Systems and methods for tilting a rotor

Abstract

A system for tilting a rotor of an aircraft may include a support structure and an actuator coupled to the support structure. The system may include a linkage rotatively coupled to the actuator and including a first link and a second link. The first link may include a first end and a second end, where the first end may be rotatively coupled to the support structure and the second end may include a pivot. The pivot may define a pivot axis and be coupled to the second link of the linkage. The system may further include a plurality of blades coupled to the pivot and movable about the pivot axis between a horizontal position and a vertical position during actuation of the actuator. The pivot may be configured to remain stationary relative to the support structure during movement of the plurality of blades about the pivot axis.

Description

SYSTEMS AND METHODS FOR TILTING A ROTORCROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims priority to U.S. Provisional Application No. 63 / 633,400, filed April 12, 2024, which is incorporated by reference herein in its entirety.TECHNICAL FIELD

[0002] Embodiments of this disclosure are directed to tilting a rotor, and in particular, systems and methods for tilting a rotor of an aircraft.BACKGROUND

[0003] A tiltrotor is a type of aircraft that includes one or more rotors that may be dynamically tilted to support horizontal and vertical flight, including vertical takeoff and landing (“VTOL”). Such rotors are also referred to herein as “tilt-capable rotors.” Often times, a tiltrotor includes a wing component to which a boom or nacelle is attached. The boom or nacelle may be coupled to and / or house at least part of a rotor. When the tiltrotor undergoes conversion (e.g., a change in configuration), the orientation of one or more of the aircraft’s rotors begins to change. For example, a rotor may transition from a wingborne orientation configured to provide horizontal thrust, to a rotorborne orientation configured to provide vertical thrust. However, on some tiltrotors, the boom (or nacelle) to which the rotor is coupled includes a notch or cut-out to provide clearance for the rotor when the rotor is positioned for rotorborne flight. This notch may hinder the aerodynamics of a tiltrotor and detract from the aircraft’s appearance. Further, many tiltrotors include a moveable cover which may be positioned to seal the notch when the rotor is no longer positioned for rotorborne flight. However, such a cover increases the complexity of a tiltrotor. Accordingly, there is a need for an improved system and technique for tilting a rotor of an aircraft.

[0004] The background description provided herein is for the purpose of generally presenting the context of the disclosure. Unless otherwise indicated herein, the materials described in this section are not prior art to the claims in this application and are not admitted to be prior art, or suggestions of the prior art, by inclusion in this section.SUMMARY OF THE DISCLOSURE

[0005] According to certain aspects of the disclosure, systems and methods are disclosed for tilting (e.g., converting) a rotor of an aircraft.

[0006] In one aspect, a system for tilting a rotor of an aircraft is provided. The system may include a support structure and an actuator coupled to the support structure. The systemmay include a linkage rotatively coupled to the actuator and including a first link and a second link. The first link may include a first end and a second end, where the first end may be rotatively coupled to the support structure and the second end may include a pivot. The pivot may define a pivot axis and be coupled to the second link of the linkage. The system may further include a plurality of blades coupled to the pivot and movable about the pivot axis between a horizontal position and a vertical position during actuation of the actuator. The pivot may be configured to remain stationary relative to the support structure during movement of the plurality of blades about the pivot axis.

[0007] In another aspect, a method for tilting a rotor of an aircraft is provided. The method may include actuating an actuator to move, via a linkage including a first link and a second link, a hub in a substantially linear motion during a first stage of movement. A tilt of the hub may be substantially unchanged during the first stage of movement. The first link may include a first end rotatively coupled to the support structure and a second end including a pivot that defines a pivot axis. The second link of the linkage may be coupled to the actuator and the pivot. The method may further include moving the hub about the pivot axis between a horizontal position and a vertical position to change the tilt of the hub during a second stage of movement that is subsequent to the first stage of movement. The pivot may be configured to remain stationary relative to the support structure during the second stage of movement.

[0008] In yet another aspect, a system for tilting a rotor of an aircraft is provided. The system may include a support structure and an actuator coupled to the support structure. The system may include a linkage rotatively coupled to the actuator and including a first link and a second link. The first link may include a first end and a second end. The first end may be rotatively coupled to the support structure and the second end may include a pivot. The pivot may define a pivot axis and be coupled to the second link of the linkage. The system may further include a catch mechanism coupled to the support structure and configured to catch and to release an end of a third link of the linkage. The system may include a plurality of blades coupled to the pivot and movable about the pivot axis between a horizontal position and a vertical position during actuation of the actuator. The release of the end of the third link may cause the plurality of blades to move about the pivot axis from the horizontal position to the vertical position. The pivot may be configured to remain stationary relative to the support structure during movement of the plurality of blades about the pivot axis.

[0009] Additional objects and advantages of the disclosed embodiments will be set forth in part in the description that follows, and in part will be apparent from the description,or may be learned by practice of the disclosed embodiments. The objects and advantages of the disclosed embodiments will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims.

[0010] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosed embodiments, as claimed.BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate the disclosed embodiments, and together with the description, serve to explain the principles of the disclosed embodiments. There are many aspects and embodiments described herein. Those of ordinary skill in the art will readily recognize that the features of a particular aspect or embodiment may be used in conjunction with the features of any or all of the other aspects or embodiments described in this disclosure. In the drawings:

[0012] FIG. 1 depicts an aircraft according to various aspects of the present disclosure.

[0013] FIGS. 2A-2E depict an operation of a system for tilting a rotor of an aircraft, according to various aspects of the present disclosure.

[0014] FIG. 3 depicts an assembly for tilting a rotor of an aircraft, according to various aspects of the present disclosure.

[0015] FIG. 4 depicts a method for tilting a rotor of an aircraft, according to various aspects of the present disclosure.DETAILED DESCRIPTION

[0016] The terminology used below may be interpreted in its broadest reasonable manner, even though it is being used in conjunction with a detailed description of certain specific embodiments of the present disclosure. Indeed, certain terms may even be emphasized below; however, any terminology intended to be interpreted in any restricted manner will be overtly and specifically defined as such in this Detailed Description section. Both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the features, as claimed.

