passing through the gear-type rotary actuator 140 and the crankshaft 144 of the flap actuator system 140, the torque shaft 152 receives torque from a section of the torque tube 150 on the side of the gear-type rotary actuator 140 and transfers the torque to another section of the torque tube 150 on the opposite side of the gear-type rotary actuator 140. In Figure 7 it, two flap actuator systems 140 are configured to actuate a respective one of the two flaps 126 in the direction of the oncoming airflow 170 while allowing the torque shaft 152 to pass through the flap actuator system 140 at an angle relative to the oncoming airflow 170.

[0062] Referring to Figure 8 and Figure 13, the flap actuation system 140 further includes a crank arm 156 that is coupled to the flap 126 to translationally move (e.g., extend or retract) the flap 126 upon rotation. The crank arm 156 is commonly rotatably coupled to a central portion 184 of the crankshaft 144. In some examples, to facilitate coupling of the crank arm 156 to the central portion 184 after the torque shaft 152 passes through the crankshaft 144, the crank arm 156 includes a first part 180 and a second part 182 that are attached together around the central portion 184. In effect, the first part 180 and the second part 182 are clamped down onto the central portion 184 to maintain the common rotatable coupling of the crank arm 156 to the crankshaft 144. In some examples, the first part 180 and the second part 182 are attached together by a fastener 192.

[0063] To facilitate the common rotation of the crank arm 156 relative to the crankshaft 144, the central portion 184 has a non-circular cross-sectional shape along a plane perpendicular to the second axis of rotation 174. In one example, the non-circular cross-sectional shape is octagonal. However, in other examples, the non-circular cross-sectional shape can be hexagonal, oval, triangular, or any other non-circular cross-sectional shape. The first part 180 and the second part 182 of the crank arm 156 together define a crank hole 190 that has a shape complementary (e.g., matching) to the cross-sectional shape of the central portion 184. In this way, when the first part 180 and the second part 182 are attached around the central portion 184, the complementary non-circular shapes of the crank hole 190 and the central portion 184 resist relative rotation between the crank arm 156 and the crankshaft 144. A second portion 182 of the crank arm 156 further includes an arm hole 191 configured to pivotally engage a support arm 166. The arm hole 191 is located at a distance from the crank hole 190. This distance corresponds to the desired stroke or range of motion of the support arm 166 as the crankshaft 144 rotates, and thus corresponds to the desired stroke or range of motion of the flap 126.

[0064] The flap actuation system 140 further includes a first support rib 146A and a second support rib 146B. The first support rib 146A is spaced from the second support rib 146B along the second axis of rotation 174. Additionally, the first support rib 146A and the second support rib 146B are parallel to each other and perpendicular to the second axis of rotation 174. The first support rib 146A and the second support rib 146B facilitate attachment of the gear-type rotary actuator 142 and the crankshaft 144 inside the wing 114. Refer to Figure 8, the second support rib 146B includes a mounting surface 147 that is angled relative to the second axis of rotation 174. The mounting surface 147 helps to facilitate the angled attachment of the geared rotary actuator 142 to the second support rib 146B. More specifically, the geared rotary actuator 142 is directly coupled (e.g., flush) to the mounting surface 147 of the second support rib 146B. To provide further support for the angled attachment of the geared rotary actuator 142 to the second support rib 146B, the second support rib 146B may also include a mounting pad 181 that projects from the second support rib 146B. The mounting pad 181 defines a mounting surface that is coplanar with the mounting surface 147 such that the mounting surface of the mounting pad 181 is also angled relative to the second axis of rotation 174.

[0065] The crankshaft 144 is disposed between the first support rib 146A and the second support rib 146B and is rotatably coupled to the first support rib 146A and the second support rib 146B. More specifically, each of the first support rib 146A and the second support rib 146B includes a hole 149 that is configured to receive and rotatably support a respective end portion 159 of the crankshaft 144. In some examples, a first bearing 178A is fitted in the hole 149 of the first support rib 146A, and a second bearing 178B is fitted in the hole 149 of the second support rib 146B. The first bearing 178A and the second bearing 178B are respectively inserted between the respective end portions 159 of the crankshaft 144 and facilitate low-friction rotation of the crankshaft 144 relative to the first support rib 146A and the second support rib 146B. The first bearing 178A and the second bearing 178B may be ball bearings or other similar types of bearings.

