Systems, methods, and devices for a tiltrotor vehicle

Abstract

A rotor tilting system is configured to be used with a tiltrotor aircraft. The rotor tilting system includes a first pylon movable between a vertical position and a horizontal position, a second pylon movable between the vertical position and the horizontal position, and a torque tube having a first end and a second end. The first pylon is operatively connected to the torque tube, the second pylon operatively connected to the torque tube, the torque tube being configured to rotate in a first direction and in a second direction to move the first pylon and the second pylon between the vertical position and the horizontal position, respectively. The torque tube rotates about a longitudinal axis that extends in a direction that is offset from a first pivot axis of the first pylon and offset from a second pivot axis of the second pylon.

Description

SYSTEMS, METHODS, AND DEVICES FOR A TILTROTOR VEHICLECROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims priority to U.S. Provisional Application No. 63 / 634,698, filed April 16, 2024, which is incorporated by reference herein in its entirety.TECHNICAL FIELD

[0002] Embodiments of this disclosure are directed to vehicle operation, and in particular, systems and methods for converting a tiltrotor aircraft between flight configurations.BACKGROUND OF THE INVENTION

[0003] Transitions between high-speed and low-speed flight of vertical takeoff and landing vehicles (VTOL) result in a significant change in how forces are imparted from the rotors and control surfaces to the vehicle. Due to these changes, the vehicle operator may make more precise movements at low-speeds in which vertical lift is generated by rotors and provide inputs that seek to maintain speed, orientation, and / or direction at higher speeds.

[0004] Some types of VTOL aircraft, such as helicopters, are effective at creating vertical lift. However, some VTOL aircraft have reduced horizontal thrust capability and are not easily scalable to efficiently transport persons or goods over longer distances. With regards to VTOL aircraft having multiple rotors for creating vertical lift, these VTOL aircraft can include several systems to change the position of the rotors between vertical and horizontal orientations, these systems resulting in increased complexity and weight.

[0005] There is a need for vehicle systems that aid the transition the a rotor between rotorborne and wingborne flight configurations. Additionally, there is a need to simplify moving one or more rotors between vertical and horizontal positions as the tiltrotor aircraft transitions between rotorborne and wingborne flight.

[0006] 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

[0007] The present disclosure generally provides for a rotor tilting system configured to be used with a tiltrotor aircraft. The rotor tilting system may include a first pylon movable between a vertical position and a horizontal position, a second pylon movable between the vertical position and the horizontal position, and a torque tube having a first end and a second end. The first pylon may be operatively connected to the torque tube, the second pylonoperatively connected to the torque tube, the torque tube being configured to rotate in a first direction and in a second direction to move the first pylon and the second pylon between the vertical position and the horizontal position, respectively. The torque tube may rotate about a longitudinal axis that extends in a direction that is offset from a first pivot axis of the first pylon and offset from a second pivot axis of the second pylon.

[0008] The present disclosure may further provide for a method of changing position of tilt rotors of a tiltrotor aircraft. The method may include rotating a torque tube from a first position to a second position and converting the rotation of the torque tube to movement of a first link and a second link. The method may further include moving the first pylon and the second pylon about a first pivot axis and about a second pivot axis, respectively, the first pylon and the second pylon being pivotally connected to the torque tube through the first link and the second link such that the first pylon and the second pylon pivot when the torque tube moves from the first position to the second position. The first pivot axis of the first pylon and the second pivot axis of the second pylon may each be substantially orthogonal to a longitudinal axis of the torque tube.

[0009] The present disclosure may further provide a rotor-tilting system configured to be used with a tiltrotor aircraft. The system may include a boom defining a longitudinal axis, the boom having a first end and a second end, a first pylon and a second pylon pivotally connected to the boom, the first pylon and the second pylon movable between a vertical position and a horizontal position, and a torque tube. The torque tube may extend between the first end and the second end of the boom, the torque tube being operatively connected with the first pylon and the second pylon, the torque tube being configured to rotate in a first direction and in a second direction to move the first pylon and the second pylon between the vertical position and the horizontal position. Rotation of torque tube may be configured to move the first pylon in a first direction and the second pylon in a second direction different than the first direction.BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate various examples and, together with the description, serve to explain the principles of the disclosed examples and embodiments.

[0011] Aspects of the disclosure may be implemented in connection with embodiments illustrated in the attached drawings. These drawings show different aspects of the present disclosure and, where appropriate, reference numerals illustrating like structures, components,materials, and / or elements in different figures are labeled similarly. It is understood that various combinations of the structures, components, and / or elements, other than those specifically shown, are contemplated and are within the scope of the present disclosure.