[0017] In this disclosure, the term “based on” means “based at least in part on.” The singular forms “a,” “an,” and “the” include plural referents unless the context dictates otherwise. The term “exemplary” is used in the sense of “example” rather than “ideal.” The terms “comprises,” “comprising,” “includes,” “including,” or other variations thereof, are intended to cover a non-exclusive inclusion such that a process, method, or product thatcomprises a list of elements does not necessarily include only those elements, but may include other elements not expressly listed or inherent to such a process, method, article, or apparatus. In addition, the terms “first,” “second,” and the like, herein do not denote any order, quantity, or importance, but rather are used to distinguish an element or a structure from another. Relative terms, such as, “substantially” and “generally,” are used to indicate a possible variation of ±10% of a stated or understood value.

[0018] Embodiments of the present disclosure may be incorporated on an aircraft or other vehicle. As used herein, “aircraft” may refer to an aerial, floating, soaring, hovering, airborne, aeronautical aircraft, airplane, plane, spacecraft, vessel, or virtually any other vehicle moving, or capable of moving, through air. Some non-limiting embodiments may include a helicopter, tiltrotor, an airship, an aerostat, a hot air balloon, a flight simulator, a vertical takeoff vehicle (e.g., an electric vertical takeoff and landing (“eVTOL”) vehicle), an unmanned aerial vehicle, a drone, a spacecraft, or commercial airplanes. Further, aspects of the present disclosure may be used in conjunction with any vehicle, including, but not limited to, vehicles designed for operation on land, on water, in the air, in space, or any combination thereof. The above list is not, in any matter, supposed to signify a limited list of what the term “aircraft” defines in terms of structure.

[0019] Notably, for simplicity and clarity of illustration, certain aspects of the figures depict the general structure and / or manner of construction of the various embodiments. Descriptions and details of well-known features and techniques may be omitted to avoid unnecessarily obscuring other features. Elements in the figures are not necessarily drawn to scale; the dimensions of some features may be exaggerated relative to other elements to improve understanding of the example embodiments. For example, one of ordinary skill in the art appreciates that the side views are not drawn to scale and should not be viewed as representing proportional relationships between different components. The side views are provided to help illustrate the various components of the depicted assembly, and to show their relative positioning to one another.

[0020] Reference will now be made in detail to embodiments of the present disclosure, which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.

[0021] The present disclosure generally provides for systems and methods for tilting a rotor of an aircraft configured for horizontal and vertical flight (e.g., a tiltrotor aircraft). In some embodiments, a system may include a support structure and an actuator coupled to thesupport structure. The system may also include a linkage rotatively coupled to the actuator and including a first link and a second link. The first link of the linkagemay include a first end and a second end. In some aspects, the first end may be rotatively coupled to the support structure, and the second end may be coupled to the second link of the linkage. Further, the second end may include a pivot that defines a pivot axis. The system may also include a plurality of blades coupled to the pivot and movable about the pivot axis. For example, during actuation of the actuator, the plurality of blades may move about the pivot axis between a horizontal position (e.g., for wingborne or horizontal flight) and a vertical position (e.g., for rotorbome or vertical flight). The pivot may be configured to remain stationary relative to the support structure during movement of the blades about the pivot axis.

[0022] In some embodiments, the system may also include a catch mechanism that is coupled to the support structure and configured to catch and release an end of a third link of the linkage. When the catch mechanism releases the end of the third link, the plurality of blades may move about the pivot axis from the horizontal position to the vertical position.

[0023] In some aspects, the system may further include a housing, such as a boom or nacelle, configured to house at least the actuator. However, unlike conventional systems for tilting a rotor, in which a boom (or nacelle) includes a notch or cutout to provide clearance for the rotor when the rotor is positioned for vertical flight, the housing of the present disclosure does not require such a notch or cutout. Consequently, embodiments of the present disclosure provide for improved aerodynamics and aesthetics. In addition, while many of the conventional systems include a cover to seal the notch or cutout, the disclosed embodiments do not include or require such a cover, and therefore provide a simpler design.

[0024] The subject matter of the present disclosure will now be described more fully hereinafter with reference to the accompanying drawings, which form a part hereof, and which show, by way of illustration, specific exemplary embodiments. An embodiment or implementation described herein as “exemplary” is not to be construed as preferred or advantageous, for example, over other embodiments or implementations; rather, it is intended to reflect or indicate that the embodiment s) is / are “example” embodiment(s). Subject matter may be embodied in a variety of different forms and, therefore, covered or claimed subject matter is intended to be construed as not being limited to any exemplary embodiments set forth herein; exemplary embodiments are provided merely to be illustrative. Likewise, a reasonably broad scope for claimed or covered subject matter is intended. Among other things, forexample, subject matter may be embodied as methods, devices, components, or systems. The following detailed description is, therefore, not intended to be taken in a limiting sense.

[0025] Throughout the specification and claims, terms may have nuanced meanings suggested or implied in context beyond an explicitly stated meaning. Likewise, the phrase “in one embodiment” or “in some embodiments,” or “in one aspect” or “in some aspects” as used herein does not necessarily refer to the same embodiment or aspect, and the phrase “in another embodiment” or “in another aspect” as used herein does not necessarily refer to a different embodiment or aspect. It is intended, for example, that claimed subject matter include combinations of exemplary embodiments in whole or in part.

[0026] With reference to FIG. 1 , an exemplary aircraft 100 according to various aspects of the present disclosure is depicted. The aircraft 100 may function to travel short and long distances to provide transportation to passengers, luggage, cargo, and / or other objects that one of ordinary skill in the art will appreciate. The aircraft 100 may include a fuselage 104, front wings 106, rear wings 107, tilt-capable rotors 130, 132, and 134, fixed rotors 133, and control surfaces 136. The aircraft 100 may be, for example, an eVTOL aircraft, and include one or more batteries in the fuselage 104.

