Constant-velocity joint link with reduced axial stiffness

Patent metadata

Field	Value
Publication number	US-11066157-B2
Application number	US-201816006552-A
Country	US
Kind code	B2
Filing date	Jun 12, 2018
Priority date	Apr 29, 2013
Publication date	Jul 20, 2021
Grant date	Jul 20, 2021

Abstract

The present application provides a drive link for a constant-velocity joint of an aircraft rotor, the link connecting a drive hub attached to a driveshaft to a rotor yoke. The link comprises a leading bearing connected to the drive hub, a trailing bearing connected to the yoke, a central portion between the bearings, and a tension loop connecting the bearings. The tension loop is formed from a composite material and is formed as a continuous band. The tension loop transfers drive forces from the leading bearing to the trailing bearing for driving the yoke in rotation with the driveshaft.

First claim

The invention claimed is:

1. A drive link for a constant-velocity joint of a rotor of an aircraft, the link configured for connecting a drive hub attached to a driveshaft to a rotor yoke for driving the yoke in rotation with the driveshaft, the link comprising:
a leading bearing located in a leading bearing pocket and configured for connection to the drive hub;
a trailing bearing located in a trailing bearing pocket and configured for connection to the yoke, the trailing bearing pocket being spaced from the leading bearing pocket by a central portion; and
a tension loop having a cross-section formed from a composite material or a metal depending on a desired spring rate of the tension loop, the tension loop being formed as a continuous band connecting the bearing pockets, the desired spring rate being based on the cross-section of the tension loop;
wherein an edge of the tension loop runs tangentially from the leading bearing pocket to the trailing bearing pocket on both horizontal lengths of the tension loop;
wherein a thickness of the tension loop varies such that the tension loop is radially thicker around the bearing pockets and thinner between the bearing pockets; and
wherein the tension loop transfers drive forces from the leading bearing to the trailing bearing for driving the yoke in rotation with the driveshaft.

2. The drive link of claim 1 , wherein the central portion comprises an elastomeric material.

3. The drive link of claim 1 , wherein the central portion comprises an aperture.

4. The drive link of claim 1 , wherein the central portion comprises a stiff web.

5. The drive link of claim 1 , wherein the tension loop has a constant width.

6. The drive link of claim 1 , wherein the tension loop is formed as a separate component.

7. The drive link of claim 1 , wherein tension loop is formed as an integral component.

8. A method for controlling the spring rate of a drive link in a constant-velocity joint of a rotor of an aircraft, the method comprising:
(a) providing a link having a leading bearing configured for connection to a drive hub and a trailing bearing configured for connection to a rotor yoke and spaced from the leading bearing by a central portion; and
(b) forming a tension loop connecting the bearings, the tension loop having a cross-section with a selected axial spring rate based on the cross-sectional shape, configuration, or material type;
wherein the material type is chosen from among multiple possible materials to form the tension loop; and
wherein an edge of the tension loop runs tangentially from the leading bearing pocket to the trailing bearing pocket on both horizontal lengths of the tension loop; and wherein a thickness of the tension loop varies such that the tension loop is radially thicker around the bearing pockets and thinner between the bearing pockets.

9. The method of claim 8 , wherein step (a) comprises providing the central portion with an elastomeric material.

10. The method of claim 8 , wherein step (a) comprises providing the central portion with an aperture.

11. The method of claim 8 , wherein step (a) comprises providing the central portion with a stiff web.

12. The method of claim 8 , wherein step (b) forming the tension loop with a constant width.

13. An aircraft having a constant-velocity joint for transferring torque from a driveshaft to rotor hub assembly, the joint having a plurality of drive links configured for connecting a drive hub to a rotor yoke, at least one link comprising:
a leading bearing located in a leading bearing pocket and configured for connection to the drive hub, the leading bearing fixed to an inner surface of the leading bearing pocket;
a trailing bearing located in a trailing bearing pocket and configured for connection to the yoke, the trailing bearing fixed to an inner surface of the trailing bearing pocket, the trailing bearing pocket being spaced from the leading bearing pocket by a central portion having an aperture; and
a tension loop having a cross-section formed from a metal or a single, continuous layered composite material, the tension loop being formed as a continuous band externally connecting the bearing pockets;
wherein the metal or the single, continuous layered composite material is chosen based on a selectively chosen spring rate of the tension loop;
wherein the selectively chosen spring rate of the tension loop is determined by a number of fibers in the cross-section of the tension loop;
wherein an edge of the tension loop runs tangentially from the leading bearing pocket to the trailing bearing pocket on both horizontal lengths of the tension loop;
wherein the tension loop only transfers axial drive forces from the leading bearing to the trailing bearing for driving the yoke in rotation with the driveshaft; and
wherein the tension loop is formed as an integral component with the central portion; and the thickness of the tension loop varies such that the tension loop is radially thicker around the bearing pockets and thinner between the bearing pockets.

14. The drive link of claim 13 , wherein the central portion comprises an elastomeric material.

15. The drive link of claim 13 , wherein the central portion comprises a stiff web.

16. The drive link of claim 13 , wherein the tension loop is formed as a separate component.

17. The drive link of claim 13 , wherein tension loop is formed as an integral component.

18. The method according to claim 8 , wherein step (b) comprises forming the tension loop to have the selected axial spring rate, a fiber count associated with the cross-sectional shape or configuration, and a selected radial spring rate; and
wherein the fiber count determines the selected axial spring rate.

19. The drive link of claim 1 , wherein the cross-section of the tension loop has a number of fibers that determines the desired spring rate.

Assignees

• Bell Helicopter Textron Inc
• Bell Textron Inc

Inventors

• Rauber Richard E
• Stamps Frank B

Classifications

• B64C27/41 Primary

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

• B64C27/32

  Rotors · CPC title

• B64C29/0033

  the propellers being tiltable relative to the fuselage · CPC title