Pump operation
The pump element consists of a rotor with a number of slits, a vane for each slit, a pump ring and two end plates with inlet and outlet ports for power steering fluid. If for some reason the power steering pump of a petrol engine is damaged and thus starts running sluggishly or stops, there is a disconnect function integrated in the drive shaft to the power steering pump which runs at approx. 80 Nm. This protects the cam train.
Due to the oval shape of the pump ring, 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 ring by the pressure of the fluid. The fluid is directed into the slots inside the vanes.
See also POWER STEERING PUMP .