[0066] The first support rib 146A and the second support rib 146B are immovably fixed to the wing 114. In some examples, the flap actuator system 140 further includes a rear spar bracket 148 that helps to immovably fix the first support rib 146A and the second support rib 146B to the rear spar 164 of the wing 114.

[0067] According to some examples, a method 200 of using a flap actuation system 140 to actuate a flap 126 includes (block 210) rotating a drive gear 160 of a geared rotary actuator 142 about a first axis of rotation 168. In one example, a torque shaft 152 is rotated by a selectively controllable torque generator and thus rotates a torque tube 150 to rotate the drive gear 160. The method 200 further includes (block 220) transferring torque to a driven gear 162 of a crankshaft 144 to rotate the driven gear 162 of the crankshaft 144 about a second axis of rotation 174. For example, torque is transferred from the drive gear 160 to the driven gear 162 through gear meshing engagement between the driven gear 162 and the drive gear 160. The method 200 further includes (block 230) rotating a crank arm 156 in a downstream airflow direction 170 in response to rotation of the driven gear 162 about the second axis of rotation 174. The crank arm 156 rotates as the driven gear 162 rotates because the driven gear 162 is rotatably coupled to the crankshaft 144 (e.g., formed integrally with the crankshaft 144), and the crank arm 156 is rotatably coupled to the crankshaft 144. The method 200 further includes (block 240) translating the flap 126 in the downstream airflow direction 170 in response to movement of the crank arm 156 in the downstream airflow direction 170. The crank arm 156 is movably coupled to the flap 126 via an actuator arm 166 and any one of a variety of other linkages, brackets, or beams.

[0068] In the above description, certain terms may be used, such as "upward", "downward", "upper", "lower", "horizontal", "vertical", "left", "right", "above", "below", and the like. These terms are used, when applicable, to provide some clarity in dealing with relative relationships. However, these terms are not intended to imply absolute relationships, positions, and / or directions. For example, for an object, simply turning the object over, the "upper" surface can become the "lower" surface. Nevertheless, it is still the same object. Additionally, unless otherwise expressly stated, the terms "comprises", "comprising", "has", and their variants mean "including but not limited to". Unless otherwise expressly stated, a list of enumerated items does not imply that any or all of the items are mutually exclusive and / or mutually inclusive. Unless otherwise expressly stated, the terms "a", "an", and "the" also refer to "one or more". Additionally, the term "plurality" may be defined as "at least two".

[0069] Additionally, as used in this specification, an example of one element "coupled" to another element may include direct coupling and indirect coupling. Direct coupling may be defined as one element being coupled to and making some form of contact with another element. Indirect coupling may be defined as a coupling between two elements that do not directly contact each other, but have one or more additional elements between the coupled elements. Further, as used herein, fixing one element to another element may include direct fixing and indirect fixing. Additionally, as used herein, "adjacent" does not necessarily mean in contact. For example, one element may be adjacent to another element without contacting that element.

[0070] As used herein, the phrase "at least one" when used with a list of items means that different combinations of one or more of the listed items may be used and only one of the items in the list may be required. The item may be a particular object, thing, or category. In other words, "at least one" means any combination or several of the items that may be used from the list, but not necessarily all of the items in the list. For example, "at least one of item A, item B, and item C" may mean item A; item A and item B; item B; item A, item B, and item C; or item B and item C. In certain cases, "at least one of item A, item B, and item C" may mean, for example but not limited to, two item As, one item B, and ten item Cs; four item Bs and seven item Cs; or other suitable combinations.