[0027] As can be seen in FIG. 1, the fuselage 104 may function as a base or a body of the aircraft 100 and support the front wings 106, the rear wings 107, the tilt-capable rotors 130, 132, and 134, the fixed rotors 133, and the control surfaces 136. The fuselage 104 may include a cockpit, as well as an interior volume configured to house passengers, cargo, the like, or a combination thereof.

[0028] The front wings 106 may be connected with a forward portion of the fuselage 104. The rear wings 107 may be connected with an aft portion of the fuselage 104. The front wings 106 and the rear wings 107 may function to assist the aircraft 100 during flight by providing lift as the aircraft travels through the air during horizontal flight. In some embodiments, the front wings 106 and the rear wings 107 may function to connect the tilt- capable rotors 130, 132, and 134, and the fixed rotors 133, as well as the control surfaces 136, to the fuselage 104.

[0029] As shown in FIG. 1, each of the front wings 106 may be connected to a boom 140. Each boom 140 may have a first end and a second end, and be connected to a boom 142 at the first end and a boom 162 at the second end. In some embodiments, each of the booms 142 and 162 may be, for example, a housing or nacelle. Further, each of the rear wings 107 may be connected to one or more booms 146, where each boom 146 may be connected to aboom 142. In some aspects, the booms 140, 142, and 162 connected to a respective one of the front wings 106, may be configured to support tilt-capable rotors 130 and 132. Further, the booms 146 and 142 connected to a respective one of the rear wings 107, may be configured to support a tilt-capable rotor 134.

[0030] With reference to the X-Y-Z coordinate system depicted in FIG. 1, the tilt- capable rotors 130 and 134 are positioned in an upward, vertical orientation (e.g., during a rotorborne or vertical flight configuration), with blades 135 and 139, respectively, configured to rotate about an axis parallel to the X axis. The tilt-capable rotors 132 are positioned in a downward, vertical orientation, with blades 137 configured to rotate about an axis parallel to the X axis. While not shown in FIG. 1, in some embodiments, the tilt-capable rotors 132 may be positioned in an upward, vertical orientation, with blades 137 configured to rotate about an axis parallel to the X axis. Further, while not shown FIG. 1, the tilt-capable rotors 130, 132, and 134 may be positioned in a horizontal orientation during at least some phases of flight (e.g., during a wingborne or horizontal flight configuration), with the blades 135, 137, and 139, respectively, configured to rotate about axes parallel to the Y axis.

[0031] The control surfaces 136 may be connected with the front wings 106 and / or the rear wings 107, the boom 140, the boom 146, or any other surface of the aircraft 100 to assist with controlling the aircraft 100 during takeoff, landing, and / or flight. In some embodiments, the control surfaces 136 may be connected with the fuselage 104. Further, in some embodiments, the control surfaces 136 may be connected with one or more of the tilt-capable rotors 130, 132, and 134, and / or the booms 140 and 142. The control surfaces 136 may function to assist with maneuvering the aircraft 100 during flight. The control surfaces 136 may be elevators, rudders, ailerons, ruddervators, flaperons, trim, nacelle, flaps or any other control surfaces known to one of ordinary skill in the art. In some aspects, the control surfaces 136 may be configured to assist with moving the aircraft 100 in a plurality of degrees of freedom (e.g., by adjusting yaw, pitch, and roll). The control surfaces 136 may be configured to assist with converting the tilt-capable rotors 130, 132, and 134 (or the aircraft 100) between horizontal and vertical flight configurations.

[0032] In some embodiments, the tilt-capable rotors 130 and 132 may be connected to the front wings 106 through the booms 140, 142, and 162. Further, the tilt-capable rotors 134 may be connected to the back wings 107 through the booms 146 and 142. In some aspects, each of the booms 140, 142, 146, and 162 may be configured to support at least one tilt-capable rotor (e.g., the tilt-capable rotor 130, 132, or 134), control surface, mechanical system, the like,or a combination thereof. Further, each of the booms 140 may be configured to extend past each end of one of the front wings 106 to support the tilt rotors 130 and 132, and other components such as motors, linkages, actuators, or the like, or a combination thereof. In some embodiments, each boom 140 may be formed as a continuous body extending beyond the front and the rear of one of the front wings 106, such that the first end of the boom 140 is in front of the wing 106 and the second end of the boom 140 is behind the wing 106. In other embodiments, each boom 140 may be discontinuous, with separate front and rear portions that are not directly connected to each other, these front and rear portions forming first and second ends, respectively, in front of and behind one of the wings 106. While each boom 140 is depicted as being distinct from the booms 142 and 162 disposed on opposite ends of each respective boom 140, in some embodiments, the booms 140, 142, and 162 may collectively form a single, continuous structure. Further, while each boom 146 is depicted as being distinct from a boom 142 disposed on one side of each respective boom 146, in some embodiments, the booms 146 and 142 may collectively form a single, continuous structure. Further, in some embodiments, each of the booms 140, 142, 146, and 162 may form a continuous structure or two or more discontinuous structures.

[0033] In some aspects, each of the tilt-capable rotors 130, 132, and 134 may include a hub and a plurality of blades coupled to the hub. More specifically, the tilt-capable rotor 130 may include a hub 131 and a plurality of blades 135, where each blade of the plurality of blades 135 is coupled to the hub 131. The tilt-capable rotor 132 may include a hub 151 and a plurality of blades 137, where each blade of the plurality of blades 137 is coupled to the hub 151. Further, the tilt-capable rotor 134 may include a hub 161 and a plurality of blades 139, where each blade of the plurality of blades 139 is coupled to the hub 161. While each of the plurality of blades 135, 137, and 139 is shown as including five blades, in some embodiments, the number of blades included in the plurality of blades 135, 137, and 139 may be fewer than five blades or more than five blades. In some aspects, each of the hubs 131, 151, and 161, and the respective blades attached thereto, may be configured to rotate about an axis parallel to the X axis when tilt-capable rotors 130, 132, and 134 are positioned for takeoff and landing, as described below.

