Patent attributes
Disclosed is a lubrication device for a four-stroke engine, including three independent spaces which are crank room, cam room and lubricant room. A chamber is in communication with the three spaces respectively. A suction path assembly is located in the lubricant room and a plurality of suction holes are defined in the path assembly. An air inlet is defined in the suction path assembly. When the piston moves upward, the crank room is in a negative pressure status so as to suck air via the suction path assembly which is in communication with the crank room and the lubricant room by the chamber. The air flows fast in the suction path assembly and generates lower pressure so as to suck the lubrication oil which is then moisturized and sent into the crank room. When the piston moves downward, the crank room and the cam room are in communication with each other and the lubrication oil is sent into the cam room.