Rotor hub vibration attenuator

Patent metadata

Field	Value
Publication number	US-11084575-B2
Application number	US-201716084970-A
Country	US
Kind code	B2
Filing date	Mar 14, 2017
Priority date	Mar 14, 2016
Publication date	Aug 10, 2021
Grant date	Aug 10, 2021

Abstract

A vibration attenuation system for attenuating vibrations in a mast of an aircraft includes a weight attached to the mast but free to orbit about the mast. The weight can be comprised of one or more weight assemblies. Embodiments can include a single weight, or plural weight assemblies wherein each weight assembly can include a mechanical interconnecting mechanism so that each weight assembly receives feedback regarding the position and movement of one or more other weight assemblies. Each weight can be associated with a spring that urges the weight towards a neutral position. Rotation of the mast can cause the weight to orbit about the mast and self-excite such that the weight acts against the urging of the spring towards an attenuating position.

First claim

What is claimed is:

1. A vibration isolation system for a rotary-wing aircraft main rotor system having a mast that is rotatable about an axis of rotation, the vibration isolation system comprising:
a first weight assembly rotatable relative to the mast coaxially about the axis of rotation and having a disk-shaped body;
a second weight assembly rotatable relative to the mast coaxially about the axis of rotation and having a disk-shaped body;
a first stop member located on the first weight assembly; and
a second stop member located on the second weight assembly;
wherein the stop members are configured to contact each other for preventing the relative rotation of the first and second weight assemblies beyond a specified angular amount, and
wherein the angular velocity of the first and second weight assemblies is operable to reduce in-plane vibration of the main rotor system.

2. The system of claim 1 , further comprising:
a resilient element mechanically linked to the first weight assembly and to the second weight assembly.

3. The system of claim 2 , wherein the resilient element comprises a torsion spring.

4. The system of claim 1 , wherein the first weight assembly includes a first concentrated mass region, and wherein the second weight assembly includes a second concentrated mass region.

5. The system of claim 4 , wherein a resilient element is mechanically linked to the first and second weight assemblies so as to urge the first concentrated mass region to be 180 degrees apart from the second concentrated mass region.

6. The system of claim 1 , wherein the first stop member extends from an outer periphery of the first weight assembly and the second stop member extends from an outer periphery of the second weight assembly.

7. An aircraft comprising:
a rotary-wing aircraft main rotor system having a mast that is rotatable about an axis of rotation;
a vibration isolation system comprising:
a first weight assembly rotatable relative to the mast coaxially about the axis of rotation and having a disk-shaped body;
a second weight assembly rotatable relative to the mast coaxially about the axis of rotation and having a disk-shaped body;
a first stop member located on the first weight assembly; and
a second stop member located on the second weight assembly;
wherein the stop members are configured to contact each other for preventing the relative rotation of the first and second weight assemblies beyond a specified angular amount, and
wherein the angular velocity of the first and second weight assemblies is operable to reduce in-plane vibration of the main rotor system.

8. The system of claim 7 , further comprising:
a resilient element mechanically linked to the first weight assembly and to the second weight assembly.

9. The system of claim 8 , wherein the resilient element comprises a torsion spring.

10. The system of claim 7 , wherein the first weight assembly includes a first concentrated mass region, and wherein the second weight assembly includes a second concentrated mass region.

11. The system of claim 10 , wherein a resilient element is mechanically linked to the first and second weight assemblies so as to urge the first concentrated mass region to be 180 degrees apart from the second concentrated mass region.

12. The system of claim 7 , wherein the first stop member extends from an outer periphery of the first weight assembly and the second stop member extends from an outer periphery of the second weight assembly.

Assignees

• Bell Helicopter Textron Inc
• Textron Innovations Inc

Inventors

• Choi Jouyoung Jason
• Heverly David
• Seifert Michael
• Smith Michael
• Stamps Frank Bradley
• Parham Jr Thomas
• Kizhakkepat Amarjit Olenchery

Classifications

• B64C2027/004

  using actuators, e.g. active systems · CPC title

• B64C29/0033

  the propellers being tiltable relative to the fuselage · CPC title

• B64C2027/003

  mounted on rotor hub, e.g. a rotary force generator · CPC title

• B64C27/001 Primary

  Vibration damping devices · CPC title

• F16F15/14

  using masses freely rotating with the system, {i.e. uninvolved in transmitting driveline torque, e.g. rotative dynamic dampers (compensation of inertia forces F16F15/22; weights for balancing rotating bodies F16F15/32)} · CPC title