Component Description For High-Pressure Pump - GF07.02-D-3010HD
ENGINES 651 in MODEL 906
with CODE (XZ1) Model generation 1
with CODE (MZ0) Blue EFFICIENCY
Location
Illustrated on model 906
The high-pressure pump is located on the crankcase at the rear left, aligned to the front.
Task
The high-pressure pump compacts the fuel delivered by the fuel pump with fuel level sensor (M3/5) (for model 906) and therefore generates the rail pressure.
The high-pressure pump is driven at 75% of the crankshaft speed by the gear drive on the output side. A venturi is integrated in the high-pressure pump for suctioning off leaked fuel at the following injectors:
- Cylinder 1 injector (Y76/14)
- Cylinder 2 injector (Y76/15)
- Cylinder 3 injector (Y76/16)
- Cylinder 4 injector (Y76/17)
Function
The function is made up of the following subfunctions:
- Low-pressure side function
- Function: high-pressure side
Low-pressure side function
The fuel delivered by the fuel pump with fuel level sensor arrives at the high-pressure pump flange and is led from there to the quantity control valve and fuel pressure relief valve. The quantity control valve regulates the volume of fuel fed through the annular passage to the two pump elements of the high-pressure pump (fuel feed to high-pressure elements). Fuel is led from the fuel feed directly into the pump drive over a cooling and lubricating throttle for cooling and lubrication of the pump drive. The fuel pressure relief valve regulates the fuel pressure at the quantity control valve to about 5 bar. The excess fuel is led back over the pump drive into the fuel tank. Any air carried along by the fuel is led via the fuel pressure relief valve and the cooling and lubricating throttle to the return flow of the high-pressure pump.
Function: High-pressure side
With its cam plate, the eccentric shaft moves the piston back and forth against the piston spring.
The high-pressure side function consists of the following subfunctions:
- Filling the piston
- Generation of high pressure
Filling the piston
The piston is moved down as a result of the piston spring. The fuel delivered by the fuel delivery pump with tank level sensor flows through the annular passage, the fuel feed and against the force of the valve spring via the valve into the cylinder. The ball valve prevents fuel from flowing back through the high pressure channel into the pump elements.
Generation of high pressure
The piston is moved upward by the upward movement of the eccentric shaft. This compresses the fuel. The valve closes the delivery volume against the fuel feed. Once the fuel pressure in the cylinder rises above the pressure in the high-pressure circuit, the ball valve opens and the fuel is delivered into the high-pressure circuit.