[0034] As shown in FIG. 1, the tilt-capable rotors 130, 132, and 134 may be connected with the front wings 106, the rear wings 107, or both. In some embodiments, the tilt-capable rotors 130, 132, and 134 may be connected with the fuselage 104. In some aspects, the tilt- capable rotors 130, 132, and 134 may be propulsion sources configured to move the aircraft100 vertically and / or horizontally. In some aspects, the tilt-capable rotors 130, 132, and 134 may be connected with one or more motors for rotating the tilt-capable rotors 130, 132, and 134 to produce thrust. In some embodiments, the tilt-capable rotors 130, 132, and 134 may pivot or tilt relative to the front wings 106 and rear wings 107 to transition between horizontal and vertical orientations (or positions). In some embodiments, the aircraft 100 may only have tilt-capable rotors 130, 132, and 134 as propulsion sources. In other embodiments, the tilt- capable rotors 130, 132, and 134 may be used in combination with other sources of propulsion, such as the fixed rotors 133, jet engines, the like, or a combination thereof. The tilt-capable rotors 130, 132, and 134 may provide a primary thrust for takeoff and landing when in the vertical position, as well as the thrust required to sustain altitude and velocity when in the horizontal position.

[0035] In some embodiments, the aircraft 100 may include two or more tilt-capable rotors. In one example, such as shown in FIG. 1, the aircraft 100 includes tilt-capable rotors 130 and 132 connected to each front wing 106, and a tilt-capable rotor 134 connected to each rear wing 107. It will be appreciated that even numbers of tilt-capable rotors may be connected to the aircraft 100. Further, the tilt-capable rotors 130, 132, and 134 may be configured to assist with moving the aircraft 100 in a plurality of degrees of freedom.

[0036] In some aspects, the fixed rotors 133 may be connected with the front wings 106, the rear wings 107, or both. As shown in FIG. 1, each of the fixed rotors 133 may have a respective, fixed axis of rotation parallel to the X axis. In some other embodiments, each of the fixed rotors 133 may have a respective, fixed axis of rotation parallel to the Y axis. In yet some other embodiments, one or more fixed rotors 133 may have a fixed axis of rotation parallel to the X axis, and one or more fixed rotors 133 may have a fixed axis of rotation parallel to the Y axis. The fixed rotors 133 may be a propulsion source to move the aircraft 100. In some embodiments, the fixed rotors 133 may provide thrust to the aircraft 100 during takeoff and landing, and may further provide enhanced maneuverability for the aircraft 100. While FIG. 1 shows that the aircraft 100 may include two fixed rotors 133, in some other embodiments, the aircraft 100 may include a different number of fixed rotors 133. Further, in some aspects, the fixed rotors 133 may be configured to assist with moving the aircraft 100 in at least one degree of freedom.

[0037] As shown in FIG. 1, each of the tilt-capable rotors 130, 132, and 134 may optionally include a housing 160 configured to house, at least in part, one or more components. In some embodiments, a housing 160 may be a structure configured connect the tilt-capablerotor 130 with the boom 142; the tilt-capable rotor 132 with the boom 162; or the tilt-capable rotor 134 with the boom 142. In some embodiments, the housings 160, like the tiltrotors 130, 132, and 134, may be configured to transition between an orientation corresponding to horizontal flight and an orientation corresponding to vertical flight. In some embodiments, the tilt-capable rotors 130, 132, and 134 may be connected to motors that are housed by the housings 160.

[0038] In some aspects, the aircraft 100 may translate and / or rotate about each of the X, Y, and Z axes. For example, the aircraft 100 may travel up or down the X axis at various times throughout a flight (e.g., during climbing, descending, takeoff, and / or landing). The aircraft 100 may also rotate about the X axis as shown by rotation arrow 120 for a yaw movement. The aircraft 100 may further move along the Y axis backward or forward, and rotate (or roll) about the Y axis, as shown by rotation arrow 122. Additionally, the aircraft 100 may travel laterally along the Z axis, and rotate about the Z axis to cause a pitch movement, as shown by rotation arrow 124.

[0039] FIGS. 2A-2E depict an operation of a system 200 for tilting a rotor 230, according to various aspects of the present disclosure. As shown in FIG. 2A, the rotor 230 includes a hub 251 configured to rotate about an axis 252. The rotor 230 also includes a plurality of blades (not shown in FIG. 2A) coupled to the hub 251. The rotor 230 may be an embodiment of the tilt-capable rotor 130, 132, and / or 134 of FIG. 1. In some aspects, the system 200 may be configured to operate (or move) in two stages to tilt or change the orientation of the rotor 230, as described below.

[0040] As shown in FIG. 2 A, the system 200 may include a structure 291, a carriage 290, and a motor 299. While the structure 291 is shown as a tapered plate in FIG. 2A, in some embodiments, the structure 291 may be a plate (or other structure) having a different shape. In some aspects, the structure 291 may be coupled to the rotor 230, the carriage 290, and the motor 299. The carriage 290 may be configured to carry (or hold) one or more components. For example, in some embodiments, the carriage 290 may be configured to carry the motor 299, an inverter, powered electronics, and / or other electronics associated with the motor 299. It is noted that the motor 299 is depicted schematically as a box in FIG. 2A. However, in some embodiments, the motor 299 may be of a different shape. In some aspects, the motor 299 may be configured to power the rotor 230 (e.g., direct or rotate the hub 251 and the plurality of blades connected thereto). While FIG. 2A shows that the system 200 includes one carriage290 and one motor 299, in some embodiments, the system 200 may include no carriage 290, more than one carriage 290, and / or more than one motor 299.

[0041] In some aspects, the system 200 may include a boom 242 configured to house one or more components. The boom 242 may be an embodiment of the boom 142 and / or 162 of FIG. 1. As shown in FIG. 2A, the boom 242 does not include (is free of) any notches or cutouts to provide clearance for the rotor 230.

[0042] The system 200 may include a support structure 269 configured to support various components. As shown in FIG. 2A, the support structure 269 may be disposed inside and outside of the boom 242. It is noted that the profile, dimensions, and positioning of the support structure 269 shown in FIG. 2A are merely examples.