[0071] Unless otherwise specified, the terms "first", "second", etc. are used herein only as labels and are not intended to impose an order, position, or hierarchical requirement on the items to which these terms refer. Further, the mention of, for example, a "second" item does not require or preclude the existence of, for example, a "first" or lower-numbered item and / or a "third" or higher-numbered item.

[0072] As used herein, a system, apparatus, structure, article, element, component, or hardware "configured to" perform a specified function is capable of performing the specified function without any change, rather than simply having the potential to perform the specified function after further modification. In other words, a system, apparatus, structure, article, element, component, or hardware "configured to" perform a specified function is specifically selected, created, implemented, utilized, programmed, and / or designed for the purpose of performing the specified function. As used herein, "configured to" means that the existing features of a system, apparatus, structure, article, element, component, or hardware enable the system, apparatus, structure, article, element, component, or hardware to perform the specified function without further modification. For the purposes of this disclosure, a system, apparatus, structure, article, element, component, or hardware described as "configured to" perform a particular function may additionally or alternatively be described as "adapted to" and / or "operable to" perform that function.

[0073] The schematic flowcharts included in this document are generally presented as logical flowcharts. As such, the depicted order and labeled steps indicate an example of the proposed method. Other steps and methods may be envisioned that are equivalent in function, logic, or effect to one or more steps or portions thereof of the illustrated method. Additionally, the format and symbols employed are provided to explain the logical steps of the method and are understood not to limit the scope of the method. Although various arrow types and line styles may be used in the flowchart, they are to be understood as not limiting the scope of the corresponding method. In fact, some arrows or other connectors may be used to merely indicate the logical flow of the method. For example, an arrow may indicate a waiting or monitoring period of unspecified duration between enumerated steps of the depicted method. Additionally, the order of occurrence of a particular method may or may not strictly follow the order of the corresponding steps shown.

[0074] In addition, the present disclosure includes embodiments according to the following clauses:

[0075] Clause 1. A system (140) for actuating a flap (126) coupled to a wing (114) of an aircraft (100) in a downstream airflow direction (170), the system (140) comprising:

[0076] A geared rotary actuator (142) including a drive gear (160) rotatable about a first axis of rotation (168);

[0077] A crankshaft (144) including a driven gear (162) that is in meshing engagement with the drive gear (160) of the geared rotary actuator (142) to rotate the crankshaft (144) about a second axis of rotation (174), wherein the second axis of rotation (174) is angled relative to the first axis of rotation (168); and

[0078] Crank arms (156) that are rotatably coupled together to the crankshaft (144) and configured to be coupled to the flap (126), wherein rotation of the crankshaft (144) about the second axis of rotation (174) causes the crank arms (166) to rotate in a direction perpendicular to the second axis of rotation (174).

[0079] Clause 2. The system (140) according to Clause 1, wherein the first axis of rotation (168) is parallel to the spanwise direction (172) of the wing (114) when the second axis of rotation (174) is perpendicular to the downstream airflow direction (170).

[0080] Clause 3. The system (140) according to Clause 1 or 2, wherein:

[0081] The drive gear (160) includes a bevel gear; and

[0082] The driven gear (162) includes a long gear.

[0083] Clause 4. The system (140) according to any one of Clauses 1 - 3, wherein:

[0084] The crankshaft (144) includes a central passage (154) that is coaxial with a second axis of rotation (174) and extends completely through the crankshaft (144); and

[0085] The diameter of the central passage 154 varies along the second axis of rotation (174).

[0086] Clause 5. The system (140) according to Clause 4, wherein the diameter of the central passage (154) decreases and increases along the second axis of rotation (174).

[0087] Clause 6. The system (140) according to any one of Clauses 1 - 5, wherein the crankshaft (144) includes:

[0088] A central portion (184) having a constant outer dimension along the second axis of rotation (174);

[0089] A first flared portion (158) having an outer dimension that increases away from the central portion (184) along the second axis of rotation (174); and

[0090] A second flared portion (158) that is spaced from the first flared portion by the central portion (184) and has an outer dimension that increases away from the central portion (184) along the second axis of rotation (174).

