Operating principle of oil-free vacuum pump
Its structure is the eccentric installation of the rotor to the cylinder block in the space surrounded by the cylinder block and the side end cover, and there is a gap between the rotor and the cylinder block. Several sliding plates are installed in the grooves on the surface of the rotor. When the sliding plates in the rotor are in contact with the cylinder wall under the action of centrifugal force.
The space enclosed by the sliding plate, rotor, cylinder block and side end cover changes with the rotation of the rotor. As shown in the figure, as it turns from ① to ②, its volume gradually increases, and the gas is sucked in under the action of atmospheric pressure difference. As it rotates from ② to ③, its volume gradually decreases, and the inhaled gas is compressed. When it changes from ③ to ④, the gas is discharged from the outside. With the continuous process, the air is transferred from the suction port to the exhaust port.
When the pump with four sliding blades rotates, it needs to carry out four suction and exhaust processes. When the large volume at the end of suction is V (L), the number of revolutions is (RPM), and 4vn (L) air is discharged within 1 minute, this theoretical value is taken as the design exhaust speed.
