# US 10,767,566 B2 · Electric propulsion motor cooling system and method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,767,566 B2 - Document ID: US10767566B2 - Status: Granted - Kind: B2 - Application number: 15/927,857 - Filed: 2018-03-21 - Published: 2019-09-26 - Granted: 2020-09-08 - Earliest claimed: 2018-03-21 - Assignees: Hamilton Sundstrand Corporation - Applicants: Hamilton Sundstrand Corporation - Inventors: Debabrata Pal - Web page: https://patentgrep.com/patent/US10767566B2 ## CPC - F02K 3/06: with front fan - B64D 27/16: of jet type - B64D 31/18: for hybrid-electric power plants - B64D 33/08: of power plant cooling systems - F01D 25/12: Cooling - F01D 25/36: using electric motors - F02C 7/32: Arrangement, mounting, or driving, of auxiliaries - F02C 7/36: Power transmission arrangements between the different shafts of the gas turbine plant, or between the gas-turbine plant and the power user ({F02C3/107 - F02C3/13 and} F02C7/32 take precedence; couplings for transmitting rotation F16D; gearing in general F16H) - F02K 5/00: Plants including an engine, other than a gas turbine, driving a compressor or a ducted fan - H02K 5/207: {with openings in the casing specially adapted for ambient air} - H02K 7/14: Structural association with mechanical loads, e.g. with hand-held machine tools or fans (with fan or impeller for cooling the machine H02K9/06) - H02K 9/04: having means for generating a flow of cooling medium - H02K 9/06: with fans or impellers driven by the machine shaft - H02P 29/40: Regulating or controlling the amount of current drawn or delivered by the motor for controlling the mechanical load - B64D 27/026: {comprising different types of power plants, e.g. combination of a piston engine and a gas-turbine (Hybrid electric aircraft B64D27/33)} - B64D 27/33: Hybrid electric aircraft - F05D 2220/323: for aircraft propulsion, e.g. jet engines - F05D 2260/20: Heat transfer, e.g. cooling - F05D 2260/4031: as in toothed gearing - F05D 2270/02: to control rotational speed (n) - Y02T 50/60: Efficient propulsion technologies, e.g. for aircraft - F02K: JET-PROPULSION PLANTS (features of jet-propulsion plants common to gas-turbine plants, air intakes or fuel supply control of air-breathing jet-propulsion plants F02C7/00, F02C9/00) - B64D: EQUIPMENT FOR FITTING IN OR TO AIRCRAFT; FLIGHT SUITS; PARACHUTES; ARRANGEMENT OR MOUNTING OF POWER PLANTS OR PROPULSION TRANSMISSIONS IN AIRCRAFT - F01D: NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES (machines or engines for liquids F03; non-positive displacement pumps F04D) - F02C: GAS-TURBINE PLANTS; AIR INTAKES FOR JET-PROPULSION PLANTS; CONTROLLING FUEL SUPPLY IN AIR-BREATHING JET-PROPULSION PLANTS (construction of turbines F01D; jet-propulsion plants F02K; construction of compressors or fans F04; generating combustion products of high pressure or high velocity F23R; using gas turbines in compression refrigeration plants F25B11/00) - H02K: DYNAMO-ELECTRIC MACHINES (dynamo-electric relays H01H53/00; conversion of DC or AC input power into surge output power {H03K3/53}) - H02P: CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS - F05D: INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract An electric propulsion system for a gas turbine engine may comprise an electric motor disposed within a nacelle of the gas turbine engine, wherein the electric motor is configured to receive a bypass air from a fan bypass duct for cooling the electric motor and the electric motor is configured to drive a low speed shaft of the gas turbine engine. ## Claims ### Claim 1 An electric propulsion system for a gas turbine engine, comprising: an electric motor disposed within a nacelle of the gas turbine engine, an inner surface of the nacelle at least partially defines a fan bypass duct, and the electric motor is disposed radially outward from the fan bypass duct; wherein the electric motor is configured to receive a bypass air from the fan bypass duct for cooling the electric motor and the electric motor is configured to drive a low speed shaft of the gas turbine engine. ### Claim 2 (depends on 1) The electric propulsion system of claim 1, wherein the electric motor is in operable communication with the low speed shaft. ### Claim 3 (depends on 2) The electric propulsion system of claim 2, wherein the electric motor comprises a stator winding, wherein the bypass air cools the stator winding. ### Claim 4 (depends on 3) The electric