Compressed air supplying device for engine

The utility model provides a compressed air supplying device comprising a casing, a motor and a blade. The compressed air supplying device is characterized in that the blade is arranged in the casing and is fixed on a moror shaft, and a power cord of the motor is connected with an engine power, and the casing is connected in series and fixed on a suction manifold. When the compressed air supplying device switches the engine power, the motor of the utility model starts to work and drives the blade to rotate to press the air into the suction manifold, and the air in the suction manifold forms a definite pressure. When an air control shutter opens, the compressed air can enter the engine to make the engine obtain enough air, so the combustion is more sufficient, the oil consumption is decreased and the exhaust pollution is reduced. The compressed air supplying device can change the original mode that the engine absorbs the air into mode that the engine provides enough compressed air, and the compressed air supplying device changes the air feeding mode of the engine and completely solves the problem that the engine air supplying is insufficient. The compressed air supplying device also overcome the defect that the compressed air supplying device is inoperative adopting a turbocharger in low speed and influences the engine performance.