Internal combustion engine (20) with
variable compression ratio (VCR) having a compression
stroke and an expansion
stroke, wherein the
internal combustion engine (20) comprises the following: an engine block (22) that defines a cylinder (30); a
cylinder head (26) mounted on the engine block (22) which defines at least part of a
combustion chamber (30); a reciprocating
piston (28) arranged and configured within the cylinder (30) to compress a mixture of air and fuel and to absorb
combustion power, wherein the compression
stroke of the
piston (28) defines a
compression ratio of the
internal combustion engine (20); and a six-rod linkage mechanism (48) configured to functionally connect the
piston (28) to the engine block (22), to articulate on seven different parallel axes (X1, ..., X7), to decouple the compression stroke from the expansion stroke such that the length of the compression stroke does not coincide with the length of the expansion stroke, and to continuously and selectively change the compression stroke of the piston (28) and the
compression ratio of the
internal combustion engine (20), wherein the six-rod linkage mechanism (48) comprises the following: a primary
crankshaft (50) which can be rotated about a first axis (X1) via the
combustion force absorbed by the piston (28); a connecting rod (52) which is pivotably connected to the piston (28) on a second axis (X2); a multi-rod linkage (58) rotatably connected to the connecting rod (52) on a third axis (X3) and to the primary
crankshaft (50) on a fourth axis (X4); a control linkage (56) which is pivotably connected to the multi-rod linkage (58) on a fifth axis (X5); a control
crankshaft (54) arranged in the engine block (22), connected to the control linkage (56) on a sixth axis (X6) and configured to rotate about a seventh axis (X7), so that the rotation of the control crankshaft (54) regulates the stroke of the piston (28) and thereby continuously changes the
compression ratio of the internal combustion engine (20); a phase-adjusting device (60) designed as a
stepper motor, configured to control a position of the control crankshaft (54) with respect to both the engine block (22) and the primary crankshaft (50), thereby controlling a position of the fifth axis (X5) with respect to the seventh axis (X7) and the third axis (X3) with respect to the first axis (X1); and a
torque transmission mechanism (62) configured to connect the control crankshaft (54) to the primary crankshaft (50) for synchronized operation between them; characterized by the fact that the
torque transmission mechanism (62) has a gear coaxial with the first axis (X1) and a gear coaxial with the sixth axis (X6) and connects them to each other for driving purposes.