01 Engine System LG956L
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Transcript of 01 Engine System LG956L
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Chapter 3 Engine System
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Chapter 3 Engine System
Section 1 overview of engine1 Model meaning2.Characteristic of engineSection 2 Crank-link mechanism1.Engine block group2.Crankshaft flywheel group3.Piston rod groupSection 3 Valve mechanism1.Overview
Section5 Lubrication system1.Function2.Method of lubrication3.Main spare partSection 6 Cooling system1.Function of cooling system2.Main spare part of cooling systemSection 7 Air intake and exhaust system1.Function of air intake and exhaust system
& 2051
1.Overview2.Main composition of valve mechanismSection 4 Fuel supply system1.Overview2.Fuel injection pump3.Regulator4.Fuel delivery pump5.Fuel injection6.7.Fuel filter
1.Function of air intake and exhaust system2.Working principle of air intake and exhaust system3.Parts of air intake and exhaust systemSection 8 Common failures1.Start unsuccessfully engine2.Underpower of engine3.Exhaust black smoke4.Exhaust white and blue smoke5.Low lubricating oil pressure6.High lubricating oil pressure7.High lubricating oil consumption8.High coolant temperature
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Section 1 Overview
1 Introduction of the meaning
LG956L is equiped with Weichai
engine which is in-line, four-
stroke, water-cooled, turbocharged
six-cylinder diesel engine, the
engien model number is
WD10G220E23, the meanings of
the words and numbers see the
WD10G220E23
WD Water Diesel 10Displacement Code(Displacement is 10L.)
G Construction machinery 220 Power(220ps)
2
the words and numbers see the
right table.
G Construction machinery 220 Power(220ps)
E2State three emission standard
3 Variant code
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Section 1 Overview
2 Characteristics of the Weichai
engine WD10G220E23
1 High reliability, long life
Using the tunnel structure, the
crankcase and the seven main bearing
cap are forged as one piece by
high-quality alloy steel, nitrided
crankshaft and connecting rod, and
3
strength bolts with flexible design, to
ensure the high reliability of the engine
moving parts. Reasonable design of the
high power function of the camshaft
profile can make the engine distribution
system has higher reliability and lower
mechanical vibration noise.
Characteristics of the use of construction
machinery are fully considered,
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Section 1 Overview2 Powerful engine large torque reserve
Using the imported Ps3000, Ps7100 fuel
injection pump with low inertia porous injector,
through fuel supply characteristics correcting
and efficiency turbocharger proper matching can
achieve a good dynamic and make the torque
reserves reach more than 20%, to provide strong
horsepower for all kinds of engineering
machinery.
3 Good economy
Three new structures of piston rings, best
4
Three new structures of piston rings, best
matching cylinder clearance, equiped with new
type of combustion chamber and the best swirl
ratio, overlapping curve is honed on the cylinder
plate form to aviod leakage, ensure a more
perfect geometry of cylinder bore, and reduce
the consumption of fuel and oil, the lowest fuel
consumption of the turbocharged engine reaches
194g/kW.h, , oil consumption less than
0.5g/kW.h.
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Section 1 Overview
4 Powerful engine High
torque reserve
The exhaust can meet the Euro II
emission standard, which are well suited
for working in limited space such as
tunnels, warehouse, cabins, etc.
5 Good ability to adopt the
plateau
5
The new type of turbocharger has a
function of air intake reflow, which can
broaden the scope of the diesel engine
high effiency workspace, compensate for
the power loss in plateau, and can
provide good adaptability in plateau.
6 Good low temperature start
The cold starting device is added to
ensure the engine can start smoothly at -
40 .
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Section 2 Crank and connecting rod mechanism
Crank and connecting rod
mechanism
1 Basic components
The crank and connecting rod
mechanism mainly consists of
three parts: the body assembly,
crankshaft flywheel assembly,
piston and connecting rod
Piston rod assembly
6
piston and connecting rod
assembly. Engine body assembly
Crankshaft flywheel assembly
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Section 2 Crank and connecting rod mechanism
Crank and connecting rod mechanism
2 Main function
The crank and connecting rod
mechanism is the main parts of the
reciprocating piston engine to transfer
the heat energy into mechanical energy,
which function is to transfer the pressure
on the piston crown acted by the gas to
the rotational torque of the crankshaft,
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the rotational torque of the crankshaft,
and output to the external.
Most of the power is tranmitted to the
outside through the flywheel, another
portion is through the gear and idler gear
of the front end of the crankshaft to drive
other mechanisms and systems of itself,
primarily to withstand high temperature,
high pressure, chemical corrosion and
the impact of inertia force.
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Section 2 Crank and connecting rod mechanism
1 The cylinder block assembly
It is mainly composed of the cylinder
block, cylinder liner, cylinder head,
cylinder gasket, oil sump, engine mounts
and other mechanical components.
1 Cylinder block
Function The cylinder block is a
basic installation for each mechanisms
and systems, which is used to maintain
the precise positional relationship
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between each moving parts of the
engine. The cylinder block is usually
forged together with crankcase as one
piece, so called cylinder-crankcase.
Structure According to the
different position of the installation
planes between the cylinder block and
the oil pan, the cylinder block is usually
divided into three types: general
crankcase, crankcase and gantry tunnel
crankcase.
FORM characteristic Application
GeneralThe lower surface of the cylinder block and the axis of the crankshaft are on the same plane, the stiffness is small
Cars, small trucks
GantryThe lower surface of the cylinder block is below the axis of the crankshaft, the stiffness is larger
Medium and heavy trucks
TunnelMain bearings are not separated (equipped with modular crankshafts), the stiffness and weight are the largest
large mechanical loadload of diesel engine
Gantry form Tunnel formGeneral type
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Section 2 Crank and connecting rod mechanism
1 Cylinder block
The structural style of the
LG956L Weichai engine
The cylinder block of the Weichai
WD10G220E23 engine is the tunnel
structure, the main bearing cover and the
crankcase forged toghther in one
piece,the crankcase and the cylinder
block are separated by the centerline of
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the crankshaft, the upper part is the
cylinder block, the lower part is the
crankcase, the crankcase and the seven
main bearings together form a integrated
framework with good stiffness.
This tunnel structure not only has a
good stiffness, and can use the sliding
bearings to reduce the noise and improve
the service life.
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Section 2 Crank and connecting rod mechanism
1) Cylinder block Precautions for the installtion of
the Cylinder block and crankcase
The WD10G220E23 engine has no
gasket between the crankcase and
cylinder, the bottom of the cylinder
block should be coated smoothly with
510 sealant, which will lower the oil
pressure, the sealant does not need too
much, and installation should be
10
much, and installation should be
implemented immediately after the
coating finished.
Notice: The cylinder block and
crankcase are required to be installed in
pairs, which are not interchangeable.
When one of the parts is damaged, both
parts should be replaced, optional
installation is not allowed.
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Section 2 Crank and connecting rod mechanism
2 Cylinder liner
Function
The main function of the cylinder liner
is to guide the piston direction and seal
the gas inside the cylinder.
Classification of cylinder
sleeve
There are two types of cylinder liners:
11
There are two types of cylinder liners:
Dry cylinder liner and wet cylinder liner,
the dry cylinder liner is not directly in
contact with the cooling liquid, but the
wet cylinder is just the opposite.
Weichai WD10G220E23 diesel engine
uses the thin-walled dry cylinder liner.
Form Characteristic Advantage Aisadvantage Demand
Wet cylinder sleeve
The outer surface is in direct contact with the cooling
Cooling effect, casting
convenient, easy
disassembly
Poor rigidity, easy
leakage(water and gas)
With upper and lower positioning
belt and lower bearing seal tape
Dry cylinder sleeve
The outer surface is not in direct
contact with the cooling water
Contrary to the aboveWith upper and
lower positioning belt
Wet cylinder liner Dry cylinder liner
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Section 2 Crank and connecting rod mechanism
2 Cylinder sleeve
Precautions for the installtion of
Weichai WD10G220E23 diesel engine
cylinder liner
Use alcohol or Loctite 755 to wash the
grease off the cylinder hole and the
cylinder liner external surface before
installation, then apply a thin layer of
molybdenum disulfide powder on the
& 20512
molybdenum disulfide powder on the
surface of the cylinder liner external
surface, and finally, use hands or tools to
pressure the cylinder liner into the
cylinder block.
