Rotorcraft with a fuselage and at least one main rotor

Patent metadata

Field	Value
Publication number	US-9527577-B2
Application number	US-201514605097-A
Country	US
Kind code	B2
Filing date	Jan 26, 2015
Priority date	Jan 27, 2014
Publication date	Dec 27, 2016
Grant date	Dec 27, 2016

Abstract

A rotorcraft with a fuselage and at least one main rotor, the at least one main rotor being drivable for controlling an associated pitch attitude of the rotorcraft in operation, and the fuselage being equipped with at least one passive wing-type aerodynamic device that is adapted for generating independently of the associated pitch attitude a lift force acting on the fuselage, the lift force being oriented perpendicular to an air flow that is directed in operation of the rotorcraft against the passive wing-type aerodynamic device.

First claim

What is claimed is:

1. A rotorcraft with a fuselage comprising a nose and with at least one main rotor suitable for rotating around a rotor mast axis, the rotorcraft assuming varying pitch attitudes in operation, and the fuselage being equipped with at least one passive wing-type aerodynamic device that is adapted for generating independently of the varying pitch attitudes a lift force acting on the fuselage, the lift force being oriented perpendicular to an air flow that is directed in operation of the rotorcraft against the passive wing-type aerodynamic device wherein the passive wing-type aerodynamic device comprises at least one wing element that is rotatable relative to the fuselage around an associated rotation axis, the at least one wing element being adapted to self-adjust its rotational orientation relative to the fuselage by rotating in reaction to the air flow, wherein the at least one wing element is positioned longitudinally closer to the nose of the fuselage than the rotor mast axis, and wherein at least one wing element comprises a combined neutral point designating a location, where a derivative of an aerodynamic pitching moment generated in operation of the rotorcraft is zero with respect to changes in an angle of attack encompassed between the air flow, that is directed in operation of the rotorcraft against the at least one wing element, and a chord line of the at least one wing element, wherein the associated rotation axis is arranged relative to the air flow at a position located upstream of the combined neutral point, if the aerodynamic pitching moment tends to increase the angle of attack.

2. The rotorcraft according to claim 1 , wherein at least one wing element is at least weight-balanced about the associated rotation axis, such that aerodynamic loads occurring in operation of the rotorcraft on the at least one wing element determine the angle of attack at least substantially.

3. The rotorcraft according to claim 1 , wherein at least one wing element is rotatably mounted to the fuselage by means of a bearing arrangement that is adapted to allow at least substantially static-friction-free rotation of the at least one wing element relative to the fuselage.

4. The rotorcraft according to claim 3 , wherein at least one wing element is equipped with a rotary shaft, wherein the bearing arrangement comprises an intermediate bearing ring that is rotatably mounted to the rotary shaft and an outer bearing ring holding the intermediate bearing ring, the intermediate bearing ring being adapted for continuous rotation or oscillation around the rotary shaft, and the outer bearing ring being non-rotatably mounted to the fuselage.

5. The rotorcraft according to claim 3 , wherein the bearing arrangement comprises at least one ball bearing with spherical ball races.

6. The rotorcraft according to claim 1 , wherein at least one wing element comprises a main wing and at least one auxiliary wing, the at least one auxiliary wing being mounted with a predetermined angle of incidence to the main wing by means of an associated wing connector, the predetermined angle of incidence being encompassed between a chord line of the main wing and a chord line of the at least one auxiliary wing.

7. The rotorcraft according to claim 6 , wherein the predetermined angle of incidence is mechanically adjustable.

8. The rotorcraft according to claim 6 , wherein at least one auxiliary wing is mounted at a position located upstream or downstream of the main wing relative to the air flow that is directed in operation of the rotorcraft against the main wing.

9. The rotorcraft according to claim 6 , wherein at least one auxiliary wing is mounted to the main wing at a predetermined distance downstream a trailing edge of the main wing.

10. The rotorcraft according to claim 1 , wherein at least one wing element is equipped with at least one winglet-like endplate.

11. The rotorcraft according to claim 1 , wherein at least one wing element comprises a S-shaped section profile.

12. The rotorcraft according to claim 1 , wherein at least one wing element is embodied as a swept wing with spanwise twist, the swept wing comprising an outer wing section that is twisted nose-up in case of forward sweep, or twisted nose-down in case of rearward sweep, relative to an associated inner wing section.

13. The rotorcraft according to claim 1 , wherein at least one wing element comprises a first wing element arranged on a first lateral rotorcraft side and a second wing element arranged on a second lateral rotorcraft side, the first and second wing elements being adapted to operate independently or in unison.

14. The rotorcraft according to claim 13 , wherein the first and second wing elements comprise differing wingspans.

15. The rotorcraft according to claim 1 , wherein the main rotor is configured to be drivable with a variable rotational speed.

16. The rotorcraft according to claim 1 , wherein a propeller is provided.

17. A rotorcraft with a fuselage comprising a nose and with at least one main rotor suitable for rotating around a rotor mast axis, the rotorcraft assuming varying pitch attitudes in operation, and the fuselage being equipped with at least one passive wing-type aerodynamic device that is adapted for generating independently of the varying pitch attitudes a lift force acting on the fuselage, the lift force being oriented perpendicular to an air flow that is directed in operation of the rotorcraft against the passive wing-type aerodynamic device wherein the passive wing-type aerodynamic device comprises at least one wing element that is rotatable relative to the fuselage around an associated rotation axis, the at least one wing element being adapted to self-adjust its rotational orientation relative to the fuselage by rotating in reaction to the air flow, wherein the at least one wing element is positioned longitudinally closer to the nose of the fuselage than the rotor mast axis, and wherein at least one wing element is at least weight-balanced about the associated rotation axis, such that aerodynamic loads occurring in operation of the rotorcraft on the at least one wing element determine the angle of attack at least substantially.

18. The rotorcraft according to claim 17 , wherein at least one wing element is rotatably mounted to the fuselage by means of a bearing arrangement that is adapted to allow at least substantially static-friction-free rotation of the at least one wing element relative to the fuselage.

19. The rotorcraft according to claim 18 , wherein at least one wing element is equipped with a rotary shaft, wherein the bearing arrangement comprises an intermediate bearing ring that is rotatably mounted to the rotary shaft and an outer bearing ring holding the intermediate bearing ring, the intermediate bearing ring being adapted for continuous rotation or oscillation around the rotary shaft, and the outer bearing ring being non-rotatably mounted to the fuselage.

20. The rotorcraft according to claim 17 , wherein at least one wing element comprises a main wing and at least one auxiliary wing, the at least one auxiliary wing being mounted with a predetermined angle of incidence to the main wing by means of an associated wing connector, the predetermined angle of incidence being encompassed between a chord line of the main wing and a chord line of the at least one auxiliary wing.

Assignees

• Airbus Helicopters Deutschland GmbH

Inventors

• Embacher Martin

Classifications

• B64C27/04

  Helicopters · CPC title

• B64C27/82

  characterised by the provision of an auxiliary rotor or fluid-jet device for counter-balancing lifting rotor torque or changing direction of rotorcraft · CPC title

• B64C3/385

  Variable incidence wings · CPC title

• Y02T50/145

  Cross-Sectional Technologies · mapped topic

• B64C5/16 Primary

  about spanwise axes · CPC title