A sliding vane pump is a positive-displacement pump that consists of vanes mounted to a rotor which rotates inside of a cavity. These vanes are variable length and/or tensioned to ensure that the maintain contact with the walls as the rotor rotates.
Sliding vane vane pumps use the simple system of a circular rotor that rotates inside of a larger circular cavity. The centers of these two are eccentric or offset. Vanes are allowed to slide into and out of the rotor and seal on all edges, creating chambers. These chambers do the pumping work as they increase and decrease in volume. At the intake valve, the chambers increase in volume, and are are filled with fluid forced in by the inlet pressure (which is often just normal atmospheric pressure) At the discharge valve, the vane chambers are decrease in volume, forcing fluid out of the pump and into the outlet pile. As all the vane chambers increase and decrease volume at the same rate as each other, the same volume of fluid is pumped consistently with each rotation.
Sliding vane pumps can be used for a wide range of pressure needs. Low pressure pumps can pump gas or air, making them useful for vapor deposition or auto exhaust emission control. High pressure pumps are used in the automotive industry for power steering and automatic transmission on cars, as well as supercharging. Mid-range pumps include applications such as carbonators, soda fountains, coffee machines and similar food industry uses.