Yanmar 4LHA-HTP Operation Manual page 481

Chapter 4 Intake and Exhaust System
4. Turbocharger
4 Turbocharger
4-1 Construction and Function
4 - 1 - 1 Construction and function
(1) Turbine
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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
4 L H A S e r i e s