Four-stroke Engine

A four-stroke engine, characterized by including

• a cylinder, setup with a main chamber therein, wherein the main chamber includes a combustion chamber and a crankshaft chamber connected to each other;
• said combustion chamber is setup with an intake passage and an exhaust passage, an intake valve component for controlling communication or cut-off of its gas path is set at the joint where said intake passage and said combustion chamber are connected, and an exhaust valve component for controlling communication or cut-off of its gas path is set at the joint where said exhaust passage and said combustion chamber are connected;
• a plunger is mounted in said combustion chamber, a crankshaft component is mounted in said crankshaft chamber, said plunger is connected with the crankshaft component and drive it to move, and said crankshaft component outputs torque externally;
• an one-way valve chamber, which is set under said crankshaft chamber and connected with the crankshaft chamber, wherein an one-way valve is set between said crankshaft chamber and said one-way valve chamber, and said one-way valve opens upon positive pressure of the crankshaft chamber and closes upon negative pressure of the crankshaft chamber;
• a carburetor, which is used for providing mixed oil and gas to the combustion chamber, wherein said mixed oil and gas goes into the combustion chamber through the intake passage;
• an ignition unit, which is used for igniting the mixed oil and gas in the combustion chamber, wherein the ignition unit is mounted on the cylinder;
• a rocker chamber set outside said cylinder, which accommodates said intake valve component, exhaust valve component as well as the upper rocker;
• a cam chamber set outside said cylinder, wherein a timing gear and a cam gear component are set therein;
• said timing gear is linked with the crankshaft component and then drives the cam gear component, said cam gear component drives said intake valve component and said exhaust valve component through the upper rocker;
• a mixed oil and gas lubrication passage set between said intake passage and said crankshaft chamber, wherein the mixed oil and gas lubrication passage opens upon negative pressure of the crankshaft chamber and closes upon positive pressure;
• said one-way valve chamber is communicated with said cam chamber, said cam chamber is communicated with the rocker chamber, said rocker chamber is communicated with the intake passage through the oil and gas passage.