IP Library Granted Patent US 12,539,973
Granted Patent B2
US 12,539,973 · App. 19/009,672 · Granted Feb 3, 2026

Systems and methods for oil maintenance in gearboxes for eVTOL aircraft

Inventors: Scott Graves (Felton, CA); Robert Wayne Moore (Auburn, CA)
Assignee: Archer Aviation Inc.
B64D27/24B60L15/06B60L15/38B64C27/54B64C29/0008B64C29/0033B64D33/08B64D35/02F16B2/06F16H57/08H02K1/27H02K1/32H02K5/124H02K5/203H02K7/08H02K7/116H02K9/19H02K11/33H02K15/03H02M7/5395H02P21/50H02P25/16H02P27/06H02P27/08B60L2200/10B60L2210/40H02K7/006
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Quick Facts
Patent No.
US 12,539,973
App. No.
19/009,672
Granted
Feb 3, 2026
Kind
B2
Abstract

A motor assembly for a propulsion system, the motor assembly including a motor housing; a rotor; a power inverter; a main shaft; wherein the main shaft extends through the rotor; and a fluid distribution system including a fluid reservoir; a pump configured to distribute a fluid to a component of the motor assembly; and a filter having a circumferential side, wherein the filter is configured to filter the fluid through the circumferential side, wherein the filter is located adjacent to the main shaft.

Claims (46)

1 . A motor assembly for a propulsion system, the motor assembly comprising:

a motor housing;

a rotor;

a power inverter;

a main shaft, wherein the main shaft extends through the rotor; and

a fluid distribution system comprising:

a fluid reservoir;

a pump configured to distribute a fluid to a component of the motor assembly; and

a filter having an inner side and an outer circumferential side, wherein the filter is configured to filter the fluid through the outer circumferential side, wherein the filter is located adjacent to the main shaft, and a circumference of the inner side contacts the main shaft.

2 . The motor assembly of claim 1 , wherein the filter is ring-shaped.

3 . The motor assembly of claim 1 , wherein the filter is located adjacent to a bearing of the main shaft.

4 . The motor assembly of claim 1 , wherein the filter is configured to filter the fluid that lubricates at least a portion of the main shaft.

5 . The motor assembly of claim 1 , wherein the filter is coupled to the main shaft.

6 . The motor assembly of claim 1 , wherein the filter includes a filter media surrounding a ring-shaped support tube.

7 . The motor assembly of claim 1 , wherein the filter is located between the power inverter and at least a portion of the motor assembly.

8 . The motor assembly of claim 1 , wherein the filter is located adjacent to the main shaft at the first end of the motor housing.

9 . The motor assembly of claim 1 , wherein the motor assembly provides propulsion for a vertical takeoff and landing (VTOL) aircraft.

10 . The motor assembly of claim 1 , wherein the fluid is distributed for at least one of cooling or lubricating parts of the motor assembly.

11 . The motor assembly of claim 1 , wherein the fluid is oil.

12 . A method of operating an electric propulsion system for an aircraft, the method comprising:

rotating a propeller by operating a motor assembly to rotate a main shaft, wherein the main shaft extends through a rotor;

distributing a fluid to a component of the motor assembly by a fluid reservoir and a pump; and

filtering the fluid through an outer circumferential side of a filter, wherein the filter is located adjacent to the main shaft and a circumference of an inner side of the filter contacts the main shaft.

13 . The method of claim 12 , wherein the filter is ring-shaped, and filtering the fluid comprises filtering through the ring-shaped filter.

14 . The method of claim 12 , wherein the filtering is performed adjacent to a bearing of the main shaft.

15 . The method of claim 12 , wherein filtering the fluid comprises filtering the fluid that lubricates at least a portion of the main shaft.

16 . The method of claim 12 , wherein the pump is a sump pump and the fluid is distributed via the sump pump.

17 . The method of claim 12 , wherein the filter includes a filter media surrounding a ring-shaped support tube, and filtering the fluid comprises filtering through the filter media.

18 . The method of claim 12 , wherein the filtering is performed between the power inverter and at least a portion of the motor assembly.

19 . The method of claim 12 , wherein the fluid is distributed for at least one of cooling or lubricating parts of the motor assembly.

20 . The method of claim 12 , wherein the fluid is oil.

21 . The method of claim 12 , further comprising directing the fluid radially inward towards the main shaft.

22 . The method of claim 12 , wherein the filter is coupled to the main shaft, and filtering the fluid comprises filtering through the filter coupled to the main shaft.

23 . An aircraft comprising:

a boom;

a propeller assembly;

a motor assembly coupled to the boom, the motor assembly comprising:

a motor housing;

a rotor;

a power inverter;

a main shaft connected to the propeller assembly, wherein the main shaft extends through the rotor; and

a fluid distribution system comprising:

a fluid reservoir;

a pump configured to distribute a fluid to a component of the motor assembly; and

a filter having an inner side and an outer circumferential side, wherein the filter is configured to filter the fluid through the outer circumferential side, wherein the filter is located adjacent to the main shaft at the first end of the motor housing, and wherein a circumference of the inner side contacts the main shaft.

24 . The aircraft of claim 23 , wherein the aircraft is a vertical take off and landing (VTOL) aircraft.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Dec 26, 2025
From: GRAVES, SCOTT; MOORE, ROBERT WAYNE
To: ARCHER AVIATION INC.
Reel/Frame 073318/0086 →
Continuity (5)
Continuation 18620917 · Mar 28, 2024
Continuation 18299276 · Apr 12, 2023
Provisional Application 63378680 · Oct 7, 2022
Provisional Application 63378536 · Oct 6, 2022
Related Publication 20250145297A1 · May 8, 2025
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