01 Engine System LG956L

download 01 Engine System LG956L

If you can't read please download the document

description

SDLG LG956L ENGINE SYTEM STEP1 TRAINING MATERIAL .

Transcript of 01 Engine System LG956L

  • Chapter 3 Engine System

  • 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

  • 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

  • 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,

  • 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.

  • 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 .

  • 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

  • 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,

    7

    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.

  • 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

    8

    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

  • 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

    9

    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.

  • 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.

  • 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

  • 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.

  • 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

    13

    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

  • 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.

  • 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

    15

    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

  • 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

    16

    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

  • 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

    17

    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

  • 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

  • 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

    19

    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

  • 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.

  • 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.

  • 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.

  • 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

    23

    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

  • 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

    24

    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.

  • 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 .

    !!!! "!"!"!"!

    ####

  • 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.

  • 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.

  • 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

  • Section 2 Crank and connecting rod mechanism

    3 Crankshaft flywheel

    assembly

    Mainly consists of crankshaft,

    flywheel and other accessories.

    & 20529

  • 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.

    *+*+*+*+ %$%$%$%$ ++++

  • 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

  • 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

  • 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

  • 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

  • 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

  • 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.-.-.-.-. ........

    -.-.-.-.

  • 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.

    -.-.-.-. ........-.-.-.-.

  • 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 $ $ $ $

    38

    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

    #1#1#1#13333%%%%$$$$

    4$4$4$4$

    %%%%

  • 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 $ $ $ $

    39

    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.

    #1#1#1#13333%%%%$$$$

    4$4$4$4$

    %%%%

  • 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

    -.$-.$-.$-.$

    5%5%5%5%

    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$61$ %%%%

  • 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 =

    -.$-.$-.$-.$

    5%5%5%5%

    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$61$ %%%%

  • 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

    -.$-.$-.$-.$

    5%5%5%5%

    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$61$ %%%%

  • 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.

    !"#$%#" !

    $ %&

  • 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.

    !"#$%

  • 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.

    !"#$%

  • 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++++

    4$4$4$4$

    ++++!0882!0882!0882!0882

  • 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

  • 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 .

    ! ! ! !

    "#$"#$"#$"#$

  • 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

  • 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

  • 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

  • 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

  • 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

  • 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

  • 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

  • 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.

    80

    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

  • 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

    81

    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.

  • 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

    82

    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.

  • 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

    83

    engine,so that it canburnmorefuel, and

    generate more power.

    Air outlet line

  • 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.

    84

    diffuserandthecompressorcasing.

    The turbine section: including turbine

    shell, single-stage radial turbine.

  • 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

    85

    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

  • 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

    86

    Air inlet

    Turbine and shaftConnection flange

    Floating bearing

    Thrust bearingand seat Exhaust

    flange

  • 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

    87

    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

  • 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.

    88

    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.

  • 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

    89

    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.

  • 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.

    90

  • 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.

    91

    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.

  • 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

    92

    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.

  • 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

    93

    3 Fuel injector poor atomization Check, repair, or replace.

    Valve clearance is excessiveAdjust valve clearance in accordance with the standard

  • 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.

    94

    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.

  • 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

    95

    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

  • 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

    96

    viscosity is largetemperature is normal

    2 Pressure relief valve blocked Check, clean

  • 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

    97

    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

  • 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

    98

    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

  • 99