# US 2020/0023951 A1 · Variable Hub-to-Hub Phasing Rotor System

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- Number: US 2020/0023951 A1
- Document ID: US20200023951A1
- Status: Published application
- Kind: A1
- Application number: 15/895,589
- Filed: 2018-02-13
- Published: 2020-01-23
- Earliest claimed: 2014-02-06
- Assignees: Bell Helicopter Textron Inc.
- Applicants: Bell Helicopter Textron Inc.
- Inventors: Brian Modrzejewski; Ken Shundo; Frank B. Stamps; David Popelka; J. Scott Drennan; Michael E. Rinehart
- Web page: https://patentgrep.com/patent/US20200023951A1

## CPC

- B64C 27/001: {Vibration damping devices}
- B64C 11/50: Phase synchronisation between multiple propellers
- B64C 27/30: with provision for reducing drag of inoperative rotor
- B64C 2027/004: {using actuators, e.g. active systems}
- G10K 2210/123: Synchrophasors or other applications where multiple noise sources are driven with a particular phase relationship
- G10K 2210/1281: Aircraft, e.g. spacecraft, airplane or helicopter
- B64C: AEROPLANES; HELICOPTERS
- G10K: SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR

## Abstract

An aircraft includes a first rotor assembly, a second rotor assembly, and a rotor phase angle control system. The system includes a phase adjustor operably associated with the first rotor assembly and the second rotor assembly. The method includes sensing vibrations exerted on the aircraft and offsetting a phase angle of the first rotor assembly and the second rotor assembly to minimize the vibrations.

## Claims

### Claim 1

A method, comprising:
sensing vibrations exerted on an aircraft via two or more rotor assemblies during flight; and
offsetting a phase angle of the two or more rotor assemblies with a phase adjustor to minimize the vibrations;
wherein the process of sensing and the process of offsetting are achieved in real-time during flight;
wherein a first rotor assembly of the two or more rotor assemblies is operably associated with a first shaft, and a second rotor assembly of the two or more rotor assemblies is operably associated with a second shaft; and
wherein the phase adjustor is a clutch configured to disengage and reengage with the first shaft and the second shaft.

### Claim 2 (depends on 1)

The method of claim 1, further comprising:
relaying the sensed vibration to a control system operably associated with the phase adjustor; and
commanding the phase adjustor via the control system to adjust the phase angle of the two or more rotor assemblies.

### Claim 3 (depends on 1)

The method of claim 1, further comprising:
disengaging and reengaging the first shaft via the phase adjustor;
wherein the disengaging and reengaging the first shaft causes the first rotor assembly to offset from the second rotor assembly, thereby creating the phase angle between the two rotor assemblies.