Vertical Takeoff and Landing Aircraft Configuration

Abstract

A vertical takeoff and landing (VTOL) aircraft is configured with a front thruster group mounted on a front wing and a rear thruster group mounted on a rear wing, where the thrusters can be repositioned by rotating them respectively about a front thrust vector axis and a rear thrust vector axis. The positioning of the thrusters relative to the thrust vector axes and the positioning of the thrust vector axes relative to the upper and lower limits of the passenger cabin ensure that when the thrusters rotate from a vertical thrust position to a horizontal thrust position, the plane of rotation of the thrusters never intersects that part of the passenger cabin where a failure of a thruster component could cause debris to penetrate the passenger cabin and cause injury.

Description

[0001] Cross - reference to related patent applications

[0002] This application claims the benefit of U.S. Provisional Patent Application No. 62 / 547,216, filed on August 18, 2017, the entire content of which is incorporated herein by reference in its entirety. Technical Field

[0003] The present disclosure relates to a vertical takeoff and landing aircraft configured to take off and land vertically and cruise horizontally while being supported by wings. Background Art

[0004] Vertical takeoff and landing (VTOL) aircraft are typically used for taking off and landing from small areas without runways while still having the cruise efficiency provided by wings. Summary of the Invention

[0005] In one embodiment, the aircraft is configured with two wings, one wing located in front of the center of gravity and one wing located behind the center of gravity, with four thrusters attached to each wing. The wings are mounted to the fuselage of the aircraft on a rotational axis such that the wings can be positioned horizontally, vertically, or at any position between horizontal and vertical. The thrusters on the front wing are mounted in front of the front wing, and the thrusters on the rear wing are mounted behind the rear wing. During forward flight, the thrusters on the front wing are pulling the aircraft, and the thrusters on the rear wing are pushing the aircraft. When the aircraft decelerates for a vertical landing, the wings and the attached thrusters begin to rotate about their rotational axis. The front wing rotates such that the plane of rotation of the thrusters attached to it is shifted upward and backward. The rear wing rotates such that the plane of rotation of the thrusters attached to it is shifted downward and forward. The thrusters attached to the front wing are mounted sufficiently in front of the rotational axis of the front wing such that when rotated to the vertical flight position, they will move to a position above the top of the passenger cabin. The thrusters attached to the rear wing are mounted sufficiently behind the rotational axis of the rear wing such that when rotated to the vertical flight position, they will move to a position below the bottom of the passenger cabin. Thus, the plane of rotation of the thrusters never passes through the passenger cabin or the portion of the fuselage containing critical systems. The length of the landing gear is such that the rear thrusters have sufficient ground clearance during takeoff and landing.

[0006] In another embodiment, the wings of the aircraft are mounted in a fixed position, and the motor nacelles attached to the thrusters rotate from horizontal to vertical, where the axis of rotation of the nacelle and the positioning of the thrusters are configured such that the plane of rotation of the thrusters never passes through the passenger cabin.

[0007] In yet another embodiment, a flexible drive shaft configuration is utilized such that the nacelles containing the motors remain in a fixed position and only the thrusters rotate between horizontal and vertical thrust positions.

[0008] In various embodiments, the number of thrusters at the front and rear of the aircraft can be greater than or less than four at each end.

[0009] In various embodiments, a protective shield on the lower rear portion of the fuselage is used to protect passengers and important aircraft systems from damage caused by thruster failures, such that the plane of the thrusters on the rear of the aircraft intersects the protected lower portion of the fuselage when they rotate to the vertical thrust position, but in any configuration of the aircraft, no thruster rotation plane will intersect the upper portion of the fuselage. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 is an isometric view of a vertical takeoff and landing aircraft according to an illustrative embodiment, where the thrusters are in the horizontal thrust position.

[0011] Figure 2 is a side view of a vertical takeoff and landing aircraft according to an illustrative embodiment, where the thrusters are in the horizontal thrust position.

[0012] Figure 3 is a side view of a vertical takeoff and landing aircraft according to an illustrative embodiment, where the thrusters are between the horizontal and vertical thrust positions.

[0013] Figure 4 is a side view of a vertical takeoff and landing aircraft according to an illustrative embodiment, where the thrusters are in the vertical thrust position.

[0014] Figure 5 is an isometric view of a vertical takeoff and landing aircraft with four rotating motor nacelles and a fixed wing according to an illustrative embodiment, where the thrusters are in the horizontal thrust position.

