Method and device for filtering the vibratory excitations transmitted between two parts especially between the rotor and the fuselage of a helicopter

An elastic linking device between two parts (3,5) for transmitting, from one part to the other part, the static forces in the axis of the device and simultaneously filtering the associated coaxial vibratory excitation which are transmitted from one part to the other part, said device comprising:

• at least one linking element (7) between said parts (3,5) comprising a transmission member (8) for the static force between said parts (3,5), and an actuator (9) associated with said transmission member (8);
• at least one means of measurement (10) of a physical quantity which is representative of the vibratory excitations transmitted from one part to the other part, said measurement means being able to supply corresponding first signals, said measurement means (10) being mounted on said linking element (7);
• and
• electronic processing means (12) for processing said first signals in order to convert them into second control signals for said actuator (9), said processing means (12) decoupling the static force and the vibratory excitations, in such a way that said second control signals drive the actuator in order to exactly oppose said vibratory excitations.

An aircraft with rotating wings, especially a helicopter, comprising a main lift rotor (2) driven by a main transmission gearbox (3) for the motive power, which gearbox supports a fuselage (5), said aircraft comprising:

• an elastic linking device between said transmission gearbox (3) and said fuselage (5) for transmitting, from said transmission gearbox (3) to the fuselage (5), the static forces in the axis of the device and simultaneously filtering the associated coaxial vibratory excitations which are transmitted from the transmission gearbox (3) to the fuselage, said device comprising;
• at least one linking element (7) between the transmission box (3) and the fuselage (5) comprising a transmission member (8) for the static force between said transmission box (3) and said fuselage (5) and an actuator (9) associated with the transmission member (8);
• at least one means of measurement (10) of a physical quantity which is representative of the vibratory excitations transmitted from the transmission box (3) to the fuselage (5), said measurement means able to supply corresponding first signals, the measurement means (10) being mounted on said linking element (7) and
• electronic processing means (12) for processing said first signals in order to convert them into second control signals for said actuator (9), said processing means (12) decoupling the static force and the vibratory excitations, in such a way that said second control signal drive the actuator in order to exactly oppose said vibratory excitations.