# US 10,309,301 B2 · Constant-volume combustion engine > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,309,301 B2 - Document ID: US10309301B2 - Status: Granted - Kind: B2 - Application number: 15/101,836 - Filed: 2014-12-03 - Published: 2016-11-17 - Granted: 2019-06-04 - Earliest claimed: 2013-12-06 - Assignees: Baustoffwerke Gebhart & Soehne GmbH & Co. KG - Applicants: Baustoffwerke Gebhart & Soehne GmbH & Co. KG - Inventors: Friedrich Gebhart; Richard Maier - Web page: https://patentgrep.com/patent/US10309301B2 ## CPC - F02B 75/04: Engines with variable distances between pistons at top dead-centre positions and cylinder heads - F01B 1/10: with more than one main shaft, e.g. coupled to common output shaft - F01B 9/042: {the connections comprising gear transmissions} - F02B 75/32: Engines characterised by connections between pistons and main shafts and not specific to preceding main groups - F01B 2009/045: {Planetary gearings} - F02B 75/065: {with double connecting rods or crankshafts} - F02B: INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL (gas-turbine plants F02C; hot-gas or combustion-product positive-displacement engine plants F02G) - F01B: MACHINES OR ENGINES, IN GENERAL OR OF POSITIVE-DISPLACEMENT TYPE, e.g. STEAM ENGINES (of rotary-piston or oscillating-piston type F01C; of non-positive-displacement type F01D; internal-combustion engines F02B; combustion-product engine plants F02G; machines or engines, other than of positive-displacement type, for liquids F03B; positive-displacement engines driven by liquids F03C; wind motors F03D; positive-displacement machines for liquids F04B; rotary-piston, or oscillating-piston, positive-displacement machines for liquids F04C) ## Abstract The invention relates to a constant-volume combustion engine (10; 110; 210), in particular a reciprocating engine for generating mechanical energy by the expansion of a gas or a hot gas from the combustion of a gas mixture or gas-fuel mixture, having at least one piston/cylinder unit, the piston (14; 114; 214) of which is connected to a piston rod (20; 120; 220), wherein said piston rod (20; 120; 220) is drivingly connected to at least two crankshafts (30, 40; 130, 140; 230a, 230b, 240), the first crankshaft (40; 140; 240) being mounted, such that it can rotate eccentrically, on the second crankshaft (30; 130; 230a, 230b), which is parallel thereto and is rotationally coupled thereto. ## Claims ### Claim 1 A constant-volume combustion engine, in particular a reciprocating piston engine for generating mechanical energy by way of expansion of a gas or a hot gas from the combustion of a gas mixture or gas/fuel mixture, having at least one piston/cylinder unit, the piston of which is connected to a piston rod, the piston rod being drive-connected to a first and a second crankshafts, wherein the first crankshaft is mounted eccentrically rotatably on the second crankshaft which is arranged parallel to it, and is rotationally coupled to said second crankshaft; wherein the first and the second crankshafts perform a sinusoidal rotational movement, and the piston rod, or at least an additional connecting part, is mounted rotatably with a first eccentricity (d1) on the first crankshaft, wherein the first crankshaft is mounted with a second eccentricity (d2) on the second crankshaft, the second eccentricity (d2) being between three and five times as great as the first eccentricity (d1), the crankshafts being arranged relative to one another in such a way that the amplitude of the sinusoidal curve of the rotational movement of the second crankshaft is between three and five times as great as the amplitude of the sinusoidal curve of the rotational movement of the first crankshaft. ### Claim 2 (depends on 1) The constant-volume combustion engine as claimed in claim 1, wherein the rotational coupling of the first crankshaft to the second crankshaft comprises at least two gearwheels. ### Claim 3 (depends on 1) The constant-volume combustion engine as claimed in claim 1, wherein the first and the second crankshafts move in opposite directions to one another. ### Claim 4 (depends on 1) The constant-volume combustion engine as claimed in claim 1, wherein the second crankshaft has at least one seating region for seating and rotatably mounting the first crankshaft. ### Claim 5 (depends on 4) The constant-volume combustion engine as claimed in claim 4, wherein the at least one additional connecting part can comprise a connecting rod and/or a lever. ### Claim 6 (depends on 1) The constant-volume combustion engine as claimed in claim 1, wherein the at least one additional connecting part can comprise a connecting rod and/or a lever. ### Claim 7 (depends on 1) The constant-volume combustion engine as claimed in claim 1, wherein the rotational coupling can comprise at least one planetary gear stage and two spur gears which roll on one another and which are each assigned to one of the crankshafts. ### Claim 8 (depends on 1) The constant-volume combustion engine as claimed in claim 1, wherein the rotational coupling of the first and second crankshafts has at least one planetary gear stage with at least one spur gear which rolls on at least one internal gear of the planetary gear stage, the spur gear or the internal gear of the at least one planetary gear stage being assigned to one of the crankshafts and the respectively other being assigned to the respectively other crankshaft. ### Claim 9 (depends on 1) A method of using a constant-volume combustion engine as claimed in claim 1 as a generator or for driving a generator, wherein the engine operates a heat and power cogeneration plant or charges the battery of a vehicle. ### Claim 10 A method for operating a combustion engine, in particular a reciprocating piston engine for generating mechanical energy by way of expansion of a gas or a hot gas from the combustion of the gas mixture or gas/fuel mixture, having at least one piston/cylinder unit, the piston of which is connected to a piston rod, the piston rod being drive-connected to and mounted rotatably with a first eccentricity (d1) on a first crankshaft, the first crankshaft being coupled to a second crankshaft, wherein the first crankshaft is mounted with a second eccentricity (d2) on the second crankshaft, the second eccentricity (d2) being between three and five times as great as the first eccentricity (d1) and wherein the rotational movements of the coupled crankshafts are superimposed in such a way that the resulting total movement generates, in at least one defined angular section, a substantially constant position of the piston rod and the piston which is connected to it in the piston/cylinder unit. ### Claim 11 (depends on 10) The method as claimed in claim 10, wherein the first and second crankshafts are coupled to one another via at least one connecting part, for example a connecting rod and/or a rocker, the connecting part being capable of transmitting the superimposed movement of the first and second crankshafts to the piston rod, and in that the crankshafts which are coupled to one another rotate relative to one another in the same direction and with a predefined rotational speed ratio. ### Claim 12 (depends on 10) The method as claimed in claim 10, wherein the defined angular section is assigned at least partially to the power or combustion stroke of the combustion engine.