Internal combustion engine with variable compression ratio and integrated setting actuator

Pistons, each having an upper dead center position, are accommodated for reciprocating motion in respective cylinders. The upper dead center position of each piston is altered to vary engine compression ratio by setting drive for turning setting shaft (11) to adjust angular position of eccentric rings (3) to radially shift crankshaft axis (13). The cylinders are arranged in line in engine block. Ring bearings (4) support the eccentric rings in engine block to rotate along the ring axis. Crankshaft bearings (2) support and carry a crankshaft (1) in respective eccentric rings to rotate along the crankshaft axis radially spaced from the ring axis. Connecting rods couple each piston to the crankshaft. A setting arm (8) is secured to and projects from the eccentric rings A toothed component (9) is carried by the setting arm. The setting shaft is rotatably supported on engine block and oriented parallel to the crankshaft. A pinion component (10) has a first pinion, a second pinion, and a resilient connecting unit. The first pinion is secured to the setting shaft and meshes with the toothed component. The second pinion rotates relative to the first pinion, and meshes with the toothed component. The connecting unit couples the first and second pinions, and resists the relative rotation of the pinions. A resilient torque biases the pinions toward each other.