Patent ID: 7347799

Claim:
An antivibration device (D) for reducing the vibration of a structure, the device comprising a stationary casing (C) mounted on the structure and with first and second sets (E 1 , E 2 ) each comprising two contra-rotary rotors ( 11 & 21 and 31 & 41 ) with eccentric flyweights ( 12 & 22 and 32 & 42 ), said flyweights ( 12 , 22 , 32 , 42 ) and said rotors ( 11 , 21 , 31 , 41 ) being disposed respectively in first and second mutually parallel planes ( 100 , 200 ), the centers of rotation of said contra-rotary rotors ( 11 , 21 , 31 , 41 ) representing the corners of a rectangular parallelogram ( 300 ) in said second plane ( 200 ), and the axes of rotation (AX 1 , AX 2 , AX 3 , AX 4 ) of said contra-rotary rotors ( 11 , 21 , 31 , 41 ) being mutually parallel and orthogonal to said first plane ( 100 ), the device including a stationary main motor (M 1 ) secured to said casing (C), with a through shaft (AM) having a first end (EX 1 ) driving said contra-rotary rotors ( 11 , 21 ) of said first set (E 1 ) and a second end (EX 2 ) driving said contra-rotary rotors ( 31 , 41 ) of said second set (E 2 ).