Material of rotary vane vacuum pump
Data selection of rotary vane vacuum pump: in order to improve the pump speed, reduce wear and temperature, and ensure the normal performance of the pump, one of the key is how to properly select the stator and vane, which is the main friction pair data. Carbon impregnated alloy, a new type of self smoothing data, is commonly used in the rotary vane of direct coupled pump. Some domestic research institutes have also made comprehensive tests on other materials used as spin sheets. The results show that carbon fiber reinforced plastics and polymer liquid crystal data are of development value.
As the friction and wear between the vane and the stator of the high-speed direct coupled pump increases, the temperature rise of the pump increases. Therefore, improving the friction, wear and smoothness between the vane and the pump cavity is the key to develop a good performance direct coupled vane pump. Through the analysis and calculation of Elastohydrodynamic smoothing theory, it is found that the motion between the vane and the pump cavity is unreasonable, which makes the wear between the vane and the rotor and the pump chamber more serious, and it is difficult to find a suitable smooth condition, which leads to the increase of temperature rise of high-speed vane pump. The way to deal with the wear is to keep the length unchanged during the rotation. However, the current round pump cavity is impossible to do. In theory, an envelope line of stator pump cavity can be proposed, which is tangent to the outside of envelope circle on a series of axisymmetric curves. Of course, the processing technology of this kind of profile is more laborious than that of circular profile, but the extra cost can be compensated from the improvement of pump performance. Such a pump, vibration, noise, temperature rise, wear will be reduced a lot.
Rotor structure and rotor: through the calculation of the geometric pumping speed of the vane pump, it can be seen that when the pump speed has reached a certain high value, increasing the rotor can improve the pumping speed without increasing the rotor eccentricity and the maximum linear speed. Therefore, it is a promising way to improve pumping speed.
At present, the direct coupled pump used by domestic manufacturers adopts the structure of three slot integral rotor, which is equipped with three rotors. The integral rotor with three blades has high strength and rigidity, which can reduce the unbalance of rotor at high speed and reduce the impact load of rotor. The geometric pumping speed calculation shows that the pumping speed of the three slot rotor is 18-20% higher than that of the two slot rotor.