Check the cylinder liner is 0.02-
0.07mm above the upper surface of the
cylinder block after the cylinder liner
pressed into the cylnder block.
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Section 2 Crank and connecting rod mechanism
3 Cylinder head
Function
The main function of the
cylinder head is to seal the upper
part of the cylinder, and form a
combustion chamber with piston
crown and cylinder wall.
Type of cylinder head
Double-cylinder split type
Single-cylinder split type
Integral-type
Cylinder head
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Type of cylinder head
The cylinder head has common
types of integral-type, single-
cylinder split type and double
cylinder split type.
form characteristic application
integral
Poor rigidity, easily deformed by heat or pressure, which will influence the seal, the whole block must be replaced when damaged.
old-fashioned engine
split
one cylinder per block
easy to be made or repaired, good rigidity wide application
two cylinder per block
three cylinder per block
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Section 2 Crank and connecting rod mechanism
3 Cylinder block
The cylinder head of Weichai
WD10G220E23 engine adopts the
structure with one cylinder and one
cover, good manufacture technics,
and easily disassembled and
transported.
Each cylinder is fixed by four
& 20514
Each cylinder is fixed by four
M16 bolt, and two adjacent
cylinder head simultaneously
pressed together by three M12 stud
with a clamping block, which
increases the engine rigidity.
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Section 2 Crank and connecting rod mechanism
2 The piston and connecting rod assembly
The Piston and connecting rod
assembly is mainly composed of piston,
piston ring, connecting rod, piston pin and
other mechanical components.
1-piston
2-Spiral spring-loaded oil ring oil ring
3-cone ring Compression ring
4-ladder ring Compression ring
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4-ladder ring Compression ring
5-connecting rod sleeve
6-connecting rod
7-connecting rod cover
8-connecting rod bolt
9-connecting rod bush
10 11connecting rod bush
12-retaining ring
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Section 2 Crank and connecting rod mechanism
1 Piston
Function of piston
The main function of the piston is
designed to withstand the pressure from
buring air, and transmit the force through the
piston pin to the connecting rod to push the
crankshaft rotate. The piston head forms a
combustion chamber with cylinder head and
cylinder wall.
Structure of piston
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Structure of piston
The basic structure of the piston can be
divided into three parts: the crown, the head
and the skirt.
The piston head forms a combustion
chamber with cylinder head and cylinder
block, bear force generated by the air
pressure in the cylinder, and transmit the
force through the piston pin to the
connecting rod to push the crankshaft rotate.
1 top 2 head 3 skirt 4 land 5 ring groove 6 pin boss 7 reinforcing rib 8 Snap ring groove 9 Oil discharge hole and Oil discharge groove
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Section 2 Crank and connecting rod mechanism
The piston head is the upper part
above the piston ring groove,
which function is as follows:
A: Withstand the air force and transmit it
to the connecting rod.
B: Working together with the piston
rings to realize the cylinder cealing.
C: Transmit the heat absorbed from the
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piston head to the cylinder wall by
passing throught the piston ring.
The piston skirt is the lower part of the
engine from the oil ring groove down to
the bottom, which function is to guide
the piston reciprocated in the cylinder
and withstand side pressure.
1 top 2 head 3 skirt 4 land 5 ring groove 6 pin boss 7 reinforcing rib 8 Snap ring groove 9 Oil discharge hole and Oil discharge groove
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Section 2 Crank and connecting rod mechanism
The structure and characteristics of the Weichai WD10G220E23 engine piston
A The piston is made of aluminum alloy, the
specific weight is small, and the thermal
conductivity is very good.
B The top of the piston has a S - shaped
combustion chamber, and a pit which can avoid
the valve, in additional, combustion chamber and
avoid the valve pit, while the product code is on
the piston top.
C: Piston top shore (also known as fire shore)
processesa thin annulargroove,calledbackslot,
18
processesa thin annulargroove,calledbackslot,
which has the function of collecting dirt and
proventing occlusion, and can improve the
running state between the top of the piston and
the cylinder.
The piston can be grouped by weight, the
difference between each group is not more than
10g, the marks of these groups are G1 G2
G3 G4 G5. When replacing the piston, the
weight of the pistons on the same machine
should be the same.
E Engine oil should be applied before the
piston installation, the opening of the piston rings
should be staggered 120 , and angle between
the opening of the first ring and the edge of the
pistonpin holeshouldnot lessthan30
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Section 2 Crank and connecting rod mechanism
(2) Piston ring
Classification
Piston ring is a resilient split ring,
which can be divided into compression
ring and oil ring.
Function of compression ring
The first and second rings are called
compression ring, which function is to
Compression ring
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ensure the seal between the cylinder and
the piston, prevent the gas leakage, and
transmit most of the heat absorbed from
the piston crown to the cylinder wall.
Function of oil ring
The third ring is oil ring, which
function is to distribute oil, scrape oil,
reduce the friction resistance and assist
the sealing.
Oil ring
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Section 2 Crank and connecting rod mechanism
(2) Piston
Sealing principle of
Gas ring has a slot, and is flexible, which
outer diameter is greater than the cylinder
diameter in free state, when installed into the
cylinder together with the piston, the outer
surface set close to the cylinder wall to form
the first sealing surface, the sealed gas can
not get throught the space between gas ring
and the cylinder, but enter the space between
20
ring and ring groove, on one hand, it can
press the ring to the surface of the groove to
form the second sealing surface, on the other
hand, the pressure acting on the back of the
ring can greatly enhance the sealing effect of
the first sealing surface.The gas ring sealing
effect is generally related to the number of
the gas ring, WeiChai diesel engine has 2 gas
rings.
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Section 2 Crank and connecting rod mechanism
(2) Piston ring
Type of the compression ring section
Rectangular ring Simple technical process,
good thermal conductivity, but the oil pumping
phenomenon is easy to occur, which will cause
the carbon deposition.
Twist ring The torque M is generated by the
left-right asymmetry, which can make the edge
of the rings to contact with the upper and lower
surface of the groove, prevent oil pumping, and
increase seal.
21
Taper face ring Scrap the oil downward, and
float on the oil film when slide upward,which
can reduce the mechanical wear, but the cone
angle is hard to be made.
Keystone ring The ring side clearance is
changed according to the changes of the direction
of the side pressure, which can squeeze the
carbon deposition out of the ring groove, but the
technical process of the upper and lower surfaces
are more complicated.
Barrell face ring Good contact can increase
sealing, but the convex surface is hard to be
made.
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Section 2 Crank and connecting rod mechanism
(2) Piston ring
Compression ring pump oil
Function Good for cylinder
lubrication.
Harm Large lubricating oil
consumption, easy to form carbon
deposition in the ring groove,
which will caused ring stuck in the
22
which will caused ring stuck in the
groove and lose the sealing effect,
scratch the cylinder wall, and even
break the ring.
Measure Reduce the ring
quality, change the shape of the
ring section, and use the
combination oil ring.
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Section 2 Crank and connecting rod mechanism(2) Piston ring
Oil ring
Function The main function of the engine oil
ring is is to distribute oil, scrape oil, and play an
assistant role to sealing the gas, which can be
divided into two types, common oil ring and
combination oil ring.
A: General oil ring
The general oil ring is also called integral oil
ring, with a groove machined in the middle of the
outer cylindrical surface of the ring, and a hold
or a slot drilled in the groove, when the piston
General oil ring
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or a slot drilled in the groove, when the piston
moves downward, the excess oil will be scraped
off the cylinder wall and flow back to the
crankcase through the small hole or slot.
B combination oil ring
The combination oil ring is composed of a
pair of upper and lower side rail rings and a
middle dilator, the side rail ring is made of
chrome-plated steel, the perimeter of the dilator
is slightly larger than the internal circumference
of the cylinder, which can tightly press the side
rail ring against the cylinder wall, and the
scraping effect is obvious.
Function of oil scraper ring
Combination oil ring Combination oil ring
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Section 2 Crank and connecting rod mechanism
2 piston ring The structure and characteristics of Weichai
WD10G220E23 engine piston rings
First ring The surface of the double sided
trapezoid tubbish ring is treated by means of
phosphating treatment, with a notch and an
installation marking "TOP"on the upper part; The
work surface is sprayed with molybdenum layer,
which will help to increase the effect of wearing
resistance and anti galling.
