An internal combustion engine including variable compression ratio and a method of operating the engine

• Main Authors: WAGENAAR, SANDER, WAGENVOORT, WILLEM-CONSTANT, DE GOOIJER, LAMBERTUS HENDRIK
• Format: Patent
• Language: English; French; German
• Published: 12.08.2015
• Subjects: BLASTING; COMBUSTION ENGINES; COMBUSTION ENGINES IN GENERAL; ENGINEERING ELEMENTS AND UNITS; GEARING; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVEFUNCTIONING OF MACHINES OR INSTALLATIONS; HEATING; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS; INTERNAL-COMBUSTION PISTON ENGINES; LIGHTING; MECHANICAL ENGINEERING; THERMAL INSULATION IN GENERAL; WEAPONS

An internal combustion engine (1) including variable compression ratio comprises a crankcase, a crankshaft (3) including a crankshaft axis (4), wherein the crankshaft (3) has at least a central main portion (5), a crankpin (6) and a crankshaft web (7) located between the central main portion (5) and the crankpin (6). The crankshaft (3) is supported by the crankcase and rotatable with respect thereto about the crankshaft axis (4). The engine comprises at least a connecting rod including a big end and a small end, a piston being rotatably connected to the small end, and a crank member (8) which is rotatably mounted on the crankpin (6), and comprises at least a bearing portion which is eccentrically disposed with respect to the crankpin (6), and has an outer circumferential wall which bears the big end of the connecting rod such that the connecting rod is rotatably mounted on the bearing portion of the crank member (8) via the big end. The engine also comprises a driving mechanism (2) for rotating the crank member (8) with respect to the crankshaft (3), which comprises a drive shaft (9) that extends concentrically through the central main portion (5). The drive shaft (9) is drivably coupled to the crank member (8) via a transmission (10) at a side of the crankshaft web (7) where the crankpin (6) is located. At the opposite side of the crankshaft web (7) the drive shaft (9) is drivably coupled to the crankshaft (3) via an external satellite gear (13) that is rotatably mounted to the crankshaft (3) and rotatable with respect to the crankshaft (3) about a satellite axis extending parallel to the crankshaft axis (4). The satellite gear (13) meshes with an internal ring gear (14) having a centre line that coincides with the crankshaft axis (4) and with an external sun gear (15) that is fixed to the drive shaft (9). The driving mechanism (2) is adapted such that under operating conditions the crank member (8) rotates at a rotation frequency with respect to the crankcase which is half of that of the crankshaft (3).