[0012] Moreover, there are many embodiments described and illustrated herein. The present disclosure is neither limited to any single aspect or embodiment thereof, nor is it limited to any combinations and / or permutations of such aspects and / or embodiments. Moreover, each of the aspects of the present disclosure, and / or embodiments thereof, may be employed alone or in combination with one or more of the other aspects of the present disclosure and / or embodiments thereof. For the sake of brevity, certain permutations and combinations are not discussed and / or illustrated separately herein. Notably, 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 the embodiment s) is / are “example” embodiment(s).

[0013] FIG. 1 A illustrates a vertical takeoff vehicle in a first configuration.

[0014] FIG. IB illustrates a vertical takeoff vehicle in a second configuration.

[0015] FIG. 2A illustrates a schematic view of a boom with tilt rotors in the vertical position according to the present disclosure.

[0016] FIG. 2B illustrates a schematic view of a boom with tilt rotors in the horizontal position according to the present disclosure.

[0017] FIG. 3 illustrates a schematic view of the rotor tilting system according to the present disclosure.

[0018] FIG. 4 is a view of an example tilt rotor system, according to the present disclosure.

[0019] FIG. 5 illustrates a flow chart corresponding to a method of transitioning the tilt rotors between vertical and horizontal positions

[0020] As used herein, the terms “comprises,” “comprising,” “includes,” “including,” or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements, but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. The term “exemplary” is used in the sense of “example,” rather than “ideal.” 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 fromanother. Moreover, the terms “a” and “an” herein do not denote a limitation of quantity, but rather denote the presence of one or more of the referenced items.

[0021] 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.DETAILED DESCRIPTION

[0022] Reference will now be made in detail to examples 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. In the discussion that follows, relative terms such as “about,” “substantially,” “approximately,” etc. are used to indicate a possible variation of a numerical range in a stated numeric value, as will be designated below.

[0023] The present disclosure generally provides for systems, methods, and devices of a vertical takeoff and landing (VTOL) aircraft at various speeds, modes, and phases of flights to control position, orientation, direction, and / or speed of the VTOL aircraft. Although the present disclosure makes reference to a VTOL aircraft, those of ordinary skill in the art will readily recognize that reference to an aircraft is exemplary, and that the concepts of the present disclosure may be used in conjunction with any suitable or comparable aircraft, e.g., airplanes, helicopters, aerostats, flight simulators, space crafts, commercial airplanes, electrical vertical takeoff and landing aircrafts (eVTOL aircrafts), or any other type of tilt rotor aircraft. Still 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.

[0024] Turning to Figures 1A and IB, perspective views of an exemplary VTOL tiltrotor aircraft 102 (herein aircraft 102), according to one or more embodiments, are provided.Aircraft 102 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. Aircraft 102 may include a fuselage 104, front wings 106, rear wings 107, tilt- capable rotors 130, 132, 230, fixed rotors 133, and control surfaces 134 (Figure 1A). Aircraft 102 may be an eVTOL aircraft and include one or more batteries located within fuselage 104.

[0025] As can be seen in Figures 1 A and IB, fuselage 104 may function as a base or a body of aircraft 102 and support front wings 106, rear wings 107, tilt-capable rotors 130, 132, 230, fixed rotors 133, and control surfaces 134. Fuselage 104 may include a cockpit, as well as an interior volume configured to house passengers, cargo, the like, or a combination thereof.

[0026] Front wings 106 may be connected with a forward portion of fuselage 104. Rear wings 107 may be connected with an aft portion of fuselage 104. Front wings 106 and rear wings 107 may function to assist VTOL aircraft 102 during flight by providing lift as the aircraft travels through the air during wingborne flight. In some examples, front wings 106 and rear wings 107 may function to connect tilt-capable rotors 130, 132, 230 and fixed rotors 133, as well as control surfaces 134, to the fuselage 104. As will be described below, control surfaces 134 are connected to the front wings 106, rear wings 107, or both to assist in maneuvering.

[0027] Each of the front wings 106 and rear wings 107 are connected one or more booms 140, 142. Each boom 140, 142 may be configured to support tilt-capable rotors 130, 132, 230 and / or fixed rotors 133. In Figures 1A and IB, booms 140 pivotally support at least one of rotors 130, 132, and booms 142 support tilt rotor 230. For example, in Figure 1 A, rotors 130, 132, 230 are in a vertical orientation or position (e.g., with an axis of rotation of each rotor being generally aligned with a vertical direction) corresponding to a rotorborne configuration 150, and in Figure IB, tilt-capable rotors 130, 132, 230 are in a horizontal orientation or position (e.g., with an axis of rotation of each rotor being generally aligned with a horizontal direction) corresponding to a wingborne configuration 152.

