Abstract: A distributed mass device for reducing the vibration generated by a rotor, includes a support suitable for being constrained in rotation about an axis of rotation of the lift rotor. The distributed mass device further includes at least two main oscillating masses each provided with a through longitudinal recess, and each being connected to the support by respective deformable elements, the main oscillating masses being constrained to move solely in a horizontal plane by the deformable elements. The distributed mass device is provided with a secondary oscillating mass per main oscillating mass, each secondary oscillating mass being suspended inside the recess of the associated main oscillating mass by resilient elements.

Abstract: The present invention relates to a rotorcraft blade (1) provided with at least one spar (3) and an outer covering (4), said blade (1) including a hollow sleeve (10) with a wall (11) that is provided at least with said outer covering (4) secured to said spar (3). The blade includes a rotary damper (20) provided with an inner tubular strength member (21) and an outer tubular strength member (22) that are coaxial and connected together by a ring (23) of viscoelastic material, said inner tubular strength member (21) being secured to said covering (4), and said outer tubular strength member (22) being provided with a fork (25) possessing first and second tines (26, 27) facing each other so as to be suitable for receiving a first ball joint (41) close to the pitch-variation axis (AX1) of said blade (1).