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EP-4737700-A1 - COMPONENT HEATING IN HYBRID ELECTRIC PROPULSION SYSTEMS

EP4737700A1EP 4737700 A1EP4737700 A1EP 4737700A1EP-4737700-A1

Abstract

A hybrid electric propulsion system (10, 50, 100, 150, 200, 250, 300) includes a gearbox (16, 58, 104, 204, 302), an electric motor (52, 103, 203, 253) operably coupled to the gearbox (16, 58, 104, 204, 302), a battery (101, 251) operably coupled to the electric motor (52, 103, 203, 253) to power the electric motor (52, 103, 203, 253), and an engine lubrication system. The engine lubrication system includes a tank (108) that holds an engine lubrication fluid. The engine lubrication system includes a pump (110, 312) that is configured to pump the lubrication fluid from the tank (108) toward one or both of the battery (101, 251) and the electric motor (52, 103, 203, 253) through a supply line to maintain one or both of the battery (101, 251) and the electric motor (52, 103, 203, 253) above a threshold temperature.

Inventors

  • SIBBACH, Arthur

Assignees

  • General Electric Company

Dates

Publication Date
20260506
Application Date
20251016

Claims (15)

  1. A hybrid electric propulsion system (10, 50, 100, 150, 200, 250, 300), comprising: a turbine engine (20, 54); a gearbox (16, 58, 104, 204, 302) operably coupled to the turbine engine (20, 54) and including an output shaft (18a, 308), the turbine engine (20, 54) configured to actuate the gearbox (16, 58, 104, 204, 302) to rotate the output shaft (18a, 308); an electric motor (52, 103, 203, 253) operably coupled to the gearbox (16, 58, 104, 204, 302) and configured to actuate the gearbox (16, 58, 104, 204, 302) to rotate the output shaft (18a, 308); a battery (101, 251) operably coupled to the electric motor (52, 103, 203, 253) to power the electric motor (52, 103, 203, 253); and an engine lubrication system (102) including a tank (108) that holds an engine lubrication fluid, the engine lubrication system including a pump (110, 312) that is configured to pump the engine lubrication fluid from the tank (108) toward the battery (101, 251) through a supply line to maintain the battery (101, 251) above a temperature threshold.
  2. The hybrid electric propulsion system (10, 50, 100, 150, 200, 250, 300) of claim 1, wherein the engine lubrication system is configured to provide the engine lubrication fluid to the electric motor (52, 103, 203, 253).
  3. The hybrid electric propulsion system (10, 50, 100, 150, 200, 250, 300) of any preceding claim, further comprising a gearbox lubrication system that is separate from and independent of the engine lubrication system.
  4. The hybrid electric propulsion system (10, 50, 100, 150, 200, 250, 300) of any preceding claim, wherein the gearbox (16, 58, 104, 204, 302) includes an electric heating element that is operably coupled to the battery (101, 251) and configured to heat gearbox lubrication fluid held in the gearbox (16, 58, 104, 204, 302).
  5. The hybrid electric propulsion system (10, 50, 100, 150, 200, 250, 300) of claim 4, wherein the electric heating element includes at least one of a resistive heating element or an inductive heating element.
  6. The hybrid electric propulsion system (10, 50, 100, 150, 200, 250, 300) of any preceding claim, wherein the gearbox (16, 58, 104, 204, 302) includes a self-contained lubrication system that is contained within the gearbox (16, 58, 104, 204, 302).
  7. The hybrid electric propulsion system (10, 50, 100, 150, 200, 250, 300) of claim 6, wherein an input shaft connects the turbine engine (20, 54) to the gearbox (16, 58, 104, 204, 302), and wherein the input shaft and the output shaft (18a, 308) are coupled together by a gear mesh disposed within the gearbox (16, 58, 104, 204, 302).
  8. The hybrid electric propulsion system (10, 50, 100, 150, 200, 250, 300) of claim 7, wherein the self-contained lubrication system of the gearbox (16, 58, 104, 204, 302) includes a gearbox tank that supports gearbox lubrication fluid, a gearbox pump that pumps the gearbox lubrication fluid through a gearbox (16, 58, 104, 204, 302) supply line, a gearbox (16, 58, 104, 204, 302) heat exchanger coupled to the gearbox (16, 58, 104, 204, 302) supply line, and a gearbox (16, 58, 104, 204, 302) return line that returns the gearbox lubrication fluid to the gearbox tank.
  9. The hybrid electric propulsion system (10, 50, 100, 150, 200, 250, 300) of claim 8, wherein the gearbox pump of the self-contained lubrication system of the gearbox (16, 58, 104, 204, 302) is supported by at least one of the input shaft or the output shaft (18a, 308).
  10. The hybrid electric propulsion system (10, 50, 100, 150, 200, 250, 300) of any preceding claim, wherein the engine lubrication system further includes a return line that returns the engine lubrication fluid to the tank (108), and wherein the engine lubrication system further includes at least one shuttle valve operably associated with at least one of the electric motor (52, 103, 203, 253) or the battery (101, 251), the at least one shuttle valve operably coupled to at least one of the supply line or the return line to enable at least one of the electric motor (52, 103, 203, 253) or the battery (101, 251) to receive at least one of the engine lubrication fluid of the engine lubrication system or a gearbox lubrication fluid from the gearbox (16, 58, 104, 204, 302).
  11. The hybrid electric propulsion system (10, 50, 100, 150, 200, 250, 300) of any preceding claim, further comprising: a control system, wherein the pump (110, 312) is operably coupled to the control system and configured to pump the engine lubrication fluid from the tank (108) toward the battery (101, 251) through a supply line to maintain the battery (101, 251) above a battery temperature threshold when the control system determines that an ambient temperature is below the ambient temperature threshold.
  12. The hybrid electric propulsion system (10, 50, 100, 150, 200, 250, 300) of claim 11, wherein the ambient temperature threshold is a function of at least one of speed or acceleration of the aircraft.
  13. The hybrid electric propulsion system (10, 50, 100, 150, 200, 250, 300) of claim 11 or claim 12, wherein the gearbox (16, 58, 104, 204, 302) supports a gearbox lubrication fluid and wherein prior to starting the turbine engine (20, 54) when the ambient temperature is below the ambient temperature threshold, the control system (99) is configured to cause the battery (101, 251) to provide power to an electric heating element to heat the gearbox lubrication fluid.
  14. The hybrid electric propulsion system (10, 50, 100, 150, 200, 250, 300) of any of claims 11 to 13, wherein actuation of the electric motor (52, 103, 203, 253) causes a gear mesh in the gearbox (16, 58, 104, 204, 302) to rotate.
  15. The hybrid electric propulsion system (10, 50, 100, 150, 200, 250, 300) of claim 14, wherein the gearbox (16, 58, 104, 204, 302) holds gearbox lubrication fluid, and wherein the control system is configured to cause the electric motor (52, 103, 203, 253) to rotate the gear mesh at a speed below which produces propulsive thrust, the speed being sufficient to heat the gearbox lubrication fluid in the gear mesh by friction.

