Laminated ball joint connection device between a rotorcraft rotor blade and a lead/lag damper of said blade

Patent metadata

Field	Value
Publication number	US-10160539-B2
Application number	US-201514962172-A
Country	US
Kind code	B2
Filing date	Dec 8, 2015
Priority date	Dec 11, 2014
Publication date	Dec 25, 2018
Grant date	Dec 25, 2018

Abstract

A rotorcraft rotor having each of its blades fitted with a lead/lag damper. A connection device between the blade root of a blade under consideration and a lead/lag damper comprises a rod passing through a laminated ball joint secured to a distal endpiece of the lead/lag damper. The rod extends in the general plane in which the blade extends, being prevented from moving firstly in rotation by being embedded in the blade root and secondly in translation along the general transversely-extending direction of the blade by being pinned to a U-shaped yoke fastened to the blade root.

First claim

What is claimed is:

1. A rotorcraft rotor comprising:
a plurality of blades mounted on a hub rotatable about an axis of rotation of the rotor, each blade individually mounted on the hub to pivot about at least one of a pitch variation axis, a flapping axis, and a lead/lag axis, wherein at least one of the plurality of blades is a blade under consideration;
at least one lead/lag damper including a proximal endpiece engaged with the hub and a distal endpiece engaged with the blade under consideration, the distal endpiece provided with a laminated ball joint including a through passage; and
a rod received in the through passage for fastening the distal endpiece to a blade root of the blade under consideration, wherein the lead/lag damper associated with the blade under consideration damps lead/lag movements, and
wherein
the rod generally extends in a longitudinal direction in which the blade under consideration extends,
wherein a first end of the rod is embedded in the blade root of the blade under consideration to prevent movement in rotation of the rod relative to the blade under consideration, and
the rod is secured at a second end to a U-shaped yoke formed of a cross-member and a pair of branches, a free end of each of the branches of the yoke provided with a fastener to secure the blade root of the blade under consideration.

2. The rotorcraft rotor according to claim 1 , wherein the rod is secured at the first end to a key for embedding the rod in a housing of the blade root of the blade under consideration, the housing being of a shape complementary to a shape of the key.

3. The rotorcraft rotor according to claim 2 , wherein the key is fabricated integrally with the rod.

4. The rotorcraft rotor according to claim 2 , wherein the shape of the key comprises a polygon provided at one end of the rod.

5. The rotorcraft rotor according to claim 2 , wherein the key is formed by at least one arm extending transversely relative to the longitudinal direction.

6. The rotorcraft rotor according to claim 5 , wherein the key is shaped as a cross.

7. The rotorcraft rotor according to claim 1 , wherein the fastener at the free ends of the branches of the yoke comprises a peg, wherein the peg passes through a corresponding branch respectively associated therewith and the blade root of the blade under consideration, in a direction that extends generally perpendicularly to the plane in which the blade under consideration extends.

8. The rotorcraft rotor according to claim 7 , wherein the fastener comprises at least two pegs that are spaced apart from each other at least in and extend at least one of a longitudinal direction and transverse from the longitudinal direction of the blade under consideration.

9. The rotorcraft rotor according to claim 7 , wherein the pegs are arranged as screw-fastener members.

10. The rotorcraft rotor according to claim 9 , wherein each peg is provided with first retaining means for retaining it against turning as a result of the yoke being fastened to the blade root of the blade under consideration.

11. The rotorcraft rotor according to claim 1 , wherein the second end of the rod is secured to the yoke by at least one pin extending in a direction that is parallel to the longitudinal direction of the blade under consideration.

12. A rotorcraft rotor comprising:
a plurality of blades mounted to rotate about a rotor axis, each blade mounted to individually pivot about at least one of a pitch variation axis, a flapping axis, and a lead/lag axis;
at least one lead/lag damper positioned between a first blade of the plurality of blades and a rotor hub, the lead/lag damper comprising:
a laminated ball joint with a through passage;
a U-shaped yoke formed of a cross-member and a pair of branches, wherein a free end of each of the branches is fastened to the first blade;
a rod extending in the through passage in a longitudinal direction of the first blade, wherein a first end of the rod is embedded in the first blade to prevent the rod from rotating relative to the first blade, and wherein a second end of the rod is pinned to the cross-member of the U-shaped yoke.

13. The rotorcraft rotor according to claim 12 , wherein the first end of the rod has a key shape and the first blade has a key opening corresponding to the key shape of the rod such that when the key shape is embedded in key opening, the rod is prevented from rotating relative to the first blade.

14. The rotorcraft rotor according to claim 13 , wherein the first end of the rod has a transverse arm extending transverse relative to the longitudinal direction.

15. The rotorcraft rotor according to claim 13 , wherein the key shape of the key comprises a polygon.

16. The rotorcraft rotor according to claim 13 , wherein the first end of the rod has a transverse arm extending transverse relative to the longitudinal direction, wherein the transverse arm defines the key shape of the rod.

17. The rotorcraft rotor according to claim 16 , comprising a plurality of transverse arms, wherein the key shape is defined as a cross.

18. The rotorcraft rotor according to claim 12 , wherein the free ends of the branches of the yoke are fastened to the first blade with a peg that extends generally perpendicularly to the plane in which the first blade extends.

19. The rotorcraft rotor according to claim 12 , wherein the second end of the rod is secured to the yoke by at least one pin extending in a direction parallel to the longitudinal direction of the first blade.

20. A lead/lag damper for a rotorcraft connecting a blade and a rotor hub, the lead/lag damper comprising:
a laminated ball joint with a through passage;
a U-shaped yoke formed of a cross-member and a pair of branches, wherein a free end of each of the branches is adapted to be fastened to the blade of the rotorcraft;
a rod extending in the through passage of the laminated ball joint in a longitudinal direction of the blade, wherein a first end of the rod is adapted to be embedded in the blade to prevent the rod from rotating relative to the blade, and wherein a second end of the rod is pinned to the cross-member of the U-shaped yoke.

Assignees

• Airbus Helicopters

Inventors

• Massal Fabien

Classifications

• B64C27/51 Primary

  Damping of blade movements · CPC title

• B64C27/39 Primary

  with individually articulated blades, i.e. with flapping or drag hinges · CPC title