[0015] Figure 6 is a side view of a vertical takeoff and landing aircraft with four rotating motor nacelles and a fixed wing according to an illustrative embodiment, where the thrusters are in the vertical thrust position.

[0016] Figure 7 is a side view of a vertical takeoff and landing aircraft with four rotating motor nacelles and a fixed wing according to an illustrative embodiment, where the thrusters are in the horizontal thrust position.

[0017] Figure 8 is a side view of a vertical takeoff and landing aircraft according to an illustrative embodiment, where the enhanced lower fuselage and thrusters are in the vertical thrust position. DETAILED DESCRIPTION

[0018] This disclosure relates to various embodiments of a vertical takeoff and landing (VTOL) aircraft configured to take off and land vertically and cruise horizontally while being supported by wings. The configurations described in detail in this disclosure allow the rotors to move from a vertical thrust configuration to a horizontal thrust configuration without the plane of the rotors intersecting the passenger cabin at any point. This improves passenger safety in the event of a mechanical failure occurring during operation of any rotor system.

[0019] It is desirable for a vertical takeoff and landing (VTOL) aircraft to be able to take off and land from a small area without a runway. Additionally, a VTOL aircraft has wings that can provide cruise efficiency. The transition from a vertical flight configuration to a horizontal flight configuration can involve rotating the thrust axis about an axis perpendicular to the thrust axis, which involves changing the plane of the rotors or thrusters relative to the aircraft fuselage. For the purposes of this disclosure, if a mechanical failure occurs, the rotors or thrusters have the same issues with respect to the safety of the aircraft occupants, and thus for the purposes of this disclosure, the rotors or thrusters will be treated interchangeably. When a thruster fails, the forces acting on the rotating components typically cause them to depart from the thruster in a direction perpendicular to the axis of rotation of the thruster (e.g., the plane of rotation of the thruster). In certain configurations of the aircraft, there is a risk that components departing from a failed thruster could cause injury to the occupants or damage the aircraft systems if they are within the plane of rotation. In certain aircraft configurations, the plane of the thrusters passes through the passenger cabin when the thrust axis rotates.

[0020] Some aircraft have thrusters with a plane of rotation that intersects the passenger cabin, creating these safety hazards if a mechanical failure occurs at the wrong time. There is a significant risk when fast-rotating thruster and engine components fail. Collisions between debris from failed rotating hardware on the aircraft and critical systems or passengers have resulted in multiple fatal accidents.

[0021] Advantageously, the aircraft configurations disclosed herein include thrusters having a plane of rotation that does not intersect the passenger cabin of the aircraft at any time. Other advantages of the aircraft configurations disclosed herein include a thruster / rotor configuration that provides improved controllability and stability of the aircraft. The problem solved by the configurations disclosed herein is how to avoid controllability and stability issues that may occur based on positioning the thrusters / rotors away from the center of gravity of the aircraft while keeping the plane of the thrusters / rotors from intersecting the passenger cabin. For example, certain systems (such as the system shown in U.S. Patent Application Publication No. 2007 / 0158494 to Burrage) show a system that significantly shifts relative to the center of gravity of the aircraft as the thrusters move from a point directly above the center of gravity of the aircraft to a point in front of or behind the entire passenger cabin. The various configurations disclosed herein avoid such issues, allowing for improved control and stability compared to conventional systems such as those shown in Burrage.

[0022] Figures 1 - 4 Shows a vertical takeoff and landing aircraft 100 according to various embodiments. The fuselage 2 includes a passenger cabin 8 in which the crew of the aircraft is seated. The passenger cabin 8 has an upper limit 60 of the passenger cabin, which is defined as the upper limit of the portion of the fuselage 2 occupied by passengers. The passenger cabin 8 also has a lower limit 62 of the passenger cabin, which is defined as the lower limit of the portion of the fuselage 2 occupied by passengers.

[0023] The inclined front wing 4 is attached to the fuselage 2 and can pivot about the forward thrust vector axis 68. The inclined rear wing 6 is attached to the fuselage 2 and can pivot about the rearward thrust vector axis 70. The front thruster 20 is wing-mounted on the front side of the inclined front wing 4. The rear thruster 30 is mounted on the rear side of the inclined rear wing 6. The vertical stabilizer 10 is attached to the fuselage 2 to improve yaw stability. The front thruster 20 is configured to provide forward thrust by pulling the aircraft, and the rear thruster 30 is configured to provide forward thrust by pushing the aircraft.

