# US 12,214,894 B1 · Motor gearbox assembly with layshaft for EVTOL aircraft > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,214,894 B1 - Document ID: US12214894B1 - Status: Granted - Kind: B1 - Application number: 18/667,065 - Filed: 2024-05-17 - Granted: 2025-02-04 - Earliest claimed: 2024-05-17 - Assignees: Archer Aviation Inc. - Applicants: Archer Aviation Inc. - Inventors: Scott Graves - Web page: https://patentgrep.com/patent/US12214894B1 ## CPC - B64D 35/021: for electric power plants - B64C 29/0033: {the propellers being tiltable relative to the fuselage} - B64D 27/33: Hybrid electric aircraft - B64D 27/34: All-electric aircraft - B64D 35/00: Transmitting power from power plants to propellers or rotors; Arrangements of transmissions - F16H 1/20: involving more than two intermeshing members - F16H 57/043: {within rotary parts, e.g. axial channels or radial openings in shafts} - F16H 57/0476: {Electric machines and gearing, i.e. joint lubrication or cooling or heating thereof} - F16H 57/0495: {with fixed gear ratio} - F16H 57/082: {Planet carriers} - F16H 3/0915: {with coaxial input and output shafts} - F16H 2001/2881: {comprising two axially spaced central gears, i.e. ring or sun gear, engaged by at least one common orbital gear wherein one of the central gears is forming the output} - F16H 2057/02034: {Gearboxes combined or connected with electric machines} - B64D: EQUIPMENT FOR FITTING IN OR TO AIRCRAFT; FLIGHT SUITS; PARACHUTES; ARRANGEMENT OR MOUNTING OF POWER PLANTS OR PROPULSION TRANSMISSIONS IN AIRCRAFT - B64C: AEROPLANES; HELICOPTERS - F16H: GEARING ## Abstract A motor gearbox assembly for an aircraft may comprise a layshaft configured to transmit torque from a rotor to a main power output shaft. The motor gearbox assembly may comprise a gearbox housing, a stator mounted inside the gearbox housing, a rotor rotatably mounted inside the stator on a main power output shaft and a layshaft rotatably mounted in the gearbox housing outside of the stator. The motor gearbox assembly may comprise a first ear reduction between the rotor and the layshaft, and a second gear reduction between the layshaft and the main power output shaft. ## Claims ### Claim 1 A motor gearbox assembly, comprising: a gearbox housing; a motor inside the gearbox housing, the motor comprising a stator and a rotor that is rotatable with respect to the stator; a main power output shaft, the rotor being rotatably mounted on the main power output shaft and coupled to a first rotor pinion gear; a layshaft rotatably mounted in the gearbox housing outside of the motor; a first layshaft gear at a first axial end of the layshaft on a first side of the rotor and the stator, the first layshaft gear being engaged with the first rotor pinion gear; and a second layshaft gear at a second axial end of the layshaft, the second axial end being on a second side of the rotor and the stator that is opposite the first side, the second layshaft gear being engaged with a power output gear coupled to the main power output shaft. ### Claim 2 (depends on 1) The motor gearbox assembly of claim 1, wherein the first rotor pinion gear and the first layshaft gear provide a gear reduction between the layshaft and the rotor. ### Claim 3 (depends on 1) The motor gearbox assembly of claim 1, wherein the second layshaft gear and the power output gear provide a gear reduction between the layshaft and the main power output shaft. ### Claim 4 (depends on 1) The motor gearbox assembly of claim 1, wherein the rotor is configured to be selectably engaged with one of: the main power output shaft at a 1:1 gear ratio, or the first rotor pinion gear. ### Claim 5 (depends on 4) The motor gearbox assembly of claim 4, further comprising a clutch, wherein a portion of the first axial end of the rotor includes axial splines, and the clutch is slidably mounted on the axial splines to selectably engage the rotor with one of the main power output shaft or the first rotor pinion gear. ### Claim 6 (depends on 1) The motor gearbox assembly of claim 1, further comprising: a second rotor pinion gear; and a third layshaft gear at the first axial end of the layshaft, wherein the rotor is configured to be selectably coupled to the layshaft by one of: the first rotor pinion gear and the first layshaft gear; or the second rotor pinion gear and the third layshaft gear. ### Claim 7 (depends on 6) The motor gearbox assembly of claim 6, further comprising a clutch, wherein a portion of the first axial end of the rotor includes axial splines, and the clutch is slidably mounted on the axial splines to selectably engage the rotor with one of the first rotor pinion gear or the second rotor pinion gear. ### Claim 8 (depends on 1) The motor gearbox assembly of claim 1, wherein the rotor is configured to rotate relative to the main power output shaft via a rotor bearing. ### Claim 9 (depends on 1) The motor gearbox assembly of claim 1, wherein the layshaft is configured to rotate relative to the gearbox housing via a first layshaft bearing and a second layshaft bearing, wherein the first layshaft gear and the second layshaft gear are located between the first layshaft bearing and the second layshaft bearing. ### Claim 10 (depends on 1) The motor gearbox assembly of claim 1, further comprising: an axial bore extending through the layshaft from the first axial end to the second axial end; an inlet opening at the first axial end, the inlet opening being in fluid communication with a fluid reservoir; and an outlet opening at the second axial end, wherein a first diameter of the inlet opening is smaller than a second diameter of the outlet opening, wherein the layshaft is configured to cause oil in the fluid reservoir to flow from the inlet to the outlet through the axial bore by centrifugal force resulting from rotation of the layshaft. ### Claim 11 (depends on 10) The motor gearbox assembly of claim 10, wherein the axial bore comprises a conical taper having a diameter that increases from the first axial end to the second axial end. ### Claim 12 (depends on 1) The motor gearbox assembly of claim 1, wherein the motor gearbox assembly is configured to be used in a propulsion system of an aircraft. ### Claim 13 (depends on 12) The motor gearbox assembly of claim 12, wherein the aircraft comprises one of an electric aircraft or a hybrid aircraft. ### Claim 14 (depends on 12) The motor gearbox assembly of claim 12, wherein the aircraft comprises a vertical takeoff and landing aircraft. ### Claim 15 (depends on 12) The motor gearbox assembly of claim 12, wherein the propulsion system comprises one of a tilt propeller or a lift propeller.