AT6602 - Chassis Component Design

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    ui

    ,RAJALArcSnui

    ENGII.,{EERING

    coLLB

    Gtr

    DEPARTMENT

    OF AUTOMBILE

    ENGINBERTNG

    AT

    6

    i" t

    z-

    AUToMorlvE

    CHASSIS

    coN{poNENTS

    D

    E

    SIGN

    ,

    Part

    A

    Unit

    1

    [. Differentiate

    betrvcctt

    horizontal

    lozenging

    ancl

    lateral

    bending

    in

    a

    laddcr'chassis.

    Horizorltal

    lozenging

    -

    the

    conditions

    like

    pot-holes,

    road

    joints,

    surface

    burnps

    and

    curbs

    cause

    thc chassis

    Ii'ame

    to

    distort

    to

    a

    parallelograur

    shape.

    Lateral

    Bending

    -

    the

    chassis

    is exposed

    to

    lateral

    side

    force

    that

    nay

    be

    due

    to

    the camber

    of

    the

    road,

    side

    lvind,

    centrifugal

    fbrce

    rvhile

    turning

    a

    comer,

    or

    collision

    rvith

    some

    object.

    2.

    Mcntion

    th-e

    different

    configurations

    of

    laminatcd

    lcaf

    spring

    srrspcnsions.

    Fully

    elliptic,

    three-quarler

    elliptic,

    half

    or

    senri

    elliptic,

    quafter

    elliptic,

    transvet'se

    mounted

    semi

    elliptic

    and

    cantilever

    mounted

    serrri

    elliptic.

    Discuss

    the

    various

    loads

    acting

    on

    a chassis

    frame

    Vcrtical

    bending

    Longitudinal

    torsion

    Lateral

    bending

    Horizontal Iozenging

    What

    is

    an energy-absorbing

    frame

    The modern

    vechile

    frames

    are made

    by constructing

    the fi-ont-

    and

    reap

    end

    of

    the

    frame

    in

    a

    manner so

    that

    it

    cmmbles

    in

    a concertina

    manner

    during collision

    and absorb

    the

    main

    shock

    of

    the

    irnpact.

    What

    are

    the factors

    considered

    rvhile

    designing

    a

    torsion

    bar?

    Torsion

    bar

    should

    be

    designed

    under

    maximum

    dynamic

    loacl

    (bump

    road) considerations

    and

    the

    corresponding

    allorvable

    stress.

    6.

    What

    are

    the functions

    of front

    axle?

    The

    liont

    axle caries

    the rveight

    of

    the

    front

    part

    of the autourobile

    as

    rvell

    as

    facilitates

    steering

    and

    absorbs

    shocks

    due

    to road

    surface

    variations.

    rf^

    \'\.

    \-,

    3.

    4.

    5.

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    7.

    What

    types

    of

    scctions

    a,

    the

    front

    arle?

    At the

    centei

    "

    l"

    section

    the

    ends

    circular

    or

    oval ,-

    load.

    8.

    Typcs of

    support

    in

    the

    :r

    Sirnply

    supported,

    Cantil

    supported.

    9.

    Name

    the

    different

    sectir

    a:

    I-section

    b.

    section

    e.

    T-sec

    10.List

    the

    function

    of

    vehic

    .

    Driving

    thrust

    or

    dri

    .

    When

    brake is

    appli

    .

    For

    practical

    purpo

    load.-

    1.

    Classify

    the

    various

    axle-

    E,lliot

    type,

    reverse

    Elliot

    rr

    2.

    What

    is

    thc

    differenct.

    Iubrication?

    AIso

    mentir,

    axles.

    Hydrodynamic

    lubrication

    separated

    by the presSurr

    lubrication.

    Hydrostatic

    lu

    lubrication

    in

    rvhich

    the

    n

    of

    oil,

    but

    instead

    of

    bc

    supplied

    by

    an

    external

    oii

    3.