[0091] Clause 7. The system (140) according to Clause 6, wherein the diameter of the central passage (154):

[0092] Is constant within the central portion (184);

[0093] Increases away from the central portion (184) within the first flared portion (158); and

[0094] Increases away from the central portion (184) within the second flared portion (158).

[0095] Clause 8. The system (140) according to Clause 6 or 7, wherein the central portion (184) has a non - circular cross - sectional shape in a plane perpendicular to the second axis of rotation (174).

[0096] Clause 9. The system (140) according to Clause 8, wherein:

[0097] The crank arm (156) includes a first part (180) and a second part (182) attached together around a central part (184) of the crankshaft (144); and

[0098] The first part (180) and the second part (182) define a crank hole (190) whose shape is complementary to the non-circular cross-sectional shape of the central part (184).

[0099] The system (140) according to any one of clauses 4 - 9 further includes a torque shaft (152) passing through a central passage (154) of the gear-type rotary actuator (142) and the crankshaft (144), wherein:

[0100] The torque shaft (152) is rotatably coupled to the drive gear (160) to drive the drive gear (160) to rotate about a first axis of rotation (168);

[0101] The torque shaft (152) passes through the central passage (154) of the crankshaft (144) without contacting the crankshaft (144); and

[0102] When the torque shaft (152) passes through the central passage (154), the torque shaft (152) is angled with respect to a second axis of rotation (174).

[0103] The system (140) according to clause 10, wherein the torque shaft (152) is capable of rotating about the first axis of rotation (168).

[0104] The system (140) according to clause 10 or 11 further includes a torque tube (150) surrounding the torque shaft (152) and concentric with the torque shaft (152), wherein:

[0105] The torque tube (150) is co-rotatably coupled with the torque shaft (152); and

[0106] The torque tube (150) is directly gear-engaged with the gear-type rotary actuator (142) to transfer torque from the torque shaft (152) to the gear-type rotary actuator (142).

[0107] The system (140) according to any one of clauses 1 - 12, wherein:

[0108] The gear-type rotary actuator (142) includes a housing (143);

[0109] The drive gear (160) is at least partially located within the housing (143); and

[0110] At least a portion of the crankshaft (144) is located within the housing (143).

[0111] Clause 14. The system (140) according to any one of Clauses 1 - 13 further includes:

[0112] A first support rib (146A) perpendicular to the second axis of rotation (174) and including a mounting surface (147); and

[0113] A second support rib (146B) parallel to and spaced from the first support rib (146A);

[0114] Wherein:

[0115] The crankshaft (144) is disposed between the first support rib (146A) and the second support rib (146B); and

[0116] The gear - type rotary actuator (142) is directly coupled to the mounting surface (147) of the first support rib (146A).

[0117] Clause 15. The system (140) according to any one of Clauses 1 - 14, wherein the crankshaft (144) is hollow and has a spool shape.

[0118] Clause 16. An aircraft (100) includes:

[0119] A fuselage (112);

[0120] Wings (114) coupled to the fuselage (112) and extending from the fuselage in the wingspan direction;

[0121] Flaps (126) coupled to the wings (114) and extendable from the wings (114); and

[0122] A system (140) coupled to the wings (114) and including:

[0123] A gear - type rotary actuator (142) including a drive gear (160) rotatable about a first axis of rotation (168);

[0124] A crankshaft (144) including a driven gear (162) in gear - meshing engagement with the drive gear (160) of the gear - type rotary actuator (142) to rotate the crankshaft (144) about a second axis of rotation (174), wherein the second axis of rotation (174) is angled relative to the first axis of rotation (168); and

[0125] A crank arm (156) is commonly rotatably coupled to a crankshaft (144) and is coupled to a flap (126), wherein rotation of the crankshaft (144) about a second axis of rotation (174) causes the crank arm (166) to rotate and moves the flap (126) in a direction perpendicular to the second axis of rotation (174).

[0126] Clause 17. The aircraft (100) according to Clause 16, wherein:

[0127] A first axis of rotation (168) is parallel to the spanwise direction of the wing (114); and

[0128] The direction perpendicular to the second axis of rotation (174) is the direction of the oncoming airflow of the wing (114).

