Like as Figure 1-2(a) it is composed of the rotor made as eccentric shape at inside of cylinder the slide pin the exhaustion valve and the front back cover. As the rotor rotates the air is inhaled into the cylinder through the suction port.
This process continues till Figure (4) and the air compression is started as passing the state of Figure(4) (Figure(5)).
After the complete compression (about over 850 Torr) the compressed air is extruded through the exhaustion valve.