propulsion system of claim 3, wherein the electric motor comprises a rotor driven by the stator winding. ### Claim 5 (depends on 4) The electric propulsion system of claim 4, further comprising a drive shaft coupled to the rotor, wherein the drive shaft is configured to extend through the fan bypass duct. ### Claim 6 (depends on 5) The electric propulsion system of claim 5, wherein the electric motor is in operable communication with the low speed shaft via the drive shaft, wherein the drive shaft is oriented substantially perpendicular to the low speed shaft. ### Claim 7 (depends on 6) The electric propulsion system of claim 6, further comprising a motor cooling duct disposed in the nacelle and configured to receive the bypass air from the electric motor and direct the bypass air away from the electric motor. ### Claim 8 (depends on 7) The electric propulsion system of claim 7, wherein the motor cooling duct directs the bypass air back into the fan bypass duct. ### Claim 9 A gas turbine engine, comprising: a nacelle comprising an inner surface at least partially defining a fan bypass duct; a low speed shaft configured to rotate about a longitudinal axis of the gas turbine engine; and an electric propulsion system, comprising: an electric motor disposed within the nacelle, the electric motor is disposed radially outward from the fan bypass duct; wherein the electric motor is configured to receive a bypass air from the fan bypass duct for cooling the electric motor and the electric motor is configured to drive the low speed shaft. ### Claim 10 (depends on 9) The gas turbine engine of claim 9, further comprising a drive shaft extending from the electric motor and through the fan bypass duct. ### Claim 11 (depends on 10) The gas turbine engine of claim 10, wherein the drive shaft is operably coupled to the low speed shaft. ### Claim 12 (depends on 9) The gas turbine engine of claim 9, further comprising a motor cooling duct disposed within the nacelle and configured to direct the fan bypass air from the electric motor. ### Claim 13 (depends on 9) The gas turbine engine of claim 9, further comprising an electric motor controller in electronic communication with the electric motor. ### Claim 14 (depends on 13) The gas turbine engine of claim 13, wherein the electric motor controller is configured to send a power signal to the electric motor during at least one of a takeoff event or a taxi event, wherein the electric motor drives the low speed shaft in response to the power signal. ### Claim 15 (depends on 12) The gas turbine engine of claim 12, further comprising a motor cooling door moveable between an open position and a closed position, wherein the motor cooling door prevents air from flowing through the motor cooling duct in the closed position. ### Claim 16 (depends on 10) The gas turbine engine of claim 10, further comprising a bevel gear coupled to the low speed shaft, whereby the drive shaft rotates the low speed shaft. ### Claim 17 A method of operating an electric propulsion system for a gas turbine engine, comprising: sending, by an electric motor controller, a power signal to an electric motor, wherein the electric motor is disposed in a nacelle for the gas turbine engine, an inner surface of the nacelle partially defines a fan bypass duct, and the electric motor is disposed radially outward from the inner surface; rotating, by the electric motor, a drive shaft in response to receiving the power signal, wherein the drive shaft extends through the fan bypass duct; driving, by the electric motor, a low speed shaft via the drive shaft in response to the rotating; sending, by the electric motor controller, a second power signal to a motor cooling door, wherein the motor cooling door is configured to open in response to the second power signal; and receiving, by the electric motor, fan bypass duct air for cooling the electric motor in response to the motor cooling door opening. ### Claim 18 (depends on 1) The electric propulsion system of claim 1, wherein the motor cooling duct comprises an inlet disposed in the inner surface and an outlet. ### Claim 19 (depends on 18) The electric propulsion system of claim 18, wherein the outlet is disposed in the inner surface forward from a fan configured to drive the bypass air along the fan bypass duct. ### Claim 20 (depends on 18) The electric propulsion system of claim 18, wherein the outlet is disposed in an outer surface of the nacelle.