    A

    steering

    gearbox

    has a

    Assumc

    thc

    driver

    to

    ex

    rvheel 0.4m

    diameter,

    dc,

    Refer

    notes

    on

    lront

    axle

    r

    provided

    at

    the

    middle

    and

    at

    the

    ends

    of

    provided

    to withstand

    vertical

    bending

    and at

    lss-section

    is

    providecl

    to

    withstand

    torsional

    .

    f

    +

    omotive

    frame

    ,er

    bean,

    .

    Over

    hanging

    beam

    and

    Hinged

    I'

    t

    irsed

    in

    the

    vehicle

    frame.

    lhannel

    section

    c.

    Circular

    section

    d. L

    )n.

    l,-

    Iramc

    F

    ng

    force

    transmitted

    to

    the u.hcels

    :

    I

    braking

    torque

    will

    be

    produced

    i

    pynamic

    load

    is

    equal

    to

    2

    times

    of static

    .

    i

    *

    i

    i

    Unit

    2

    i

    .i

    ubs

    employcd

    in

    automobiles.

     

    re,

    Lemoine

    type

    and

    reverse

    lemoine

    type

    between

    hydrostatic

    and

    hydrodynamic

    the

    kind

    of

    lubrication

    employed

    in

    dead

    i

    rs

    said

    to

    exist when the moving

    surfaces

    are

    rif a

    continuous

    unbroken

    film

    or

    layer

    of

    'ication

    is essentially

    a

    form

    of

    hydrodynamic

    'tal

    surfaces

    are

    separated

    by

    a

    complete

    film

    g

    self-generated,

    the

    separating

    pressure

    is

    ump.

    ,ear

    ratio

    of

    16:1

    and

    an

    efficiency

    of

    g5%.

    t a

    force

    of

    60

    N at

    the

    rim

    of

    the

    steering

    'mine

    the

    torque

    at the

    drop arm

    shaft.

    l

    steering

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    {.

    What

    are

    the functions

    of

    front

    axle?

    The

    fi'ont

    axle

    carries

    the

    weight

    of

    the

    front part

    oi

    the

    automobile

    as

    "l'e11

    as facilitates

    steering

    and

    absorbs

    shocks

    due

    to

    road

    surface

    variations.

    5.

    What

    types

    of

    sectiotts

    are

    provided

    at

    the

    middle

    anrl

    at the

    ends

    of

    the

    front

    axle?

    At

    tho center "

    I"

    section

    is provided

    to

    withstand

    vertical

    bending

    and

    at

    the

    ends

    circular

    or

    oval cross-section

    is

    provided

    to r,vithstand

    torsional

    load.

    6. what

    are

    the

    causes

    of

    steering

    gcomctry

    errors

    rvith up

    anrl

    dorvn

    rvheel

    movement?

    Toe-in-and.toe-out

    and

    canalrer'of

    the

    whecl

    7.

    Axial

    forci

    on

    each

    friction

    surface is

    1400

    N,

    mean

    ratlius of

    friction

    lining

    is

    90

    mm,

    the co-efficient

    of friction

    is

    0.3

    and

    the

    number

    of

    pairs

    of friction

    surface

    is 4.

    Determine

    the

    torque

    transmitted

    through

    this

    clutch

    Hint:

    Use

    tLe formula

    T:

    n

    p

    w

    R to

    find

    the

    torque

    transniitted

    by

    the

    clutch

    8.

    The

    u'lteel

    basc

    of

    a

    vchicle is 2m

    ancl

    thd

    distance

    betrvecn

    the

    points

    of

    front

    axlcs

    is 1.3

    m.

    while

    taking

    a

    turn,

    the

    outside

    lock

    makcs

    an

    angle

    of

    20o.

    Determine the inside lock

    angle

    for

    correct

    steering.

    Hint:

    use the

    formula cot

    rp

    -

    cot 0

    :9

    b

    9. In

    which

    section

    of

    the

    front

    axle,

    torsional

    and

    bending

    moments

    are

    predominant?