[0028] Control surfaces 134 may be connected with the front wings 106 and / or rear wings 107, boom 140, 142, or any other surface of aircraft 102 to assist with controlling aircraft 102 during takeoff, landing, and / or flight. In some examples, control surfaces 134 may be connected with fuselage 104. In some examples, control surfaces 134 may be connected with tilt-capable rotors 130, 132, 230, boom 140, 142, or both. Control surfaces 134 may function to assist with maneuvering aircraft 102 during flight. Control surfaces 134 may be elevators, rudders, ailerons, ruddervators, flaperons, trim, nacelle, flaps or any other control surfaces known to one of ordinary skill in the art. Control surfaces 134 may be configured to assist withmoving aircraft 102 in a plurality of degrees of freedom (e.g., by adjusting yaw, pitch, and roll). Control surfaces 134 may be configured to assist with converting aircraft 102 between rotorborne configuration 150 and wingbome configuration 152.

[0029] In some examples, tilt-capable rotors 130, 132, 230 may be connected to front wings 106 and rear wings 107 through boom 140, 142. Boom 140, 142 may be structures configured to support tilt-capable rotors 130, 132, 230, control surfaces, mechanical systems, the like, or a combination thereof. Boom 140 may be a structure configured to extend past each end of front wing 106 to support tilt rotors 130, 132, control surfaces 134, motors 192, 194, actuators 168, the like, or a combination thereof. Each boom 140 may be formed as a continuous body extending beyond the front and the rear of front wing 106, such that a first end is in front of wing 106 and a second end is behind wing 106. In other configurations, 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 in front of and behind wing 106. As used herein, “boom” refers to booms with continuous structures and discontinuous structures. Boom 142 may connect tilt rotors 230 (e.g., a single tilt-capable rotor 230 connected to a corresponding boom 142) to rear wings 107.

[0030] Tilt-capable rotors 130, 132, 230 may be connected with the front wings 106, rear wings 107, or both. In some examples, tilt-capable rotors 130, 132, 230 may be connected with fuselage 104. Tilt-capable rotors 130, 132, 230 may be propulsion sources to move aircraft 102 vertically and horizontally. Tilt-capable rotors 130, 132, 230 may be connected with one or more motors for rotating the tilt-capable rotors 130, 132, 230 to produce thrust. In some examples, tilt-capable rotors 130, 132, 230 may pivot or tilt relative to the front wings 106 and rear wings 107 to transition between the horizontal position and the vertical position. In some examples, aircraft 102 may only have tilt-capable rotors 130, 132, and / or 230 as a propulsion source. In other examples, tilt-capable rotors 130, 132, 230 may be used in combination with other sources of propulsion, such as fixed rotors 133, jet engines, the like, or a combination thereof. Tilt-capable rotors 130, 132, 230 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 longitudinal position.

[0031] In some examples, aircraft 102 may include two or more tilt-capable rotors 130, 132, 230. In one example, such as shown in Figures 1A and IB, aircraft 102 includes tilt- capable rotors 130, 132 connected to front wings 106 on each side of the aircraft 102 with tilt- capable rotors 130, 132 located on boom 140 and tilt rotors 230 located on boom 142 on rearwings 107. It will be appreciated that even numbers of tilt-capable rotors 130, 132, 230 may be provided. Tilt-capable rotors 130, 132, 230 may be configured to assist with moving aircraft 102 in a plurality of degrees of freedom.

[0032] Fixed rotors 133 may be connected with front wings 106, rear wings 107, or both. In some examples, fixed rotors 133 may have a fixed axis of rotation such that rotors 133 always rotate parallel to vertical axis 110. In some other examples, fixed rotors 133 may be positioned in vertical positions, horizontal positions, or both. Fixed rotors 133 may be a propulsion source to move aircraft 102. In other examples, fixed rotors 133 may be positioned to rotate parallel to longitudinal axis 112. In other examples, a combination of fixed rotors 133 positioned with their axis of rotation parallel to vertical axis 110 and positioned with their axis of rotation parallel to longitudinal axis 112 may be used. In some other examples, VTOL aircraft 102 may only have rotors 133 as a propulsion source. Rotors 133 may provide thrust to VTOL aircraft 102 during takeoff and landing, and may further provide enhanced maneuverability for aircraft 102. In some examples, aircraft 102 may include any number of fixed rotors 133. In one example, such as shown in Figures 1A and IB, aircraft 102 includes two fixed rotors 133 connected with front wings 106. Fixed rotors 133 may be configured to assist with moving aircraft 102 in at least one degree of freedom.

[0033] Tilt-capable rotors 130, 132, 230 may include pylons 160, 162 configured to support a motor 192, 194 (Figures 2A and 2B) with a blade assembly 164, 165. In some examples, pylons may be structures configured to connect tilt-capable rotors 130, 132, 230, with boom 140, 142. As described further below, pylons 160, 162 may be configured to transition between a vertical position corresponding to rotorbome configuration 150 and a horizontal position corresponding to wingborne configuration 152. In some examples, tilt- capable rotors 130, 132 may be connected to motors 192, 194 that are housed by pylons 160, 162 (Figures 2 A and 2B).

