# US 2020/0318534 A1 · Bearing guide device of a combustion piston for a variable compression ratio engine > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2020/0318534 A1 - Document ID: US20200318534A1 - Status: Published application - Kind: A1 - Application number: 16/303,289 - Filed: 2017-05-16 - Published: 2020-10-08 - Earliest claimed: 2016-05-24 - Assignees: MCE 5 Development; Vianney Rabhi - Applicants: MCE 5 Development - Inventors: Sylvain Bigot; Maxence Pister - Web page: https://patentgrep.com/patent/US20200318534A1 ## CPC - F01B 9/047: {with rack and pinion} - F02B 75/04: Engines with variable distances between pistons at top dead-centre positions and cylinder heads - F02B 75/045: {by means of a variable connecting rod length} - F02D 15/02: by alteration or displacement of piston stroke - 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) - F02B: INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL (gas-turbine plants F02C; hot-gas or combustion-product positive-displacement engine plants F02G) - F02D: CONTROLLING COMBUSTION ENGINES (vehicle fittings, acting on a single sub-unit only, for automatically controlling vehicle speed B60K31/00; conjoint control of vehicle sub-units of different type or different function, road vehicle drive control systems for purposes other than the control of a single sub-unit B60W) ## Abstract A bearing guide device of a combustion piston for a variable compression ratio engine. The movement of the combustion piston from a top dead center to a bottom dead center drives the movement of a synchronized roller made up of a cylindrical body and a pinion from a first position to a second position relative to first and second racks. According to the disclosure, the first and/or second racks have a different circular pitch than the pinion so that the flanks of the teeth of the pinion engage with the flanks of the teeth of the first and second racks only when the pinion is in the first or second position. ## Claims ### Claim 1 A bearing guide device of a combustion piston for a variable compression ratio engine, the device comprising: a synchronized roller comprising a cylindrical body and a pinion, the cylindrical body having an effective diameter that can vary as a result of a radial load when the engine is running, the synchronized roller cooperating with: a synchronization plate forming one piece with the engine block and comprising a first raceway for receiving the cylindrical body and a first rack for receiving the pinion; and a transmission unit forming one piece with the combustion piston and comprising a second raceway for receiving the cylindrical body and a second rack for receiving the pinion; wherein moving the combustion piston from a top dead center to a bottom dead center causes the pinion to move from a first position to a second position in relation to the first and second racks, wherein the first rack and/or the second rack has a different circular pitch from the circular pitch of the pinion so that the flanks of the teeth of the pinion engage on the flanks of the teeth of the first rack and/or second rack only when the pinion is in the first or second position. ### Claim 2 (depends on 1) The bearing guide device of claim 1, wherein the effective diameter of the cylindrical body is always smaller or always greater than the pitch diameter of the pinion when the engine is running. ### Claim 3 (depends on 2) The bearing guide device of claim 2, wherein the effective diameter of the cylindrical body is always smaller than the pitch diameter of the pinion when the engine is running, and the first rack and/or the second rack has a smaller circular pitch than the circular pitch of the pinion. ### Claim 4 (depends on 3) The bearing guide device of claim 3, wherein the first rack has a smaller circular pitch than the circular pitch pinion, the second rack has a circular pitch that is equal to the circular pitch of the pinion, and a gap between two teeth of the second rack is bigger than a thickness of a pinion tooth. ### Claim 5 (depends on 3) The bearing guide device of claim 3, wherein the first rack and the second rack have a circular pitch that is smaller than the circular pitch of the pinion. ### Claim 6 (depends on 2) The bearing guide device of claim 2, wherein the effective diameter of the cylindrical body is always larger than the pitch diameter of the pinion when the engine is running, and the first rack and/or the second rack has a bigger circular pitch than the circular pitch of the pinion. ### Claim 7 (depends on 6) The bearing guide device of claim 6, wherein the second rack has a bigger circular pitch than the circular pitch of the pinion, wherein the first rack has a circular pitch that is equal to the circular pitch of the pinion, and wherein the width of the gullet of the teeth of the first rack is bigger than the thickness of a tooth. ### Claim 8 (depends on 6) The bearing guide device of claim 6, wherein the first rack and the second rack have a circular pitch that is bigger than the circular pitch of the pinion. ### Claim 9 (depends on 1) The bearing guide device of claim 1, wherein the cylindrical body has a curved profile. ### Claim 10 (depends on 1) The bearing guide device of claim 1, wherein the effective diameter of the cylindrical body is always smaller than the pitch diameter of the pinion when the engine is running, and the first rack and/or the second rack has a smaller circular pitch than the circular pitch of the pinion. ### Claim 11 (depends on 1) The bearing guide device of claim 1, wherein the effective diameter of the cylindrical body is always larger than the pitch diameter of the pinion when the engine is running and wherein the first rack and/or the second rack has a bigger circular pitch than the circular pitch of the pinion.