Abstract: The invention relates to aeronautics in general, and in particular to a suspension device for helicopter, comprising a flexible mounting plate at the center of which is fixed the bottom of the main gear box whose top is supported by hinged oblique bars. The mounting plate offers radial arms hinged to the base of the bars and to the fuselage of the helicopter. These arms bear flapping weights creating forces of inertia with reactions at the attachment points of direction opposite the elastic reactions of deformation of the mounting plate. A device of this type enables the vibrations on board helicopters to be reduced.

Abstract: The invention relates to a device for damping the vibrations of a rotary-wing aircraft rotor. An annular weight is disposed concentrically of the rotor axis. This weight is supported by at least three resiliently deformable elements such as helical springs, radially biased in directions distributed regularly around the rotor axis. The inner ends of the springs directly bear on a part extending the rotor shaft axially. Their outer ends directly bear on the annular weight so that the spring apply statically balanced centrifugal thrusts to the annular weight. The springs are so still that they support the annular weight without substantially bending.

Abstract: The invention relates to a device for damping the vibrations of the rotor of a rotary-wing aircraft. This device comprises a flapping weight concentrated near the rotor axis and at least three resiliently deformable elements, such as helical springs. The deformable elements are radially biassed in directions regularly distributed around the rotor axis. The inner ends of the deformable elements directly bear on the flapping weight. Their outer ends directly bear on rigid structure elements, rigidly secured to the rotor hub, so that the biassed deformable elements apply statically balanced centripetal thrusts to the flapping weight.