A rotary vane vacuum pump can be an oil-sealed rotary displacement pump. The pumping system consists of a casing (1), an eccentrically set up rotor (2), vanes that move radially under spring push (3) and the inlet and store (4). … The Rotor techniques with the help of a motor attached to it.
Uses. Vane pumps are commonly used as high-pressure hydraulic pumps and in automobiles, including supercharging, power-steering, air-con and automatic-transmission pumps. Pumps 
for mid-range pressures include applications such as for example carbonators for fountain soft-drink dispensers and espresso coffee machines.
The simplest vane pump has a circular rotor rotating in the larger circular cavity. The centers of the two circles are offset, leading to eccentricity. … The actions of the vane drives out the same volume of liquid with each rotation. Multistage rotary-vane vacuum pumps can attain pressures only 10 mbar (0.0001 Pa).