[0034] Figure 1A illustrates aircraft 102 in one example of the first configuration, a rotorborne configuration 150 (also known as a VTOL configuration). Figure 1 A depicts aircraft 102 and vertical axis 110, longitudinal axis 112, lateral axis 114, which aircraft 102 may translate and / or rotate about. In rotorborne configuration 150, tilt-capable rotors 130, 132, 230 are shown in a vertical direction, such that the tilt rotors 130, 132, 230 are positioned with their axis of rotation parallel to vertical axis 110 (also referred to as the x-axis; yaw axis), in which aircraft 102 may operate. Aircraft 102 may travel generally up or down vertical axis 110 at various times throughout a flight (e.g., during climbing, descending, takeoff, and / or landing).Aircraft 102 may also rotate about vertical axis 110 as shown by rotation arrow 120 for a yaw movement. Aircraft 102 may also move along longitudinal axis 112 (also referred to as the y- axis; roll axis) generally backward or forward. Aircraft 102 may rotate (roll) relative to longitudinal axis 112 (also referred to as the y-axis) as shown by rotation arrow 122. Aircraft 102 may travel along lateral axis 114 (e.g., translate), as well as rotate about lateral axis 114 (also referred to as the z-axis; pitch axis) to cause a pitch movement, as shown by rotation arrow 124.

[0035] Turning now to Figure IB, aircraft 102 is illustrated in the wingbome configuration 152 with each of the tilt-capable rotors 130, 132, 230 arranged with their axis of rotation parallel to longitudinal axis 112. Similar to Figure 1A, aircraft 102 is capable of moving along each of vertical axis 110, longitudinal axis 112, and lateral axis 114. In the wingborne configuration 152, aircraft 102 may travel generally forwards along longitudinal axis 112 and may also roll about longitudinal axis 112 as shown by rotation arrow 122. In wingborne configuration 152, aircraft 102 may rotate about lateral axis 114 (e.g., pitch up; pitch down). Aircraft 102 may climb up and down along vertical axis 110, as well as also rotate about vertical axis 110 as shown by rotation arrow 120 causing a yaw movement of aircraft 102.

[0036] As illustrated in Figures 1 A and IB, aircraft 102 may be configured to maneuver in a plurality of degrees of freedom. In this example, aircraft 102 may be configured to move in six degrees of freedom. Aircraft 102 may be configured to translate along each of vertical axis 110, longitudinal axis 112, and lateral axis 114. Similarly, aircraft 102 may be configured to rotate about each of vertical axis 110, longitudinal axis 112, and lateral axis 114, shown as rotation arrow 120, rotation arrow 122, and rotation arrow 124, respectively.

[0037] When aircraft 102 is in rotorborne configuration 150, aircraft 102 may operate at low-speed. In some examples, “low-speed” may refer to aircraft 102 traveling at a rate of 0 Knots to 50 Knots. However, in some other examples, “low-speed” may be between 0 Knots and 150 Knots or more. For example, tilt-capable rotors 130, 132, 230 along with static rotors 132 may be used for vertical thrust when aircraft 102 is in rotorborne configuration 150. In rotorborne configuration 150, control surfaces, along with a landing gear (not shown) may be extended and / or engaged.

[0038] When aircraft 102 is in wingborne configuration 152, aircraft 102 may travel at “high-speed”. “High-speed” may refer to movement during cruise, long-distance travel, or similar. “High-speed” may be a relative range between a speed higher than the low-speed rangeand a maximum speed of the craft. In some non-limiting examples, “high-speed” may be between 30 knots and 150 Knots. In other non-limiting examples, the high-speed range may be between 30 Knots or less and 450 Knots or more. For example, the tilt-capable rotors 130, 132, 230 may be used for horizontal thrust when in the wingborne configuration 152. In the wingborne configuration 152, landing gear, or other components may be retracted and / or concealed within aircraft 102.

[0039] Aircraft 102 may operate at a transitional speed. The transitional speed may be considered a “medium” speed and correspond to aircraft 102 transitioning between rotorbome configuration 150 and wingborne configuration 152. Put differently, transitional speed may be a speed at which the physical configuration of aircraft 102 may change such that the mechanism for generating lift on aircraft 102 changes. Additionally, transitional speed may be a range of speed which the control system of aircraft 102 may change the types of commands. For example, tilt-capable rotors 130, 132, 230 may be in the process of switching from generating primarily vertical thrust to generating primarily horizontal thrust. As another example, landing gear may be in the process of moving from an extended position to a retracted position.

[0040] Transitional speed may refer to vehicle velocity during a transition between low-speed operation and high-speed operation. Transitional speed may be any speed between low-speed and high-speed operation and / or configuration. In some non-limiting examples, the transitional speed may be between 20 Knots and 60 Knot. In other non-limiting examples, the transitional speed may be between 10 Knots and 120 Knots. In other examples, the transitional speed may be more than 120 knots. Multiple components of aircraft 102 may transition between states while aircraft 102 operates at transitional speed. These components may include a combination of tilt-capable rotors 130, 132, 230 control surfaces 134, and / or landing gear(s) are contemplated during the transitional speed. Any other control surfaces, such as spoilers, throttle, pitch control of any rotors, rotor speed of rotors, any type of flaps, wing surfaces to resist rotation, rudders, etc., may be implemented to transition aircraft 102 from high-speed to low-speed or vice versa.

