Tail rotor arrangement with increased thrust for rotary wing aircraft and device for increasing the thrust of such an arrangement

Claim 3

The device of claim 1, wherein said rotor rotates with respect to a fixed hub which is coaxial to the tunnel, said fixed hub comprising an outer ring and an inner ring which are concentric to each other and between which said fixed blades are radially disposed, the outer diameter of the outer ring corresponding to the inner diameter of the part of tunnel in which said device is disposed and the inner diameter of the inner ring corresponding to the outer diameter of the part of hub gripped by said inner ring.

Claim 4

The device of claim 2 further comprising radial support arms; said fixed hub being connected to the structure of said aircraft by said radial support arms, wherein the outer and inner rings comprise recesses for the passage of said radial support arms and said plurality of fixed blades are disposed the spaced defined between said recesses.

Claim 5

A tail rotor arrangement for rotary wing aircraft comprising: a tunnel of axis transverse with respect to said aircraft a fixed hub disposed inside said tunnel with its axis coaxially arranged to said axis of said tunnel; a multiblade rotor disposed inside said tunnel and rotating about said axis of said fixed hub, said multiblade rotor having a plurality of rotating blades and generating a transverse air flow; a plurality of fixed blades disposed inside said tunnel in an at least substantially radial manner with respect to said tunnel for rigidly connecting said tunnel and said fixed hub, said plurality of fixed blades being disposed downstream of said multiblade rotor with respect to said air flow and being profiled for recovering, in the form of an axial thrust, the energy of rotation of said air flow at the outlet of said multiblade rotor; said plurality of fixed blades being arranged such that the distance separating the trailing edges of each of said plurality of rotating blades from the leading edges of each of said plurality of fixed blades is at least equal to once the length of the chord of the profile of said rotating blades.

Claim 6

A tail rotor arrangement for rotary wing aircraft comprising: a tunnel of axis transverse with respect to said aircraft a fixed hub disposed inside said tunnel with its axis coaxially arranged to said axis of said tunnel; a multiblade rotor disposed inside said tunnel and rotating about said axis of said fixed hub, said multiblade rotor having a plurality of rotating blades and generating a transverse air flow; a plurality of fixed blades disposed inside said tunnel in an at least substantially radial manner with respect to said tunnel for rigidly connecting said tunnel and said fixed hub, said plurality of fixed blades being disposed downstream of said multiblade rotor with respect to said air flow and being profiled for recovering, in the form of an axial thrust, the energy of rotation of said air flow at the outlet of said multiblade rotor; said plurality of fixed blades being arranged such that the distance separating the trailing edges of each of said plurality of rotating blades from the leading edges of each of said plurality of fixed blades is at least equal to once the length of the chord of the profile of said rotating blades.

Claim 7

The arrangement of claim 4, wherein further radial support arms are provided for rigidly connecting said tunnel to said fixed hub, said fixed blades being disposed in the space between said radial support arms.

Claim 8

The arrangement of claim 5, wherein said radial support arms present the same profile as individual said plurality of fixed blades in order to reinforce the action thereof.

Claim 9

The arrangement of claim 4, wherein said plurality of fixed blades are fastened to one another to form a monolithic assembly.

Claim 10

The arrangement of claim 7, wherein said monolithic assembly is fits by simple interlocking at the outlet of the said tunnel.