|Arrangement of the blades and conduits|
While in former times the petrol pump with all its design features was very much in the centre of interest, this is no longer the case with the newer generation of pumps. Nowadays, you do not speak any longer of
pumps, but fuel-conveyor modules. They are no longer visible, but ´disappear´ in the tank. The displacement pumps (e.g., roller cell pumps) have made way for the flow pumps.
These are less expensive, more efficient, more resistant against dirt, and they manage, in the meantime, also the required pressures for indirectly injecting fuel injection systems.
There probably is another reason for the introduction of this pump kind. It is designed by a computer, because its construction form discloses only from computer simulations. Two degrees deviation of the shovel
position and the carefully balanced flow ratios are off.The side channel pump features shovels that form a light 'V' and are symmetrical. In contrast to the peripheral pump its
external ends are connected with each other. In the figure on top the wheel should move upwards. Then, to the right would be the suction side, and to the left the pressure side. In reality, these both side channels are
attached to the paddle wheel only for approx. 270°, but of course arranged in a staggered fashion. As mentioned earlier, the geometry is computer-made and flow-technically optimised.
There are combinations of Peripheral-and side channel pumps. In this case one of them fills the container and the other feeds the injection system. In the meantime, there are even pure side channel pumps with two
paddle rims in a rotary disk which supply the reserve container inside and the fuel system at the outside.