Vane Pump

Vane pumps fall into two categories, flexible vane pumps and sliding vane pumps. Flexible Vane pumps have an impeller rotating off-centre in a housing. As the flexible vanes on the impeller rotate they are compressed against one side of the housing. Some of the fluid is returned to the inlet side and this will increase with rising discharge pressure.

Sliding vanes, which can be spring loaded or simply allow the centrifugal forces to push them outwards against the casing, move in and out as the housing casing expands and contracts creating a crescent fluid path. The vanes also seal the return path to give a consistent flow rate independent of delivery pressure. This type is nearly solely restricted to self-lubricating fluid and works best with thin fluids. Both types only work with non-abrasive fluids.