Second ring Cone ring, the cone angle of the
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torus is 90 5 , the surface is treated by
means of oxidation treatment, the work surface is
sprayed with chromium layer, and the upper part
of the ring has a installation marking "TOP"
Third ring The internal expanding circle
combined oil ring is made of cast iron, has 12
blades, double-edged surface chrome plated,
lined with spiral springs, which has the
characteristics of small abrasion, good oil seal
and scraping effect, stable performance, durable
and so on.
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Section 2 Crank and connecting rod mechanism
3 piston pin
Function
Connecting the piston and connecting rod,
transfering the force between the two parts.
Structure
Hollow cylinder.
Material
Alloy surface carburization (surface hardnessincreased)
Assembly
25
Full floating The pin rotates freely and wear
evenly in the pin hole and connecting rod
bushing, the inner of both ends of the pin seat has
clip rings.
Half floating The the floats in the pin seat,
which is connected with the small end of the
connecting rod by bolts.
Notice Heat the aluminum pistons in the 70
90 water or oil before installing the pin into
the piston to ensure the combination between the
pin and the pin seat hole in the cold state is a
transition fit .
!!!! "!"!"!"!
####
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Section 2 Crank and connecting rod mechanism
4 Connecting rod
Composition
The connec t ing rod is composed o f
connecting rod small end, shaft, connecting rod
big end, screw and connecting rod cap,etc.
Function
Connect the piston wi th the crankshaft,
transfer the force from piston to crankshaft, and
transfer the reciprocating movement of the piston
$%$%$%$%
26
into the rotary movement of the crankshaft.
&&&& Classification
Generally, the engine connecting rod can be
divided into two types, the equal type and the
oblique fractional type.
Weichai WD10G220E23 engine adopts the
oblique fractional rod.
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Section 2 Crank and connecting rod mechanism
4 Connecting rod
(((( Connecting rod of weichai
engine(WD10G220E23)
A: Weichai WD10G220E23 engine connecting
rod big end is the oblique incision type,split by
45 oblique, using the 60 teeth to locate the
combined surface, with characteristics of
positioning accuracy, combined tightly, etc.
B The weight of the connecting rod is divided
into 9 groups which are respectively marked by
C, D, E, F, G, H, J, K, I, thequality of eachlevel
& 20527
C, D, E, F, G, H, J, K, I, thequality of eachlevel
is no more than 29g, when replacing the
connecting rod, make sure the marked letter is
the same, otherwise it will cause the diesel
engine to produce abnormal vibration.
C The connecting rod and connecting rod cover
must be processed as a whole set, marked the
same number, and are not interchangeable.
The connecting rod bolts can only be used
once.
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Section 2 Crank and connecting rod mechanism
5 Bearing shell
A tile form of sliding bearing is
mounted in the connecting rod big end
hole to reduce friction and the wear of
connecting rod journal of the crankshaft,
which is called connecting rod bearing.
The bearing shell is divided into
upper and lower shell, which is currently
use the thin-walled rigid bearing, with
28
use the thin-walled rigid bearing, with
wear-resistant alloy layer casted on the
internal surface.
Function of the connecting rod
bearing shell))))
Bearing, heat conduction, protecting the
big end connecting rod and reduce the
wear.
1-steel backing 2-oil groove
3-locating tang 4-antiwear alloy layer
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Section 2 Crank and connecting rod mechanism
3 Crankshaft flywheel
assembly
Mainly consists of crankshaft,
flywheel and other accessories.
& 20529
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Section 2 Crank and connecting rod mechanism
1 Crankshaft
Composition
The crankshaft is composed of main
journal, connecting rod shaft neck,
crank, counterbalance, front-end and
back-end, etc.
A connecting rod shaft neck and a
crankshaft constitute a crank.
Function
30
Function
The crankshaft interacts closely with
the connecting rod to change the gas
pressure into rotation power, transfer the
force to the transmission mechanism,
and drive the valve mechanism and other
auxiliary devices.
*+*+*+*+ %$%$%$%$ ++++
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Section 2 Crank and connecting rod mechanism
2 Flywheel
Function: Depending on the flywheel
inertia to keep the engine running
balance, and help engine to overcome
short time overloading.
Material: High strength, wear-resistant
material (Grey cast iron)
31
1 flywheel 3 bush 4 bolt 5 support 7 gear ring8 flange
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Section 2 Crank and connecting rod mechanism
3 AbsorberIn the process of engine working, each
cylinder has its own working stroke, the
magnitude and direction of the force transfered
from the connecting rod to the crank pin are
changed periodically, the exciting force caused
by the periodic variation acts on the crankshaft to
cause the the instantaneous angular velocity of
the crank is also changed periodically. But the
flywheel fixed on the crankshaft has a big rotary
inertia, which can be regarded to do uniform
32
rotation, so at one moment the crank speed is
faster than the flywheel and the next the crank
speed is slower than the flywheel, which can
form a torsional oscillation against the flywheel,
such is the crankshaft torsional vibration. When
the ratio of the excitation frequency to the
natural frequency of the crankshaft is an integer,
the crankshaft will produce resonance.
Function Reduce the vibration, avoid
resonance
Principle Friction in the damper gradually
consumes the energy of the crankshaft torsional
vibration to gradually reduce the amplitude.
1 2 Pulley 3 Bolt
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Section 2 Crank and connecting rod mechanism
4 Six cylinder engine crank layout
Principle))))
1.The firing interval should be uniform
to ensure that the engine is running
smoothly.
2.The two continuous working cylinders
should be as far as possible To reduce
the load of the main journal, and avoid
1-6
33
the load of the main journal, and avoid
the overlap of the air influences the air
intake.
5-2 3-4
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Section 2 Crank and connecting rod mechanism
5 Firing order of six-stroke engine
The four stroke inline six cylinder
engine firing angle is 720/6=120 , six
cranks are respectively arranged on the
three planes, the firing order is 1-5-3-6-
2-4.
The cy l inde r o f the We icha i
WD10G220E23 engine, near the fan, is
thefirst cylinder.
Crank corner
Cylinder 1
Cylinder 2
Cylinder 3
Cylinder 4
Cylinder 5
Cylinder 6
0~60power
exhaust intake power compression intake60~120
compression
exhaust120~180
intake power180~240exhaust compres240~300
34
thefirst cylinder.sion
240~300power intake300~360
compression
exhaust360~420intake power420~480
exhaust compression480~540
power intake540~600compression
exhaust600~660intake power660~72
0exhaus
tcompression
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Section 3 Valve mechanism1 Overview
The function of valve mechanism is to control
the air inlet and outlet, which regularly controls
the opening and closing of the intake and exhaust
valve, supply mixture fresh air to the cylinder
and timely draw used air out according to the
requirement of the cylinder working order and
working process. In addition, when the inlet and
outlet valve closed, it can ensure the cylinder
seal.
When the engine works, the camshaft is
35
driven by the crankshaft through the timing gear,
the cams push the tappet and rod and pass the
action to the rocker arm which rotate around an
axis to overcome the spring force to push the
valve moves down and be opened. When the
camshaft continue to rotate and cross the
maximum pushing process, the valves will return
to the original position and be closed.
1-pushrod 2-tappet 3-camshaft 4-valve
5-valve spring 6-locking plate 7-rocher arm
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Section 3 Valve mechanism2 Main composition of valve mechanism
The valve mechanism is maily composed of
Va lve assemb ly and va lve transm iss ion
assembly.
1 Valve group
The valve assembly includes valves, valve
seats, valve guides, valve springs, locking plate
and retainer.
(1) Valve
The function of the valve is to control the
opening and closing of the inlet and outlet valve,
resist high temperature,high pressureand####
,%,%,%,%
-.-.-.-.
36
resist high temperature,high pressureand
impact, require the valve to have the following
characteristic: sufficient stiffness, strength, wear
resistance, high temperature resistance, corrosion
resistance, impact resistance.
(2) Valve guide
Its function is to guide the valve, ensure the
valves do straight reciprocating motion. In
adition, it has the function of heat transfer, pass
heat from the valve head to the rod shaft, and
spread out through the cylinder head.-.-.-.-. ........
