Sliding vane rotary vacuum pumps

Instruction of working principle of sliding vane rotary vacuum pumps The functional diagram of rotating vane pumps is shown in the figure. The rotating vane pump mainly consists of the stator, rotor, rotary vane, fixed cover, spring and components. The structure is formed by rotor which eccentricly installed in the chamber of the stator (the outer circle of the stator is tangental to the inner surface of rotor, and the gap between the two is very small) and the two rotary vanes which adhere to the inner wall of the stator with the assistance of spring tension and centrifugal force and slide in the rotor slot, and when the rotor rotating, the two rotary vanes are always sliding along the inner wall of the stator. The two rotary vanes divide the crescent-shape space formed by surrounding by the rotor, chamber of stator and fixed cover into three parts A, B and C.

When the rotor rotating by the direction shown in the figure, the capacity of space A, which is connected to the air entry, continuously increases, and the pressure in space A continuously gets down. When the pressure in space A is lower than that in the container in which the gas is pumped, according to the principle of gas pressure balance, the pumped gas is continuously drawn into the suction chamber A, that is the pump is in the process of suction. At this time, the capacity of the space of chamber B is gradually reduced, the pressure continuously increases, that is the pump is in the process of compression. With the capacity of space C which is connected with the air outlet is further reduces, the pressure in space C further increases. When the gas pressure is higher than the exhaust pressure, the compressed gas opens the exhaust valve, and the pumped gas continuously pass through the oil layer of the oil tank to the atmosphere. In the continuous running of the pump, it continuously repeats the process of suction, compression, and exhaust, so as to achieve continuous pumping.

The exhaust valve is immersed in the oil to prevent air flowing into the pump. The oil gets into the pump chamber through the gap on the pump body, oil hole and the exhaust valve, to cover the moving surfaces in the chamber and form the seal of the suction chamber and exhaust chamber; in addition, the oil also full up all the harmful space to remove their impact on the ultimate vacuum.
Two-stage sliding vane rotary vacuum pump consists of two working chambers which are connected in series and rotating at the same speed by the same direction. ChamberⅠis at a low vacuum level, while chamber is at a high vacuum level. The pumped gas enters chamber through the air inlet. When the intake gas pressure is higher, the gas will be compressed in chamber , so that the pressure rapid increases, and the compressed gas will be not only exhausted from the senior exhaust valve, but also pass through the passage of the intermediate wall and enter chamber , then be compressed in chamber and exhausted from the low-level exhaust valve; when the pressure of the gas entering chamber Ⅰis low, despite the gas is compressed in chamber Ⅰ, it still can not open the senior exhaust alue to get out. All the gas enters chamber Ⅰ through the passage of the intermediate wall, and by compressed in chamber Ⅰ, it is exhausted from the low-level exhaust valve. Therefore, the ultimate vacuum of the two-stage sliding vane rotary vacuum pump is higher than that of the single-stage sliding vane rotary vacuum pump.