User Manual

SENR9977 17
Systems Operation Section
Delivery
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Illustration 13
Center view of the Bo sch VP30 fuel injection pum p
(16) Fuel tra
nsfer pump
Fuel is supplied by the head pressure of the priming
pump. The fue
l 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 p
ump 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
relatedtot
he speed of the fuel injection pump shaft.
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Illustration 14
Fuel transfer pum p for the Bosc h 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.
The eccentric position of the rotor is relative to the
cam ring. A volu
me 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 th
e 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 i
nlet 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 deliver
y 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.
Generation of High Pressure
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Illustration 15
The distr
ibutor rotor and the cam plate of the B osch V P30 fuel
injecti
on pump
(23) Ca m ring
(24) Cam plate
(25) Roller
(26) Head of the distributor
(27) Distributor plunger
(28) S prings
The fuel comes from the outlet passage of the fuel
transfer pump. The high pressure is generated
by the axi
al 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 corr
esponds 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
movemen
t and the lifting movement of the cam plate
makes the generation of high pressure.