Patent ID: 8555829

Claim:
A variable compression ratio apparatus for an engine receiving combustion force of an air-fuel mixture from a piston and a rotating crankshaft, and which changes compression ratio of the air-fuel mixture, the variable compression ratio apparatus comprising: a connecting rod including one end formed with a mounting hole and an other end eccentrically and rotatably connected to the crankshaft, wherein a piston pin is inserted in the mounting hole and the one end of the connecting rod is rotatably connected to the piston through the piston pin; an eccentric link including one end connected to an eccentric bearing concentrically and rotatably mounted in the mounting hole and an other end, the piston pin being eccentrically and rotatably mounted in the eccentric bearing; a variable link including one end rotatably connected to the other end of the eccentric link, and including an other end; a variable gear link configured to pivot with respect to a fixed shaft and including a first gear teeth at an exterior circumference thereof, an external circumferential portion thereof being rotatably connected to the other end of the variable link; a control shaft including a second gear teeth engaged to the first gear teeth at an exterior circumference thereof and rotating so as to pivot the variable gear link; and a guide bar, together with the connecting rod, limiting horizontal movement of the eccentric link.