-.-.-.-.
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Section 3 Valve mechanism
3 valve seat
The valve seat interacts closely with the valve
head sealing conical surface to seal the cylinder,
and the heat from the valve head can be
transmitted to the outside through the valve seat.
4 valve spring
The function of the valve spring is to ensure
the valves return, prevent the transmission parts
detachment during movement. When the valve
closed, the valve spring should ensurethe seal
####
,%,%,%,%
-.-.-.-.
37
closed, the valve spring should ensurethe seal
between valve and valve seat. when the valve
opened, it should ensure the valve cant be
separated from the cam by the inertial force
created during the movement. The valve spring is
a cylindrical spiral spring, one end is supported
on the cylinder head and the other end is pressed
against the spring seat which is at the end of the
valve rod, the spring seat is fixed to the end of
the valve rod with a locking plate.
-.-.-.-. ........-.-.-.-.
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Section 3 Valve mechanism
2 Valve transmission assembly
The valve transmission assembly transfers
movement between camshaft and valve, which
includes camshaft, tappet, push rod, rocker arm,
valve clearance adjusting screw and other
components.
1 Camshaft
The camshaft controls the opening and
closing of the valve, each intake valve and
exhaustvalve respectivelyhas corresponding
/%01$2/%01$2/%01$2/%01$2 $ $ $ $
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exhaustvalve respectivelyhas corresponding
intake cam and exhaust cam, the valve opening
and closing time and height can be influenced by
the rotation of the cam, the cam arrangement
influences the opening and closing time of the
valve and working order.
The cam has two types, the inlet cam and
outlet cam, the number of cams is the same as the
number of inlet and outlet valves. For each
working cycle, the crankshaf will turn two
cycles, and the camshaft will turn one cycle.
360/60=60
The angle between the same name valves for
each cylinder is 360/60=60
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4$4$4$4$
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Section 3 Valve mechanism
2 Tappet
The function of the cam tappet is to
transmit the thrust from the cam to the
push rod, and bear the lateral force
exerted by the rotation of the camshaft.
3 Pushrod
The function of the push rod is to
transmit the thrust from the camshaft to
the rockerarm, which is the mosteasily
/%01$2/%01$2/%01$2/%01$2 $ $ $ $
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the rockerarm, which is the mosteasily
flexible parts of the gas distribution
mechanism
4 rocker arm and seat
The function is to transmit the thrust
from the tappet and push rod to the
rocker arm to push the rocker arm swing
to open and close the valve.
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Section 3 Valve mechanism
3 valve clearance
definition
Valve clearance means the clearance
between the end of the valve rod and
rocker arm or tappet when the valve is
comp lete ly c losed under the co ld
condition.
function))))
The function is to compensate for the
40
The function is to compensate for the
amount of expansion after the valve is
heated. Different models have different
size of valve clearance, the exhaust valve
clearance is larger than the inlet valve
clearance in common cold state.
-
Section 3 Valve mechanism
3 valve clearance
Valve clearance is too large or too small
will cause certain harms:
If the valve clearance is too large, which will
cause the the open of the inlet and exhaust valve
delayed, the exhaust time shortened , the valve
opening height reduced, and the normal gas
distribution phase changed , result in insufficient
air intake and incompletely air exhaust, parts of
the gas distribution mechanism impact increased
Intake valve Exhaust valve
41
and wear accelerated. If the valve clearance is
too small, when the parts heated and expanded,
which will push the valve open, cause the valve
can not be tightly closed to prevent the gas to be
released, reduce the engine power, result in
serious carbon deposition or burn, and even the
valve strike the piston.
The Weichai WD10G220E23 engine air intake
valve clearance(cold machine) is 0.3mm and the
exhaust valve clearance is 0.40mm
Intake valve Exhaust valve
0.3mm 0.4mm
-
Section 3 Valve mechanism
3 valve clearance
adjustment and inspection of valve
clearance
1 Using the 13mm socket wrench to
remove the 6 cylinder head cover.
2 Use the 32mm Crank Wrench to
slowly rotate the diesel engine, adjust the
tick mark on the flywheel house point to
42
tick mark on the flywheel house point to
the OT mark and the piston of the first
cylinder point to the compression top
dead center(The inlet and exhaust valves
of the first cylinder are closed.)
The first cylinder is from the fan end.
-
Section 3 Valve mechanism3 Valve clearance
Adjustment and inspection of valve
clearance
5 Take the intake and exhaust valve
clearance with a feeler
Intake valve clearance: 0.3mm
Exhaust valve clearance:0.4mm
Notice: When measuring the valve clearance,
the accurate value is taken under the
condition that the diesel engine should be in
43
a cold state(lower 60 ), and there should be
a obstacles sticky feeling as the feeler slides
between the valve lifter and the rocker.
6 When adjusting the valve clearance,
first unscrew loosen the locknut and the
adjusting bolt, and then place the required
thickness feeler between the rocker arm and
the valve, tighten the adjusting bolts, and
then tighten the lock nut.
-
Section 3 Valve mechanism
3 valve clearance
adjustment and inspection of valve
clearance
7 Rotate the engine until the first cylinder
to the compression top dead center, adjust
the clearance of the intake and exhaust valve
of the first cylinder, the intake valve of the
second cylinder, the exhaust valve of the
third cylinder, the intake valve of the fourth
44
cylinder, the exhaust valve of the fifth
cylinder, the sixth cylinder should not be
adjusted. See right picture(I means the air
intake, E means the air exhaust).
8 Keep on rotating the engine until the
sixth cylinder to the compression top dead
center, then adjust the other valve clearance
which have not been adjusted in the seventh
adjusting step.
-
Section 3 Valve mechanism
4 valve phase
1 Intake valve early opening and late
closing
Enlarge the valve opening height at the
beginning of the air intake stroke, reduce the air
intake resistance, and increase the air intake
quantity.
Intake valve late closing
Delaying the intake time, and increasing the air
intake quant i ty under the e f fec t o f the
atmosphericpressureandthegasinertia force.
45
atmosphericpressureandthegasinertia force.
Exhaust valve open early
The cylinder can exhaust the gas by itself with
the help of the high pressure in the cylinder,
which can reduce the exhaust resistance,and
ensure the gas discharged cleanly.
Exhaust valve close late
Extending the air exhaust time, and ensure the
air completely discharged the pressure and
inertia force of the exhaust air.
-
Section 3 Valve mechanism
4 valve phase
2 valve overlap
As the inlet valve opens early, the exhaust
valve closes late, the inlet valve opened before
the upper dead point, while the exhaust valve
closed after the upper dead point, which
inevitably cause the phenomenon of two valves
opened at the same time, in this case the valve
angle will be overlapped, when two valves
openedat thesametime, thecorrespondingcrank
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46
openedat thesametime, thecorrespondingcrank
angle is called the valve overlap angle.
3 A i r ac tua l intake and exhaust valve
opening, closing and duration time.
The actual air intake and duration time:
At the end of the air exhaust stroke, the piston
reaches the upper dead po int, when the
crankshaft turned to a position where the angle
between the crankshaft and the upper dead point
is a, the inlet valve begin to open, and will be
closed until the piston accross the bottom dead
point.
61$61$61$61$ %%%%
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Section 3 Valve mechanism4 valve phase
3 Air actual intake and exhaust
valve opening, closing and duration
time.
The actual time and duration of the air
intake.
The duration of the entire intake
process is equivalent to the crank
rotation angle: 180 + + .
: Intake advance angle, generally =
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47
: Intake advance angle, generally =
10-30
: Intake lag angle generally =40-
80
Weichai WD10G220E23 engine:
Exhaust advance angle =34 39
Exhaust lag angle =61 67
61$61$61$61$ %%%%
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Section 3 Valve mechanism
4 valve phase
3 Intake and exhaust valve opening
and closing time and duration.
The actual time and duration of the air
intake.
When the working process is closing to the
end, and the piston angle before the bottom
dead point is , the exhaust valve opens.
When the piston passes the up dead point,
and the after angle is , the exhaust valve is
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48
and the after angle is , the exhaust valve is
closed. The crankshaft rotates 180 + +
during the whole process.
