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2) Timing Chain and Gear
(1) Timing chain
Simple layout: optimized timing, enhanced
NVH
Single stage layout: minimized chain load -
-
Chain upper bush
- Single bush type (112 EA)
Chain lower bush
- Single bush type (60 EA)
(2) Tensioner
Tensioner adjusts the chain tension to keep it tight during engine running. This reduces the wear in guide
rail and spoke.
Operating principle
- Use the spring tension in tensioner and hydraulic pressure
Tensioner type
- Compensation and impact absorbing
Static and dynamic force
- Spring + Hydraulic pressure 1.
2.
3.
Plunger
HousingSpring
Check valve
Hydraulic tensioner assembly
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Oil pan sassembly
8. OIL PAN
The oil pan in D20DTR engine improves the NVH. Especially, the oil draining is much easier than before.
Components
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9. DUAL MASS FLYWHEEL (DMF) & DRIVE PLATE
1) Overview
Flywheel is installed on crankshaft. When
starting the engine, this functions as follows:
Reducing the irregular speed of crankshaft
due to unbalanced combustion -> Improving
the power train NVH, Improving the driving
performance
Reducing the clutch noise by using ball
bearing
Improving the durability of DMF by using
strong arch spring -
-
-
2) Layout
Spring guide
Drive plate
Primary cover
Primary flywheel
Internal/external ringSecondary flywheel
Ring gear
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Torque change curve of engine and drive shaft
Compression stroke Combustion stroke
Small changes from engine (k):
Damper increases the torque changes to clutchLarge changes from engine (j):
Damper decreases the torque changes to
transaxle by absorbing the impact
3) Operation
Compensating the irregular operation of engine: The secondary flywheel operates almost evenly so
does not cause gear noises
The mass of the primary flywheel is less than conventional flywheel so the engine irregularity
increases more (less pulsation absorbing effect).
Transaxle protection function: Reduces the torsional vibration to powertrain (transaxle) by reducing
the irregularity of engine. -
-
-
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4) Features
Reduced vibration noise from the powertrain by blocking the torsional vibrations
Enhanced vehicle silence and riding comforts: reduced engine torque fluctuation
Reduced shifting shocks
Smooth acceleration and deceleration -
-
-
-
5) Advantages
Improved torque response by using 3-stage type spring: Strengthens the torque response in all
ranges (low, medium, and high speed) by applying respective spring constant at each range.
Stable revolution of the primary and secondary wheel by using planetary gear: Works as auxiliary
damper against spring changes
Less heat generation due to no direct friction against spring surface: Plastic material is covered on
the spring outer surface
Increased durability by using plastic bushing (extends the lifetime of grease) -
-
-
-
6) Drive Plate
Drive plate receives the power from the start motor when starting the engine. With this, the drive plate
initially drives the power train system. And, it is connected to the torque converter to transfer the engine
torque to the power train system.
Trigger ring
Drive plate
Components
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1) Piston
(1) Overview
Piston assembly contains piston, #1 ring, #2
ring, oil ring, piston pin and snap ring. The
expansion energy from engine is transferred to
the crankshaft through connecting rod to convert
the linear movement to rotating energy.
(2) Layout
#1 ring
Oil ring
Snap ring
#2 ringMaterial: B2+
Skirt coating:
MoS2
Piston cooling gallery for
connecting rod
Wide bawl type (CR 16.5)
Cooling jet
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(3) Functions
Piston transfers the combustion energy from engine to connecting rod. Especially in the direct injection
engine such as D20DTF, it provides the combustion space and largely effects to the engine performance
and exhaust gas.
Piston ring
#1 ring (Top ring) : Prevents the high pressurized combustion gas from leaking into crank chamber,
and prevents the engine oil getting into combustion chamber.
#2 ring: Scrapes the engine oil on the cylinder bore, and prevents the leaked combustion gas from #1
ring from leaking into the crank chamber.
Oil ring: Scrapes the engine oil on the cylinder bore.
Piston pin
Connects the piston the connecting rod, and transfers the linear movement of piston to connecting rod
to convert it to rotating energy
Snap pin
Locks the piston pin.
-
-
-
-
-
(4) Assembling the piston
Install the piston rings with the "Y" mark on the
ring facing upwards.
away from the end gap of #1 ring.
away from the end gap of coil spring, and
from the end gap of #2 ring. 1.
2.
3.
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EnginePiston Cylinder bore
Part NO Marking NO.-
D20DTF 671 030 06 17 - -
671 037 07 01 A A
671 037 08 01 X X
671 037 09 01 B B
671 037 10 01 +5 -
671 037 11 01 +10 -
Selecting piston oversize
Top of piston Top of cylinder block