Belarus 1523, Operating Manual

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BELARUS-1523/1523 В /1523.3 /1523В.3 Construction and Operation
65
rpm, and an antismoking pneumatic ad-
juster which is connected with the engine
induction manifold through an air duct.
The
Fuel-Booster Pump (16) is
mounted on the fuel injection pump body
and driven by the camshaft eccentric.
For bleeding the air from the feed sys-
tem, a hand- operated piston-type lift
pump is provided, and the plugs serve
for bleeding the air from the fuel-pump
head and the FFF, respectively.
The fuel supply is controlled by means of
the pedal and lever.
The fuel pump parts are lubricated from
the engine lubrication system.
Turbocharger
The turbocharger serves for charging air
into the engine cylinders using the en-
ergy of exhaust gases. It consists of a
centrifugal one-stage compressor (6) and
a radial centripetal turbine (1).
The turbine wheel (1) is cast of a refrac-
tory nickel allow and welded to the rotor
shaft. The compressor wheel (6) is an
aluminium alloy casting and is attached
on the rotor shaft by means of a special
nut (7).
The principle of operation of the turbo-
charger is as follows. The exhaust gases
from the cylinders enter the gas-turbine
chamber from the exhaust manifold. Ex-
panding, the gases rotate the turbine
wheel together with its shaft, on the other
end of which the compressor impeller is
fitted.
From the turbine gases are discharged
into the atmosphere through the exhaust
pipe.
The excess air pressure downstream the
compressor under engine design condi-
tion should be 0.07…0.10 MPa (0.7…1.0
kgf/cm
2
).
1 – turbine wheel and shaft unit; 2 – turbine hous-
ing; 3 – bearing; 4 – oil deflector; 5 – O-ring; 6 –
compressor impeller; 7 – special nut; 8 – bush-
ing; 9 – diffuser; 10 – disk; 11 – compressor
housing; 12 – lock ring; 13 – retaining holdfast;
14 – intermediate body; 15 – bushing.
The engine lubricating system is com-
bined: some parts are force-lubricated;
others are splashed lubricated. The sys-
tem includes an oil pump, oil filter with a
paper filter element, centrifugal oil filter,
and an oil-to-water heat exchanger. The
lubrication system diagram is shown be-
low.
The Oil Pump
(20) is a gear-type, sin-
gle-stage unit driven from the crankshaft.
It contains an overflow, or transfer, valve
which opens at a pressure above
0.7…0.75 MPa (7…7.5 kgf/cm
2
) and
passes oil from the discharge chamber
into the suction chamber.