[0043] In some embodiments, the system 200 may include an actuator 263 (also referred to herein as a “hydraulic cylinder 263” or a “cylinder 263”). The hydraulic cylinder 263 may include a rod configured to extend telescopically away from the cylinder 263. As shown in FIG. 2A, the actuator 263 may be coupled to the support structure 269 via a fixed joint 268. In some embodiments, the actuator 263 may also be coupled to a connector 271 and a bar 264, via a movable joint 266. In some aspects, the actuator 263 may be configured to apply a force in a substantially rightward direction (e.g., a direction away from the fixed joint 268), to cause the connector 271 and the bar 264 to move. For example, the actuator 263 may elongate to push the connector 271 and bar 264 in a direction away from the joint 268, generally rightward in the view of FIG. 2A. The actuator 263 may be, for example, a linear actuator, piston actuator, rotary actuator, electrical actuator, mechanical actuator, or any combination thereof.

[0044] As shown in FIG. 2A, the system 200 may include the bar 264 (e.g. a rod), which may be coupled to a bracket 267 via a joint 265. In some embodiments, the bracket 267 may be coupled to, or be part of, the support structure 269. Further, the joint 265 may be fixed to the bracket 267, and configured to move (or rotate) the bar 264 in direction A.

[0045] In some aspects, the system 200 may further include a support structure 270. The support structure 270 may include at least a first end 372 and a second end 371. In some embodiments, the support structure 270 may also include a third end 373 and a fourth end 374. It is noted that the shape of the support structure 270 in FIG. 2A is merely an example. The first end 372 of the support structure 270 may be coupled to the support structure 269. In some embodiments, the support structure 270 may include the support structure 269. As shown in FIG. 2A, the second end 371 of the support structure 270 may include a joint 277, which maybe a fixed joint or a movable joint. The joint 277 may define an axis of rotation 297 (denoted by a star in FIG. 2A). In some embodiments, the second end 371 of the support structure 270 may include a recess and a pin, and be coupled to a rod 375. Further, in some embodiments, the support structure 270 may be coupled to a catch link 273. As shown in FIG. 2A, the support structure 270 may be coupled to a cam-shaped link 280 (also referred to herein as a “link 280”), via the joint 277.

[0046] As shown in FIG. 2 A, the system 200 may optionally include the catch link 273, which may be a bar or structure having a first end and a second end. The first end of the catch link 273 may be coupled to the support structure 270 via the joint 277. The second end of the catch link 273 may include a catch mechanism 276. In some embodiments, the catch mechanism 276 may include a recess and be configured to catch (e.g., lock or hold) and release a joint 292. In some aspects, the joint 292 may be a movable joint and be configured to connect the links 272 and 274 to each other. In some embodiments, the joint 292 may include a pin configured to be caught by the catch mechanism 276. Further, in some other embodiments, the joint 292 may include a first portion of a pin, and the catch mechanism 276 may include a second (or remaining) portion of the pin configured to catch the first portion of the pin. In some embodiments, the catch mechanism 276 may include a hook instead of a portion of a pin. Further, in some embodiments, the catch mechanism 276 may include an electronically-driven actuator, an electronically-driven jaw, or a mechanical actuator (as shown) configured to catch and release the pin of the joint 292. It is noted that the shape of the catch link 273 in FIG. 2A is merely an example.

[0047] In some aspects, the system 200 may include a catch mechanism 377 in lieu of, or in addition to, the catch link 273. The catch mechanism 377 may include a recess and be configured to catch (e.g., lock or hold) and release the joint 292. As shown in FIG. 2A, the catch mechanism 377 may be coupled to the third end 373 of the support structure 270 by, for example, a link and / or one or more movable joints. In some embodiments, the catch mechanism 377 may include an electronically-driven actuator, an electronically-driven jaw, or a mechanical actuator (as shown) configured to catch and release the joint 292. It is noted that the shape, dimensions, and position of the catch mechanism 377 in FIG. 2A are merely examples.

[0048] In some embodiments, the system 200 may include the rod 375 and a spring 376 (shown as a box in FIG. 2A for simplicity). In some aspects, the rod 375 may be coupled to the third end 373 of the support structure 270. The rod 375 may also be coupled to, and extendthrough, the fourth end 374 of the support structure 270. The rod 375 may also be coupled to the spring 376 and the second end 371 of the support structure 270. More specifically, the rod 375 may be configured to be positioned with the recess of the second end 371 of the support structure 270. In some aspects, the rod 375 may be configured to move laterally (e.g., into or out of the recess within the second end 371 of the support structure 270) depending on the position of the moveable joint 292. For example, the rod 375 may be configured to move away from the second end 371 of the support structure 270 or leftward in the view of FIG. 2A (while the spring 376 retracts or compresses), when the joint 292 moves toward the catching mechanism 377. Conversely, the rod 375 may also be configured to move toward the second end 371 of the support structure 270 or rightward in the view of FIG. 2A (while the spring 376 expands), when the joint 292 moves away from the catching mechanism 377.

[0049] The system 200 may further include the cam-shaped link 280. In some embodiments, the link 280 may include a first end and a second end. The first end of the link 280 may be coupled to the support structure 270 via the joint 277, and be configured to rotate about the axis of rotation 297. The second, enlarged, end of the link 280 may be coupled to the structure 291 via a joint 279 (e.g., a pivot or pivot joint). In some aspects, the joint 279 may define an axis of rotation 298 (also referred to herein as a “tilt axis 298”) that is denoted by a plus sign (+) in FIG. 2 A. The structure 291, and in turn the rotor 230, the carriage 290, and the motor 299, may be configured to tilt or rotate about the tilt axis 298 via the joint 279. In some aspects, the link 280 (including the joint 279 and tilt axis 298) may be configured to rotate about the axis 297 of the joint 277 during a first stage of operation (also referred to herein as “a first stage of movement”) of the system 200. The link 280 (including the joint 279 and tilt axis 298) may be configured to remain stationary (or be fixed) during a second stage of operation (also referred to herein as “a second stage of movement”) of the system 200.

