A rotary vane vacuum pump is an oil-sealed rotary displacement pump. The pumping program consists of a casing (1), an eccentrically set up rotor (2), vanes that move radially under spring power (3) and the inlet and outlet (4). ... The Rotor movements 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 conditioning and automatic-transmitting 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 in the larger circular cavity. The centers of these two circles are offset, leading to eccentricity. ... The action of the vane drives out the same volume of liquid with each rotation. Multistage rotary-vane vacuum pumps can attain pressures as low as 10 mbar (0.0001 Pa).