Systems for cooling an electrical engine for eVTOL aircraft using an end bell assembly connected to a thermal plate
An electric propulsion system for a vertical take-off and landing (VTOL) aircraft having a heat exchanger to cool fluids used in an electrical engine, the electric propulsion system comprising at least one electrical engine mechanically connected directly or indirectly to a fuselage of the VTOL aircraft and electrically connected to an electrical power source. The electrical engine may comprise an electrical motor having a stator and a rotor; a gearbox assembly comprising a sun gear; at least one planetary gear; a ring gear; and a planetary carrier. The electric engine may include an inverter assembly comprising a thermal plate and an inverter assembly housing; an end bell assembly that is connected to the thermal plate of the inverter assembly; and a heat exchanger comprising an array of cooling fins and tubes.
1. An electric propulsion system for a vertical take-off and landing (VTOL) aircraft having a heat exchanger configured to cool fluids used in an electrical engine, the electric propulsion system comprising:
at least one electrical engine comprising:
an electrical motor having a stator and a rotor;
a gearbox assembly comprising:
a sun gear;
at least one planetary gear;
a ring gear; and
a planetary carrier;
an inverter assembly comprising a thermal plate and an inverter assembly housing;
an end bell assembly that is connected to the thermal plate of the inverter assembly, wherein the end bell assembly is disposed between the electrical motor and the inverter assembly; and
a heat exchanger.
2. The system of claim 1 , wherein the heat exchanger comprises an array of cooling fins and tubes.
3. The system of claim 1 , wherein the heat exchanger is connected to the thermal plate of the inverter assembly.
4. The system of claim 1 , wherein the heat exchanger is configured to cool a fluid that is used to cool the electrical motor, gearbox assembly, and inverter assembly.
5. The system of claim 1 , wherein the heat exchanger is configured to cool a fluid that is used to lubricate the electrical motor, gearbox assembly, and inverter assembly.
6. The system of claim 1 , wherein the heat exchanger is configured to cool the electrical engine with oil, wherein an amount of the oil does not exceed one quart.
7. The system of claim 1 , wherein the heat exchanger is configured to cool the electrical engine with oil, wherein an amount of the oil does not exceed three quarts.
8. The system of claim 1 , wherein the electrical motor, gearbox assembly, inverter assembly, end bell assembly, and heat exchanger are concentrically aligned along a main shaft.
9. The system of claim 1 , wherein a distance from a central axis of the inverter assembly housing to a radially inner surface of the heat exchanger is greater than a distance from the central axis of the inverter assembly housing to a radially outer surface of the inverter assembly housing.
10. The system of claim 1 , wherein the heat exchanger is positioned to allow an air flow to enter the heat exchanger.
11. The system of claim 1 , wherein the heat exchanger is positioned to allow an air flow from a propeller to enter the heat exchanger.
12. The system of claim 1 , wherein an inner arc length of the heat exchanger is less than an outer circumference of the inverter assembly housing.
13. An electric propulsion system for a vertical take-off and landing (VTOL) aircraft possessing a heat exchanger configured to cool fluids used in an electrical engine, the electric propulsion system comprising:
at least one electrical engine comprising:
an electrical motor having a stator and a rotor,
a gearbox assembly providing a gear reduction;
an inverter assembly comprising a thermal plate and an inverter assembly housing;
an end bell assembly that is connected to the thermal plate of the inverter assembly, wherein the end bell assembly is disposed between the electrical motor and the inverter assembly; and
a heat exchanger.
14. The system of claim 13 , wherein the heat exchanger comprises an array of cooling fins and tubes.
15. The system of claim 13 , wherein the heat exchanger is connected to the thermal plate of the inverter assembly.
16. The system of claim 13 , wherein the heat exchanger is configured to cool a fluid that is used to cool the electrical motor.
17. The system of claim 13 , wherein the heat exchanger is configured to cool a fluid that is used to cool the inverter assembly.
18. The system of claim 13 , wherein an inner arc length of the heat exchanger is smaller than an outer circumference of the inverter assembly housing.
19. The system of claim 13 , wherein a distance from a central axis of the inverter assembly housing to a radially inner surface of the heat exchanger is greater than a distance from the central axis of the inverter assembly housing to a radially outer surface of the inverter assembly housing.
20. The system of claim 13 , wherein the heat exchanger is configured to cool the electrical engine with oil, wherein an amount of the oil does not exceed three quarts.
21. The system of claim 13 , wherein the heat exchanger is positioned to allow an air flow from a propeller to enter the heat exchanger.