Rotor dome, a rotor, and a rotorcraft

Patent metadata

Field	Value
Publication number	US-2016137296-A1
Application number	US-201514939275-A
Country	US
Kind code	A1
Filing date	Nov 12, 2015
Priority date	Nov 14, 2014
Publication date	May 19, 2016
Grant date	—

Abstract

A dome for a rotor comprising a cap extending radially from an axis of rotation in elevation towards a periphery and in azimuth over 360 degrees, the cap extending in thickness from a bottom face towards a top face above the bottom face. The dome includes at least one slot extending between the periphery and the axis of rotation in elevation, each slot passing right through a thickness of the cap by extending in elevation from the bottom face to the top face.

First claim

What is claimed is:

1 . A dome for a rotor of a rotorcraft, the dome comprising a cap extending radially from an axis of rotation in elevation towards a periphery and in azimuth over 360 degrees, the cap extending in thickness from a bottom face for facing a hub of the rotor towards a top face above the bottom face, the dome including notches enabling a blade to pass therethrough in order to allow the blade to flap;
wherein the dome includes at least one slot extending between the periphery and the axis of rotation in elevation, each slot being distinct from a notch, each slot passing right through a thickness of the cap by extending in elevation from the bottom face to the top face, the dome including in azimuth along at least one internal circle a succession of solid surfaces represented by the top face and of openings represented by each slot facing an incident air stream so that the incident air stream impacts in succession against a solid surface and an opening during rotation of the dome about the axis of rotation in elevation.

2 . A dome according to claim 1 , wherein the number of notches is different from the number of slots.

3 . A dome according to claim 2 , wherein the number of notches and the number of slots are mutually prime.

4 . A dome according to claim 1 , wherein the cap comprises a plurality of arms extending spanwise from the axis of rotation in elevation towards the periphery, each arm extending in azimuth between two slots open out to the periphery, each arm presenting an airfoil profile extending in azimuth between a leading edge in the vicinity of a slot and a trailing edge in the vicinity of another slot.

5 . A dome according to claim 4 , wherein at least one arm presents a twist relationship determining a twist angle for each section of the arm as a function of a reference section, each section representing a cross-section of the arm in a plane extending in elevation from the trailing edge to the leading edge of the arm and perpendicular to a geometrical stacking line of the arm.

6 . A dome according to claim 4 , wherein at least one arm presents a width in azimuth that increases on going away from the axis of rotation in elevation.

7 . A dome according to claim 1 , wherein at least one slot extends along a radius of the dome.

8 . A dome according to claim 1 , wherein at least one slot does not extend entirely in a single plane containing the axis of rotation.

9 . A dome according to claim 1 , wherein the dome being for rotation in a particular direction of rotation, at least one slot presents a convex shape that is convex pointing in the direction of rotation (ROT) of the dome.

10 . A dome according to claim 1 , wherein at least one slot presents a width in azimuth that varies radially.

11 . A dome according to claim 1 , wherein at least one slot extends in an annulus of the dome lying between the periphery and the axis of rotation in elevation, the annulus not reaching the periphery and/or the axis of rotation.

12 . A dome according to claim 1 , wherein at least one slot opens out to the periphery.

13 . A rotorcraft rotor having a hub carrying a plurality of blades, wherein the rotor includes a dome according to claim 1 , the blades being unable to penetrate into the slots.

14 . A rotorcraft, wherein the rotorcraft includes at least one rotor according to claim 13 .

Assignees

• Airbus Helicopters

Inventors

• Alfano David
• Desvigne Damien
• Fukari Raphael

Classifications

• B64C2027/003

  mounted on rotor hub, e.g. a rotary force generator · CPC title

• B64C27/001 Primary

  Vibration damping devices · CPC title

• B64C27/32

  Rotors · CPC title

• B64C7/00 Primary

  Structures or fairings not otherwise provided for · CPC title

• B64C11/14

  Spinners · CPC title