Devices And Methods For Modifying Width Of Rotor Aircraft During Operational Flight

Abstract

Devices, systems, and methods are provided in which a wing of a tiltrotor aircraft is rotated during operational flight, for example from a position perpendicular to the aircraft's fuselage through an angle of 30 or more in the direction of flight. This effectively narrows the maximum width of the aircraft, and facilitates maneuvering through closely spaced obstacles.

Claims

1. A rotorcraft comprising: a first rotor mounted on first portion of a wing; and a second rotor mounted on a second portion of the wing, wherein the first and second portions of the wing are coupled to a rotating mechanism positioned to rotate the first and second wing portions between a first position and a second position; and a control system configured to utilize the rotating mechanism to horizontally rotate the wing between the first and second positions during operational flight, or before take-off, wherein the second position is at least angled at least 30 from the first position in the then-current direction of flight.

2. The rotorcraft of claim 1, wherein when the wing is in the first position, the wing is substantially perpendicular to the long dimension of the fuselage.

3. The rotorcraft of claim 1, wherein when the wing is in the first position, the wing is substantially perpendicular to a then-current direction of flight.

4. The rotorcraft of claim 1, wherein the second position is angled at least 45 from the first position.

5. The rotorcraft of claim 1, wherein the second position is angled at least 60 from the first position.

6. The rotorcraft of claim 1, wherein the aircraft has a maximum flight width when the wing is in the first position.

7. The rotorcraft of claim 6, wherein moving the wing from the first position to the second position reduces the flight width by at least 25%.

8. The rotorcraft of claim 6, wherein moving the wing from the first position to the second position reduces the flight width by at least 50%.

9. The rotorcraft of claim 1, wherein the wing has a maximum flight width of more than 80 feet when the wing is in the first position, and a flight width of less than 75 feet when the wing is in the second position.

10. The rotorcraft of claim 1, wherein the wing has a maximum flight width of more than 80 feet when the wing is in the first position, and a flight width of less than 65 feet when the wing is in the second position.

11. The rotorcraft of claim 1, wherein the first and second rotors are mounted on outboard termini of the wing.

12. The rotorcraft of claim 1, wherein the first and second wing segments are portions of a unitary wing.

13. The rotorcraft of claim 1, wherein the first and second wing segments are separate segments coupled to the rotating mechanism.

14. The rotorcraft of claim 1, wherein the rotating mechanism is a turntable.

15. The rotorcraft of claim 1, wherein the first and second wing segments extend beyond tips of the first and second rotors, respectively.

16. The rotorcraft of claim 1, wherein the first and second wing segments when in the second position extend beyond fore and aft ends of the fuselage, respectively.

17. A method of modifying a tiltrotor aircraft comprising a wing by: coupling the wing to a rotating mechanism, wherein the rotating mechanism is mounted on a fuselage of the aircraft; and providing a controller that rotates the wing using the rotating mechanism during operational flight, or before take-off, wherein rotation displaces the wing at least 30 between a first position to a second position in the then-current direction of flight, wherein the wing comprises one or more rotors.

18. The rotorcraft of claim 17, wherein the second position is displaced at least 45 from the first position.

19. The rotorcraft of claim 17, wherein the second position is displaced at least 60 from the first position.

20. The rotorcraft of claim 17, wherein the wing is perpendicular to the then-current direction of flight when in the first position.

21. A method of operating a tiltrotor aircraft, comprising rotating a wing of the tiltrotor aircraft during operational flight, or before take-off, using a rotating mechanism, wherein rotation displaces the wing at least 30 between a first position to a second position in the then-current direction of flight, and wherein the wing comprises one or more rotors.

22. The method of claim 21, wherein the second position is displaced at least 45 from the first position.

23. The method of claim 21, wherein the second position is displaced at least 60 from the first position.

24. The method of claim 21, wherein the wing is perpendicular to the direction of flight when in the first position.

Description

DESCRIPTION OF THE FIGURES

[0017] FIGS. 1A and 1B: FIG. 1A provides a top-down view of an embodiment of a tiltrotor aircraft of the inventive concept with the wing positioned approximately perpendicular to the fuselage of the aircraft, presenting a maximum wing aspect ratio, where the rotors are positioned at the ends of the wing. FIG. 1B provides a top-down view of a tiltrotor aircraft of FIG. 1A with the wing pivoted about a central point relative to the fuselage of the aircraft, presenting a minimized wing aspect ratio without reducing the distance between the rotors.

