Chapter IX Turbocharging System
Great Wall Baoding Internal Combustion Engine
Manufacturing Company Limited
447
Fig. 9-1-4 Turbocharger intermediate housing
and rotor assembly
Fig. 9-1-5 VGT Adjuster (VGT turbocharger)
Fig 9-1-6 Turbocharger structure
(WGT turbocharger with bypass valve)
and is pressed tightly by the self-locking nut. Subject to
the precise dynamic balancing, the whole rotor
assembly is ensured to be working normally in case of
high-speed rotation.
2.4
VGT Adjuster (VGT Turbocharger)By changing the
flow geometry of the turbine, VGT turbocharger
(variable geometry turbocharger) realizes its optimal
match with the diesel engine under different working
conditions. All operating points match well with the
diesel engine to make the diesel engine performs in an
optimal condition.
As the diesel engine speed declines, the outlet area of
the turbine nozzle ring will be reduced to increase the
rotation speed of the turbine and the outlet pressure of
the gas compressor; While the diesel engine speed
increases, the outlet area of the turbine nozzle ring will
be expanded to reduce the outlet pressure of the gas
compressor and the maximum ignition pressure so as to
prevent overspend of the diesel engine mechanical
load.
The structure of the VGT adjuster is shown in the Fig.
9-1-5.
2.5 Bypass valve (WGT Turbocharger)
In case of high rotation speed, WGT turbocharger
(turbocharger with the bypass valve) will release a
portion of the exhaust gas from the turbine front via the
exhaust valve. The air release valve in front of the
turbine is automatically controlled by the turbocharged
pressure. When the diesel engine speed exceeds a
certain value, the turbocharged pressure will open the
air release valve to release the air by overcoming the
reaction of the spring.
The structure of the WGT turbocharger with bypass
valve is shown in Fig. 9-1-6.
Attention:
(1) The specified value of the start pressure of the air
release valve is set by the manufacturer and no
adjustment should be conducted by the user, namely,
the adjusting nut at the linkage push rod should not be
screwed. Otherwise, the performance regarding
dynamic, economy and reliability will be seriously
damaged.
(2) Under no circumstances, linkage push rod should be
used as the handle or the bench for loading or stepping.
(3) If the air induction pipe is found to be leaking or the
linkage push rod to be inflexible during the usage, the
operator should stop the vehicle for troubleshooting.
(4) The air release valve and the sealed pressure
Gas
compressor
impellor
Rotor assembly
Turbine impellor
Lubricating
oil inlet
Lubricating
oil outlet
Intermediate housing
Floating shaft
bearing
VGT actuator
Adjusting rod
Nozzle ring
Nozzle ring
blade
Turbocharged air
Exhaust head pipe
Turbine
Gas
compressor
impellor
Fresh air
Exhaust
outlet
Axis pin
Rocker arm
Bypass valve
Adjusting nut
Linkage push
rod
Exhaust inlet
Diaphragm
Spring
Sealed pressure
chamber