[0041] As described above, aircraft 102 may transition between rotorbome configuration 150 to wingborne configuration 152 by transitioning tilt-capable rotors 130, 132, 230. In some examples and as shown in Figures 2A and 2B, tilt-capable rotors 130, 132 are moved by a rotor tilting system 154 to move tilt-capable rotors 130, 132 between a vertical position corresponding to rotorbome configuration 150 and a horizontal position corresponding to wingborne configuration 152. In some examples, tilt rotor system 154 may include pylons160, 162, boom 140, torque tube 166, links 176, 177, and actuator 168, as shown in Figure 2A, for example.

[0042] Rotor tilting system 154 may be configured to move tilt-capable rotors 130, 132 which are connected with pylons 160, 162, respectively, relative to boom 140. In some examples, pylons 160, 162 may be configured to move with tilt-capable rotors 130, 132 between the vertical position (also referred to as the first position) corresponding with rotorborne configuration 150, and the horizontal position (also referred to as the second position) corresponding with wingborne configuration 152. Pylons 160, 162 may be configured to support a motor 192, 194, which is connected with tilt-capable rotors 130, 132. In some examples, each pylon 160, 162 may house one or more drive motors 192, 194.

[0043] As described above, pylons 160, 162 may be pivotally connected to boom 140. Boom 140 may be connected with front wings 106. Boom 140 may be configured to support tilt-capable rotors 130, 132. Boom 140 may be configured as any suitable shape to support tilt- capable rotors 130, 132. Boom 140 may include a longitudinal axis 113 extending between a first end 144 and a second end 146. In some examples, boom 140 may be tubular and configured to allow torque tube 166 to extend between first end 144 and second end 146 of boom 140.

[0044] With reference to Figure 3, boom 140 may include pivot connections 184, 186 (pivot connection 186 shown in Figure 4) configured to connect with pylons 160, 162, respectively. In some examples, pivot connection 184 may be connected to the first end of boom 140 (portions of boom 140 other than connection 184 not shown in Figure 3), and connection 186 may be connected to the second end of boom 140. Connections 184, 186 may each define a tilt conversion axis 170, 172 (Figures 2A-3) about which connections 184 allow pylons 160, 162 to pivot. Tilt conversion axis 170, 172 may be the axis which pylons 160, 162 pivot about boom 140.

[0045] With reference to Figures 3 and 4, pylons 160, 162 include pivot mounts 174, 175 that may be configured to connect with pivot connections 184, 186 of boom 140, respectively. For example, pivot mount 174 of pylon 160 connects with and surrounds a rodshaped connection 184 of boom 140 at the first end 144, and pivot mount 175 of pylon 162 connects with connection 186 of boom 140 at the second end 146. In some examples, each pivot mount 174, 175 may be pivotally connected with connections 184, 186, respectively. In some examples, pivot mounts 174, 175 may be configured to rotate about connections 184, 186. Further, pivot mounts 174, 175 may be configured to rotate relative to connections 184,186, such that pylons 160, 162 move relative to boom 140 about pivot axes 170, 172. For example, pylon 160 rotates about pivot axis 170, and pylon 162 rotates about pivot axis 172.

[0046] In some examples, to move pylons 160, 162 between positions, each pivot mount 174, 175 includes a drive horn 188 to connect pylon 160, 162 to torque tube 166. As shown in Figure 3, drive horn 188 may be configured to receive a member connected to torque tube 166 (such as a link 176, 177, described further below) to provide a force to pivot each pylon 160, 162 about tilt conversion axis 170, 172.

[0047] Torque tube 166 may be connected with pylon 160, 162 to move pylon 160, 162 relative to boom 140. Torque tube 166 may be configured to rotate in a first direction and in a second direction, such that rotating torque tube 166 in the first direction moves each pylon 160, 162 to a first position, and rotating toque tube 166 in the second direction moves pylon 160, 162 to a second position, respectively. Torque tube 166 may be made of a steel, a composite material (e.g., carbon fiber), an alloy, or a combination thereof. In some examples, torque tube 166 may have a generally cylindrical shape or a cylindrical shape. In other examples, torque tube 166 may have a square or rectangular cross-section. Torque tube 166 may have any shape, cross-section, length, and / or profile which may be configured to rotate about a longitudinal axis.

