Compact air compressor

A compact air compressor, comprising:

• an air tank, a casing disposed on a top of the air tank, and a motor, a fan, a driving wheel, a driven wheel, a transmission belt, a cam, and a cylinder that are located in the casing, wherein
• the fan is disposed on a first output shaft of the motor;
• the driving wheel is disposed on a second output shaft of the motor;
• a plurality of blades are disposed on the driving wheel;
• the driven wheel is disposed on a connecting shaft that is connected to the cam;
• a central shaft on the cam extends into a pivot hole at a free end of a piston rod of the cylinder;
• a bearing is disposed at an end of the central shaft on the cam;
• through contact between the bearing and an interior of the pivot hole of the piston rod, the piston rod is driven to move back and forth;
• an extension portion perpendicular to the cylinder is disposed on a cylinder mounting seat;
• an inner side of the extension portion is arc-shaped to accommodate the driving wheel;
• a plurality of grooves are formed at an end of the extension portion to serve as an air inlet passage;
• corresponding locating holes are respectively formed in a motor mounting seat and the extension portion of the cylinder mounting seat;
• the driving wheel is inserted into the extension portion, and connected by a threaded rod penetrating through the locating hole in the motor mounting seat and the locating hole in the extension portion as well as a nut;
• an external extension portion extending circumferentially relative to an arc-shaped inner side of the extension portion is disposed at an outer side of the extension portion;
• an air vent is formed in the external extension portion;
• the driven wheel is in transmission connection with the driving wheel through the transmission belt;
• an air outlet of the cylinder communicates with the air tank through an air inlet tube and a one-way valve;
• the air tank communicates with an air outlet connector through an air outlet tube;
• and a first pressure gauge and a second pressure gauge that are respectively configured to detect an air pressure in the air tank and an air outlet pressure are disposed at the air outlet connector.