A rotary vane vacuum pump can be an oil-sealed rotary displacement pump. The pumping system consists of a housing (1), an eccentrically set up rotor (2), vanes that move radially under springtime push (3) and the inlet and store 
(4). … The Rotor movements by using a motor mounted on 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 consist of applications such as carbonators for fountain soft-drink dispensers and espresso coffee machines.
The simplest vane pump includes a circular rotor rotating inside a bigger circular cavity. The centers of these two circles are offset, leading to eccentricity. … The actions of the vane drives out the same level of liquid with each rotation. Multistage rotary-vane vacuum pumps can attain pressures as low as 10 mbar (0.0001 Pa).