Bottom abutment device for a rotorcraft rotor, a rotorcraft rotor, and a rotorcraft

Patent metadata

Field	Value
Publication number	US-10464665-B2
Application number	US-201615377647-A
Country	US
Kind code	B2
Filing date	Dec 13, 2016
Priority date	Jan 20, 2016
Publication date	Nov 5, 2019
Grant date	Nov 5, 2019

Abstract

A bottom abutment device for a rotor having a plurality of lift assemblies. The bottom abutment device comprises at least one abutment track per lift assembly. The bottom abutment device comprises a plate with a ring and one branch per lift assembly. The bottom abutment device has a plurality of supports, each support fastenable to a rotary member of the rotor, each support extending in part in an opening in a branch, the supports giving the plate a restricted degree of freedom to move in translation, the supports giving the plate at least one restricted degree of freedom to move in rotation about the axis of symmetry.

First claim

What is claimed is:

1. A bottom abutment device for a rotor having a plurality of lift assemblies for rotating about an axis of rotation (AX 1 ), the bottom abutment device comprising at least one abutment track per lift assembly, the bottom abutment device comprising a plate with a ring extending circumferentially around an axis of symmetry (AX 2 ), the plate having one branch per lift assembly, each branch extending radially from the ring towards a free end, wherein the bottom abutment device includes a plurality of supports, each support comprising fastener means for fastening to a rotary member of the rotor, each support extending in part in an opening of a branch so as to co-operate with the branch, the opening extending in elevation in a direction parallel to the axis of symmetry (AX 2 ), the supports giving the plate a degree of freedom to move in translation (TRANS) that is restricted by shape interference with the branches, and the supports giving the plate at least one degree of freedom to move in rotation (ROT) about the axis of symmetry that is restricted by shape interference with the branches.

2. The bottom abutment device according to claim 1 , wherein at least one fastener means comprises two elongate members together with two orifices in the support, each elongate member passing through one of the orifices and being designed to pass through a link of the rotor.

3. The bottom abutment device according to claim 1 , wherein the supports give the plate three restricted degrees of freedom to move in rotation respectively about the axis of symmetry (AX 2 ) and about two “horizontal” axes (AXR 1 , AXR 2 ) that are perpendicular to each other and perpendicular to the axis of symmetry (AX 2 ).

4. The bottom abutment device according to claim 1 , wherein each support includes a radially-open U-shaped housing, the housing being defined by a top wall and by a bottom wall of the support that are connected together by an end wall of the support extending in elevation, each end wall being arranged in the opening of a branch, the top wall and the bottom wall extending in elevation (direction Z) respectively above and below the branch.

5. The bottom abutment device according to claim 4 , wherein the branch co-operating with a support has a plane body, the plane body extending in elevation from a bottom face facing a bottom wall of the support towards a top face facing the top wall of the support, the branch having at least one rim projecting in elevation from the plane body in order to limit a degree of freedom to move of the ring by shape interference.

6. The bottom abutment device according to claim 5 , wherein the branch includes at least one rim referred to as a “tangential” rim for limiting movement in translation of the plate, radial clearance lying between the support and each corresponding tangential rim when the axis of symmetry (AX 2 ) of the plate coincides with an axis of rotation (AX 1 ) of the rotor.

7. The bottom abutment device according to claim 5 , wherein the branch has at least one pair of rims referred to as “circumferential” rims arranged circumferentially on either side of abutment walls of the support in order to limit the amplitude of movement in rotation for the plate about the axis of symmetry (AX 2 ), circumferential clearance lying between the support and at least one circumferential rim of a pair.

8. The bottom abutment device according to claim 5 , wherein the plane body comprises:
a tangential rim referred to as a “top” tangential rim extending in elevation upwards from the top face, and a pair of circumferential rims referred to as “top” circumferential rims extending in elevation upwards from the top face, the top tangential rim being radially in alignment with the top wall of the support, and the top circumferential rims being arranged circumferentially on either side of the top wall; and
a tangential rim referred to as a “bottom” tangential rim extending downwards in elevation from the bottom face, and a pair of circumferential rims referred to as “bottom” circumferential rims extending downwards in elevation from the bottom face, the bottom tangential rim being in alignment with the bottom wall of the support, and the bottom circumferential rims being arranged circumferentially on either side of the bottom wall.

9. The bottom abutment device according to claim 5 , wherein maximum clearance in elevation between the plane body and the support is less than a height in elevation of a rim.

10. The bottom abutment device according to claim 1 , wherein the ring is perforated between two branches.

11. The bottom abutment device according to claim 1 , wherein at least one branch includes a wear shoe removably mounted on the free end.

12. The bottom abutment device according to claim 1 , wherein the plate is for occupying a middle position (POS 1 ) in the absence of contact with an abutment track, the supports giving the plate a degree of freedom to move in translation perpendicularly to the axis of rotation that is restricted to an amplitude of plus or minus 12 cm about the middle position (POS 1 ), the supports giving the plate a degree of freedom to move in rotation about the axis of symmetry that is restricted to plus or minus 5° about the middle position (POS 1 ).

13. The bottom abutment device according to claim 1 , wherein the bottom abutment device includes one support per branch.

14. The bottom abutment device according to claim 1 , wherein each abutment track fastens to a lift assembly and faces a free end in order to come into abutment against the free end under predetermined conditions.

15. A rotor having a plurality of lift assemblies, wherein the rotor includes a bottom abutment device according to claim 1 , each lift assembly carrying at least one of the abutment track, each support being constrained in rotation with a rotary member of the rotor, the plate being carried by the supports.

16. The rotor according to claim 15 , wherein the rotor includes a hub carrying the lift assemblies, and the rotary member is the hub.

17. The rotor according to claim 15 , wherein the rotor includes at least three lift assemblies.

18. An aircraft, wherein the aircraft includes a rotor according to claim 15 .

19. A bottom abutment device for a rotor having a plurality of lift assemblies for rotating about an axis of rotation, the bottom abutment device comprising at least one abutment track per lift assembly, the bottom abutment device comprising a plate with a ring extending circumferentially around an axis of symmetry, the plate having one branch per lift assembly, each branch extending radially from the ring towards a free end, wherein the bottom abutment device includes a plurality of supports, each support comprising a rotary member fastener, each support extending at least in part in an opening of a branch, the opening extending in elevation in a direction parallel to the axis of symmetry, the supports giving the plate a degree of freedom to move in translation that is restricted by shape interference with the branches, and the supports giving the plate at least one degree of freedom to move in rotation about the axis of symmetry that is restricted by shape interference with the branches.

20. A bottom abutment device for a rotor having a plurality of lift assemblies for rotating about an axis of rotation, the bottom abutment device comprising at least one abutment track per lift assembly, the bottom abutment device comprising a plate with a ring extending circumferentially around an axis of symmetry, the plate

Assignees

• Airbus Helicopters

Inventors

• Eberhard Alain
• Massal Fabien

Classifications

• B64C27/322 Primary

  Blade travel limiting devices, e.g. droop stops · CPC title

• B64C27/41

  with flapping hinge or universal joint, common to the blades · CPC title

• B64C27/08

  with two or more rotors · CPC title

• B64U10/10

  Rotorcrafts · CPC title