VIBRATION DAMPER MECHANISM, AND A FLYING MACHINE INCLUDING A CARRIER STRUCTURE AND A ROTOR PROVIDED WITH SUCH A MECHANISM

• US 20110155841A1
• Filed: 12/15/2010
• Published: 06/30/2011
• Est. Priority Date: 12/17/2009
• Status: Active Grant

• Current Assignee: Airbus Helicopters
• Original Assignee: Eurocopter
• Inventors: Re, Joachim, Pula, Matthieu, Manfredotti, Thomas, Cranga, Paul
• Granted Patent: US 8,695,917 B2
• Time in Patent Office: Days
• US Class Current: 244/17.11
• CPC Class Codes: B64C 2027/005 using suspended masses
• CPC Class Codes: B64C 27/001 Vibration damping devices
• CPC Class Codes: F16F 15/1471 with a kinematic mechanism, i.e. linkages, levers

Abstract

The present invention provides a mechanism (90) for damping vibrations to prevent coupling of vibration modes of the carrier structure (106) with vibration modes of a rotor (100) secured to said carrier structure (106). The mechanism comprises a support (3) suitable for being fastened to said rotor (100) and at least one resonator (1) including a mass (5) carried by said support (3) via mobile mounting means (6) for mounting said mass (5) to move on said support (3), said mechanism (90) including damper means (8) for damping the resonator (1), which means are interposed between the resonator (1) and an engagement member (9) on said support (3).

Claims

1. A mechanism for damping vibrations to prevent coupling of vibration modes of the carrier structure with vibration modes of a rotor secured to said carrier structure, wherein the mechanism comprises a support suitable for being fastened to said rotor and at least one resonator including a mass carried by said support via mobile mounting means for mounting said mass to move on said support, said mechanism including damper means for damping the resonator, which means are interposed between the resonator and an engagement member on said support.

2. A mechanism according to claim 1, wherein said mobile mounting means comprise one hinged arm per mass, the resonator being of the pendular type comprising a mass carried in pendular manner by said support via a hinged arm.

3. A mechanism according to claim 1, wherein the resonator constitutes means suitable for opposing vibration over a first narrow frequency range as induced by forced excitation to which the rotor is subjected, and wherein the damper means associated with the resonator are suitable for opposing vibration originating from instability in a second frequency range that is wider than said first frequency range and being adapted as a function of the characteristics of the carrier structure of the flying machine and/or as a function of imperfections observed in the damping of vibration.

4. A mechanism according to claim 1, wherein the engagement member may equally well be a stationary member or a movable member of said mechanism.

5. A mechanism according to claim 1, wherein the mass is carried in pendular manner to be movable in pivoting about at least one pivot axis (A2) that may equally well be oriented parallel to and/or perpendicular to an axis of rotation (A1) of the support.

6. A mechanism according to claim 1, wherein said mobile mounting means comprise one hinged arm per mass, each hinged arm being arranged as a lever arm, being hinged to the support and being hinged to the damper means at one end and carrying the mass at another end.

7. A mechanism according to claim 1, wherein the damper means are of the elastic or mechanical deformation type.

8. A mechanism according to claim 7, wherein the resonator is mounted to move on a first branch of the support, and wherein the damper means are interposed between the mobile mounting means of the resonator and a second branch of the hub that is adjacent to the first branch and that constitutes said engagement member.

9. A mechanism according to claim 7, wherein a plurality of resonators are movably mounted on the support, the damper means being interposed between the mobile mounting means of two adjacent resonators and on which the damper means are jointly engaged.

10. A mechanism according to claim 1, wherein the damper means are of the electromagnetic type, associating constituting magnetic members associated respectively with the resonator and with the support, one of the magnetic members being arranged as a cage incorporating at least one magnetic element, said cage housing a body forming at least part of the other magnetic member.

11. A mechanism according to claim 10, wherein said mobile mounting means comprise one hinged arm per mass, the hinged arm being mounted to move in pivoting on the support above a pivot axis (A2) parallel to the axis of rotation (A1) of the support.

12. A mechanism according to claim 11, wherein the cage is carried by a branch of the support on which the resonator is mounted, the cage being located so as to be axially offset relative to the general plane (P) in which the pendular resonator moves, and the body being connected to the resonator via a driving crank.

13. A mechanism according to claim 11, wherein the cage is carried by a branch of the support on which the resonator is mounted, at least one magnetic element integrated in the cage being located in axially offset manner relative to the general plane (P) in which the resonator moves, and the body constituting at least part of the mass of the resonator.

14. A mechanism according to claim 11, wherein the cage is carried by the hinged arm of the resonator, the body constituting at least a portion of the mass of the pendular resonator and being tangentially hinged to the end of a retaining connecting rod hinged to at its other end to the engagement member of the support.

15. A mechanism according to claim 1, wherein said mechanism is passive.

16. A mechanism according to claim 1, wherein the damper means are of hydraulic, pneumatic, elastic, or magnetic type.

17. A flying machine having a rotor and a carrier structure including an airframe and a mounting structure for mounting the rotor to said airframe, wherein said rotor includes a vibration damper mechanism according to claim 1 to prevent vibration modes of said carrier structure coupling with vibration modes of said rotor.