Patent ID: 8646420
Filing Date: 2014-02-11
Classification: F02B,F02D

Abstract:
1. A variable compression ratio apparatus that is mounted at an engine receiving combustion force of air-fuel mixture from a piston and driving a vehicle, and that changes compression ratio of the air-fuel mixture, the variable compression ratio apparatus comprising: a cylinder block having a cylinder formed at an upper portion thereof and a mounting hole formed at a side surface thereof; a connecting rod, one end of which is pivotally connected to the piston to receive the combustion force from the piston; a crankshaft provided with a central axis, a bearing seat coaxially disposed with the central axis, and a crank pin formed in a crank arm connecting the bearing seat with the central axis of the crank pin eccentrically, wherein the crank pin is rotatably connected to the other end of the connecting rod so as to receive the combustion force; an eccentric bearing provided with a bearing central axis and a crank mounting hole formed eccentrically to the bearing central axis, the eccentric bearing being rotatably mounted in the mounting hole of the cylinder block and the crank mounting hole of the eccentric bearing being rotatably coupled to the bearing seat which is rotatably inserted in the crank mounting hole, wherein the eccentric bearing changes the compression ratio of the air-fuel mixture by controlling a distance between the central axis of the crankshaft and a combustion chamber of the engine according to driving condition of the vehicle; and a control rod rotatably connected to a circumferential portion of the eccentric bearing which deviates from the bearing central axis with a predetermined distance so as to control an angular displacement of the eccentric bearing according to the driving condition of the vehicle; wherein one end of the control rod is rotatably connected to the circumferential portion of the eccentric bearing which deviates from the bearing central axis, and the other end of the control rod is eccentrically and rotatably connected to a control cam rotating according to the driving condition of the vehicle.