[0050] In some aspects, the system 200 may include a linkage 370. The linkage 370 may include the links 272, a274, and 280 — and a link 275, each of which is denoted by a dashed line in FIG. 2A. While the linkage 370 includes four links in FIG. 2A, in some other embodiments, the linkage 370 may include fewer than four links or more than four links. In some aspects, the linkage 370 is configured to move. For example, when the actuator 263 is actuated, the linkage 370 moves, thereby causing the structure 291, the rotor 230, the carriage 290, and the motor 299, to move as well.

[0051] As shown in FIG. 2A, the linkage 370 may be coupled to the actuator 263 via the connector 271. The connector 271 may include a first end that is rotatively coupled to theactuator 263 and the bar 264 via the movable joint 266. The connector 271 may also include a second end rotatively coupled to the linkage 370 via a movable joint 281. However, as explained above, in some embodiments, the system 200 may not include the connector 271. In such embodiments, the linkage 370 may be directly connected to the actuator 263 and the bar 264, via the movable joint 281 (or 266).

[0052] In some aspects, each of the links 272, 274, 275, and 280 may include a first end and a second end. The first end of the link 272 may be coupled to the link 275 and the connector 271, via the movable joint 281. The second end of the link 272 may be coupled to the link 274 via the movable joint 292. The first end of the link 274 may be coupled to the link 272 via the movable joint 292, and the second end of the link 274 may be coupled to the link 280, the support structure 270, and optionally the catch link 273, via the movable joint 277. In some aspects, the link 274 may be configured to pivot about the axis 297 of the joint 277. The first end of the link 275 may be coupled to the link 272 and the connector 271, via the movable joint 281, and the second end of the link 275 may be coupled to the link 280, the carriage 290, the motor 299, and the structure 291. The first end of the link 280 may be coupled to the link 274, the support structure 270, and optionally the catch link 273, via the movable joint 277. The second end of the link 280 may be coupled to the link 275, the carriage 290, the motor 299, and the structure 291.

[0053] During operation, the system 200 may undergo two stages of movement to tilt the rotor 230. The first stage of movement begins when the actuator 263 actuates (e.g., the rod of the cylinder 263 extends) while the rotor 230 is positioned horizontally, as shown in FIG. 2A. As the actuator 263 actuates, the rod of the actuator 263 exerts a force on the bar 264 and the connector 271. As shown in FIG. 2B, the bar 264 may begin to rotate about the joint 265 while the connector 271 moves away from the fixed joint 268; and the link 272 may begin to rotate about the joint 292. The link 275 may begin to move away from the fixed joint 268, which may cause the link 280 to rotate about the joint 277. As the link 280 rotates, the structure 291, the rotor 230, the carriage 290, and the motor 299 begin to move in a substantially linear motion.

[0054] Once the link 280 has rotated 90 degrees about the joint 277 (as shown in FIG. 2C), the recess (and a pin) within the second end 371 of the support structure 270 may cause the link 280 to become fixed or locked in place. At this point, the second stage of movement begins and the catch mechanism 276 releases the joint 292, while the actuator 263 continues to actuate. During the second stage of movement, the joint 279 and tilting axis 298 are stationaryrelative to the support structure 270, while the joint 292 moves downward and to the right (e.g., away from the catching mechanism 276 and the fixed joint 268), as shown in FIGS. 2C and 2D. Further, the links 272, 274, and 275, the carriage 290, the motor 299, the structure 291, and the rotor 230 may rotate about the tilting axis 298, as shown in FIGS. 2C and 2D.

[0055] In some embodiments, the second stage of movement may conclude when the rotor 230, including the plurality of blades (not shown in FIG. 2E), are positioned vertically for rotorbome flight (e.g., for VTOL), as shown in FIG. 2E. Put differently, the second stage of movement may conclude when the joint 292 reaches its lowest position (e.g., as far away from the catch mechanism 276 as possible), While not shown in FIG. 2E, in some embodiments, the system 200 may further include a pitch control system to adjust the pitch of the plurality of blades of the rotor 230 during the first and / or second stages of movement. An example of such a pitch control system is described in 00379-0033-00600, which is incorporated herein by reference.

[0056] In some aspects, the system 200 may be configured to return to the configuration shown in FIG. 2A from the configuration shown in FIG. 2E, by operating in reverse. That is, actuator 263 may begin to retract, causing the rotor 230, the structure 291, the carriage 290, the motor 299, and the links 272, 274, and 275 to rotate about the pivot axis 298 during a third stage of movement, as shown in FIGS. 2D and 2C, until, for example, a pin of the joint 292 is caught by the catch mechanism 276. At this point, the link 280 may become unlocked and begin to rotate about the joint 277 during a fourth stage of movement, as shown in FIG. 2B, until the link 280 reaches a final position (or has rotated 90 degrees), as shown in FIG. 2A.

[0057] In some embodiments, when the system 200 is configured to use the catch mechanism 377 (not the catch mechanism 276), the system 200 may perform operations substantially similar to those described above during the first, second, third, and fourth stages of movement. However, the second stage of movement may begin when the catch mechanism 377 releases the joint 292 (not shown in FIGS. 2A-2E), while the actuator 263 continues to actuate. Once the joint 292 is released, the rod 375 may begin to move toward the recess in the second end 371 of the support structure 270, and the spring 376 may begin to expand. The second stage of movement may conclude when the rod 375 becomes fixed (or locked) in the recess of the second end 371 of the support structure 270, and the rotor 230 is positioned vertically for rotorborne flight. Further, the third stage of movement may begin when the actuator 263 begins to retract, the rod 375 becomes unlocked and begins to move away from the recess in the second end 371 of the support structure 270, and the spring 376 begins toretract (or compress). The third stage of movement may conclude when the catch mechanism 377 catches the joint 292 and the link 280 begins to rotate about the joint 277.

