Anti-vibratory suspension device for a helicopter

DETAILED DESCRIPTION In order to simplify such a device and make it perfectly capable of filtering all vibrations and transferring to the fuselage the reaction from the rotor drive torque and the dynamic moments originating from this rotor, the subject of the present invention is a suspension device of the type in question, wherein each support consists of a preferably straight bar made in one piece and fixed rigidly in its central part to the bottom of the transmission box, this bar comprising flexible parts between its central part and its articulated joints with the strong points of the fuselage and, beyond these articulated joints, relatively rigid parts ballasted at their ends with the above-mentioned swinging weights, whilst associated with this pair of bars is a vertical connecting rod located substantially in the axis of the rotor and connected by articulated joints, on the one hand, to the bottom of the transmission box and, on the other hand, to the structure of the fuselage, the suspension device consisting essentially of said pair of bars and said rod and being located completely between the bottom of the transmission box of the helicopter and its fuselage.
The device according to the invention has the advantage of being simple, light-weight and inexpensive.
It also makes it possible to eliminate the set of oblique bars conventionally provided between the fuselage and the head of the transmission box so as to maintain the latter in position.
In a preferred embodiment, the bars have in their various parts a cross-section varying in size according to the forces to be withstood and the flexibility required.
These bars can, on the other hand, be made of a composite material based on longtitudinal glass fibers and resin.
Because of its arrangement, the whole of the device described, which makes the connection between the rotor and the fuselage of a helicopter, effectively filters out the excitations of moments of force originating from the vibrations generated by the rotor in its own plane of rotation