Variable compression ratio apparatus

Abstract

A variable compression ratio apparatus for an engine receiving combustion force of an air-fuel mixture from a piston and rotating a crankshaft, and for changing compression ratio of the air-fuel mixture. The apparatus may include a connecting rod including one end with a mounting hole and an other end eccentrically and rotatably connected to the crankshaft, an eccentric link including one end connected to an eccentric bearing concentrically and rotatably mounted in the mounting hole, a piston pin eccentrically and rotatably mounted in the eccentric bearing, a variable link including one end rotatably connected to an other end of the eccentric link, a variable gear link pivoting with respect to a fixed shaft and formed of first gear teeth at an exterior circumference, an external circumferential portion rotatably connected to an other end of the variable link, a control shaft including second gear teeth engaged to the first gear teeth and rotating to pivot the variable gear link, and a guide bar, together with the connecting rod, limiting horizontal movement of the eccentric link.