[0018] FIGS. 2A and 2B provide top down and frontal views of another tiltrotor aircraft as contemplated herein.

[0019] FIGS. 3A, 3B, 3C, and 3D provide frontal and perspective views of an embodiment of an unmanned tiltrotor aircraft as contemplated herein.

DETAILED DESCRIPTION

[0020] The following description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.

[0021] The inventive subject matter provides apparatus, systems and methods in which a rotorcraft has first and second rotors mounted on a wing, and a control system is configured to allow the wing to rotate horizontally during operational flight. Such a wing can be a single element wing, mounted to the tiltrotor aircraft's fuselage at a central point by a rotating or pivoting mechanism. Unlike the pivoting mechanism of the V-22 which is used for folding and takes loads only in high surface wind (on ship) and in taxi, the inventive pivoting mechanism will take flight loads and provide the required stiffness for safe flight dynamics. Alternatively, the inventive subject matter can include independent wing elements joined at one terminus to a central element mounted on the fuselage of a tiltrotor aircraft. The wing elements can support tiltable rotors, and such wing elements can be moved in concert to effectively provide a pivoting wing. Such pivoting wings can be rotated at least 45, at least 60, or more than 60 relative to the long axis of the tiltrotor aircraft's fuselage.

[0022] Various objects, features, aspects and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components.

[0023] The following discussion provides many example embodiments of the inventive subject matter. Although each embodiment represents a single combination of inventive elements, the inventive subject matter is considered to include all possible combinations of the disclosed elements. Thus if one embodiment comprises elements A, B, and C, and a second embodiment comprises elements B and D, then the inventive subject matter is also considered to include other remaining combinations of A, B, C, or D, even if not explicitly disclosed.

[0024] As used herein, and unless the context dictates otherwise, the term coupled to is intended to include both direct coupling (in which two elements that are coupled to each other contact each other) and indirect coupling (in which at least one additional element is located between the two elements). Therefore, the terms coupled to and coupled with are used synonymously.

[0025] In some embodiments, a rotorcraft or tiltrotor aircraft of the inventive concept can include first and second rotors mounted on left and right portions of a wing, respectively. The wing can be mounted on a turntable configured to horizontally rotate the wing relative to the aircraft's fuselage. A control system can be configured to utilize the turntable to horizontally rotate the wing during operational flight at angles of at least 45, at least 60, or more than 60 relative to the long axis of the fuselage. In some embodiments the wing portion and the associated rotor are rotated together. In other embodiments a nacelle that includes the rotor can be rotated while the wing portion or a segment of the wing portion remains horizontal.

[0026] In other embodiments, a rotorcraft or tiltrotor aircraft of the inventive concept can include first and second rotors mounted on left and right wing segments, respectively. Such left and right wing segments are discontinuous, but can move in concert to effectively act as a unitary wing structure. One end of each wing segment can be coupled to a turntable or other rotating structure (such as a rotatable column or shaft) configured to horizontally rotate each wing segment relative to the aircraft's fuselage. A control system can be configured to utilize the turntable to horizontally rotate the wing segments during operational flight so as to provide a continuous wing structure oriented at angles of at least 45, at least 60, or more than 60 relative to the long axis of the fuselage. In some embodiments the wing portion and the associated rotor are rotated together. In other embodiments a nacelle that includes the rotor can be rotated while the wing portion or a segment of the wing portion remains horizontal. In another embodiment the control system can be configured to horizontally rotate the wing while simultaneously tilting the rotors.

[0027] As noted above, such control systems are preferably configured to horizontally rotate the wing, during operational flight, at least 30 from a first position to a second position, more preferably up to at least 45 from the first position to the second position, and most preferably up to at least 60 from the first position to the second position. In such embodiments the second position provides the tilt rotor aircraft with a reduced wing aspect ratio relative to the first position without altering the distance between the rotors. As such an aircraft so equipped can maintain rotor lift at low operational speeds for maneuvering through closely spaced obstacles that would not be accessible to similar aircraft having fixed wings mounted perpendicular to the fuselage.