:exhaust advance angle generally =40-
80
:Intake lag angle generally: =10-30
Weichai WD10G220E23 engine:
exhaust advance angle =76 81
Intake lag angle =26 34
61$61$61$61$ %%%%
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Section 4 Fuel supply system
1.overview
(1) composition of fuel supply system
The fuel supply system consists of injection
pump, fuel supply pump, fuel filter, injector,
high pressure oil pipe, low pressure oil pipe
and other accessories.
2 function of fuel supply system
The main function of the fuel supply
system is to continuously feed the engine
with filtrated clean fuel, and inject certain
High pressure pipeOil injector
49
with filtrated clean fuel, and inject certain
amount of diesel into combustion chamber as
certain pressure and quality according to
different engine performance requirements,
which will mix and burn with the air rapidly
. Fuel supply system consists of fuel
injection pump, fuel delivery pump, fuel
filter, fuel injector, high pressure oil pipe,
low pressure oil pipe and accessories.High pressure
pumpFuel filter
Low pressure
pipe
-
Section 4 Fuel supply system1.overview
3 working process of fuel supply system
The engine rotation is transfered from the
coupling or drive gear to the injection pump
camshaft through the advance device. The
camshaft rotation drives the fule delievery pump
suck oil from the fuel tank, the filter clean oil
will be delivered to the plunger through fuel
channel in the fuel injection pump, the plunger
will move upward through the cam shaft rotation,
the piston, the fuel pressure will increased to a
high pressure,and the fuel oil will flow into the
50
high pressure,and the fuel oil will flow into the
injector nozzle through the high pressure oil pipe
and the injector.
When the pressure of the fuel oil delivered to
the injector nozzle reaches above the specified
starting injection pressure of the injector, the oil
will be sprayed into the engine combustion
chamber in the form of mist.
The overflowed or left fuel oil of the fuel
injector and fuel injection pump will flow back to
the fuel tank through their respective fuel pipe.
-
Section 4 Fuel supply system2.Oil injection pump
1 function of injection pump
The main function of the fuel injection pump is
to supply certain amount of high pressure fuel to
the injector in regulation time while at the same
time accomplishing the engine rotary speed
control.
2 basic demand of injection pump
The fuel pressure should ensure the
requirement o f t h e injection pressure and
atomization quality.
The fuel supply should meet the exact
Injection pump high pressure fuel pump
51
The fuel supply should meet the exact
amount of fuel required by the diesel engine.
Ensure the diesel engine working order and
accurate fuel supply within the given time.
The amount of fuel supply and fuel injection
timing could be adjusted to ensure each cylinder
oil supply evenly.
The fuel supply regulation should ensure the
diesel fuel burned completely.
The beginning and ending of the oil supply
must act quickly, the oil cut off must act swiftly
to avoide oil drip.
Injector assemblyconnectoroil return pipe
-
Section 4 Fuel supply system
(3)working principle of injection pump
oil intake process
The plunger will move downward under
the force of spring after the cam convex
portion turned over the highest position
which will creat vacuum in the plunger
upper space (called the pump oil chamber),
when the hole on the plunger sleeve
opened by the plunger upper end, the
52
opened by the plunger upper end, the
diesel fuel in the oil channel of the pump
upper space will enter the the pump oil
chamber through the oil inlet, when the
plunger moves to the bottom dead center,
the oil inlet progress ended.
-
Section 4 Fuel supply system
3 working principle of injection pump
oil supply process
When the camshaft turned to the cam convex
portion and lift up the roller body, the plunger
will move upward under the force of the spring,
the diesel oil will be compressed, and part of the
fuel will return to the upper oil chamber of the
injection pump through the oil hole. When the
plunger upper end cover the upper edge of the
inlet hold on the sleeve,the pump oil chamber
53
inlet hold on the sleeve,the pump oil chamber
will become a sealed oil chamber at the top of
the plunger, the p lunger continues to move
upward, the pressure in the pump oil chamber
will rapidly increased, when the pump oil
pressure > the spring force of the oil outlet valve
+ the residual pressure of the high pressure pipe,
the oil outlet valve will be pushed open, the high
pressure oil will enter the high pressure pipe
through the oil outlet valve, and sprayed into the
combustion chamber through the injector.
-
Section 4 Fuel supply system
3 working principle of injection pump
oil return process
The plunger supply oil upward, when the
plunger moves to a position where the chute
connected to the oil return hole on the sleeve, the
low pressure oil channel of the pump oil chamber
will be connected with
the mid level outlet, radial hole and the chute, the
oil pressure will be lowered, the oil outlet valve
will rapidly closed under the spring force, and
54
the oil supply will be stopped. Then the plunger
will still move upward, when the cam convex
portion turned over the highest position the
plunger will move downward under the spring
force, and the next cycle is begin.
-
Section 4 Fuel supply system
3.governor
1 working principle
The fuel injection volume can be
changed by the governor by controlling
the movement of the governor rake.
When the engine load increased and
the rotation speed decreased, the
governor will automatically increase the
amount of fuel injection to prevent
55
amount of fuel injection to prevent
engine power off.
When the engine load decreased and
the rotation speed increased, the
governor will automatically reduce the
amount of fuel injection to prevent the
engine speed is too high.
Right picture shows the basic structure
of the RAD type speed governor.
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Section 4 Fuel supply system
4.Fuel delivery pump
1 structure
The fuel delivery pump is installed on one
side of the oil injection pump and is droven
by the eccentric cam of the injection pump
camshaft.
2 function
The function of the delivery pump is to
send the fuel from the fuel tank to the low
pressure oil chamber of the oil injection
pump by passing through the oil filter.
56
pump by passing through the oil filter.
The fuel delievery pump is equipped with a
manual pump, which is used to exclude the
air in the low pressure oil channel, and
ensure the channel full of diesel oil, so that
the engine can easily be started.
The screw in the air filter inlet channel is
equipped with a strainer to filter the
impurities in the fuel.
-
Section 4 Fuel supply system4. Fuel delivery pump
3 working principle
The eccentric gear pushes the piston move
downward through the push rod, volume of the
working chamber under the pistion decreased,
the inlet valve closed, the outlet valve opened,
and the volumn of the pressure chamber above
the piston increases, which causes the generation
of a vacuum, and the diesel can flow into the
pressure chamber along the direction of the
arrow by passing through the outlet valve.
Eccentricgear turns away, the piston moves
57
Eccentricgear turns away, the piston moves
upward under the force of the spring, negative
pressure created in the working chamber beneath
the piston, the outlet valve closed, and the inlet
valve openned, oil flows into the working
chamber, the volume of pressure chamber B
decreased by the upward movement of the
piston, the pressure of the diesel in the chamber
increased, oil flowed to the outside, which
pressure controlled by the spring pretightening
force.
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Section 4 Fuel supply system
4. Fuel delivery pump
3 working principle
When the oil input of the fuel delivery
pump is greater than the output, the
pressure of the oil pipeline and the
pressure chamber B will increased to be
greater than or equal to the spring
pretightening force. At this time, the
58
piston can not return to the upper dead
point, the piston stroke will be
decreased, and the amount of the oil
supply will also be increased
accordingly, such as to achieve the
automatic adjustment of the oil volume
and oil pressure.
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Section 4 Fuel supply system
5.Oil injector
1 working principle
The fuel outlet is closed by the injector
nozzle needle under the pressure of the
injector spring. When the injection
pressure reaches the injector spray
pressure, the needle will be jached up,
and the fuel will be sprayed out in the
form of mist.
++++7777........
59
form of mist.
Rotating the regulating screw, the
spring pressure will be changed, that is
the adjustment of the fuel injection
pressure.
-
Section 4 Fuel supply system
5.Oil injector
2 Function and requirement
The function of the fuel injection pump
is to spray the high pressure fuel oil from
the fuel injection pump, under a certain
pressure, in the form of mist.
Requirement:
& Uniform atomization
Rapid injection
Vaporific +1+1+1+1
%%%%
7.7.7.7.
4+4+4+4+........
++++
60
Rapid injection
No post-drop phenomenon
( The shape and direction of the oil
beam suit the form of the combustion
chamber.
3 333++++
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Section 4 Fuel supply system
6.Fuel water-separator
The fuel water-separator contains electric
pump, water filtration, electronic controllers and
other three parts.
