Patent ID: 8397684

Claim:
A variable compression ratio apparatus which is mounted at an engine receiving combustion force of an air-fuel mixture from a piston and rotating a crankshaft, and which changes compression ratio of the air-fuel mixture, the variable compression ratio apparatus comprising: a connecting rod having a mounting hole formed at one end thereof, the one end being rotatably connected to the piston through a piston pin inserted in the mounting hole and the other end being eccentrically and rotatably connected to the crankshaft; an eccentric bearing link having one end concentrically and rotatably mounted in the mounting hole and the other end, the piston pin being eccentrically and rotatably mounted in the one end of the eccentric bearing link; a control link having both ends and a middle portion, the one end being rotatably connected to the other end of the eccentric bearing link; a first shake link having both ends, the one end being rotatably connected to the middle portion of the control link; a second shake link having both ends, the one end being rotatably connected to the other end of the control link; and a control shaft eccentrically connected to a first eccentric cam rotatably connected to the other end of the first shake link and a second eccentric cam rotatably connected to the other end of the second shake link respectively, and rotating together with the first and second eccentric cams.