    At centre

    portion

    of

    front

    axle,

    bending

    moment

    is

    predominant

    at ends

    of

    the

    front axle due

    to

    braking

    of

    the wheels.

    l0.Give

    the

    type

    sections

    provided

    at

    the

    middle

    and

    at the end of the

    front

    axle.

    Front

    axle is made of I-section

    in

    the

    center

    portion,

    while

    the

    ends

    are

    made

    either

    circular

    or elliptical.

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    Unit

    3

    what

    are

    the

    factors

    to

    be

    considered

    whire

    design_ing

    an

    automoti'e

    friction

    clutch?

    --E-----'

    a.

    selection

    of proper

    type

    of

    clutch

    that

    is

    suitabre

    for

    given

    apprication.

    b'

    Selection

    of

    suitable

    material

    at

    the

    contacting

    surfaces.

    c.

    Designing

    the

    clutch

    for

    sufficient

    torque

    capacity.

    d.

    Engage,rent

    and

    discngagement

    srrourd

    u.

    *irtrort

    shock

    or

    jerk.

    e'

    Provision

    for

    carrying

    arvay

    the

    heat

    generated

    at

    the

    rubbing

    surfaces

    with

    an

    cxar,pre

    gi'e

    any

    hvo

    materiar

    p.op..ii..

    for

    designing

    a

    friction

    clutch.

    a.

    The

    two

    materials

    in

    contact

    must have

    a

    high c-refficient of friction.b'

    The

    materiars

    in

    contact

    must

    resist

    *"ur.fi..ts,

    such

    as

    s"oring,

    galling,

    and

    ablation

    c'

    The

    materiars

    shourd

    possess

    good

    thermarproperties,

    high

    heat

    capaciry,

    good

    thermal

    conductivity,

    rvithsr*a

    rrlgr,

    iffiratures

    Why

    is cone

    clutch

    more

    effective

    flrat

    plate

    clutch

    Simple

    in

    construction

    More

    area

    of

    tiictional

    contact

    .

    4'

    what

    are the

    types

    of

    ciutch

    operating mec,anisms used

    in

    automobile?

    Mechanical

    -

    Movcment

    at

    the

    pedal

    pad

    is

    transferred

    through

    an

    operating

    mechanism,

    to

    the

    crutch

    assembry

    on

    the

    rear

    of

    trre

    flywheel.

    Hydraulic

    -

    The

    pedar

    acts

    on

    a

    master

    cylinder,

    co,nected

    by

    a

    hydrauric

    pipe

    and

    flexible

    hose,

    to

    a

    slave

    cylinder,

    mounted

    on

    the

    clutch

    hou'bing.

    5.

    When

    is

    the

    torque

    capacity

    of

    the

    clutch

    greates.t?

    At

    minimum

    or zero

    srip, the torque capacity

    of

    the

    crutcrr

    is

    greatest.

    6.

    List

    out

    the

    various

    components

    of

    a

    clutch.

    Driving

    member

    -

    pressure

    plate

    assembly

    and

    fly

    wheel

    Driven

    member

    -

    disc

    or

    prate

    assembiy

    and

    the

    clutch

    shaft.

    7'

    Axiar

    force

    on

    each

    friction

    surface

    is

    1400

    N,

    mean

    radi,s

    of

    friction

    Iining

    is

    90

    mm,

    the

    co-efficient

    of

    friction

    is

    0.3

    and

    the

    number

    of

    pairs

    of

    friction

    surface

    is

    4.

    Determine

    the

    torq,e

    transmitted

    through

    this

    clutch.

    :ilXlrr.

    rhe

    formula

    T:

    n

    p

    W

    R

    to

    find

    the

    torque

    transmi*ed

    by

    rhe

    l.

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    8.

    What

    is

    thc

    purpose

    of

    transnrission

    system

    in

    an automobilfl

    Transmission

    is the

    mechanism

    which is used to

    tiansfer

    the

    power

    developed

    by

    engine

    to

    the wheels

    of an

    automobile. The transmission

    system

    of

    an

    automobile

    includes clutch,

    gear

    box,

    propeller

    shaft

    axle

    and

    wheels,

    etc.

