A rotary vane vacuum pump is an oil-sealed rotary displacement pump. 
The pumping program consists of a casing (1), an eccentrically installed rotor (2), vanes that move radially under spring force (3) and the inlet and wall plug (4). … The Rotor techniques with the aid of 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-transmitting 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 action 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).