[0058] As explained above, the system 200 provides a number of advantages. For example, the boom 242 does not include a notch or cutout to provide clearance for the tilt- capable rotor 230 when the rotor 230 is positioned for vertical flight, unlike conventional systems for tilting a rotor. As a result, in at least some embodiments, the boom 242 is more aerodynamic, efficient, and aesthetic. Further, the system 200 does not include or require a cover to seal a notch or cutout in the boom 242, and thus has a more simple design. Moreover, in embodiments in which the system 200 includes the connector 271, the connector 271 and the bar 264 increase the mechanical advantage of the system 200 during the first stage of movement (e.g., allowing the rotor 230, the structure 291, the carriage 290, the motor 299 and other components to extend farther away from the nacelle 242 than they would otherwise). Consequently, the blades of the rotor 230 are exposed to more free air and may thus generate more thrust (or lift) when in rotation. The blades of the rotor 230 also produce less downwash when in this configuration, which results in less interference to the boom 242. Further, when the system 200 includes the connector 271, and when the rotor 230 is extended away from the boom 242, the system 200 experiences greater stability, in part because the joints 265, 266 and 268 help to anchor various components to the support structure 269 and / or the boom 242. As a result, the likelihood of whirl flutter is reduced.

[0059] While the system 200 is described above as being implemented on an aircraft, in some aspects, the system 200 may be adapted for other contexts. That is, the system 200 may be modified to operate in any environment in which a device is moved from a horizontal position to a vertical position. In such an environment, the system 200 may not include various components, such as the rotor 230, the boom 242, the carriage 290, the motor 299, and / or the connector 271.

[0060] FIG. 3 depicts an assembly 300 for tilting a rotor of an aircraft, according to various aspects of the present disclosure. In some aspects, the assembly 300 may include tapering support plates 395, which may include surfaces 396 and 397. The assembly 300 may also include a plate 391, which may include a surface 398. The assembly 300 may further include a joint 379 (e.g., a pivot or pivot joint) that defines a pivot axis 380, as denoted by a star in FIG. 3. In some aspects, the joint 379 may be configured to rotatively couple the tapering support plates 395 and the plate 391 to each other.

[0061] In some embodiments, a motor and a rotor (neither of which is shown in FIG. 3), may be coupled to the surface 398 of the plate 391. The rotor may be an embodiment of the rotor 130, 132, and / or 134 of FIG. 1, and / or the rotor 230 of FIGS. 2A-2E, and may be used in the aircraft 100 instead of or in addition to one or more rotors having the structure described with respect to rotor 230.

[0062] Each of the surfaces 396 and 397 of the tapering support plates 395 may be connected to a boom or nacelle (not shown in FIG. 3). An actuator (not shown in FIG. 3) may be disposed between the surfaces 396 and 397, and coupled to the plate 391, near the joint 379. The actuator may be configured to apply a force to the plate 391, which may cause the plate 391 to rotate about the pivot axis 380.

[0063] In some other embodiments, the assembly 300 may be included in the system 200 of FIG. 2. For example, the tapering support plate 395 that includes surface 396 may be coupled to the link 275. The plate 391 may replace the structure 291, such that the rotor 230 is connected to the plate 391 at the surface 398. Further, the second end of the link 280 may be positioned between, or on either side of, the tapering support plates 395, and coupled to the plate 391 via the joint 379 (which may be an embodiment of the joint 279). In some aspects, the plate 391 may be configured to rotate about the pivot axis 380 from a vertical position (as shown in FIG. 3) to a horizontal position.

[0064] FIG. 4 depicts a method 400 for tilting a rotor of an aircraft, according to various aspects of the present disclosure. The method 400 may be performed by the system 200 of FIGS. 2A-2E, and the rotor may be an embodiment of the rotor 130, 132, and / or 134 of FIG. 1 and / or the rotor 230 of FIGS. 2A-2E.

[0065] As shown in FIG. 4, the method 400 may include, at step 402, actuating an actuator (e.g., the actuator 263 of FIGS. 2A-2E) to move a hub during a first stage of movement. In some embodiments, the actuator may be actuated to move, via a linkage including a first link and a second link, the hub in a substantially linear motion during the first stage of movement. The actuator may be, for example, a linear actuator. In some aspects, the actuator may be directly coupled to the support structure via a first joint (e.g., the joint 268 of FIGS. 2A-2E), and indirectly coupled to the support structure via a second joint (e.g., the joint 265 of FIGS. 2A-2E), where each of the first and second joints is configured to stabilize the rotor. The linkage may be an embodiment of the linkage 370 of FIGS. 2A-2E, and the hub may be an embodiment of the hub 131, 151, and / or 161 of FIG. 1 and / or the hub 251 of FIGS. 2A-2E. The hub may be included in the rotor, and be coupled to a motor. In some aspects, the motormay be configured to cause the hub, and a plurality of blades attached thereto, to rotate about a horizontal axis for horizontal flight when the hub and the plurality of blades are in the horizontal position. Further, the motor may be configured to cause the hub and the plurality of blades to rotate about a vertical axis for vertical flight when the hub and the plurality of blades are in the vertical position. In some aspects, the tilt of the hub may be substantially unchanged during the first stage of movement. The linkage may be coupled to a support structure, such as the support structure 270 of FIGS. 2A-2E. In some embodiments, the first link of the linkage may include a first end rotatively coupled to the support structure and a second end including a pivot defining a pivot axis. The first link may be an embodiment of the link 280 of FIGS. 2A-2E. The second link of the linkage may be coupled to the actuator and the pivot, and be an embodiment of the link 275 of FIGS 2A-2E. More specifically, in some embodiments, the second link of the linkage may be coupled to the actuator via a connector (e.g., the connector 271 of FIGS. 2A-2E), which may include a first end and a second end. The first end of the connector may be rotatively coupled to the actuator, and the second end of the connector may be rotatively coupled to the second link.

