# US 9,039,567 B2 · Device with multiple reduction gear transmission between a drive shaft and a pair of propellers coaxial with this shaft > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,039,567 B2 - Document ID: US9039567B2 - Status: Granted - Kind: B2 - Application number: 14/321,956 - Filed: 2014-07-02 - Published: 2015-01-08 - Granted: 2015-05-26 - Earliest claimed: 2013-07-03 - Assignees: Snecma - Applicants: Snecma - Inventors: Adrien Jacques Philippe Fabre - Web page: https://patentgrep.com/patent/US9039567B2 ## CPC - B64D 35/04: characterised by the transmission driving a plurality of propellers or rotors - B64D 35/06: the propellers or rotors being counter-rotating - F02C 3/067: having counter-rotating rotors (F02C3/073 takes precedence) - F02C 3/107: with two or more rotors connected by power transmission - F02C 7/06: Arrangements of bearings (bearings F16C); Lubricating ({of turbo machines F01D25/18; of machines or} engines in general F01M) - 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) - F16H 1/46: Systems consisting of a plurality of gear trains each with orbital gears, {i.e. systems having three or more central gears} - F16H 37/0813: {with only one input shaft} - B64D 2027/005: {Aircraft with an unducted turbofan comprising contra-rotating rotors, e.g. contra-rotating open rotors [CROR]} - F05D 2220/325: to drive unshrouded, high solidity propeller - F05D 2240/40: Use of a multiplicity of similar components - F05D 2260/40311: of the epicyclical, planetary or differential type - 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 - 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) - F16H: GEARING - 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 transmission to drive two propellers through a single shaft comprises several, generally three planetary gear systems, each of which comprises one principal element directly supported on fixed surrounding structures that resist cantilever forces, support the rotating bodies and carry fluid and electrical cable ducts to control the operation of the downstream propeller elsewhere than through the central shaft of the machine in which the volume is reduced. ## Claims ### Claim 1 Aircraft propulsion device comprising a drive shaft, a pair of propellers coaxial with the drive shaft, and a transmission between the drive shaft and the pair of propellers, the transmission including a planetary gearing speed reduction device for the drive shaft, the reduction device comprising a plurality of planetary gear systems each comprising a toothed sun gear, a toothed ring gear and toothed planet gears mounted on a planet gear carrier and each engaged with the sun gear and the ring gear, the sun gear, the ring gear and the planet gear carrier forming three principal elements of each planetary gear system, one of the principal elements of two of the planetary gear systems being fixed to one of the propellers, wherein there are three planetary gear systems, one of the principal elements of a first of said three planetary gear systems is fixed to the drive shaft, a second and a third of said three planetary gear systems comprise the principal elements fixed to the propellers, and one of the principal elements of each of the planetary gear systems is fixed to a fixed structure surrounding the drive shaft. ### Claim 2 (depends on 1) Device according to claim 1, wherein the elements fixed to the fixed structure are the planet gear carrier in the first planetary gear system, the planet gear carrier in the second planetary gear system and the ring gear in the third planetary gear system. ### Claim 3 (depends on 2) Device according to claim 2, wherein the ring gear in the first planetary gear system, the sun gear in the second planetary gear system and the sun gear in the third planetary gear system are fixed to each other and form a rotating assembly. ### Claim 4 (depends on 1) Device according to claim 1, wherein the principal elements fixed to the fixed structure are the ring gear in the first planetary gear system, the planet gear carrier in the second planetary gear system and the ring gear in the third planetary gear system. ### Claim 5 (depends on 2) Device according to claim 2, wherein the principal elements fixed to the propellers are the ring gear in the second planetary gear system and the planet gear carrier in the third planetary gear system. ### Claim 6 (depends on 1) Device according to claim 1, wherein the principal elements fixed to the fixed structure are the ring gear in the first planetary gear system, the planet gear carrier in the second planetary gear system and the planet gear carrier in the third planetary gear system. ### Claim 7 (depends on 4) Device according to claim 4, wherein in that the planet gear carrier in the first planetary gear system, the sun gear (35) in the second planetary gear system and the sun gear in the third planetary gear system are fixed to each other and form a rotating assembly. ### Claim 8 (depends on 6) Device according to claim 6, wherein the principal elements fixed to the propellers are the ring gear in the second planetary gear system and the ring gear in the third planetary gear system. ### Claim 9 (depends on 1) Device according to claim 1, wherein it comprises propeller control modules, and networks for supplying said modules, said networks extending along said fixed structure. ### Claim 10 (depends on 9) Device according to claim 9, wherein propeller control modules are placed adjacent to each other on the fixed structure. ### Claim 11 (depends on 4) Device according to claim 4, wherein the principal elements fixed to the propellers are the ring gear in the second planetary gear system and the planet gear carrier in the third planetary gear system. ### Claim 12 (depends on 6) Device according to claim 6, wherein the planet gear carrier in the first planetary gear system, the sun gear in the second planetary gear system and the sun gear in the third planetary gear system are fixed to each other and form a rotating assembly.