Assembly for connecting a rotor to a helicopter

Claim 2

An assembly for securing a main rotor of a helicopter to the fuselage therof, the assembly being adapted to prevent vibrations from being transmitted from the rotor to the fuselage, wherein the rotor mast and the elements rigidly secured thereto form a rigid but resiliently deformable, vertically elongated system ballasted near its upper and lower ends and having at least one flexible vertically elongated intermediate portion, the system being adapted to vibrate in a vibration mode causing vibration nodes to appear in vertically spaced parts of the flexible vertically elongated portion, the connecting elements between such system and the fuselage being disposed at such vertically spaced nodes.

Claim 3

An assembly for securing a main rotor of a helicopter to the fuselage thereof, the assembly being adapted to prevent vibrations from being transmitted from the rotor to the fuselage wherein the rotor mast and the elements rigidly secured thereto form a rigid but resiliently deformable elongated system ballasted near its ends and having flexible intermediate portions, the system being adapted to vibrate transversely at a natural frequency very slightly below the frequency to be removed, in a vibration mode causing vibration nodes to appear in the flexible portions, the connecting elements between such system and the fuselage being disposed at such nodes, said elongated system connected to the fuselage at the top node nearest the rotor by way of a rigid securing adapted to transmit horizontal and vertical forces and at the bottom node by way of a flexible device adapted to tRansfer to the fuselage the driving torque applied to the elongated system and to transmit horizontal forces with the possibility of slight lateral movements.

Claim 4

An assembly for securing a main rotor of a helicopter to the fuselage thereof, the assembly being adapted to prevent vibrations from being transmitted from the rotor to the fuselage wherein the rotor mast and the elements rigidly secured thereto form a rigid but resiliently deformable elongated system ballasted near its ends and having flexible intermediate portions, the system being adapted to vibrate transversely at a natural frequency very slightly below the frequency to be removed, in a vibration mode causing vibration nodes to appear in the flexible portions, the connecting elements between such system and the fuselage being disposed at such nodes, said elongated system connected to the fuselage at the top node nearest the rotor by way of a rigid securing adapted to transmit horizontal and vertical forces and at the bottom node by way of a flexible device adapted to tRansfer to the fuselage the driving torque applied to the elongated system and to transmit horizontal forces with the possibility of slight lateral movements.

Claim 5

An assembly for securing a main rotor of a helicopter to the fuselage thereof, the assembly being adapted to prevent vibrations from being transmitted from the rotor to the fuselage wherein the rotor mast and the elements rigidly secured thereto form a rigid but resiliently deformable elongated system ballasted near its ends and having flexible intermediate portions, the system being adapted to vibrate transversely at a natural frequency very slightly below the frequency to be removed, in a vibration mode causing vibration nodes to appear in the flexible portions, the connecting elements between such system and the fuselage being disposed at such nodes, said elongated system substantially straight and vertical and, with the rotor forming the ballast at the top end, the main transmission box forming a central weight, a ballast disposed at the bottom end, the intermediate flexible portions being comprised between such box and each of the two ballasts.

Claim 6

An assembly for securing a main rotor of a helicopter to the fuselage thereof, the assembly being adapted to prevent vibrations from being transmitted from the rotor to the fuselage wherein the rotor mast and the elements rigidly secured thereto form a rigid but resiliently deformable elongated system ballasted near its ends and having flexible intermediate portions, the system being adapted to vibrate transversely at a natural frequency very slightly below the frequency to be removed, in a vibration mode causing vibration nodes to appear in the flexible portions, the connecting elements between such system and the fuselage being disposed at such nodes, said elongated system substantially straight and vertical and, with the rotor forming the ballast at the top end, the main transmission box forming a central weight, a ballast disposed at the bottom end, the intermediate flexible portions being comprised between such box and each of the two ballasts.

Claim 7

An assembly according to claim 3, wherein the bottom ballast is an extra weight.

Claim 8

An assembly according to claim 3 wherein the bottom ballast is the rotor-driving motor.

Claim 9

An assembly for securing a main rotor of a helicopter to the fuselage thereof, the assembly being adapted to prevent vibrations from being transmitted from the rotor to the fuselage wherein the rotor mast and the elements rigidly secured thereto form a rigid but resiliently deformable elongated system ballasted near its ends and having flexible intermediate portions, the system being adapted to vibrate transversely at a natural frequency very slightly below the frequency to be removed, in a vibration mode causing vibration nodes to appear in the flexible portions, the connecting elements between such system and the fuselage being disposed at such nodes, said elongated system comprising a vertical straight portion comprising the main transmission box and the rotor separated by an intermediate flexible portion, and a portion which is transverse to the first portion and which is rigidly secured to the base thereof and which comprises flexible portions terminating in ballasts.

Claim 10

An assembly for securing a main rotor of a helicopter to the fuselage thereof, the assembly being adapted to prevent vibrations from being transmitted from the rotor to the fuselage wherein the rotor mast and the elements rigidly secured thereto form a rigid but resiliently deformable elongated system ballasted near its ends and having flexible intermediate portions, the system being adapted to vibrate transversely at a natural frequency very slightly below the frequency to be removed, in a vibration mode causing vibration nodes to appear in the flexible portions, the connecting elements between such system and the fuselage being disposed at such nodes, said elongated system comprising a vertical straight portion comprising the main transmission box and the rotor separated by an intermediate flexible portion, and a portion which is transverse to the first portion and which is rigidly secured to the base thereof and which comprises flexible portions terminating in ballasts.

Claim 11

An assembly according to claim 6 wherein the transverse portion is perpendicular to fuselage length and forms an inverted T with the first portion.

Claim 12

An assembly according to claim 7, wherein the stroke of the inverted T is disposed along the fuselage longitudinal axis.

Claim 13

An assembly according to claim 7, wherein the means connecting the flexible portions of the transverse part are resilient securing positions.

Claim 14

An assembly according to claim 7, wherein the elements for connecting the flexible portions of the transverse part allow transverse shifting of such portions.

Claim 15

An assembly according to claim 6, wherein the transverse part comprises a first portion perpendicular to fuselage length and forming an inverted T with the first part, and a second portion which extends in the direction of fuselage length and which is assembled resiliently to the first part near each of its two flexible portions, such second portion being connected to the fuselage by its own flexible portions.