Common Rail Fuel System and Exhaust Valve Control
The fuel supply pumps are arranged on one side of the drive gear and the hydraulic servo-oil pumps are on the other side. This pump arrangement allows a very short, compact supply unit with reasonable service access. The numbers, size and arrangement of Pumps are adapted to the engine type and the number of engine cylinders.
The fuel supply pumps are driven through a camshaft with three-lobe cams. This camshaft cannot be compared with the traditional engine camshaft. It is very short and of much smaller diameter, and is quite differently loaded.
The fuel delivery volume and rail pressure are regulated according to engine requirements through suction control with helix-controlled filling volume regulation of the fuel supply pumps. Suction control was selected for its low power consumption as no excess fuel is pressurized.
The fuel pumps deliver the pressurized fuel to an adjacent collector from which two independent, double walled delivery pipes lead upwards to the fuel rail. Each delivery pipe is dimensioned for full fuel flow. The collector is equipped with a safety relief valve set to 1250 bar.
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