[0024] During cruise flight, the inclined front wing 4 and the inclined rear wing 6 are configured in a horizontal position so that the wings can provide lift. This configuration is visible in Figure 1 and 2 In this configuration, the thrust used from the front thruster 20 and the rear thruster 30 is minimized, enabling the vertical takeoff and landing aircraft 100 to advantageously use less energy to maintain flight. During cruise flight, the front thruster 20 is positioned in front of the passenger cabin 8, and the rear thruster 30 is positioned behind the passenger cabin 8.

[0025] When the vertical takeoff and landing aircraft 100 approaches the landing position, the forward speed decreases, and the inclined front wing 4 rotates about the forward thrust vector axis 68, while the inclined rear wing 6 rotates about the rearward thrust vector axis 70 substantially simultaneously, changing the forward thrust axis 72 and the rearward thrust axis 74 to provide a horizontal component of thrust and a vertical component of thrust. Figure 3 Shows the vertical takeoff and landing aircraft 100, where the inclined front wing 4 and the inclined rear wing 6 are in an intermediate position between the horizontal and vertical configurations.

[0026] As the vertical takeoff and landing aircraft 100 further decelerates, the inclined front wing 4 and the inclined rear wing 6 transition to the Figure 4 vertical position as seen in. In this configuration, the aircraft remains airborne by the thrust generated by the front thruster 20 and the rear thruster 30.

[0027] For increased safety, the front thruster 20, the rear thruster 30, the forward thrust vector axis 68, the rearward thrust vector axis 70, the upper limit 60 of the passenger cabin, and the lower limit 62 of the passenger cabin are configured such that in the Figure 2 horizontal flight configuration as seen in andFigure 4 During the transition between the vertical flight configurations seen in Figure 4 , the plane 64 of the front thrusters and the plane 66 of the rear thrusters never intersect the passenger cabin 8. The distance between the plane 64 of the front thrusters and the front thrust vector axis 68 is greater than the distance between the front thrust vector axis 68 and the upper limit 60 of the passenger cabin. The distance between the plane 66 of the rear thrusters and the rear thrust vector axis 70 is greater than the distance between the rear thrust vector axis 70 and the lower limit 62 of the passenger cabin. The relationship between these distances ensures that the thrusters 64 rotate about the front thrust vector axis 68 and that the plane 64 of the front thrusters always lies in front of or above the passenger cabin 8. The relationship between these distances also ensures that when the plane 66 of the rear thrusters rotates about the rear thrust vector axis 70, the plane 66 of the rear thrusters always lies behind or below the passenger cabin 8.

[0028] Figures 5 - 7 Shows an alternative embodiment of the vertical takeoff and landing aircraft 200. The fixed front wing 40 and the fixed rear wing 50 are rigidly attached to the fuselage 2. The inclined front maneuvering nacelle 42 is attached to the fixed front wing 40 such that it can rotate about the front thrust vector axis 80. The inclined rear maneuvering nacelle 52 is attached to the fixed rear wing 50 such that it can rotate about the rear thrust vector axis 82.

[0029] The distance between the plane 84 of the front thrusters and the front thrust vector axis 80 is greater than the distance between the front thrust vector axis 80 and the upper limit 60 of the passenger cabin. The distance between the plane 86 of the rear thrusters and the rear thrust vector axis 82 is greater than the distance between the rear thrust vector axis and the lower limit 62 of the passenger cabin.

[0030] Figure 8 Shows additional configurations for the vertical takeoff and landing aircraft 300 according to various embodiments. The portion of the fuselage 2 around the passenger cabin 8, above the lower limit 62 of the passenger cabin and below the upper limit 90 of the reinforced portion of the fuselage is strengthened to protect the occupants from debris in the event of a mechanical failure of the rear thruster 94. The rear thruster 94 and the inclined rear maneuvering nacelle 92 rotate about the rear thrust vector axis 98. The distance between the plane 96 of the rear thrusters and the rear thrust vector axis 98 is greater than the distance between the rear thrust vector axis 98 and the upper limit 90 of the reinforced portion of the fuselage. This configuration prevents the plane 96 of the rear thrusters from intersecting the portion of the passenger cabin 8 above the upper limit 90 of the reinforced fuselage when the rear thruster 94 rotates about the rear thrust vector axis 98. This configuration also allows the windows in the upper non-reinforced fuselage above the upper limit of the reinforced portion of the fuselage to be lighter compared to the case where debris generated by a failed thruster needs to be prevented from entering the passenger cabin 8.

