An engine oil circulation and drainage device of an air compressor

The invention relates to an engine oil circulation and drainage device of an air compressor, comprises an air compressor 1, a vent pipe 4a and a gas tank 2 and is characterized in that air vented by the air compressor 1 is directly guided into the gas tank 2 through the vent pipe 4a, which means the gas tank 2 serves as an oil and gas separator; a built-in oil and gas separator 9 is arranged between the gas tank 2 and an air supply valve 6 in order to get cleaner air supply and an air-off automatic oil return valve is distributed on the built-in oil and gas separator 9; besides, an oil water trap 10 is arranged and oil and water separated from the gas tank 2 are guided out through an oil guide pipe 5b and go into the oil water trap 10 and return to the air compressor 1 through an oil suction pipe 10d, a control valve 12 and an oil return pipe 5a. Finally, a drain valve 8b and a visualized oil water observer 11 are also arranged on the oil water trap 10 for the convenience of drainage operation and observation