    The main function of

    the transmission

    is

    to

    provide

    the

    necessary variation

    to

    the

    torque

    applied

    by

    tlre

    engine to

    the wheels.

    This

    is

    achieved

    by

    changing

    the

    gearing

    ratio

    between

    the

    engine and

    the

    drive

    shaft.

    9. What

    is the

    major factor

    limiling

    the

    clutch capacity?

    .

    Clutch

    temperature

    is

    the

    rnajor factor

    limiting

    the clutch

    capacitl,.

    10.Why

    is a

    cone

    cltch more cffcctive

    than

    plate

    clutch?

    In

    cone

    clutch

    normaf

    force

    acting on

    the contact

    surfaces

    is

    larger

    than

    the axial

    force

    as

    compared

    to

    single

    plate

    clutch in

    u,hich the normal

    force acting

    on

    the

    contact.surfaces is equal

    to the

    axial

    f,orce

    Unit

    4

    1.

    Mention

    the

    merits

    and

    limitations

    of

    gear.drives.

    Mcrits:

    o

    No

    chain

    or

    belt

    to

    break .

    .

    High

    po\\rer

    transmission

    rvithin compact

    space

    Disadvantages:

    o

    Noisy

    .

    Cannot

    transmit

    power to longer

    distance.

    What

    is

    meant by

    dynamic

    and

    static

    tooth

    loading in

    gear

    drives?

    Holv

    it

    is

    calculated?

    Static

    gear

    loads

    are

    generated

    by

    statically

    loading

    the input

    shaft

    at the

    specified

    input

    torque,

    without

    any

    motion being

    imparted

    to the

    gears.

    Dynamic

    load

    occurs

    when.

    a

    pair

    of

    teeth

    is

    just

    coming

    into

    mesh.

    What

    are

    the

    possible

    arrangements

    to

    achicve

    12 speeds

    from

    a

    gear

    box?

    Quick

    change

    gear

    box

    What

    are

    the

    differcncc

    betrveen

    a constant

    mesh

    gear

    box

    and

    sliding

    mesh

    gear

    box?

    In

    sliding

    mesh

    gear

    box,

    the

    individual

    gear

    ratio

    is

    chosen

    by sliding

    the

    selected

    gearwheel

    axially

    along

    the splined

    main output

    shaft,

    but in

    constant mesh

    gear

    box,

    the

    gears on

    the lay

    shaft

    and

    the main shaft

    are

    (5/

    )

    4.

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    W

    5.

    always

    in

    a

    constant

    mesh,

    the

    gear

    ratio

    clutch.

    is

    selected

    by

    engage

    the

    dog

    Why

    is

    geomctric

    progression

    in

    gcar ratios?

    For

    heavy

    commercial

    vehicres,

    the

    gear

    ratios

    are

    usualry

    arranged

    in

    geometric

    progression.

    The

    basis

    for

    this

    is

    to

    have

    the

    engine

    operating

    within

    the

    same

    speed

    range

    in

    each

    gear.

    This

    r.l,ourd

    ensure

    that

    in

    each

    gear,

    the

    operating

    fuel economy

    is

    similar

    When

    is

    maximum

    vchicle

    speed

    attained?

    The

    maximum

    vehicre

    speeci

    is

    attained

    when

    the gear

    is

    set

    in

    top

    and

    the

    throttle

    is

    held

    fully

    open.

    7.

    Compare

    sFur

    gear

    and

    hericar

    gear

    transmission

    in

    automcbire.

    In

    a

    spur

    gear

    trre

    teeth

    are

    straight-cut

    and

    the

    edge

    of the

    teeth

    isfarrlet

    to

    tlie

    axis

    of

    rotation.