Claims

1. A vertical takeoff and landing aircraft, comprising: A fuselage; A passenger cabin within the fuselage; At least two front thrusters positioned in front of the center of gravity of the aircraft, with at least one of the front thrusters positioned on each side of the fuselage; And At least two rear thrusters positioned behind the center of gravity of the aircraft, with at least one of the rear thrusters positioned on each side of the fuselage; wherein: The front thrust axis of each of the at least two front thrusters is substantially perpendicular to the front thrust vector axis, wherein in the horizontal flight mode, the at least two front thrusters are positioned in front of the front thrust vector axis, and wherein the at least two front thrusters and the front thrust axis of each of the at least two front thrusters are configured to rotate about the front thrust vector axis; The rear thrust axis of each of the at least two rear thrusters is substantially perpendicular to the rear thrust vector axis, wherein in the horizontal flight mode, the at least two rear thrusters are positioned behind the rear thrust vector axis, and wherein the at least two rear thrusters and the rear thrust axis of each of the at least two rear thrusters are configured to rotate about the rear thrust vector axis; A front thrust offset distance is defined between the rotation plane of the at least two front thrusters and the front thrust vector axis, wherein the front thrust offset distance is greater than a first vertical distance from the front thrust vector axis to the top of the passenger cabin; and A rear thrust offset distance is defined between the rotation plane of the at least two rear thrusters and the rear thrust vector axis, wherein the rear thrust offset distance is greater than a second vertical distance from the rear thrust vector axis to the bottom of the passenger cabin; When the at least two front thrusters rotate about the front thrust vector axis between positions related to the horizontal flight mode and the vertical flight mode, the rotation plane of the at least two front thrusters does not intersect the passenger cabin; and When the at least two rear thrusters rotate about the rear thrust vector axis between positions related to the horizontal flight mode and the vertical flight mode, the rotation plane of the at least two rear thrusters does not intersect the passenger cabin.

2. The vertical takeoff and landing aircraft according to claim 1, wherein the at least two front thrusters are mounted on a front wing, and the at least two rear thrusters are mounted on a rear wing.

3. The vertical takeoff and landing aircraft according to claim 2, wherein the front wing rotates about the front thrust vector axis, and the rear wing rotates about the rear thrust vector axis.

4. The vertical takeoff and landing aircraft according to claim 3, wherein when the front wing rotates about the front thrust vector axis, the at least two front thrusters also rotate about the front thrust vector axis.

5. The vertical takeoff and landing aircraft according to claim 3, wherein when the rear wing rotates about the rear thrust vector axis, the at least two rear thrusters also rotate about the rear vector axis.

6. The vertical takeoff and landing aircraft according to claim 2, wherein the nacelles of the at least two front thrusters rotate independently of the front wing about the front thrust vector axis.

7. The vertical takeoff and landing aircraft according to claim 6, wherein the front wing is fixed relative to the fuselage.

8. The vertical takeoff and landing aircraft according to claim 2, wherein the nacelles of the at least two rear thrusters rotate independently of the rear wing about the rear thrust vector axis.

9. The vertical takeoff and landing aircraft according to claim 8, wherein the rear wing is fixed relative to the fuselage.

10. The vertical takeoff and landing aircraft according to claim 2, wherein the front wing is attached to the fuselage at a point in front of the center of gravity, and the rear wing is attached to the fuselage at a point behind the center of gravity.

11. The vertical takeoff and landing aircraft according to claim 1, wherein the at least two front thrusters and / or the at least two rear thrusters are rotors or thrusters.

12. The vertical takeoff and landing aircraft according to claim 1, wherein the at least two front thrusters include four front thrusters, and the at least two rear thrusters include four rear thrusters.

13. The vertical takeoff and landing aircraft according to claim 1, wherein when the at least two front thrusters are configured in the vertical flight mode, the front thrust axis of each of the at least two front thrusters is positioned in front of the passenger cabin, and when the at least two rear thrusters are configured in the vertical flight mode, the rear thrust axis of each of the at least two rear thrusters is positioned behind the passenger cabin.

