Hybrid-electric drive system

Patent metadata

Field	Value
Publication number	US-2018163558-A1
Application number	US-201615377080-A
Country	US
Kind code	A1
Filing date	Dec 13, 2016
Priority date	Dec 13, 2016
Publication date	Jun 14, 2018
Grant date	—

Abstract

A propulsion system includes a propulsor having a driveshaft, an electric machine coupled to the driveshaft of the propulsor, and a combustion engine having an output shaft. The propulsion system additionally includes a one-way clutch operable with at least one of the driveshaft of the propulsor and the output shaft of the combustion engine. The one-way clutch allows for a differential angular velocity of the driveshaft relative to the output shaft in a first circumferential direction and prevents a differential angular velocity of the driveshaft relative to the output shaft in a second circumferential direction.

First claim

What is claimed is:

1 . A propulsion system comprising:
a driveshaft; an electric machine coupled to the driveshaft; a combustion engine comprising an output shaft; and a one-way clutch operable with at least one of the driveshaft and the output shaft of the combustion engine, the one-way clutch allowing for a differential angular velocity of the driveshaft relative to the output shaft in a first circumferential direction and preventing a differential angular velocity of the driveshaft relative to the output shaft in a second circumferential direction.

2 . The propulsion system of claim 1 , wherein the combustion engine further comprises a turbine engine, wherein the output shaft is rotatable with the turbine engine.

3 . The propulsion system of claim 2 , wherein the one-way clutch is configured to decouple the driveshaft from the output shaft passively based on an angular velocity of the output shaft generated by the turbine engine relative to an angular velocity of the driveshaft generated by the electric machine.

4 . The propulsion system of claim 3 , wherein the one-way clutch is configured to decouple the driveshaft from the output shaft when the power applied to the driveshaft by the electric machine exceeds the power applied to the output shaft by the turbine engine by a predetermined threshold.

5 . The propulsion system of claim 3 , wherein the one-way clutch is configured to couple the driveshaft to the output shaft when the power applied to the driveshaft by the electric machine is less than or equal to the power applied to the output shaft by the turbine engine.

6 . The propulsion system of claim 1 , wherein the driveshaft is configured as a driveshaft of a propulsor, wherein the propulsor further comprises a propeller, and wherein the driveshaft is configured for rotating the propeller.

7 . The propulsion system of claim 5 , wherein the propulsor further comprises a gearbox, and wherein the driveshaft is configured for rotating the propeller across the gearbox.

8 . The propulsion system of claim 1 , wherein the one-way clutch is configured as a mechanical one-way clutch passively controlled by the output shaft and the driveshaft.

9 . The propulsion system of claim 1 , wherein the one-way clutch is configured as at least one of a sprag clutch or a cam clutch.

10 . The propulsion system of claim 1 , wherein the driveshaft is configured as a driveshaft of a propulsor, wherein the propulsor is a first propulsor, wherein the electric machine is a first electric machine, and wherein the propulsion system further comprises:
a second propulsor comprising a driveshaft; and a second electric machine coupled to the driveshaft of the second propulsor for driving the second propulsor, wherein the second electric machine is electrically coupled to the first electric machine and powered by the first electric machine.

11 . A method of operating a propulsion system comprising a propulsor including a driveshaft, an electric machine coupled to the driveshaft, a combustion engine comprising an output shaft, and a one-way clutch operable with at least one of the driveshaft and the output shaft, the method comprising:
operating the propulsion system to power the propulsor at least in part with the combustion engine such that the one-way clutch couples the output shaft of the combustion engine to the driveshaft of the propulsor; and operating the propulsion system to power the propulsor at least in part with the electric machine such that the one-way clutch decouples the output shaft of the combustion engine from the driveshaft of the propulsor.

12 . The method of claim 11 , wherein the combustion engine is a gas turbine engine further comprising a turbine engine, and wherein the output shaft is rotatable with the turbine engine.

13 . The method of claim 12 , wherein operating the propulsion system to power the propulsor at least in part with the gas turbine engine further comprises operating the electric machine as an electric generator.

14 . The method of claim 13 , wherein operating the electric machine as an electric generator comprises powering a second propulsor of the propulsion system.

15 . The method of claim 12 , wherein operating the propulsion system to power the propulsor at least in part with the gas turbine engine further comprises operating the propulsion system to power the propulsor with both the gas turbine engine and the electric machine.

16 . The method of claim 15 , wherein operating the propulsion system to power the propulsor with both the gas turbine engine and the electric machine comprises operating the gas turbine engine in a high power mode.

17 . The method of claim 16 , wherein the high power mode is a takeoff operating mode.

18 . The method of claim 11 , wherein operating the propulsion system to power the propulsor at least in part with the electric machine comprises operating the propulsion system to power the propulsor substantially completely with the electric machine.

19 . The method of claim 11 , wherein the one-way clutch transitions from coupling the output shaft to the driveshaft to decoupling the output shaft from the driveshaft automatically based on a torque applied to the output shaft by the gas turbine engine relative to a torque applied to the driveshaft by the electric machine.

20 . The method of claim 11 , wherein the one-way clutch is configured as a mechanical one-way clutch passively controlled by the output shaft and the driveshaft.

Assignees

• Gen Electric

Inventors

• Vondrell Randy M
• Crabtree Glenn

Classifications

• Y02T50/60

  Efficient propulsion technologies, e.g. for aircraft · CPC title

• B64D35/024

  of series type · CPC title

• B64D35/025 Primary

  of parallel type · CPC title

• F02C7/36

  Power transmission arrangements between the different shafts of the gas turbine plant, or between the gas-turbine plant and the power user ({F02C3/107 - F02C3/13 and} F02C7/32 take precedence; couplings for transmitting rotation F16D; gearing in general F16H) · CPC title

• F05D2220/32

  in gas turbines · CPC title