Chapter 4 Intake and Exhaust System
4. Turbocharger
4LHA Series
4 Turbocharger
4-1 Construction and Function
4-1-1 Construction and
function
v
(1)
Turbine
The
exhaust gas coming out of the engine is accelerated of its flowing speed through the nozzle of
the turbine housing and blown against the turbine wheel to give the torque to the turbine shaft.
This
is called the turbine, in which the
seal
rings and shrouds are built in to prevent adverse
influence to the bearings by the gas.
(2)
Blower
The
compressor impeller mounted on the turbine shaft receives torque from the turbine shaft, sucks
the air and compress it to be fed to the air intake pipe. This is called the compressor or blower.
(3) Bearing
1) Thrust bearing
Since
thrust force is continuously applied to the turbine shaft, it is designed to prevent the shaft
from movement by the thrust.
2) Radial bearing
The
floating bearing type is adopted.
Since
this type has double oil film layers at inside and
outside surfaces of the bearing, causing the bearing itself to rotate together
with
the shaft, the
slippage
speed of bearing is lower than the turbine shaft revolution, thereby, the dynamic
stability is improved, when compared
with
the normal type bearing.
(4) Sealing
structure
at
blower
side
The
dual-wall structure is adopted for the rear of compressor housing for preventing leakage of
intake air and oil. Further,
seal
ring and oil defensive plate are provided.
4-4