[0048] Torque tube 166 may extend along and define a longitudinal axis 113. Longitudinal axis 113 may be a rotation axis of torque tube 166. In some examples, longitudinal axis 113 may be offset from axes 170, 172. In particular, longitudinal axis 113 may be orthogonal or substantially orthogonal to tilt conversion axes 170, 172 (e.g., offset from axes 170, 172, but forming an angle of about 90 degrees, with “about” referring to ± 10% of the stated value) so as to effectively pivot pylons 160, 162. Although not shown, in other examples, longitudinal axis 113 may be located in another configuration where tilt conversion axes 170, 172 are at angle greater than or less than 90 degrees relative to longitudinal axis 113, such as in a canted configuration (e.g., the tilt conversion axes 170, 172 may not be perpendicular to longitudinal axis 113).

[0049] The torque tube 166 may include arms 178, 179. Each arm 178, 179 may be configured to connect with pivot mount 174, 175, through link 176, 177. In some examples, arms 178, 179 may be configured to move with torque tube 166, pushing and / or pulling link 176, 177 and pivot mount 174, 175 to move pylon 160, 162 between the vertical position and the horizontal position. In some examples, arm 178 and arm 179 may have the same shape, length, thickness, profile, etc. In other examples, arm 178 may have a different shape, length,thickness, profile, etc. In the example shown in Figure 4, arms 178, 179 have the same shape and length. Arms 178, 179 may be made of the same material as torque tube 166. In some examples, arms 178, 179 may be made of a different material than that of torque tube 166. Arms 178, 179 may be integral to torque tube 166. In other examples, arms 178, 179 are attached with torque tube 166. In some examples, arms 178, 179 may be positioned at the same circumferential location about torque tube 166 at the first end and second end. In some other examples, arms 178, 179 may be positioned in different circumferential locations relative to one another at the first end and the second end of torque tube 166, as shown in Figure 4 where arms 178, 179 are offset by about 180 degrees.

[0050] As stated above, pylon 160, 162 may each include a respective pivot mount 174, 175. Pivot mounts 174, 175 may be configured to rotate about pivot connections 184, 186 of boom 140 when torque tube 166 is rotated. For example, pivot mount 174 may be connected with connection 184 at the first end of boom 140, and pivot mount 175 may be connected with pivot connection 186 at the second end of boom 140.

[0051] Pivot mounts 174, 175 may each include a respective drive horn, with drive horn 188 of pivot mount 174 being shown in Figure 3. Each drive horn 188 may be formed as a protrusion configured to receive an end of link 176, 177, and form a portion of a spherical joint 180, 182. Pivot mounts 174, 175 may pivot about pivot axis 170, 172.

[0052] Links 176, 177 may extend between arms 178, 179 and pivot mounts 174, 175 operatively coupling torque tube 166 with pylon 160, 162. Links 176, 177 may be configured to transmit rotational movement from torque tube 166 to pylons 160, 162. Links 176, 177 may be any suitable shape, length, or profile to extend between arms 178, 179 of torque tube 166 and pivot mounts 174, 175 of pylons 160, 162. For example, links 176, 177 may be a rod, a member with another shape, an extension, etc. As shown in Figure 3, links 176, 177 may be generally shaped as a rod. Links 176, 177 may be made of steel, composite material, alloy, the like, or a combination thereof. In some examples, link 176 extends between arm 178 at the first end of torque tube 166 to pivot mount 174 on pylon 160, and link 177 extends between arm 179 at the second end of torque tube 166 to pivot mount 175 on pylon 162.

[0053] In some examples, links 176, 177 may include enlarged ends (e.g., ball-shaped portion at each end of the link) received at socket portions (e.g., recesses) of pivot mounts 174, 175, and of arms 178, 179, respectively. Each spherical joint 180, 182 of links 176, 177 may be configured to allow link 176, 177 move in two or more degrees of freedom as torque tube 166 moves between positions. As torque tube 166 is rotated between positions, one end of eachlink 176, 177 is rotationally moved with arms 178, 179 around longitudinal axis 113. At the same time that links 176, 177 are moving with arms 178, 179 around longitudinal axis 113, links 176, 177 move with pivot mounts 174, 175, which rotate about pivot axes 170, 172. With both ends of links 176, 177 moving in tandem to actuate rotor tilt system 154, spherical joints 180, 182 allow for links 176, 177 to move with both arms 178, 179 and pivot mounts 174, 175, as they each rotate around their respective rotation axes, such as longitudinal axis 113, and pivot axis 170, 172. The ability of spherical joints 180, 182 to move in two or more degrees of freedom when torque tube 166 is rotated between positions may assist in converting pylon 160 between the vertical position and the horizontal position while providing a light-weight system with relatively low complexity.

[0054] Although the present examples show rod-shaped links 176, 177, other mechanisms, such as gears, may be used to convert rotational force from torque tube 166 to pylons 160, 162 in order to move pylons 160, 162 between the first position and the second position.

