# US 12,601,276 B2 · High efficiency aircraft parallel hybrid gas turbine electric propulsion system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,601,276 B2 - Document ID: US12601276B2 - Status: Granted - Kind: B2 - Application number: 15/200,128 - Filed: 2016-07-01 - Published: 2018-01-04 - Granted: 2026-04-14 - Earliest claimed: 2016-07-01 - Assignees: Rtx Corporation - Applicants: RTX Corporation - Inventors: Charles E. Lents; Christopher J. Hanlon; Larry W. Hardin; Jonathan Rheaume - Web page: https://patentgrep.com/patent/US12601276B2 ## CPC - F01D 15/10: Adaptations for driving, or combinations with, electric generators - B64D 27/10: of gas-turbine type (jet aircraft B64D27/16) - B64D 27/35: Arrangements for on-board electric energy production, distribution, recovery or storage - B64D 41/00: Power installations for auxiliary purposes - F02C 6/14: Gas-turbine plants having means for storing energy, e.g. for meeting peak loads - 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) - B64D 27/33: Hybrid electric aircraft - F05D 2220/76: an electrical generator - F05D 2240/60: Shafts - Y02T 50/60: Efficient propulsion technologies, e.g. for aircraft - F01D: NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES (machines or engines for liquids F03; non-positive displacement pumps F04D) - B64D: EQUIPMENT FOR FITTING IN OR TO AIRCRAFT; FLIGHT SUITS; PARACHUTES; ARRANGEMENT OR MOUNTING OF POWER PLANTS OR PROPULSION TRANSMISSIONS IN AIRCRAFT - 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 gas turbine engine includes a compressor section having a first compressor and a second compressor, the second compressor having a higher pressure than the first compressor, and a turbine section having a first turbine and a second turbine, the second turbine having a higher pressure than the first turbine. The first compressor is connected to the first turbine via a first shaft. The second compressor is connected to the second turbine via a second shaft. An electric motor is connected to the first shaft such that rotational energy generated by the electric motor is translated to the first shaft. A fan is connected to the first shaft via a gear system. The gas turbine engine includes at least a takeoff mode of operations, a top of climb mode of operations and a maximum cruise mode of operations. The gas turbine engine is sized to operate at peak efficiency in the maximum cruise mode of operations. ## Claims ### Claim 1 An aircraft including a gas turbine engine comprising: a core including a compressor section having a first compressor and a second compressor, the second compressor having a higher pressure than the first compressor, a turbine section having a first turbine and a second turbine, the second turbine having a higher pressure than the first turbine, the first compressor is connected to the first turbine via a first shaft, the second compressor is connected to the second turbine via a second shaft; an electric motor connected to the first shaft such that rotational energy generated by the electric motor is translated to the first shaft, the electric motor being connected to an on-board energy storage device such that the electric motor is capable of generating rotation using the electric power from the on-board energy storage device during takeoff; a fan connected to the first shaft via a gear system and the gear system is configured to translate a combined power from the first turbine and the electric motor to the fan to provide thrust for takeoff; and wherein the gas turbine engine includes at least a takeoff mode of operations, a top of climb mode of operations and a maximum cruise mode of operations; the gas turbine engine being configured to operate at a maximum allowable inlet temperature of the second turbine while operating in said maximum cruise mode of operations, the inlet temperature of the second turbine corresponding to a thrust output of the core; wherein an aircraft thrust requirement on the gas turbine engine in at least one of the takeoff mode of operations and the top of climb mode of operations is higher than a thrust requirement in the maximum cruise mode of operations; and wherein the engine core has insufficient available thrust to complete a takeoff mode of operations due to being configured to operate at the maximum inlet temperature of the second turbine in said maximum cruise mode of operations. ### Claim 2 (depends on 1) The aircraft of claim 1, wherein the electric motor is a motor/generator. ### Claim 3 (depends on 1) The aircraft of claim 1, wherein the electric motor is connected to the first shaft via a towershaft. ### Claim 4 (depends on 1) The aircraft of claim 1, further comprising a fan section forward of the first compressor, the fan section including the fan. ### Claim 5 (depends on 1) The aircraft of claim 1, wherein a geometry of the gas turbine engine is physically sized such that a turbine inlet temperature of the second turbine is at a maximum while said engine is in said maximum cruise mode of operations. ### Claim 6 (depends on 1) The aircraft of claim 1, wherein a flow rate through the gas turbine engine is configured to be controlled by a controller such that the turbine inlet temperature of the second turbine is at a maximum while said engine is in said maximum cruise mode of operations. ### Claim 7 (depends on 1) The aircraft of claim 1, wherein the electric motor is configured to provide rotational input power to the first shaft during at least one of the takeoff mode of operations and the top of climb mode of operations. ### Claim 8 (depends on 7) The aircraft of claim 7, wherein the electric motor is configured to provide rotational input power to the first shaft during each of the takeoff mode of operations and the top of climb mode of operations.