[0129] Clause 18. The aircraft (100) according to Clause 16 or 17, wherein:

[0130] The crankshaft (144) includes a central passage (154) that is coaxial with the second axis of rotation (174) and extends completely through the crankshaft (144);

[0131] The diameter of the central passage (154) varies along the second axis of rotation (174);

[0132] The system (140) further includes a torque shaft (152) that passes through the central passage (154) of the gear-type rotary actuator (142) and the crankshaft (144);

[0133] The system (140) further includes a torque tube (150) that is commonly rotatably coupled to the torque shaft (152) and is rotatably coupled to the drive gear (160) to drive the drive gear (160) to rotate about the first axis of rotation (168);

[0134] The torque shaft (152) passes through the central passage (154) of the crankshaft (144) without contacting the crankshaft (144); and

[0135] The torque shaft (152) and the torque tube (150) are rotatable about the first axis of rotation (168).

[0136] Clause 19. The aircraft (100) according to Clause 18, further comprising:

[0137] A second flap (126) that is coupled to the wing (114) and is extendable from the wing (114); and

[0138] A second system (140) that has the same characteristics as the system (140) and is coupled to the wing;

[0139] Wherein:

[0140] The crank arm (156) of the second system (140) is coupled to the second flap (126); and

[0141] The system (140) further includes a second torque tube (150) that is rotatably coupled with the torque shaft (152) and rotatably coupled with a drive gear (160) of a gear-type rotary actuator (142) of the second system (140), so as to drive the drive gear (160) of the gear-type rotary actuator (142) of the second system (140) to rotate about a first rotation axis (168).

[0142] Clause 20. A method (200) for actuating a flap (126) coupled to a wing (114) of an aircraft (100) in a downstream air flow direction (170) relative to the wing (114), the method (200) comprising:

[0143] Rotating a drive gear (160) of a gear-type rotary actuator (142) about a first rotation axis (168) parallel to the spanwise direction (172) of the wing (114);

[0144] Transmitting torque to a driven gear (162) of a crankshaft (144) to cause the driven gear (162) of the crankshaft (144) to rotate about a second rotation axis (174) that is angled relative to the first rotation axis (168) and perpendicular to the downstream air flow direction (170);

[0145] Rotating a crank arm (156) in the downstream air flow direction (170) in response to the rotation of the driven gear (162) about the second rotation axis (174); and

[0146] Translating the flap (126) in the downstream air flow direction (170) in response to the movement of the crank arm (156) in the downstream air flow direction (170).

[0147] Clause 21. An aircraft (100) comprising:

[0148] A fuselage (112);

[0149] A wing (114) coupled to the fuselage (112) and extending from the fuselage in the spanwise direction;

[0150] A flap (126) coupled to the wing (114) and extendable from the wing (114); and

[0151] The system (140) according to any one of Clauses 1-15.

[0152] Without departing from the spirit or essential characteristics of the present invention, the subject matter may be embodied in other specific forms. The described examples are to be considered illustrative only and not restrictive in all respects. All changes that come within the meaning and range of equivalency of the claims are to be embraced within their scope.

Claims

1. A system (140) for actuating a flap (126) coupled to a wing (114) of an aircraft (100) in a direction of the oncoming airflow (170), the system (140) comprising: A gear - type rotary actuator (142) including a drive gear (160) capable of rotating about a first axis of rotation (168); A crankshaft (144) including a driven gear (162) that is in gear - meshing engagement with the drive gear (160) of the gear - type rotary actuator (142) to cause the crankshaft (144) to rotate about a second axis of rotation (174), wherein the second axis of rotation (174) is angled relative to the first axis of rotation (168); and Crank arms (156) that are rotatably coupled together to the crankshaft (144) and configured to be coupled to the flap (126), wherein rotation of the crankshaft (144) about the second axis of rotation (174) causes the crank arms (156) to rotate in a direction perpendicular to the second axis of rotation (174), wherein the crankshaft (144) includes a central passage (154) that is coaxial with the second axis of rotation (174) and extends completely through the crankshaft (144); and The diameter of the central passage (154) varies along the second axis of rotation (174).