[0055] With reference to Figures 2A and 2B, in some examples, an actuator 168 may be connected with torque tube 166. In some examples, actuator 168 may be a rotatory actuator. Other actuator types are contemplated for moving torque tube 166, such as linear actuators connected via a linkage. Actuator 168 may be configured to rotate torque tube 166 between the first position and the second position. Actuator 168 may be configured to connect to torque tube 166 directly, or indirectly, such as through a transmission or linkage. In some examples, more than one actuator 168 may be used to rotate torque tube 166.

[0056] In Figure 2A, pylon 160 at the first end 144 of boom 140 and pylon 162 at the second end 146 of boom 140 are shown in the vertical position corresponding to rotorbome configuration 150. As can be seen in this example, pylon 160 and blade assembly 164 are shown facing a first direction, and pylon 162 with blade assembly 165 are shown facing a second direction, opposite of the first direction of pylon 160. The axis of rotation of blade assembly 164 and the axis of rotation of blade assembly 165 are parallel to one another, perpendicular to longitudinal axis 113. Although not shown, it is contemplated that pylon 160 and pylon 162 may be configured to have blade assemblies 164, 165 on the same side of torque tube 166 when in the vertical position.

[0057] To transition to the horizontal position (shown in Figure 2B), torque tube 166 is rotated by actuator 168 so that links 176, 177 push pylons 160, 162 to pivot about pivot axes 170, 172, respectively. Pivot axes 170, 172 are offset from and substantially orthogonal tolongitudinal axis 113, about which torque tube 166 rotates. In some examples, by pivoting pylons 160, 162 about pivot axes 170, 172, respectively, rotor tilting system 154 may be configured to take up reduced space on wings 106, while moving tilt-capable rotors 130, 132 between rotorborne configuration 150 and wingbome configuration 152.

[0058] In wingborne configuration 152 shown in Figure 2B, each axis of rotation 196, 198 of blade assemblies 164, 165 are parallel to longitudinal axis 113. In some examples, to transition pylons 160, 162 from the horizontal position to the vertical position, torque tube 166 may be rotated to pull links 176, 177 and cause pylons 160, 162 to pivot about rotational axes 170, 172.

[0059] Figure 4 is an end view of the rotor tilting system 154. From the perspective of Figure 4, rotating torque tube 166 counterclockwise may transition pylons 160, 162 from the vertical position to the horizontal position. As torque tube 166 is rotated about longitudinal axis 113, links 176, 177 are pushed or pulled, depending on the direction of the rotation. In some examples, arms 178, 179 may rotate about the same axis, and may be configured to move in opposite directions.

[0060] When torque tube 166 is rotated counterclockwise from the perspective of Figure 4, links 176, 177 are pushed by arms 178, 179. In some examples, torque tube 166 may be limited to about 90 degrees of rotation to positions pylons 160, 162 in rotorborne configuration 150 and wingbome configuration 152. In other examples, torque tube 166 may be configured to rotate more or less than 90 degrees. The use of a single torque tube 166 may provide the tilt rotor system 154 with high strength and low weight. The pushing movement of links 176, 177 is transferred to pivot mounts 174, 175 to pivot pylons 160, 162 about pivot axes 170, 172 relative to boom 140.

[0061] Figure 5 illustrates a flow chart of an operation 200 of the rotor tilting system 154 to change the position of the tilt-capable rotors 130, 132. For example, rotor tilting system 154 may be configured to rotate torque tube 166 in a first direction to convert the tilt-capable rotors 130, 132 between vertical position and horizontal position by moving links 176, 177 and causing pylons 160, 162 to pivot relative to boom 140 in the manner described above.

[0062] At step 202, torque tube 166 is rotated by generating signals to activate actuator 168. This rotation may be performed based on a request by an operator of aircraft 102 and / or in response to an automated request from a flight control system. The rotational movement of the torque tube 166 may be about the above-described longitudinal axis 113.

[0063] At step 204, the rotational movement of torque tube 166, is transferred from arms 178, 179 to links 176, 177. Depending on the direction, rotation of torque tube 166 creates a pushing or pulling force on links 176, 177. Links 176, 177 may, in turn, transfer this force to pivot mounts 174, 175 via drive horns 188, 189.

[0064] At step 206, pylons 160, 162 move between the vertical position and the horizontal position depending on the direction of rotation of the torque tube 166 about pivot axis 113. In some examples, the torque tube 166 may be rotated in a first direction (e.g., clockwise from the perspective of Figure 3; counterclockwise from the perspective of Figure 4), moving pylons 160, 162 from the vertical position to the horizontal position. In another example, rotating the torque tube 166 in a second direction (e.g., counterclockwise from the perspective of Figure 3; clockwise from the perspective of Figure 4) may transition the pylons 160, 162 from the horizontal position to the vertical position.

