Helicopter rotor having lead-lag damper operable with pitch and flap decoupling

• US 4,178,130 A
• Filed: 11/07/1977
• Issued: 12/11/1979
• Est. Priority Date: 04/06/1976
• Status: Expired due to Term

• Current Assignee: United Technologies Corporation (Raytheon Technologies Corporation d/b/a RTX)
• Original Assignee: United Technologies Corporation (Raytheon Technologies Corporation d/b/a RTX)
• Inventors: Noehren, William L., Ferris, Donald L.
• Primary Examiner(s): Powell, Jr., Everette A.
• Application Number:
  US05/849,064
• Time in Patent Office: 764 Days
• Field of Search: 416/104, 416/106, 416/107, 416/134 A, 416/140 A, 416/143, 416/141
• US Class Current: 416/107
• CPC Class Codes: B64C 27/51 Damping of blade movements

Abstract

A helicopter rotor having at least one blade projecting from the central hub and mounted for pitch change, flapping and lead-lag motion and including a lead-lag damper mounted to be pivotally movable in a selected plane and connected to the blade through a pivotal link connection to avoid the adverse effects of pitch and flap coupling.

Claims

1. A helicopter rotor including:

1. a hub mounted for rotation about an axis of rotation,

2. at least one helicopter blade projecting from said hub and having an inboard end adjacent the hub and an outboard end away from the hub,

3. means supporting said blade inboard end from said hub so that said blade will rotate with said hub about said axis of rotation and so that said blade is capable of universal motion with respect to said hub about intersecting lead-lag and flapping axes, and for pitch change motion with respect to said hub about a pitch change axis intersecting said lead-lag and flapping axes,

4. a lead-lag damper supported from said hub so as to be movable in pivot motion in a trajectory lying substantially in a selected plane with respect to said hub,

5. link means extending between said lead-lag damper and said blade,

6. a universal connection connecting said link means to said lead-lag damper, and

7. means pivotally connecting said link means to said blades for pivot motion therebetween about a pivot axis offset from at least one of said pitch change and flapping axes.

2. A helicopter rotor according to claim 1 wherein said pivot axis of said pivotal connecting means is offset from both said pitch change axis and said flapping axis.

3. A helicopter rotor according to claim 2 wherein said pivot axis is parallel to said pitch change axis.

4. A helicopter rotor according to claim 2 wherein said pivot axis is perpendicular to said pitch change axis.

5. A helicopter rotor according to claim 1 wherein said pivot axis is concentric with said pitch change axis and offset from said flapping axis.

6. A helicopter rotor according to claim 1 wherein said lead-lag damper is a cylinder-piston with rod mechanism with the cylinder portion thereof connected to said hub and the piston portion thereof connected to the link member.

7. A helicopter rotor according to claim 6 and including means to pivotally connect said damper cylinder to the hub.

8. A helicopter rotor according to claim 7 wherein said damper cylinder is pivotally connected to said hub at a station along the cylinder length.