# US 12,595,746 B2 · Aircraft propulsion system with clocked electric machine and accessory gearbox > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,595,746 B2 - Document ID: US12595746B2 - Status: Granted - Kind: B2 - Application number: 18/756,448 - Filed: 2024-06-27 - Published: 2026-01-01 - Granted: 2026-04-07 - Earliest claimed: 2024-06-27 - Assignees: Pratt & Whitney Canada Corp. - Applicants: Pratt & Whitney Canada Corp. - Inventors: Bruno Chatelois; Paul Weaver; Eric S. Durocher - Web page: https://patentgrep.com/patent/US12595746B2 ## CPC - B64D 27/33: Hybrid electric aircraft - F01D 15/10: Adaptations for driving, or combinations with, electric generators - B64D 35/022: of hybrid-electric type - B64D 35/025: of parallel type - F02C 6/206: {the vehicles being airscrew driven} - 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) - F05D 2260/4031: as in toothed gearing - Y02T 50/60: Efficient propulsion technologies, e.g. for aircraft - 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) - 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 A propulsion system is provided for an aircraft. This propulsion system includes a geartrain, a propulsor rotor, a turbine engine core, an electric machine and an accessory gearbox system. The propulsor rotor is disposed to a first side of the geartrain. The turbine engine core is disposed to a second side of the geartrain. The turbine engine core is operatively coupled to the propulsor rotor through the geartrain. The electric machine is disposed to the second side of the geartrain. The electric machine is operatively coupled to the propulsor rotor and/or the turbine engine core through the geartrain. The accessory gearbox system is operatively coupled to the turbine engine core. The accessory gearbox system is circumferentially offset from the electric machine about a centerline axis of the turbine engine core. The accessory gearbox system axially overlaps the electric machine along the centerline axis of the turbine engine core. ## Claims ### Claim 1 A propulsion system for an aircraft, comprising: a geartrain; a propulsor rotor disposed to a first side of the geartrain; a turbine engine core disposed to a second side of the geartrain, the turbine engine core operatively coupled to the propulsor rotor through the geartrain; an electric machine disposed to the second side of the geartrain, the electric machine operatively coupled to at least one of the propulsor rotor or the turbine engine core through the geartrain; and an accessory gearbox system operatively coupled to the turbine engine core, the accessory gearbox system circumferentially offset from the electric machine about a centerline axis of the turbine engine core, and the accessory gearbox system axially overlapping the electric machine along the centerline axis of the turbine engine core; wherein the accessory gearbox system comprises an accessory gearbox and an engine accessory mounted to an axially forward side of the accessory gearbox; and wherein an entirety of the electric machine is disposed axially between the geartrain and an aft end of the accessory gearbox system. ### Claim 2 (depends on 1) The propulsion system of claim 1, wherein the electric machine and the accessory gearbox system are disposed to opposing sides of the turbine engine core. ### Claim 3 (depends on 1) The propulsion system of claim 1, wherein a center of the accessory gearbox system is spaced circumferentially from a center of the electric machine between thirty degrees and one-hundred and eighty degrees about the centerline axis of the turbine engine core. ### Claim 4 (depends on 1) The propulsion system of claim 1, wherein the electric machine is disposed vertically above the turbine engine core. ### Claim 5 (depends on 4) The propulsion system of claim 4, wherein the accessory gearbox system is disposed vertically below the turbine engine core. ### Claim 6 (depends on 4) The propulsion system of claim 4, wherein the accessory gearbox system is disposed to a horizontal side of the turbine engine core. ### Claim 7 (depends on 1) The propulsion system of claim 1, wherein the accessory gearbox system is circumferentially aligned with an airflow inlet into the propulsion system. ### Claim 8 (depends on 7) The propulsion system of claim 7, wherein the accessory gearbox system is coupled to the first rotating structure through a tower shaft, the tower shaft is circumferentially aligned with a lateral midpoint of the airflow inlet at a vane arrangement having a plurality of vanes, and a first vane of the plurality of vanes aligned with the lateral midpoint is sized larger than remaining vanes of the plurality of vanes to accommodate the tower shaft. ### Claim 9 (depends on 1) The propulsion system of claim 1, wherein the electric machine is configurable at least as an electric motor. ### Claim 10 (depends on 1) The propulsion system of claim 1, wherein the electric machine is configurable at least as an electric generator. ### Claim 11 (depends on 1) The propulsion system of claim 1, wherein the accessory gearbox operatively couples the engine accessory to the turbine engine core. ### Claim 12 (depends on 1) The propulsion system of claim 1, wherein the turbine engine core comprises a first rotating structure; the first rotating structure includes a first structure compressor rotor and a first structure turbine rotor; and the accessory gearbox system is coupled to the first rotating structure through a tower shaft. ### Claim 13 (depends on 12) The propulsion system of claim 12, wherein the turbine engine core further comprises a second rotating structure; the second rotating structure includes a second structure turbine rotor; and the second rotating structure is operatively coupled to the propulsor rotor through the geartrain. ### Claim 14 (depends on 13) The propulsion system of claim 13, wherein the second rotating structure further includes a second structure compressor rotor; and the tower shaft is disposed axially between the first structure compressor rotor and the second structure compressor rotor. ### Claim 15 (depends on 13) The propulsion system of claim 13, wherein the turbine engine core further comprises a third rotating structure; and the third rotating structure includes a third structure compressor rotor and a third structure turbine rotor. ### Claim 16 (depends on 1) The propulsion system of claim 1, wherein a rotational axis of the propulsor rotor is offset from the centerline axis of the turbine engine core. ### Claim 17 (depends on 1) The propulsion system of claim 1, wherein the propulsor rotor is an open propulsor rotor.