Main function of the fuel water-separator
1 To solve problems, such as engine start
failure, engine power off and lack of motivation
in cold regions caused by fuel wax.
2 To solve the problem of high rate of starter
failure caused by the using of starter to discharge
Oil inlet M16X1.5
Electric pump
Electronic controller
61
gas.
3 To solve users complain about the artificial
air exhaust when doing filter maintanance, or
when there were air in the pipe.
4 To solve engine start failures caused by big
temperature changes in some places, sharp
temperature decrease and Cross-regiona l
operation.
Oil outlet M16X1.5
Water filter
controller
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Section 4 Fuel supply system
6.Fuel water-separator
Working principle of electric pump
1 Pump oil and discharge gas: Open the electric
pump by the electronic controller of the electric
oil pump filter, a vacuum negative pressure is
formed by the high-speed rotation of the inner
roller, which will make the fuel oil flow in the
low pressure oil pipe, so that the air will be
discharged from the fuel pipe.
2 T u r n t h e i gnition switch to the ON
position,the fuel water-separatorwill begin to
62
position,the fuel water-separatorwill begin to
pump oil, and will be automatically stopped in 10
minutes, if need to pump oil again, turn off the
ignition switch, restart it again, the new cycle
will begin.
3 When the environment temperature is below
7 , and the ignition switch turned to the ON
position, the fuel water-separator begins to start
heating, and will be automatically stopped when
the tempreture reaches 24 .
! ! ! !
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Section 4 Fuel supply system
7.Fuel filter
Fuel filter is a two-stage series, the
primary filter is felt filter, the fine filter is
paper filter, both of them are mounted on the
same filter seat, with a " " mark casted on
the surface to indicate the flow direction of
the fuel oil.
The function of the filter is to remove
harmful particles and water from the engine
fuel gas system to protect the pump nozzle,
63
fuel gas system to protect the pump nozzle,
cylinder liner, piston rings, etc., reduce wear
and avoid jam.
Fuel oil filtered in the fuel water-seperator,
then into the fuel filter to further filtration,
and finally into the fuel supply pump of the
high-pressure pump.
-
Section 4 Fuel supply system
5.Oil injector
3 injector style
Currently the fuel injectors adopted by the
diesel engine are all closed injector, which
has two kinds, hole type and shaft needle
type.
T h e i n j e c t o r o f t h e W e i c h a i
WD10G220E23 engine is the closed hole
type, the opening pressure is 225+5bar, the
nozzle is thin-walled heat-resistant steel
Pressure adjusting
adjusting washer
Injector body
Filter needle
Inlet port
Outlet port
64
nozzle is thin-walled heat-resistant steel
sleeve, with a insulation sheath in the nozzle
head, the purpose of this design is to reduce
the direct contact between the nozzle and the
gas, so as to reduce the temperature of the
nozzle head, and improve the working
reliability and service life of the nozzle.
Needle-valve part
Tensioning cap
Spring seat
spring
block
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Section 5 Lubrication system
1 Function
The function of lubrication system is to
delivery certain amount of lubricating oil to the
surface of the parts with relative motion,
realizing the liquid friction, reducing the friction
resistance and mechanical wear, and cleaning
and cooling the surface of the parts. Summarized
as follows:
Lubrication lubricating parts surface, reducing
wear and engine power consumption.
65
Wash Cleaning the friction surface, removing
abrasive dust and other foreign matters.
cooling Engine oil can take away heat
generated by friction when cycles in the
Lubricating system.
sealing Forming a film of oil between parts to
improve sealing, prevent leakage of gas and oil.
antirust Forming a film of oil on the surface of
parts to prevent the corrosion and rust.
1- pressure limiting valve;2-oil strainer;3-engine oil pump;4-radiator;
5- pressure limiting valve;6-crankshaft;7-connecting rod small end;
8-camshaft;9-rocker arm shaft;10-tappet;11-injector pump
12-air compressor;13-supercharger;14-main oil passage;
15-pressure limiting valve;16-engine oil filter;17-filter by-pass valve
-
Section 5 Lubrication system
2 lubrication method
1 Pressure lubrication)))) Using the oil
pump to continuously send certain pressure
of lubricating oil to the friction surface,
which is called pressure lubrication, such as
crankshaft bearings, connecting rod bearings
and camshaft bearings, etc.
2 Splash lubrication)))) The way o f
using oil droplets or oil mist flied up by
engine parts to lubricate friction surface is
66
called the splash lubrication, such as cylinder
wall, piston pin, valve cam tappet surface,
etc.
3 Composition lubrication))))
Lubrication of two or more than two kinds.
4 Grease lubrication)))) Such as
lubrication in water pump.
1- pressure limiting valve;2-oil strainer;3-engine oil pump;4-radiator;
5- pressure limiting valve;6-crankshaft;7-connecting rod small end;
8-camshaft;9-rocker arm shaft;10-tappet;11-injector pump
12-air compressor;13-supercharger;14-main oil passage;
15-pressure limiting valve;16-engine oil filter;17-filter by-pass valve
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Section 5 Lubrication system
3 Main parts
The lubrication system is mainly
composed of oil strainer, oil pump, oil
filter, main oil pressure limiting valve,
oil radiator and oil pan and other
components.
67
Oil pan
Engine oil pump
Engine oil filter
Engine oil cooler
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Section 5 Lubrication system
3 main spare part
1 oil strainer
Oil strainer installed in the oil pan for
coarse filter, as shown in the right
picture.
1-oil strainer
2-gasket
3-washer
68
3-washer
4-bolt
-
Section 5 Lubrication system
3 main spare part
2 engine pump
When the gear oil pump works, the driving
gear drives the driven gear to rotate in
counterclockwise direction, the engine oil
fully filled between the alveolar will flow
from the oil inlet chamber to the oil outlet
chamber along the wall of the pump housing,
on the side of the oil inlet chamber, because
of the vaccum generated by the gear
disengagingand the oil continuouslybeing
Drive gear Pump body Pump cover
69
disengagingand the oil continuouslybeing
brought out, the oil in the oil pan will enter
the oil inlet chamber through the oil strainer
under the atmospheric pressure, but on the
other side of the oil outlet chamber, because
of the pressure effect generated by the gear
engaging and oil continuously being brought
in, the oil will be pumped out at a certain
pressure.
Driven gear
Driving gear
spring Pressure limiting valveDriving gear shaft
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Section 5 Lubrication system3.Engine filter
When the engine works, metal wear debris,
dust in the air and carbon particles generated by
incomplete combustion of the fuel oil will go into
the engine oil, and the engine itself will generate
gelatinous precipitates due to thermal oxidation,
if such dirty oil were directly delivered to the
surface of the moving part, mechanical
impurities in the engine will become abrasive
which will accelerate the parts wear and cause
the oil duct obstruction, piston ring, engine
spring
By-pass valve
lever
70
valves and other components cementation.
Therefore, oil filter is designed in the lubricating
system to filter the engine oil and extend the
service life of the machine.
The oil flow direction shown by the arrows in
the right picture, there is a bypass valve on the
upper cover, when the filter insert is blocked, the
bypass valve will be openned by the pressure of
the engine oil, the lubricating oil will flow
directly into the main oil channel without passing
through the valve insert, thus guarantees the
engine oil supply could not be interrupted.
Filter insert
pressing spring
Paper filter
-
Section 5 Lubrication system
4.Enging cooler
The engine oil cooler placed in the engine oil
cooling channel, using the coolant temperature to
control the temperature of the lubricating oil, the
lubricating oil could be cooled by the coolant
when the its temperature is high, when the engine
starts, heat will be absorbed from the coolant to
quickly raise the temperature of lubricating oil.
The Weichai WD10G220E23 uses the plate-fin
radiator, which is installed in the coolant channel
Water inlet port
by-pass valveWater outlet
cover
insert
Water inlet port
Oil outlet port
Oil outlet port
insert
71
on the right side of the engine, with good cooling
capacity, and ensure the engine oil works in a
suitable temperature range.
The engine oil cooler has a safety valve, with an
opening pressure of 0.6Mpa to ensure the engine
is lubricated as usual, the pressure can prevent
the safety valve openned and the engine oil flow
directly into the main channel without by passing
through the oil cooler when the engine oil cooler
blocked.
