# US 2017/0283045 A1 · Translation thrust system engagement and disengagment for rotary wing aircraft

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- Number: US 2017/0283045 A1
- Document ID: US20170283045A1
- Status: Published application
- Kind: A1
- Application number: 15/508,991
- Filed: 2015-09-28
- Published: 2017-10-05
- Earliest claimed: 2014-10-01
- Assignees: Sikorsky Aircraft Corporation
- Applicants: Sikorsky Aircraft Corporation
- Inventors: Todd A. GARCIA; Erez ELLER; William J. EADIE; David H. HUNTER
- Web page: https://patentgrep.com/patent/US20170283045A1

## CPC

- B64C 27/16: Drive of rotors by means, e.g. propellers, mounted on rotor blades
- B64C 1/0009: {Aerodynamic aspects}
- B64C 7/00: Structures or fairings not otherwise provided for
- B64C 13/04: actuated personally
- B64C 13/18: using automatic pilot
- B64C 13/50: using electrical energy
- B64C 13/503: {Fly-by-Wire}
- B64C 19/00: Aircraft control not otherwise provided for
- B64C 27/001: {Vibration damping devices}
- B64C 27/006: {Safety devices}
- B64C 27/008: {Rotors tracking or balancing devices}
- B64C 27/10: arranged coaxially
- B64C 27/12: Rotor drives
- B64C 27/14: Direct drive between power plant and rotor hub
- B64C 27/32: Rotors
- B64C 27/322: {Blade travel limiting devices, e.g. droop stops}
- B64C 27/33: having flexing arms
- B64C 27/467: Aerodynamic features
- B64C 27/473: Constructional features
- B64C 27/48: Root attachment to rotor head
- B64C 27/51: Damping of blade movements
- B64C 27/52: Tilting of rotor bodily relative to fuselage (of see-saw type construction B64C27/43)
- B64C 27/54: Mechanisms for controlling blade adjustment or movement relative to rotor head, e.g. lag-lead movement
- B64C 27/57: automatic or condition responsive, e.g. responsive to rotor speed, torque or thrust
- B64C 27/78: in association with pitch adjustment of blades of anti-torque rotor
- B64C 27/80: for differential adjustment of blade pitch between two or more lifting rotors
- B64C 27/82: characterised by the provision of an auxiliary rotor or fluid-jet device for counter-balancing lifting rotor torque or changing direction of rotorcraft
- B64D 35/06: the propellers or rotors being counter-rotating
- B64D 39/00: Refuelling during flight
- B64D 39/06: Connecting hose to aircraft; Disconnecting hose therefrom
- B64D 45/02: Lightning protectors; Static dischargers
- F16F 15/02: Suppression of vibrations of non-rotating, e.g. reciprocating systems; Suppression of vibrations of rotating systems by use of members not moving with the rotating systems ({F16F15/005 takes precedence } ; layered products B32B; suppression of vibration in ships B63; {relieving load on bearings, using magnetic means F16C39/06})
- F16H 37/02: comprising essentially only toothed or friction gearings
- G05D 1/0077: {using redundant signals or controls}
- G05D 1/0202: {specially adapted to aircraft}
- G05D 1/0816: {to ensure stability}
- G05D 1/0858: {specially adapted for vertical take-off of aircraft}
- G05D 1/49: Control of attitude, i.e. control of roll, pitch or yaw
- G05D 1/689: Pointing payloads towards fixed or moving targets (positioning towed, pushed or suspended implements G05D1/672)
- B64C 27/08: with two or more rotors
- B64C 2027/004: {using actuators, e.g. active systems}
- B64C 2027/8209: {Electrically driven tail rotors}
- B64C 2027/8227: {comprising more than one rotor}
- B64C 2027/8236: {including pusher propellers}
- B64C 2027/8263: {comprising in addition rudders, tails, fins, or the like}
- B64C 2027/8272: {comprising fins, or movable rudders}
- B64C 2027/8281: {comprising horizontal tail planes}
- B64U 10/10: Rotorcrafts
- F02C 9/28: Regulating systems responsive to plant or ambient parameters, e.g. temperature, pressure, rotor speed (F02C9/30 - F02C9/38, F02C9/44 take precedence)
- F05D 2220/329: in helicopters
- F05D 2270/021: to prevent overspeed
- F16D 13/52: Clutches with multiple lamellae {; Clutches in which three or more axially moveable members are fixed alternately to the shafts to be coupled and are pressed from one side towards an axially-located member (F16D13/385 takes precedence)}
- F16D 13/72: Features relating to cooling
- F16D 13/74: Features relating to lubrication
- G05D 1/0204: {to counteract a sudden perturbation, e.g. cross-wind, gust}
- G05D 1/08: Control of attitude, i.e. control of roll, pitch, or yaw
- G05D 2105/22: of humans
- G05D 2105/35: for combat
- G05D 2109/25: Rotorcrafts
- Y02T 50/10: Drag reduction
- B64C: AEROPLANES; HELICOPTERS
- B64D: EQUIPMENT FOR FITTING IN OR TO AIRCRAFT; FLIGHT SUITS; PARACHUTES; ARRANGEMENT OR MOUNTING OF POWER PLANTS OR PROPULSION TRANSMISSIONS IN AIRCRAFT
- F16F: SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
- F16H: GEARING
- G05D: SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
- B64U: UNMANNED AERIAL VEHICLES [UAV]; EQUIPMENT THEREFOR
- F02C: GAS-TURBINE PLANTS; AIR INTAKES FOR JET-PROPULSION PLANTS; CONTROLLING FUEL SUPPLY IN AIR-BREATHING JET-PROPULSION PLANTS (construction of turbines F01D; jet-propulsion plants F02K; construction of compressors or fans F04; generating combustion products of high pressure or high velocity F23R; using gas turbines in compression refrigeration plants F25B11/00)
- F05D: INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
- F16D: COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
- Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION

## Abstract

An aircraft is provided including an airframe, an extending tail, one or more engines supported by the airframe, and a counter rotating, coaxial main rotor assembly including an upper rotor assembly and a lower rotor assembly. A translational thrust system positioned at the extending tail. The translational thrust system providing translational thrust to the airframe. A gearbox configured to transfer power from the engine to the main rotor assembly. A flight control computer to independently control one or more of the engine, the upper rotor assembly, the lower rotor assembly, and the translational thrust system. The flight control computer, in response to at least one control command, engages or disengages the translational thrust system, while maintaining controlled powered flight.

## Claims

### Claim 1

An aircraft comprising:
an airframe;
an extending tail;
one or more engines supported by the airframe;
a counter rotating, coaxial main rotor assembly including an upper rotor assembly and a lower rotor assembly;
a translational thrust system positioned at the extending tail, the translational thrust system providing translational thrust to the airframe; and
a gearbox configured to transfer power from the one or more engines to the main rotor assembly;
a flight control computer to independently control the one or more engines, the upper rotor assembly, the lower rotor assembly, and the translational thrust system;
wherein in response to at least one control command, the flight control computer engages or disengages the translational thrust system, while maintaining controlled powered flight.

### Claim 2 (depends on 1)

The aircraft of claim 1 wherein:
the translational thrust system comprises a propeller, wherein the propeller comprises a plurality of propeller blades.

### Claim 3 (depends on 2)

The aircraft of claim 2 wherein:
the propeller is driven by the gearbox through a drive system.

### Claim 4 (depends on 3)

The aircraft of claim 3 wherein:
the propeller may be engaged, disengaged and re-engaged from the gearbox by a clutch.

### Claim 5 (depends on 4)

The aircraft of claim 4 wherein:
the flight control computer is configured to disengage the propeller and reduce the angular velocity of the propeller.

### Claim 6 (depends on 5)

The aircraft of claim 5 wherein:
the angular velocity of the propeller is reduced through pitch adjustment of the propeller blades to reduce rotation due to free stream airflow.

### Claim 7 (depends on 4)

The aircraft of claim 4 wherein:
the flight control computer is configured to increase the angular velocity of the propeller for re-engagement of the clutch and command the re-engagement of the clutch.

### Claim 8 (depends on 7)

The aircraft of claim 7 wherein:
the angular velocity of the propeller is increased by pitch adjustment of the propeller blades to induce rotation of the blades by free stream air flow.

### Claim 9 (depends on 8)

The aircraft of claim 8 wherein:
the main rotor assembly is configured to be back driven by the propeller through the drive system and the gearbox.

### Claim 10 (depends on 1)

The aircraft of claim 1 wherein:
the at least one control command includes one or more of pilot inputs, auto-pilot inputs, navigation system based inputs, and control inputs from one or more control loops executed by the flight control computer.

### Claim 11

A method of operating an aircraft, comprising:
receiving, with a flight control computer, at least one control command to engage or disengage a translational thrust system;
commanding, with a flight control computer, the translational thrust system to engage or disengage, while maintaining controlled powered flight.

### Claim 12 (depends on 11)

The method according to claim 11 wherein:
the translational thrust system comprises a propeller, wherein each propeller comprises a plurality of propeller blades.

### Claim 13 (depends on 11)

The method according to claim 11 wherein:
the propeller is driven by a gearbox through a drive system.

### Claim 14 (depends on 13)

The method according to claim 13 wherein:
the propeller may be engaged, disengaged and re-engaged from the gearbox by a clutch.

### Claim 15 (depends on 14)

The method according to claim 14 wherein:
the propeller is disengaged and the angular velocity of the propeller is reduced.

### Claim 16 (depends on 15)

The method according to claim 15 wherein:
the angular velocity of the propeller is reduced through adjusting the pitch of the propeller blades to reduce rotation due to free stream airflow.

### Claim 17 (depends on 14)

The method according to claim 14 wherein:
the angular velocity of the propeller is increased for re-engagement of the clutch prior to commanding the re-engagement of the clutch.

### Claim 18 (depends on 17)

The method according to claim 17 wherein:
the angular velocity of the propeller is increased by adjusting the pitch of the propeller blades so as to induce rotation by free stream air.

### Claim 19 (depends on 18)

The method according to claim 18 wherein:
the propeller back drives the main rotor assembly through the drive system and the gearbox.

### Claim 20 (depends on 12)

The method according to claim 12 wherein:
the at least one control command includes one or more of pilot inputs, auto-pilot inputs, navigation system based inputs, and any control inputs from one or more control loops executed by the flight control computer.