# US 2016/0355272 A1 · Aircraft propulsion system

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- Number: US 2016/0355272 A1
- Document ID: US20160355272A1
- Status: Published application
- Kind: A1
- Application number: 15/133,728
- Filed: 2016-04-20
- Published: 2016-12-08
- Earliest claimed: 2015-05-13
- Assignees: ROLLS-ROYCE plc
- Applicants: ROLLS-ROYCE plc
- Inventors: Matthew MOXON
- Web page: https://patentgrep.com/patent/US20160355272A1

## CPC

- B64D 35/04: characterised by the transmission driving a plurality of propellers or rotors
- B64D 27/31: within, or attached to, wings
- B64D 27/33: Hybrid electric aircraft
- B64D 35/023: of series-parallel type
- B64D 27/026: {comprising different types of power plants, e.g. combination of a piston engine and a gas-turbine (Hybrid electric aircraft B64D27/33)}
- Y02T 50/40: Weight reduction
- B64D: EQUIPMENT FOR FITTING IN OR TO AIRCRAFT; FLIGHT SUITS; PARACHUTES; ARRANGEMENT OR MOUNTING OF POWER PLANTS OR PROPULSION TRANSMISSIONS IN AIRCRAFT
- Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION

## Abstract

An aircraft propulsion system includes at least first and second propulsor arrangements. Each propulsor arrangement includes an internal combustion engine configured to mechanically drive a plurality of propulsors. At least one of the propulsors of each propulsor arrangement is driveable via a shaft and at least one reduction gearbox. Each internal combustion engine is coupled to a motor generator arrangement configured to drive at least one of the mechanically driven propulsors when in a motor mode, and to generate electrical power when in a generating mode. The system further includes an electrical interconnector configured to transfer electrical power between the first and second propulsor arrangements.

## Claims

### Claim 1

An aircraft propulsion system comprising:
at least first and second propulsor arrangements, each propulsor arrangement comprising an internal combustion engine, a plurality of propulsors, a shaft, a reduction gearbox arrangement and a motor generator arrangement, the internal combustion engine being configured to drive the plurality of propulsors via the shaft and the reduction gearbox arrangement, each internal combustion engine being coupled to the motor generator arrangement, the motor generator arrangement being configured to drive at least one of the mechanically driven propulsors when in a motor mode, and to generate electrical power when in a generating mode; and
an electrical interconnector configured to transfer electrical power between the first and second propulsor arrangements.

### Claim 2 (depends on 1)

A system according to claim 1 wherein each of the first and second propulsor arrangements is mounted to a respective wing.

### Claim 3 (depends on 1)

A system according to claim 1, wherein one or more of the propulsors is located such that a wing flap is located in a slipstream of the respective propulsor.

### Claim 4 (depends on 1)

A system according to claim 1, wherein the propulsion system comprises at least one propulsor located so as to ingest a boundary layer airflow in use.

### Claim 5 (depends on 4)

A system according to claim 4, wherein the system comprises a boundary layer ingesting electrically driven propulsor mounted at a rearward end of an aircraft fuselage, having an inlet downstream of a trailing edge of the aircraft fuselage.

### Claim 6 (depends on 2)

A system according to claim 2, wherein the system comprises a tip propulsor comprising a propulsor mounted to a wing tip, having an inlet adjacent the wing tip.

### Claim 7 (depends on 6)

A system according to claim 6, wherein the system comprises a tip propulsor controller configured to control thrust generated by the tip propulsor in accordance with a yaw demand.

### Claim 8 (depends on 1)

A system according to claim 1, wherein the one or more shafts are configured to disconnect in the event of a failure of one of a coupled component.

### Claim 9 (depends on 1)

A system according to claim 1, wherein at least one of the propulsors comprises one of a ducted fan and an unducted propeller.

### Claim 10 (depends on 1)

A system according to claim 1, wherein the reduction gearbox arrangement comprises a bevel gearbox configured to transfer shaft power from a gas turbine engine driving shaft to a first shaft having an axis of rotation generally coaxial to the gas turbine engine driving shaft, and to a second shaft having an axis of rotation generally normal to the gas turbine engine driving shaft.

### Claim 11 (depends on 9)

A system according to claim 9, wherein at least one motor generator is coupled to the second shaft.

### Claim 12 (depends on 9)

A system according to claim 9, wherein the propulsion system comprises one or more further bevel gearboxes configured to transfer shaft power from the second shaft to a propulsor driving output shaft having an axis of rotation generally normal to the axis of rotation of the second shaft.

### Claim 13 (depends on 1)

An aircraft comprising a propulsion arrangement in accordance with claim 1.