Water outlet port Oil outlet port
Oil outlet port
Oil inlet port
Engine cooler
-
Section 5 Lubrication system
5.Crankshaft case ventilation
When the engine works, part of the
combustible gas mixture and the exhaust
gas leaks into he crankcase through the
piston rings, which will be condensed
into droplets to dilute the lubricating oil.
Meanwhile, high temperature of the
exhaust gas and the acidic substances or
water vapor in the exhaust gas will erode
Air filter
72
water vapor in the exhaust gas will erode
parts, and make the oil performance
deterioration. In addition, since the
mixture gas and the exhaust gas enters
the crankcase, the pressure in the
crankcase will be inceased, temperature
will be raised, and engine oil will easily
leak outward from the oil seals, gaskets,
etc.
Air inlet pipe
Natural ventilation
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Section 5 Lubrication system
5.Crankshaft case ventilation
The c rankcase o f the We icha i
WD10G220E23 engine uses natural
ventilation, the crankcase is connected to
the air through oil and gas separator.
The funct ion of the o i l and gas
separator is to ensure crankcase pressure
and environmental pressure balanced,
and separatethe high temperatureoil in
73
and separatethe high temperatureoil in
the crankcase, the separated liquid
engine oil will flow back to the oil pan,
which will reduce oil consumption.
-
Section 5 Lubrication system
3.Engine oil filter
The Weichai WD10G220E23 engine
oil filter is a rotary type paper filter,
good filtering effect, strong filtering
pass-ability, and an opening pressure of
250 ) 17.5kPa bypass valve to prevent
the pressure limiting valve openned
when the filter blocked.
The engine oil filter should be changed
74
The engine oil filter should be changed
according to the using condition and
maintenance requirements, can not be
washed and reused.
1-assembly seat
2-washer
3 4-bolt
5-engine oil filter
-
Section 6 Cooling system
1 Cooling system function
The function of the cooling system is to
timely distribute heat absorbed by the
heated parts to ensure the engine
working in the most suitable temperature
conditions.
According to the cooling mode, It can
be divided into two types, the air-cooled,
water-cooled.
Cooling water line
Radiator cap
Radiator
Shutter
Water pump
Water temperature indication
Divide water pipe
Water temperature sensor
75
water-cooled.
The Weichai WD10G220E23 engine
using the forced closed pressure
circulating water cooling.
It consists of the radiator, water
pump,fan, cooling water jacket and a
thermostat device.
Fan
Drain plug
-
Section 6 Cooling system
3 main spare part of cooling system
1 radiator
Radiator is also called water tank,
which is composed of upper water
chamber, radiator core and the lower
water chamber, etc.
Its main function is to increase the heat
dissipation area, accelerate the water
cooling.
76
cooling.
The coolant temperature can be reduced
by 10-15 after passing through the
radiator, a fan installed behind the
radiator to take away the heat released
from the radiator by coordination with
the radiator.
-
Section 6 Cooling system
2 Water pump
The coolant is pumped into the right side water
chamber of the engine by the water pump, first
cool the oil cooler, then entering the water
channel inside the engine to cool the cylinder,
next entering the cylinder head water chamber
through the string holes on the cylinder block and
cylinder head to cool the gas valve, injector and
cylinder head, finally flow back to the water
outlet pipe which end connect with the
Pump shaft
Pump impeller
Water outlet pipe
77
thermostat.
Water inlet pipe
pipe
-
Section 6 Cooling system
3.Thermostat
The engine thermostat contains a thermal
element( wax which could expand when
heated and contract when cooled ) which can
be moved up and down according to the
different remperature.
When the coolant temperature is low, the
wax will contract, which will close the
mouth of the channel leading to the radiator,
and open the channel leading to the water
Thermostat in the small circulation
Thermostat in the large circulation
to radiator
Thermostat Spring
to radiator
Thermostat Spring
78
and open the channel leading to the water
pump(small circulation).
When the coolant temperature rises to a
certain extent, the was will expand, which
will open the mouth of the channel leading to
the radiator, and close the channel leading to
the water pump(large circulation).
From engine
valve
Plunger
Hot sensing body
To pumpCooling water in low
temperature
From engine
valve
Plunger
Hot sensing body
To pump
Cooling water in high temperature
Open the entrance to radiator
Open the entrance to pump
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Section 6 Cooling system
3.Thermostat
Thermostat of the Weichai
WD10G220E23 engine, as shown in the
right picture.
Valve seat
Small spring
& 20579
Valve
spring
Large spring
Vice valve
Shell Support
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Section 6 Cooling system4.Cooling water circulation
The cooling water cycle is divided into small
circulation and circulation which are two kinds
of circulation state of the coolant circulation.
When the temperature is below 71 , the
cooling ability will be weak, which will lead the
coolant temperature rise rapidly, so as to ensure
all parts of the engine rapidly hot or avoid the
engine to be too cold, at this time, the circuit is
short, and the flow is small, which is called samll
circulation, the flow path: thermostat - pumps - -
water- oil radiatorthermostat.
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water- oil radiatorthermostat.
When the temperature is higher than 82 , the
cooling ability will be strong, which will lead the
coolant temperature decrease so as not to get too
high, at this time, the cooling circuit is long, and
flow is large, so called large circulation.The path:
thermostat - water pump-engine oil radiator-
water sleeve-thermostate.
When the temperature is between 71-82 , the
cycle enter mixed circulation, namely, the small
circulation and large circulation are carried on at
the same time.
Large spring
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Section 7 Air intake and exhaust system
1 Function
The intake and exhaust system draws air into
the cylinder, mix and burn it with the fuel oil,
and then discharg the exhaust gas to the outside.
The fresh air enters the turbocharger inlet after
passing through the air cleaner, the pressure and
a ir dens i ty w i l l be increased , and the
temperature will rised.
The fresh air enters the turbocharger inlet after
passing through the air cleaner, the pressure will
be increased, and the air density and temperature
will be increasedaccordingly.
Valve seat
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will be increasedaccordingly.
The cooled air will be burned in the cylinder
after passing through the valve, changed into
exhaust gas and discharged outside the cylinder
through the compression stroke. The exhaust air
will enter the turbocharger through the exhaust
pipe, and will be discharged outside from the
outlet of the turbocharger after pushing the
turbine rotate at high speed.
Exhaust gas from the turbocharger will be
discharged into the atmosphere after passing
through the silencer and carbon removal.
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Section 7 Air intake and exhaust system3 Spare part
1.Air filter
Function The cleaned air will enter the
combustion chamber after filtered from dust and
impurities to reduce the wear between the piston
and cylinder liner, the piston group and valve
group.
Principle After entering the air cleaner, the air
will rotate between the air cleaner housing and
air filter insert under the action of the shroud,
larger particles and dust in the air will be thrown
to the air cleaner housing due to the centrifugal
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to the air cleaner housing due to the centrifugal
force, and will fall along the housing into the
bottom cover and dust collecting bag, the
centrifuged and purified air will pass through the
paper filter and the felt security filter to filter out
fine dust, and at last enter the turbocharger inlet
pipe through the central channel of the safety
filter.
If the filter is dirty, when the engine works, the
degree of the vacuum will be increased, and the
indicator of the filter will turn red to warn that
the air cleaner needs to be cleaned or replaced.
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Section 7 Air intake and exhaust system
3 Spare part
2.Turbocharger
Principle )))) Using the engine exhaust
pressure waves to drive the turbine,
bring the compressor impeller on the
other side to blow air.
Function: Supply additional air to the
engine,so that it canburnmorefuel, and
Engine
Turbocharger
Air inlet port
Air outlet line
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engine,so that it canburnmorefuel, and
generate more power.
Air outlet line
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Section 7 Air intake and exhaust system
3 Spare part
2.Turbocharger
&&&& Structure))))
The turbocharger is mainly composed
two parts , the compressor and t h e
turbine.
The compressor in mainly includes
single stage centrifugal compressor,
diffuserandthecompressorcasing.
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diffuserandthecompressorcasing.
The turbine section: including turbine
shell, single-stage radial turbine.