[0028] An example of an embodiment of a tiltrotor aircraft of the inventive concept is shown in FIGS. 1A and 1B, which depict an exemplary V-22 Osprey rotorcraft 100 modified to provide rotation of the aircraft's wing (along with its terminally mounted rotors). FIG. 1A shows such an aircraft in the first position, which provides maximum wing aspect ratio. FIG. 2B shows such an aircraft in the second position, which provides a reduced or minimized wing aspect ratio. As shown, such an aircraft 100 has a fuselage 110, and left and right rotors 130A, 130B mounted on the ends of a horizontally rotating wing 120. The wing 120 is mounted on a turntable 140, which rotates the wing 120 relative to the fuselage. When the wing 120 is in a first position (shown in FIG. 1A), substantially perpendicular to a long dimension of the fuselage, the flight width 150A of the aircraft 100 is at a maximum (in this example, approximately 84.6 feet). When the wing 120 is in a second position (shown in FIG. 1B) that is pivoted 45 from the first position, the flight width 150B of the aircraft 100 is reduced to approximately 71.0 feet. depict a contemplated aircraft in a three dimensional surface presentation. As shown in the figures, the nacelles of rotors of rotorcraft can be positioned at the outboard ends of the wing. However, it is also contemplated that there could be additional wing outboard of the nacelles.

[0029] Although not explicitly shown in the figures, it should be appreciated that in aircraft of the inventive concept the wing 120 of rotorcraft 100 can be further rotated horizontally to at least 60 off from the first position, in which case the flight width 150B of the aircraft 100 is reduced to about 61.3 feet. Such extreme reduction is considered to be viable for helicopter mode of a modified V-22 aircraft, with nacelle tilt angle deviations of 75 to 105.

[0030] In more generalized cases, a rotorcraft according to the inventive concept can include a control system configured to allow the wing to be angled about 30, about 45, about 60 or more than about 60 relative to the first position. In preferred embodiments the control system allows the wing to be angled at least 60 from the first position. Accordingly, it is contemplated that tilt-rotorcraft are contemplated as having a flight width no more that 85%, 75%, 70%, 65%. 60%, 55%, 50%, or less than 50% of the maximum flight width when the wing is rotated.

[0031] FIGS. 2A and 2B provide top down and frontal views of another tiltrotor aircraft as contemplated herein.

[0032] FIGS. 3A, 3B, 3C, and 3D: FIG. 3A provides a top-down view of an embodiment of an unmanned tiltrotor aircraft of the inventive concept with the wing positioned approximately parallel to the fuselage of the aircraft, presenting a minimum wing aspect ratio, where the rotors are positioned inboard of the wing tip. FIG. 3B provides an isometric view of an unmanned tiltrotor aircraft of FIG. 3A with the wing positioned approximately perpendicular to the fuselage of the aircraft. FIG. 3C provides an isometric view of an unmanned tiltrotor aircraft of FIG. 3A with the wing positioned approximately parallel to the fuselage of the aircraft. FIG. 3D provides an isometric view of an alternative embodiment to the aircraft of FIG. 3B.

[0033] As can be seen in FIGS. 3C and 3D, 15, the first and second wing segments can extend beyond tips of the first and second rotors, respectively, and can even extend beyond fore and aft ends of the fuselage, respectively.

[0034] It should be apparent to those skilled in the art that many more modifications besides those already described are possible without departing from the inventive concepts herein. The inventive subject matter, therefore, is not to be restricted except in the spirit of the appended claims. Moreover, in interpreting both the specification and the claims, all terms should be interpreted in the broadest possible manner consistent with the context. In particular, the terms comprises and comprising should be interpreted as referring to elements, components, or steps in a non-exclusive manner, indicating that the referenced elements, components, or steps may be present, or utilized, or combined with other elements, components, or steps that are not expressly referenced. Where the specification claims refers to at least one of something selected from the group consisting of A, B, C . . . and N, the text should be interpreted as requiring only one element from the group, not A plus N, or B plus N, etc.