[0066] The method 400 may include, at step 402, moving the hub about the pivot axis between a horizontal position and a vertical position to change the tilt of the hub during a second stage of movement. In some embodiments, the second stage of movement may occur subsequent to the first stage of movement. Further, in some aspects, the pivot may be configured to remain stationary relative to the support structure during the second stage of movement. Further, in some embodiments, the support structure may be coupled to a catch mechanism configured to catch and to release an end of a third link of the linkage. The catch mechanism may be an embodiment of the catch mechanism 276 or 377 of FIGS. 2A-2E, and the third link may be an embodiment of the link 272 or 274 of FIGS. 2A-2E. Releasing the end of the third link from the catch mechanism may cause the hub to move about the pivot axis from the horizontal position to the vertical position during the second stage of movement. In some embodiments, the actuator may be housed by a housing (e.g., a nacelle) that does not include a notch to provide clearance for the rotor when the hub is in the vertical position. The housing may be an embodiment of the booms 142 and / or 162 of FIG. 1, and / or the boom 242 of FIGS. 2A-2E.

[0067] In some aspects, there is no overlap between step 402 and step 404. Therefore, the first stage and the second stage do not overlap. However, in some embodiments, there is a period of overlap between the first stage and second stage, such that only the first stage isperformed for a first period of time (e.g., the pivot axis translates without altering the tilt of the hub), the first stage and the second stage are performed for a second period of time (e.g., the pivot axis translates while the tilt of the hub is changed), and only the second stage is performed for a third period of time (e.g., the tilt of the hub changes due to tilt about the tilt axis while the tilt axis remains stationary).

[0068] From the foregoing detailed description, it will be evident that there are a number of changes, adaptations and modifications of the present disclosure which come within the province of those persons having ordinary skill in the art to which the aforementioned disclosure pertains. However, it is intended that all such variations not departing from the spirit of the disclosure be considered as within the scope thereof as limited by the appended claims.

Claims

CLAIMS1. A system for tilting a rotor of an aircraft, the system comprising: a support structure; an actuator coupled to the support structure; a linkage rotatively coupled to the actuator and including a first link and a second link, wherein the first link includes a first end and a second end, the first end being rotatively coupled to the support structure and the second end including a pivot, the pivot defining a pivot axis and being coupled to the second link of the linkage; and a plurality of blades coupled to the pivot and movable about the pivot axis between a horizontal position and a vertical position during actuation of the actuator, the pivot being configured to remain stationary relative to the support structure during movement of the plurality of blades about the pivot axis.

2. The system of claim 1, further comprising: a catch mechanism coupled to the support structure and configured to catch and to release an end of a third link of the linkage.

3. The system of claim 2, wherein the release of the end of the third link causes the plurality of blades to move about the pivot axis from the horizontal position to the vertical position.

4. The system of claim 1, further comprising a motor coupled to the plurality of blades.

5. The system of claim 4, further comprising: a housing configured to house at least the actuator, wherein the housing does not include a notch to provide clearance for the rotor when the plurality of blades is in the vertical position.

6. The system of claim 5, wherein the housing comprises a nacelle.

7. The system of claim 1, wherein the actuator comprises a linear actuator.

8. The system of claim 1, further comprising:a connector including a first end and a second end, the first end being rotatively coupled to the actuator and the second end being rotatively coupled to the linkage.

9. The system of claim 1, wherein the actuator is directly coupled to the support structure via a first joint, and indirectly coupled to the support structure via a second joint, and wherein each of the first and second joints is configured to stabilize the rotor.

10. The system of claim 4, wherein the motor is configured to cause the plurality of blades to rotate about a horizontal axis for horizontal flight when the plurality of blades is in the horizontal position.

11. The system of claim 4, wherein the motor is configured to cause the plurality of blades to rotate about a vertical axis for vertical flight when the plurality of blades is in the vertical position.

12. A method for tilting a rotor of an aircraft, the method comprising: actuating an actuator to move, via a linkage including a first link and a second link, a hub in a substantially linear motion during a first stage of movement, wherein a tilt of the hub is substantially unchanged during the first stage of movement, wherein the first link includes a first end rotatively coupled to the support structure and a second end including a pivot defining a pivot axis, wherein the second link of the linkage is coupled to the actuator and to the pivot; and moving the hub about the pivot axis between a horizontal position and a vertical position to change the tilt of the hub during a second stage of movement subsequent to the first stage of movement, the pivot being configured to remain stationary relative to the support structure during the second stage of movement.

13. The method of claim 12, wherein the support structure is coupled to a catch mechanism configured to catch and to release an end of a third link of the linkage, the method further comprising: releasing the end of the third link from the catch mechanism to cause the hub to move about the pivot axis from the horizontal position to the vertical position during the second stage of movement.

14. The method of claim 12, wherein the hub is coupled to a motor.

15. The method of claim 14, wherein at least the actuator is housed by a housing that does not include a notch to provide clearance for the rotor when the hub is in the vertical position.

16. The method of claim 15, wherein the housing comprises a nacelle.

17. The method of claim 12, wherein the actuator comprises a linear actuator.

18. The method of claim 12, wherein the second link of the linkage is coupled to the actuator via a connector, wherein the connector includes a first end rotatively coupled to the actuator and a second end rotatively coupled to the second link..

19. A system for tilting a rotor of an aircraft, the system comprising: a support structure; an actuator coupled to the support structure; a linkage rotatively coupled to the actuator and including a first link and a second link, wherein the first link includes a first end and a second end, the first end being rotatively coupled to the support structure and the second end including a pivot, the pivot defining a pivot axis and being coupled to the second link of the linkage; a catch mechanism coupled to the support structure and configured to catch and to release an end of a third link of the linkage; and a plurality of blades coupled to the pivot and movable about the pivot axis between a horizontal position and a vertical position during actuation of the actuator, wherein the release of the end of the third link causes the plurality of blades to move about the pivot axis from the horizontal position to the vertical position, and wherein the pivot is configured to remain stationary relative to the support structure during movement of the plurality of blades about the pivot axis.

20. The system of claim 19, further comprising:a motor coupled to the plurality of blades; and a housing configured to house at least the actuator, wherein the housing does not include a notch to provide clearance for the rotor when the plurality of blades is in the vertical position.

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