Delphi-Common Rail System – High pressure pump
1 Drive shaft
2 Transfer pump (vane-type pump)
3 Cam ring
4 Feed bore
5 Fuel temperature sensor
6 Venturi in fuel return
7 Fuel metering valve
8 High pressure connection to the fuel rail
9 High-pressure channel
10 High-pressure chamber
Fuel is delivered by a transfer pump (vane type pump) incorporated into the high-pressure pump; the transfer pump is driven by the drive shaft.
From the transfer pump, the fuel is sent via a feed bore to the high-pressure chamber.
In the feed bore, between the transfer pump and the high-pressure chamber, is the fuel metering valve. The fuel metering valve is actuated electromagnetically by the IDM and thereby regulates the cross-section of the feed bore and thus the quantity of fuel destined for the high-pressure chamber.