Pump operation
The pump element consists of a rotor containing a number of slots, a vane for each slot, a pump casing and two end plates with inlet and outlet ports for the power steering fluid.
Due to the oval shape of the pump casing, the volume between the vanes increases and decreases twice during each revolution of the rotor. Inlet ports lead to the areas in which the volume increases and outlet ports lead from those in which the volume decreases, thereby producing a pumping effect. Apart from being forced outwards by centrifugal force, the vanes are also pressed outwards against the pump casing by the pressure of the fluid. The fluid is directed into the slots inside the vanes.