[0065] 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 rotor tilting system configured to be used with a tiltrotor aircraft, the rotor-tilting system comprising: a first pylon movable between a vertical position and a horizontal position; a second pylon movable between the vertical position and the horizontal position; and a torque tube having a first end and a second end, the first pylon being operatively connected to the torque tube, the second pylon being operatively connected to the torque tube, and the torque tube being configured to rotate in a first direction and in a second direction to move the first pylon and the second pylon between the vertical position and the horizontal position, respectively, wherein the torque tube rotates about a longitudinal axis that extends in a direction that is offset from a first pivot axis of the first pylon and offset from a second pivot axis of the second pylon.

2. The rotor tilting system of claim 1, wherein the longitudinal axis is substantially orthogonal to the first pivot axis of the first pylon and substantially orthogonal to the second pivot axis of the second pylon.

3. The rotor tilting system of claim 1, wherein the first pylon includes a first pivot mount and the second pylon includes a second pivot mount, the first and second pivot mounts being connected with a boom.

4. The rotor tilting system of claim 3, wherein the torque tube extends along a length of the boom, the boom having a first end with a pivot connection configured to connect with the pivot mount of the first pylon and a second end with a pivot connection configured to connect with the pivot mount of the second pylon, wherein the pivot mount of the first pylon and the pivot connection at the first end of the boom define the first pivot axis and the pivot mount of the second pylon and the pivot connection at the second end of the boom define the second pivot axis.

5. The rotor tilting system of claim 3, wherein the torque tube includes a first arm at the first end of the torque tube and a second arm at the second end of the torque tube.

6. The rotor tilting system of claim 5, further including a first link and a second link, the first link extending between the first arm and the first pivot mount, and the second link extending between the second arm and the second pivot mount.

7. The rotor tilting system of claim 6, further including a first motor connected with the first pylon and a second motor connected with the second pylon.

8. The rotor tilting system of claim 7, wherein each of the first motor and the second motor are connected with a plurality of blades, wherein the first pylon and the second pylon in the vertical position directs the plurality of blades in a horizontal plane for vertical takeoff and / or landing, and the first pylon and the second pylon in the horizontal position directs the plurality of blades in a vertical plane for wingborne flight.

9. The rotor tilting system of claim 8, wherein the plurality of blades have a first pitch when in the horizontal position, and have a second pitch when in the vertical position.

10. The rotor tilting system of claim 6, wherein the rotation of the torque tube in the first direction and in the second direction is converted into pivotal movement of the first pylon and of the second pylon.

11. The rotor tilting system of claim 6, wherein the first link and the second link are formed as rods that extend from the first arm and from the second arm to a first drive horn of the first pivot mount and to a second drive horn of the second pivot mount, respectively.

12. The rotor tilting system of claim 11, wherein the first link and the second link each include a spherical joint at each end of the first link and the second link, respectively, to allow the first link and the second link to move in two or more degrees of freedom as the first pylon and the second pylon move between the horizontal position and the vertical position.

13. The rotor tilting system of claim 12, wherein the torque tube includes a first arm and a second arm, the first arm and the second arm positioned on opposite ends of the torque tube and forming portions of the respective spherical links.

14. The rotor tilting system of claim 1, wherein the torque tube is connected to an actuator configured to rotate the torque tube.

15. A method of changing position of rotors of a tiltrotor aircraft, the method comprising: rotating a torque tube from a first position to a second position; converting the rotation of the torque tube to movement of a first link and a second link connected with the torque tube and connected with a first pylon and a second pylon; and moving the first pylon and the second pylon about a first pivot axis and about a second pivot axis, respectively, the first pylon and the second pylon being pivotally connected to the torque tube through the first link and the second link such that the first pylon and the second pylon pivot when the torque tube moves from the first position to the second position, wherein the first pivot axis of the first pylon and the second pivot axis of the second pylon are each substantially orthogonal to a longitudinal axis of the torque tube.

16. The method of claim 15, wherein, when the torque tube is in first position the first pylon is in a horizontal position, and when the torque tube is in the second position the first pylon is in a vertical position.

17. The method of claim 15, further including actuating an actuator to rotate the torque tube.

18. The method of claim 15, wherein the first pylon pivots in a first direction from the first position to the second position, and the second pylon pivots in a second direction from the first position to the second position, the second direction being different than the first direction.

19. A rotor-tilting system configured to be used with a tiltrotor aircraft, the rotor-tilting system comprising: a boom defining a longitudinal axis, the boom having a first end and a second end; a first pylon and a second pylon pivotally connected to the boom, the first pylon and the second pylon movable between a vertical position and a horizontal position; and a torque tube extending between the first end and the second end of the boom, the torque tube being operatively connected with the first pylon and the second pylon, the torquetube being configured to rotate in a first direction and in a second direction to move the first pylon and the second pylon between the vertical position and the horizontal position, wherein rotation of torque tube is configured to move the first pylon in a first direction and the second pylon in a second direction different than the first direction.

20. The system of claim 19, wherein rotation of torque tube is about an axis that is substantially orthogonal to a pivot axis of the first pylon and the second pylon.

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