2. The system (140) according to claim 1, wherein the first axis of rotation (168) is parallel to the spanwise direction (172) of the wing (114) when the second axis of rotation (174) is perpendicular to the direction of the oncoming airflow (170).

3. The system (140) according to claim 1, wherein the crankshaft (144) comprises: A central portion (184) having a constant outer dimension along the second axis of rotation (174); A first flared portion having an outer dimension that increases away from the central portion (184) along the second axis of rotation (174); and A second flared portion that is spaced from the first flared portion by the central portion (184) and has an outer dimension that increases away from the central portion (184) along the second axis of rotation (174).

4. The system (140) according to claim 3, wherein the diameter of the central passage (154): is constant within the central portion (184); increases away from the central portion (184) within the first flared portion; and increases away from the central portion (184) within the second flared portion.

5. The system (140) according to claim 3, wherein the central portion (184) has a non-circular cross-sectional shape along a plane perpendicular to the second axis of rotation (174).

6. An aircraft (100) comprising: An airframe (112); A wing (114) coupled to the airframe (112) and extending from the airframe along the spanwise direction; A flap coupled to the wing (114) and capable of extending from the wing (114); and A system (140) according to any one of claims 1 - 5, coupled to the wing (114).

7. The aircraft (100) according to claim 6, wherein: The system (140) further includes a torque shaft (152) passing through the central passage (154) of the gear - type rotary actuator (142) and the crankshaft (144); The system (140) further includes a torque tube (150) that is rotatably coupled together with the torque shaft (152) and rotatably coupled to the drive gear (160) to drive the drive gear (160) to rotate about the first axis of rotation (168); The torque shaft (152) passes through the central passage (154) of the crankshaft (144) without contacting the crankshaft (144); and The torque shaft (152) and the torque tube (150) are capable of rotating about the first axis of rotation (168).

8. The aircraft (100) according to claim 7, further comprising: A second flap coupled to the wing (114) and capable of extending from the wing (114); and A second system having the same features as the system (140) and coupled to the wing; wherein: The crank arm (156) of the second system is coupled to the second flap; and The second system includes a second torque tube that is rotatably coupled with the torque shaft (152) of the system and rotatably coupled with the drive gear (160) of the gear-type rotary actuator (142) of the second system, so as to drive the drive gear (160) of the gear-type rotary actuator (142) of the second system to rotate about the first rotation axis (168).

9. A method (200) for actuating a flap (126) coupled to a wing (114) of an aircraft (100) in a downstream airflow direction (170) relative to the wing (114), the method (200) comprising: Rotate the torque tube about the first rotation axis; Transfer the torque of the torque tube to the planetary gear set of the gear-type rotary actuator; Rotate the drive gear (160) of the gear-type rotary actuator (142) about the first rotation axis (168) parallel to the span direction (172) of the wing (114), wherein the rotation speed of the drive gear (160) is less than the rotation speed of the torque tube, and wherein the drive gear is driven by the planetary gear set; Transfer the torque of the drive gear to the driven gear (162) of the crankshaft (144) to cause the driven gear (162) of the crankshaft (144) to rotate about a second rotation axis (174) that is angled relative to the first rotation axis (168) and perpendicular to the oncoming airflow direction (170), wherein the torque of the drive gear (160) is greater than the torque of the torque tube; Rotate the crank arm (156) in the oncoming airflow direction (170) in response to the rotation of the driven gear (162) about the second rotation axis (174); and Translate the flap (126) in the oncoming airflow direction (170) in response to the movement of the crank arm (156) in the oncoming airflow direction (170), wherein the crankshaft (144) includes a central passage (154) that is coaxial with the second rotation axis (174) and extends completely through the crankshaft (144); and The diameter of the central passage (154) varies along the second rotation axis (174).

Images