Systems and methods for oil management in gearboxes for evtol aircraft
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, the electric propulsion system comprising:
at least one electrical engine mechanically configured to be connected to a fuselage of the VTOL aircraft and electrically connected to an electrical power source, the electrical engine comprising:
a gearbox assembly;
an end bell assembly comprising a first wall and a second wall, the first wall having a first diameter that is greater than the second wall having a second diameter;
a dry zone between the first wall and the second wall;
an electrical engine housing at least partially enclosing the end bell assembly;
a fluid reservoir between the electrical engine housing and the first wall; and
a main shaft having a first end positioned within the second wall.
2. The system of claim 1 , wherein the gearbox assembly is concentrically aligned with the main shaft.
3. The system of claim 1 , wherein the gearbox assembly comprises:
at least one planetary gear;
a ring gear; and
a planetary carrier.
4. The system of claim 3 , wherein the at least one planetary gear is located in the dry zone.
5. The system of claim 3 , wherein the planetary carrier is present in the dry zone.
6. The system of claim 3 , wherein the at least one planetary gear establishes an end of the dry zone.
7. The system of claim 3 , wherein the ring gear is removably coupled to the end bell assembly.
8. The system of claim 1 , wherein the dry zone is surrounded by the fluid reservoir.
9. The system of claim 1 , wherein the fluid reservoir contains oil.
10. The system of claim 1 , wherein the second wall further comprises at least one port hole configured to receive a liquid used to cool and lubricate the electrical engine.
11. The system of claim 1 , wherein the end bell assembly further comprises an end bell plate, wherein the end bell plate establishes an end of the dry zone.
12. The system of claim 1 , further comprising a tilting mechanism configured to change an orientation of the electrical engine, wherein a volume of the dry zone remains constant throughout the change in the orientation of the electrical engine.
13. The system of claim 1 , wherein the electrical engine further comprises an electrical motor, wherein the electrical motor includes a stator and a rotor.
14. The system of claim 1 , wherein the fluid reservoir contains a fluid for lubricating the gearbox assembly.
15. The system of claim 1 , wherein the fluid reservoir contains a fluid for cooling the gearbox assembly.
16. The system of claim 1 , wherein the fluid reservoir contains a fluid for lubricating the electrical engine.
17. The system of claim 1 , wherein the fluid reservoir contains a fluid for cooling the electrical engine.
18. The system of claim 17 , wherein the electrical engine further comprises an electrical motor and inverter assembly.
19. A method of operating a vertical take-off and landing (VTOL) aircraft electric propulsion system, the method comprising:
operating at least one electrical engine mechanically connected to a fuselage of the VTOL aircraft and electrically connected to an electrical power source, the electrical engine comprising:
a gearbox assembly; an an end bell assembly comprising a first wall and a second wall, the first wall having a first diameter that is greater than the second wall having a second diameter;
a dry zone between the first wall and the second wall;
an electrical engine housing at least partially enclosing the end bell assembly;
a fluid reservoir between the electrical engine housing and the first wall; and
a main shaft having a first end positioned within the second wall.
20. The method of claim 19 , wherein the gearbox assembly is concentrically aligned with the main shaft.
21. The method of claim 19 , wherein the gearbox assembly comprises:
at least one planetary gear;
a ring gear; and
a planetary carrier.
22. The method of claim 21 , wherein the at least one planetary gear is located in the dry zone.
23. The method of claim 21 , wherein the planetary carrier is present in the dry zone.
24. The method of claim 21 , wherein the at least one planetary gear establishes an end of the dry zone.
25. The method of claim 21 , wherein the ring gear is removably coupled to the end bell assembly.
26. The method of claim 19 , wherein the dry zone is surrounded by the fluid reservoir.
27. The method of claim 19 , wherein the fluid reservoir contains oil.
28. The method of claim 19 , wherein the second wall further comprises at least one port hole configured to receive a liquid used to cool and lubricate the electrical engine.
29. The method of claim 19 , wherein the end bell assembly further comprises an end bell plate, wherein the end bell plate establishes an end of the dry zone.
30. The method of claim 19 , further comprising a tilting mechanism configured to change an orientation of the electrical engine, wherein a volume of the dry zone remains constant throughout the change in the orientation of the electrical engine.