Independent compression and expansion ratio engine with variable compression ratio

An internal combustion engine comprising:

• an engine block defining a cylinder bore;
• a piston slideably supported within the cylinder bore in a reciprocating motion through a compression stroke having a compression stroke length, and an expansion stroke having an expansion stroke length;
• a crankshaft rotatably supported by the engine block and rotatable about a crank axis;
• a control shaft rotatably supported by the engine block and rotatable about a control axis, wherein the control axis is laterally offset from the crank axis;
• a link rod rotatably connected to the crankshaft;
• a lower connecting rod rotatably connected to the link rod and the control shaft;
• and
• an upper connecting rod rotatably connected to the link rod and the piston;
• wherein rotational movement of the control shaft about the control axis rotates the second end of the lower connecting rod about the control axis to adjust the compression stroke length of the piston within the bore during the compression stroke of the piston.

An internal combustion engine comprising:

• an engine block defining a cylinder bore;
• a piston slideably supported within the cylinder bore;
• a crankshaft rotatably supported by the engine block and rotatable about a crank axis;
• a link rod rotatably connected to the crankshaft;
• a lower connecting rod having a first end rotatably connected to the link rod, and a second end moveably coupled to the engine block;
• an upper connecting rod having a first end rotatably connected to the link rod, and a second end rotatably connected to the piston;
• and
• an actuator coupled to the lower connecting rod and operable to move the lower connecting rod relative to the crankshaft to adjust a compression stroke length of the piston within the bore during a compression stroke of the piston.