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Section 7 Air intake and exhaust system
3 Spare part
2.Turbocharger
Air compressor casing, impeller casing
and the middle connection are the main
fasteners, the impeller casing and the
middle connection connected with each
other by bolts and cover plate, the
compressor cas ing and the m idd le
connectorconnectedwith eachother by
Air compressor casing
outlet connectionAir outlet
Rear cover
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connectorconnectedwith eachother by
the rear plate of the , bolts and cover
plate.
A ir compressor cas ing cou ld be
installed in different directions around
the axle.
Inlet connection
Air inletAir compressor impeller
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Section 7 Air intake and exhaust system
3 Spare part
2.Turbocharger
Turbocharger rotor bearing is the inner
supporting type, with floating bearing
locating in the middle connector between
the two impeller, axle force of the rotor
depends on the end surface of the thrust
bearing to support.
Airoutlet
Heat shield
Thrust bearing
Double flowing way
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Air inlet
Turbine and shaftConnection flange
Floating bearing
Thrust bearingand seat Exhaust
flange
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Section 7 Air intake and exhaust system
3 Spare part
2.Turbocharger
Turbine shaft and turbine are welded
together as a whole part, impeller is
installed on the turbine shaft with
clearance coordinate, and be compressed
by nut.
Rotor working rotation speed is from
tens of thousand to more than two
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tens of thousand to more than two
hundred rotation per minute.
Purpose of the moving balance
lengthen the bearing life.
reduce vibration
reduce noise
reduce power lose
reduce rotor load Rotor
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Section 7 Air intake and exhaust system
3 Spare part
2.Turbocharger
Lubrication of the turbocharger
The turbocharger adopts pressure
lubricaiton, the lubricating oil flows into
the oil inlet through the main oil channel
on the fuselage, enter the lubrication
system, and then return back to the oil
panthroughtheoil outlet.
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panthroughtheoil outlet.
Function of the lubrication system.
Coo l hea t gene ra ted f rom the
turbocharger working.
Supply lubricating oil to the bearing
system.
Provide film support for the rotor
moving balance.
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Section 7 Air intake and exhaust system
3 Spare part
3.Intercooler
Function: Cool the heated air from the
turbocharger, increase the air density,
improve engine gas charging efficiency.
Generally speaking, the temperature of
the air will be increased more than
100 a f ter pass ing th rough the
turbocharger,the air will expandafter
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turbocharger,the air will expandafter
being heated, which is not good for the
air inlet, but the temperature could be
reduced by passing through the charge
air cooler.
Classification: air-air charge air
cooler, water-air charge air cooler.
Notice: LG956L engine doesnt have a
charge air cooler.
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Section 7 Air intake and exhaust system
3 Spare part
4.Silencer
Change the flow direction of the
exhaust air to consume the energy of the
exhaust air by ways of , and balance air
flow pressure fluctuation to get the
needed attenuation character, so as to
reduce the noise.
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Section 8. Common malfunction
1. Engine does not startSerial
numberCause of malfunction Repairing method
1 Starter motor speed is too low Check the starting system, cranking speed shall not be less than 110 r/min.
2 Air in fuel supply system
1. Check fuel pipe connector for loose. Release bleed screw on the fuel filter, and use hand pump to pump fuel, until the overflow of fuel without air bubbles. 2.Release high pressure fuel pipe connection on injector, and use hand pump to pump fuel, until the overflow of fuel without air bubbles.
3 Fuel line blocked Check fuel supply lines for unobstructed.
4 Fuel filter blocked Replace the spin-on filter element of fuel filter assembly.
5The delivery pump can not feed fuel or feed intermittently
Check the fuel inlet lines for leaks and fuel delivery pump for malfunction.
6Fuel injection less, no injection or injection pressure low
1. Check the injector spray condition; 2. whether the injection pump plunger and the outlet valve is worn or stuck, whether the plunger spring and outlet valve spring is broken.
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7Starting system circuit wiring error or poor contact
Check the wiring is correct and reliable.
8 The battery power insufficient Charge the battery.
9Starter motor carbon brushes and commutator contact poor
Repair or replace the electric brush; clean the commutator surface by abrasive paper and blow it clean.
10Low compression pressure low due to piston ring excessive wear or valve leaks
Check valve clearance, valve spring, valve guides and sealing of valve seat, it is necessary to grinding valve seats if the sealing is poor.
11Fuel shut-off solenoid connector may be loose or dirty, corroded
Tighten, clean or replace.
12Fuel injection timing is not assembled correctly
Check and adjust.
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Section 8. Common malfunction
2. Engine lacks of powerSerial
numberCause of malfunction Repairing method
1 Air intake blockedCheck the air filter and air intake, clean or replace the air filter element.
2Exhaust back pressure is too high
Check valve timing, adjust if necessary; clean exhaust pipes.
3 Fuel lines leaking or blockedCheck sealing conditions of fuel lines and fittings,check fuel filter for blocked, replace spin-on filter element, check injection pump sealing.
4Fuel injection pump plunger excessive wear
Check and replace the plunger and barrel assembly.
5 Fuel injector poor atomizationCheck fuel injection pressure,clean up the carbon
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5 Fuel injector poor atomizationCheck fuel injection pressure,clean up the carbon deposit, adjust and repair.
6Fuel injection advance angle is smaller or larger than normal
Check and adjust.
7 The air phase is error Check and adjust valve timing and valve clearance.
8 Cylinder head gasket air leaksTighten the cylinder head bolts in sequence in accordance with specified torque or replace cylinder head gasket.
9 Valve sealing poor Grind or replace to regrind.
10Piston rings is worn excessively
Replace piston rings.
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Section 8. Common malfunction
3. Exhaust black smoke
Serial number
Cause of malfunction Repairing method
1 Air intake blocked Check the air filter and air intake pipes and clean-up.
2 Poor fuel quality Use fuel up to specification
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3 Fuel injector poor atomization Check, repair, or replace.
Valve clearance is excessiveAdjust valve clearance in accordance with the standard
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Section 8. Common malfunction
4. Exhaust white smoke, blue smoke
Serial number
Cause of malfunction Repairing method
1Poor fuel quality, with excessive water in fuel
Replace fuel up to specification.
2Compression pressure is low, incomplete combustion
Check piston ring and cylinder head gasket and replace it.
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2incomplete combustion replace it.
3Air supply or fuel feed timing is not correct
The specialized staff to check and adjust.
4Compression pressure is low, incomplete combustion
Check piston ring and cylinder head gasket and replace it.
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Section 8. Common malfunction
5. Oil pressure is too low
Serial number
Cause of malfunction Repairing method
1 Oil thin, or use improper oilSelect appropriate oil according to specification
2The oil pump rotor is worn or assembly clearance is too large
Replace the pump
3 Oil filter pressure regulator valve failure Repair
4 The pump inlet pipe cracks Repair, replace
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4 The pump inlet pipe cracks Repair, replace
5 The pump inlet pipe mounting bolts loose tighten to specified torque
6 Shaft bearing clearance is too large Check and replace
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Section 8. Common malfunction
6. Oil pressure is too high
Serial number
Cause of malfunction Repairing method
1Temperature is too low, the oil viscosity is large
Choose specified type of oil, it is required to run at slow speed after start, check wheel the oil temperature is normal
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viscosity is largetemperature is normal
2 Pressure relief valve blocked Check, clean
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Section 8. Common malfunction
7. Excessive oil consumption
Serial number
Cause of malfunction Repairing method
1 External oil line leaks Check and repair
2 Diesel engine is overload Reduce the load
3 The type of oil is improperly Use as required
4 The piston is stuck or excessively worn Check, repair, and replace if necessary
5 Cylinder bore is worn excessivelyCylinder boring for increased piston or
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5 Cylinder bore is worn excessivelyCylinder boring for increased piston or installing the repair-using cylinder liner
6Valve guide is worn, valve stem sealing failure
Check and replace
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Section 8. Common malfunction
8. High coolant temperature
Serial number
Cause of malfunction Repairing method
1Insufficient cooling water, the water flow is too small
Check whether the cooling water is sufficient and add if necessary
2 Whether the belt is too loose Adjust
3 Water pump leakage Repair in time
4Thermostat is failure or damaged
Check and replace
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damaged
5Water temperature sensor is damaged, the water temperature sensor failure
Check whether the actual temperature is identical to the gauge indicating value; if not, replace the temperature sensor or the temperature gauge
6The cylinder head gasket is blow-out
Check and replace
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