Description

TECHNICAL FIELD This disclosure relates to hybrid electric propulsion systems for aircraft applications and, more particularly, to methods and systems for heating one or more components (e.g., batteries) in such propulsion systems. BACKGROUND Temperature plays a significant role in the performance of one or more components of hybrid electric propulsion systems. For instance, batteries function based on chemical reactions and in cold weather, the chemicals cannot react as fast as in warm weather. A cold battery will, thus, not have the same power as a warm one. In order to provide sufficient electrical power in all weather conditions, it is sometimes necessary to increase the number of batteries or use bigger batteries. However, this results in weight increase, which makes hybrid electric power plants less attractive for aircraft applications. BRIEF DESCRIPTION OF THE DRAWINGS A better understanding of the features and advantages of the disclosed technology will be obtained by reference to the following detailed description that sets forth illustrative aspects, in which the principles of the technology are utilized, and the accompanying drawings of which: FIG. 1 is a schematic view of a hybrid electric propulsion system in accordance with the principles of this disclosure, the hybrid electrical propulsion system having an electrical machine on an aft end of a shaft at an aft end of the propulsion system for driving a gearbox on a forward end of the propulsion system, which, in turn, drives a propeller at the forward end of the propulsion system, the gearbox including a lubrication system that is separate from a turbine engine of the propulsion system;FIG. 1A is a block diagram of a control system of the hybrid electric propulsion system of FIG 1, in accordance with principles of this disclosure;FIG. 2 is a schematic view of another hybrid electric propulsion system in accordance with the principles of this disclosure, the view illustrating the hybrid electric propulsion system with an electric motor disposed at a forward end of the propulsion system and including a gearbox with a self-contained lubrication system;FIG. 3 is a schematic view of still another hybrid electric propulsion system in accordance with the principles of this disclosure, the view illustrating the hybrid electric propulsion system having a gearbox with a lubrication system that is separate from a turbine engine of the propulsion system, the view further illustrating an electric motor and a battery operably coupled to an engine lubrication system;FIG. 4 is a schematic view of a hybrid electric propulsion system in accordance with the principles of this disclosure, the view illustrating the hybrid electric propulsion system having a gearbox with a lubrication system that is separate from a turbine engine of the propulsion system, the gearbox shown with an electric heating element in the gearbox, the view further illustrating an electric motor and a battery operably coupled to an engine lubrication system;FIG. 5 is a schematic view of another hybrid electric propulsion system in accordance with the principles of this disclosure, the view illustrating the hybrid electric propulsion system having a gearbox with a lubrication system that is separate from a turbine engine of the propulsion system, the view illustrating an electric motor and a battery operably coupled to an engine lubrication system with the electric motor operably coupled to the lubrication system of the gearbox;FIG. 6 is an enlarged, schematic view of the electric motor of the hybrid electric propulsion system of FIG. 5;FIG. 7 is a schematic view of yet another hybrid electric propulsion system in accordance with the principles of this disclosure, the view illustrating the hybrid electric propulsion system with an electric motor, a battery, and shuttle valves operably coupled to an engine lubrication system;FIG. 8 is an enlarged, schematic view illustrating the shuttle valves of the hybrid electric propulsion system of FIG. 7;FIG. 9 is a schematic view of another hybrid electric propulsion system in accordance with the principles of this disclosure, the view illustrating a gearbox with a self-contained lubrication system;FIG. 10 is an enlarged, schematic view of the gearbox of the hybrid electric propulsion system of FIG. 9; andFIG. 11 illustrates a flow chart of a method for regulating temperature of a battery and/or an electric motor. Further exemplary aspects of the disclosure are described in more detail below with reference to the appended figures. Aspects of this disclosure may be combined without departing from the scope of the disclosure. DETAILED DESCRIPTION Reference will now be made in detail to present embodiments of the disclosure, one or more examples of which are illustrated in the accompanying drawings. The detailed description uses numerical and letter designations to refer to features in the drawings. Like or similar designations in the drawings and descripti