# US 11,512,628 B2 · Transmission device of an engine, particularly for an engine with variable compression rate and/or variable displacement > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,512,628 B2 - Document ID: US11512628B2 - Status: Granted - Kind: B2 - Application number: 16/996,199 - Filed: 2020-08-18 - Published: 2020-12-03 - Granted: 2022-11-29 - Earliest claimed: 2014-12-12 - Assignees: Vianney Rabhi; MCE 5 Development - Applicants: MCE 5 Development; Vianney Rabhi - Inventors: Rodolphe Hugon; Sylvain Bigot; Matthieu Duchemin; Guillaume Delobre; Benoit Schwenck - Web page: https://patentgrep.com/patent/US11512628B2 ## CPC - F02B 75/045: {by means of a variable connecting rod length} - F02B 75/04: Engines with variable distances between pistons at top dead-centre positions and cylinder heads - F16C 7/023: {for piston engines, pumps or the like} - F16C 9/04: Connecting-rod bearings; Attachments thereof - F16H 19/04: comprising a rack - F16C 23/04: self-adjusting - F16C 2360/22: Internal combustion engines - F02B: INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL (gas-turbine plants F02C; hot-gas or combustion-product positive-displacement engine plants F02G) - F16C: SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS - F16H: GEARING ## Abstract A transmission device, particularly for an engine with variable compression rate and/or variable displacement, includes, in a cylinder housing: a combustion piston capable of moving in a combustion cylinder of the engine and secured to a transmission member; a gear engaging with a first rack of the transmission member and providing transmission of the movement between the combustion piston and a crankshaft of the engine; a connecting rod engaging, at a first end, with the gear and, at a second end, with the crankshaft; and a control member engaging with the gear and secured to a control piston. The combustion piston and the transmission member are slidably linked with the cylinder housing in a main direction. ## Claims ### Claim 1 A transmission device for an engine with a variable compression rate and/or a variable displacement, the transmission device comprising, in a cylinder housing: a combustion piston capable of moving along a main direction in a combustion cylinder of the engine and secured to a transmission member, the transmission member being engaged with a first connecting device supported by a wall of the cylinder housing configured to block any movement of the transmission member other than a translation in the main direction; a gear engaged with a first rack of the transmission member and with a rack of a control member secured to a control piston, the gear having a central hole wherein a bore opens for positioning a connecting rod head; wherein the gear presents a spacing between inner surfaces of the central hole and side faces of the connecting rod allowing for the translation in a longitudinal direction of the connecting rod head; and a connecting rod engaged, at a first end, in the central hole of the gear and linked, at a second end, with a crankshaft of the engine, the crankshaft defining a longitudinal direction; wherein the gear, the transmission member and the connecting rod are maintained in alignment with each other while the connecting rod head may translate in a longitudinal direction relative to the gear to make it possible to hold the connecting rod parallel to the main direction even when the connecting rod head is moved as a result of differential expansion of a crank shaft relative to the cylinder housing; and wherein the cylinder housing is provided by a body comprising a spherical portion in contact with a matching hole of the cylinder housing, with the body having, on the side opposite the spherical portion, a tab or a groove respectively engaging with a groove or a tab of the control member. ### Claim 2 (depends on 1) The transmission device according to claim 1, wherein the first connecting device is provided by a roller bearing on a plate of the cylinder housing and on the transmission member. ### Claim 3 (depends on 2) The transmission device according to claim 2, wherein the transmission member and the cylinder housing comprises a rib and a guide groove adapted to receive the rib, with one being arranged on the roller and the other one being arranged on the transmission member. ### Claim 4 (depends on 1) The transmission device according to claim 1, wherein the connecting rod head has a rod eye bore allowing for swiveling of the connecting rod in the central hole of the gear. ### Claim 5 (depends on 1) The transmission device according to claim 1, wherein a roll band of the gear is in contact with a raceway of the transmission member, bulging and U-shapes of which are engaged one in the other. ### Claim 6 (depends on 1) The transmission device according to claim 1, wherein a roll band of the gear is in contact with a raceway of the control member, bulging and U-shapes of which are engaged one in the other. ### Claim 7 (depends on 1) The transmission device according to claim 1, wherein a bearing surface of the control member contacts a surface of the cylinder housing, with one being cylindrical with a longitudinal axis, and the other one being flat. ### Claim 8 (depends on 1) The transmission device according to claim 1, wherein the cylinder housing is provided with a pressing device for compensating running clearances.