14. A vertical takeoff and landing aircraft, comprising: a fuselage; a passenger cabin within the fuselage; at least two front thrusters positioned in front of the center of gravity of the vertical takeoff and landing aircraft, wherein at least one of the front thrusters is positioned on each side of the fuselage; at least two rear thrusters positioned behind the center of gravity, wherein at least one of the rear thrusters is positioned on each side of the fuselage; wherein: the front thrust axis of each of the at least two front thrusters is substantially perpendicular to the front thrust vector axis, wherein the at least two front thrusters are positioned in front of the front thrust vector axis in the horizontal flight mode, and wherein the at least two front thrusters and the front thrust axis of each of the at least two front thrusters are configured to rotate about the front thrust vector axis; the rear thrust axis of each of the at least two rear thrusters is substantially perpendicular to the rear thrust vector axis, wherein the at least two rear thrusters are positioned behind the rear thrust vector axis in the horizontal flight mode, and wherein the at least two rear thrusters and the rear thrust axis of each of the at least two rear thrusters are configured to rotate about the rear thrust vector axis; an upper limit of a reinforced portion of the fuselage, wherein a first portion of the fuselage below the upper limit is reinforced to prevent debris from a thruster failure from damaging the occupants within the fuselage, and wherein a second portion of the fuselage above the upper limit is not reinforced to prevent debris from a thruster failure from damaging the occupants within the fuselage; a front thrust offset distance is defined between the rotation plane of the at least two front thrusters and the front thrust vector axis, wherein the front thrust offset distance is greater than a first vertical distance from the front thrust vector axis to the top of the passenger cabin; and The rear thrust offset distance is defined between the rotation plane of the at least two rear thrusters and the rear thrust vector axis, wherein the rear thrust offset distance is greater than a second vertical distance from the rear thrust vector axis to the upper limit of the first reinforced portion of the fuselage; When the at least two front thrusters rotate about the front thrust vector axis between positions related to the horizontal flight mode and the vertical flight mode, the rotation plane of the at least two front thrusters does not intersect the unreinforced second portion of the fuselage; and When the at least two rear thrusters rotate about the rear thrust vector axis between positions related to the horizontal flight mode and the vertical flight mode, the rotation plane of the at least two rear thrusters does not intersect the unreinforced second portion of the fuselage.

15. The vertical takeoff and landing aircraft according to claim 14, wherein the at least two front thrusters and / or the at least two rear thrusters are rotors or thrusters.

16. The vertical takeoff and landing aircraft according to claim 14, wherein when the at least two front thrusters are configured in the vertical flight mode, the front thrust axis of each of the at least two front thrusters is positioned in front of the passenger cabin, and when the at least two rear thrusters are configured in the vertical flight mode, the rear thrust axis of each of the at least two rear thrusters is positioned behind the passenger cabin.

17. The vertical takeoff and landing aircraft according to claim 14, wherein the at least two front thrusters are mounted on the front wing, and the at least two rear thrusters are mounted on the rear wing.

18. The vertical takeoff and landing aircraft according to claim 17, wherein the front wing rotates about the front thrust vector axis, and the rear wing rotates about the rear thrust vector axis.

19. The vertical takeoff and landing aircraft according to claim 17, wherein the nacelles of the at least two front thrusters rotate independently of the front wing about the front thrust vector axis, and the nacelles of the at least two rear thrusters rotate independently of the rear wing about the rear thrust vector axis.

20. A vertical takeoff and landing aircraft, comprising: a fuselage; a passenger cabin within the fuselage; front thrusters positioned in front of the center of gravity of the vertical takeoff and landing aircraft; and rear thrusters positioned behind the center of gravity; wherein: the front thrusters are configured to rotate about a front thrust vector axis; the rear thrusters are configured to rotate about a rear thrust vector axis; a front thrust offset distance is defined between the rotation plane of the front thrusters and the front thrust vector axis, wherein the front thrust offset distance is greater than a first vertical distance from the front thrust vector axis to the top of the passenger cabin; and a rear thrust offset distance is defined between the rotation plane of the rear thrusters and the rear thrust vector axis, wherein the rear thrust offset distance is greater than a second vertical distance from the rear thrust vector axis to the bottom of the passenger cabin; when the front thrusters rotate about the front thrust vector axis between positions related to the horizontal flight mode and the vertical flight mode, the rotation plane of the front thrusters does not intersect the passenger cabin; and when the rear thrusters rotate about the rear thrust vector axis between positions related to the horizontal flight mode and the vertical flight mode, the rotation plane of the rear thrusters does not intersect the passenger cabin.

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