System and method for linkage length adjustment

• US 9,731,819 B2
• Filed: 12/20/2013
• Issued: 08/15/2017
• Est. Priority Date: 12/21/2012
• Status: Active Grant

• Current Assignee: Textron Innovations Incorporated (Textron Inc)
• Original Assignee: Bell Helicopter Textron Incorporated (Textron Inc)
• Inventors: Wiinikka, Mark A.
• Primary Examiner(s): Kim, Craig
• Assistant Examiner(s): Mikus, Jason
• Application Number:
  US14/136,814
• Publication Number:
  US 20140178199A1
• Time in Patent Office: 1,334 Days
• Field of Search: 416 1
• CPC Class Codes: B64C 27/008 Rotors tracking or balancing devices
• CPC Class Codes: B64C 27/32 Rotors
• CPC Class Codes: B64C 27/51 Damping of blade movements
• CPC Class Codes: F16C 11/0614 the female part of the joint being open on two sides

Abstract

A rotor system has a rotor, an axis of rotation about which the rotor may be rotated, a linkage system having a first adjustable length portion and a second adjustable length portion, wherein the second adjustable length portion is configured to provide a relatively finer adjustment of an overall effective length of the linkage system as compared to the first adjustable length portion and wherein the rotor is configured to rotate about the axis in response to changing the overall effective length of the linkage system.

Claims

1. A rotor system, comprising:

a rotor;

an axis of rotation about which the rotor may be rotated;

a linkage system having an overall effective length, comprising;

a first adjustable length portion comprising a threaded component having a lengthwise axis in which the overall effective length is measured;

a second adjustable length portion connected to the first adjustable length portion, the second adjustable length portion comprising an eccentric bushing carried by a pitch horn connected to the rotor, the eccentric bushing having a bushing central axis that is substantially orthogonal to the lengthwise axis, wherein the second adjustable length portion adjusts the overall effective length of the linkage system by rotating the eccentric bushing about the bushing central axis;

wherein the second adjustable length portion is configured to provide a relatively finer adjustment of the overall effective length of the linkage system as compared to the first adjustable length portion; and

wherein the rotor is configured to rotate about the axis in response to changing the overall effective length of the linkage system.

2. The rotor system of claim 1, wherein the axis comprises a lead-lag axis.

3. The rotor system of claim 1, wherein the linkage system comprises an elastomeric damper.

4. The rotor system of claim 3, wherein the elastomeric damper comprises a lead-lag damper.

5. The rotor system of claim 1, wherein the axis comprises a pitch change axis.

6. The rotor system of claim 1, wherein the linkage system comprises a pitch link.

7. The rotor system of claim 1, wherein each of the first adjustable length portion and the second adjustable length portion are adjustable while maintaining a link between a first rotor system component from a second rotor system component via the linkage system.

8. The rotor system of claim 1, wherein the first adjustable length portion is adjusted by rotating about the lengthwise axis.

13. The rotor system of claim 1, wherein the eccentric component comprises:

the eccentric bushing having a head and a plurality of location teeth on the head;

an index bracket having a plurality of complementary teeth formed in an aperture of the index bracket that is configured to receive the head of the eccentric bushing.

14. The rotor system of claim 13, further comprising a set of bracket markings on the index bracket and a set of bushing markings on the eccentric bushing that provide a frame of reference for monitoring, recording, and/or reliably adjusting a rotation of the eccentric bushing.

9. A method of adjusting a rotational position of a rotor relative to an axis of rotation, comprising:

linking a first rotor system component to a second rotor system component via a linkage system having a variable overall effective length, the linkage system comprising a first adjustable length portion comprising a threaded component having a lengthwise axis and a second adjustable length portion connected to the first adjustable length portion, the second adjustable length portion comprising an eccentric bushing carried by a pitch horn connected to the rotor, the eccentric bushing having a bushing central axis that is substantially orthogonal to the lengthwise axis; and

while maintaining the link between the first rotor system component and the second rotor system component via the linkage system, adjusting the overall effective length of the linkage system by at least one of adjusting the first adjustable length portion by rotating the threaded component and adjusting the second adjustable length portion by rotating the eccentric bushing about the bushing central axis, wherein the second adjustable length portion is configured to provide a relatively finer adjustment of an overall effective length of the linkage system as compared to the first adjustable length portion.

10. The method of claim 9, wherein a lead-lag position of the rotor is changed as a function of the adjusting the overall effective length of the linkage system.

11. The method of claim 9, wherein a pitch of the rotor is changed as a function of the adjusting the overall effective length of the linkage system.

12. The method of claim 9, wherein the threaded component is rotated about the lengthwise axis.

15. The method of claim 9, wherein the eccentric component comprises:

the eccentric bushing having a head and a plurality of location teeth on the head;

an index bracket having a plurality of complementary teeth formed in an aperture of the index bracket that is configured to receive the head of the eccentric bushing.

16. The method of claim 15, further comprising a set of bracket markings on the index bracket and a set of bushing markings on the eccentric bushing that provide a frame of reference for monitoring, recording, and/or reliably adjusting a rotation of the eccentric bushing.