Passively stable hovering system

• US 5,070,955 A
• Filed: 09/17/1990
• Issued: 12/10/1991
• Est. Priority Date: 05/04/1990
• Status: Expired due to Fees

• Current Assignee: Aerovironment
• Original Assignee: Aerovironment
• Inventors: Lissaman, Peter B. S., Drees, Herman M., Sink, Charles J., Watson, William D.
• Primary Examiner(s): Rice, Kenneth R.
• Assistant Examiner(s): Hurley, Kevin
• Application Number:
  US07/583,477
• Time in Patent Office: 449 Days
• Field of Search: 180/116, 180/117, 180/118, 180/119, 180/120, 180/121, 180/123, 244/7 C, 244/12.4, 244/12.5, 244/21, 244/23 A, 244/23 D
• US Class Current: 180/117
• CPC Class Codes: B64C 27/20 Rotorcraft characterised by having shrouded rotors, e.g. flying platforms
• CPC Class Codes: B64C 39/024 of the remote controlled vehicle type, i.e. RPV
• CPC Class Codes: B64U 10/13 Flying platforms
• CPC Class Codes: B64U 10/14 with four distinct rotor axes, e.g. quadcopters
• CPC Class Codes: B64U 2201/10 autonomous, i.e. by navigating independently from ground or air stations, e.g. by using inertial navigation systems [INS]
• CPC Class Codes: B64U 2201/20 Remote controls
• CPC Class Codes: B64U 30/20 Rotors; Rotor supports
• CPC Class Codes: B64U 30/26 Ducted or shrouded rotors
• CPC Class Codes: B64U 50/11 using internal combustion piston engines
• CPC Class Codes: B64U 50/14 ducted or shrouded
• CPC Class Codes: B64U 50/19 using electrically powered motors
• CPC Class Codes: B64U 60/50 with landing legs

Abstract

A flight system capable of passively stable hover and horizontal translatory flight, comprises an apparatus defining a vertical axis, and including multiple ducts with substantially vertical axes in hover mode, spaced the axis; fluid momentum generators in the ducts to effect flow of fluid downwardly in the ducts in hover; and fluid flow deflector structure in the path of the flowing duct fluid, and angled to deflect the fluid flow away from the axis, in such manner as to provide stability in hover of the apparatus, as well as stability when the entire device is tilted through approximately 90° to execute horizontal translatory flight.

Claims

1. In a passively stable hovering system, the combination comprising:

a) apparatus defining a principle central axis in hover mode, and including multiple upright ducts spaced about said axis, said ducts having central axes, parallel to said apparatus principle central axis,

b) multiple fluid momentum generators, at least one in each of said ducts to effect axial flow of fluid downwardly in the ducts,

c) and fluid flow deflector means extending in flow deflecting relation with said axially flowing fluid, and angled to deflect the fluid flow away from said central axis, in such manner as to provide stability,

d) said ducts having exit nozzles and said deflector means projecting outwardly from the central axis and below each of said duct exit nozzles, respectively.

2. The combination of claim 1 wherein said deflector means comprise plates projecting axially downwardly and outwardly, from and below said duct exit nozzles, and away from said central axis.

3. The combination of claim 2 wherein said plates are attached to the duct exit nozzles.

4. The combination of claim 3 wherein the plates extend at angles between 30°

and 60°

relative to said central axis.

5. The combination of claim 2 wherein said plates are substantially flat.

6. The combination of claim 2 wherein each of said plates has width less than the diameter of each associated duct.

7. The combination of claim 2 wherein said plates are supported to have controllable angularly relative to said central axis and including control means for controlling said angularity.

8. The combination of claim 1 including control means connected with said multiple generators to differentially control operation thereof for flight direction control.

9. The combination of claim 1 wherein there are at least three of said ducts symmetrically located about said central axis.

10. The combination of claim 1 wherein said momentum generators comprise rotatable about axes substantially coincident with duct axes.

11. The combination of claim 10 including drive means for rotating the propellers.

12. The combination of claim 11 wherein said drive means comprises at least one electric motor operatively connected with said propellers.

13. The combination of claim 12 including electrical cable means connected with said drive means to controllably supply electrical energy thereto.

14. The combination of claim 11 wherein said drive means comprises internal combustion engine means connected with the propellers.

15. The combination of claim 11 wherein said drive means includes at least one motor carried by said apparatus and operatively connected with said propellers.

16. In a passively stable hovering system also capable of stable horizontal flight, the combination comprising:

a) apparatus defining a principle central axis in hover mode, and including multiple ducts spaced about said axis, said ducts having central axes, substantially parallel to said apparatus principle central axis,

b) multiple fluid momentum generators, at least one in each of said ducts to effect axial flow of fluid downwardly in the ducts,

c) and fluid flow deflector means extending in flow deflecting relation with said axially flowing fluid, and angled to deflect the fluid flow away from said central axis, in such manner as to provide stability in hover and in horizontal flight,

d) each said duct having an exit nozzle and said deflector means comprising plates each projecting outwardly of the central axis and below one of said duct exit nozzles.

17. The method of operating a passively stable hovering system, the system having a principle central axis in hover mode, multiple upright ducts spaced about said principle axis and having central axes and exit nozzles, and multiple momentum generators, at least one in each of said ducts to effect axial flow of fluid downwardly in the ducts, the method including:

a) providing fluid flow deflector means to combine plates extending in flow deflecting relation with said axially flowing fluid,

b) angling said plates to deflect the fluid flow away from said central axis, in such manner as to provide stability in hover and in horizontal flight,

c) and further locating said flow deflector plates to project outwardly from the central axis and below each of said duct exit nozzles, respectively.

18. The method of claim 17 including orienting said plates to project axially downwardly and outwardly, from and below said duct exit nozzles, and away from said central axis.

19. The method of claim 18 including controlling at least one of said momentum generators and said flow deflector means to control fluid flow discharge from the ducts to achieve directed flight with a horizontal component.

20. The method of claim 18 including supporting said plates to have controllable angularity relative to said central axis, and including providing and operating control means for controlling said angularity.

21. The combination of claim 17 wherein said momentum generators comprise propellers rotatable about axes substantially coincident with axes defined by the ducts, and drive means for rotating the propellers, and including controlling said drive means to achieve directed flight, with a horizontal component.

22. The method of claim 17 including providing at least three of said ducts symmetrically located about said apparatus central axis.