SENR9977 17 Systems Operation Section Delivery The eccentric position of the rotor is relative to the cam ring. A volume is created between the vanes, the rotor, and the cam ring. The fuel is transported by the eccentric position. The eccentric position is relative to the rotor and the outlet passage (19). The fuel is transferred to the outlet passage into the distributor plunger. The volume of the fuel is reduced between the inlet passage and the outlet passage. This creates pressure before the delivery to the distributor plunger. The quantity of fuel increases as the speed of the engine increases. Increased engine speed increases the delivery pressure of the fuel.
The pressure inside the pump is limited by a pressure regulator. The pressure regulator controls the fuel pressure. The fuel forces the valve spring open and the fuel flows back into the inlet passage from the inside of the fuel injection pump. g01132094 Illustration 13 Center view of the Bosch VP30 fuel injection pump (16) Fuel transfer pump Fuel is supplied by the head pressure of the priming pump. The fuel enters the fuel transfer pump (16) of the fuel injection pump. The fuel transfer pump is a vane pump. The transfer pump is driven by the fuel injection pump shaft. The pump supplies a constant amount of fuel to the interior of the fuel injection pump.
The revolution of the transfer pump is directly related to the speed of the fuel injection pump shaft. Generation of High Pressure g01132111 Illustration 15 The distributor rotor and the cam plate of the Bosch VP30 fuel injection pump (23) Cam ring (24) Cam plate (25) Roller (26) Head of the distributor (27) Distributor plunger (28) Springs The fuel comes from the outlet passage of the fuel transfer pump. The high pressure is generated by the axial movement of the distributor plunger. The cam plate is driven by the fuel injection pump shaft. The cam plate has four cams. The number of cams corresponds to the number of cylinders of the engine. The cams on the cam plate run on the rollers.
The rollers are fixed on the cam ring. The rotating movement and the lifting movement of the cam plate makes the generation of high pressure. g01132095 Illustration 14 Fuel transfer pump for the Bosch VP30 fuel injection pump (17) Pump housing (18) Cam ring (19) Outlet passage (20) Rotor (21) Vane (22) Inlet passage The rotor (20) rotates inside the cam ring (18). The ring is firmly attached to the pump housing (17). The vanes (21) are pressed against the ring by centrifugal force. The fuel flows through the inlet passage (22) then into a recess in the pump housing.