    In

    a

    helical

    gear

    the

    teeth

    are

    cut

    at

    an

    angre

    and

    the edge

    of

    the

    teeth

    is

    non parailel

    to

    the

    axis

    of

    rotation.

    Helical

    gears

    operate

    quietry

    compared

    to

    spur

    gears.

    Spur

    gear

    can

    be used

    onry

    in

    a

    transmission

    involving

    parallel

    orientgtion;

    the

    gears

    can

    be

    meshecr

    correctly

    only

    if'they

    are perfectly

    parallel

    ,o

    .r"h

    other.

    A

    h.li.;i;;;;

    on

    the

    other

    hand

    can

    be

    mesrred

    in parailel

    or

    cross

    orientation.

    8.

    sketch

    and

    name

    the

    parts

    of

    a propeiler

    srraft

    in

    heavy

    road

    trucks.

    9'

    At

    rvhat

    conditions

    the

    vehicre

    attains

    maximum

    speed.

    Maximum

    road

    speed

    is

    achieved

    in

    the gear

    ,rh.n

    power

    availabre

    equals

    to required power.

    [0.Define

    term

    traction

    and

    tractive

    effort

    The

    force

    ava,abre

    at

    the

    contact

    between

    the

    rear

    rvheer

    tyres

    and

    road

    is

    knorvn

    as

    tractive

    effort.

    The

    ability

    of

    the

    rear

    wheels

    to

    transmit

    this

    effort

    without

    slipping

    is

    knor.vn

    as

    traction.

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    2.

    3.

    5.

    Unit

    5

    1. Write

    down

    the

    types

    of

    rear

    axle

    housing.

    Semi

    floating

    axle

    housin-q

    Three-quarter

    fl oating

    axle

    housing

    Full

    floating

    axle housing

    In

    a single

    plate

    dry

    clutch,

    the

    ratio

    of rnean

    raclius

    to

    ilre

    facc

    lvidth

    is 4

    and the

    mean

    radius

    of the

    friction

    lining

    is

    110

    mm.

    determine

    face

    width

    of

    the

    friction

    lining.

    Hint

    :

    use

    the formula

    R/

    b

    :

    4.

    Why

    is

    the

    propcller

    shaft

    critical

    speed

    irnportant?

    It is the

    speed

    at

    rvhich

    the

    propcllcr

    shaft

    rotates

    violently

    lencling

    to

    failure

    of the

    propeller

    shaft.

    This

    should,

    be avoided.

    The

    length

    of the

    propeller shaft

    govems

    the

    critical speed

    of

    the

    propeller

    shaft.

    What

    are

    the typcs

    of

    stresses

    expcrienced

    by

    semi-floating

    axlc

    shafts?

    Driving

    torque

    as

    r.vell

    as

    both

    vertical

    and

    horizontal

    loads.

    Vertical

    load

    produces

    shearing

    force and

    bending moment.

    The

    horizorrtal

    force

    due

    to

    tilting of

    the

    vehicle. cornering

    centrifu-eal

    fqrce

    or

    side r.vind

    gives

    rise

    to

    both side

    thrust

    and

    a

    bending

    moment.

    State the

    formula

    used to cornpute

    critical speed

    of

    a

    propeller

    shaft.

    Why it

    is

    so important?

    Critical speedN"

    :ry99

    -

    ^W

    Y

    It

    is important

    to

    calculate

    the

    critical

    speed

    because,

    whirling

    may

    occur

    at certain

    critical

    speed leading

    to

    failure

    of

    the

    material.

    So,

    the

    speed

    of

    operation

    of

    the

    propeller

    shaft should

    be ahvays

    lower

    than the critical

    speed.

    6.

    What

    are

    the types of

    stress

    expericnced

    by semi-floating

    axlc?

    Driving

    torque as

    well

    as both vertical

    and

    horizontal

    loads.

    Verlical

    load

    produces

    shearing

    force

    and

    bending

    moment. The

    horizontal

    force

    due

    to

    tilting

    of

    the

    vehicle, cornering centrifugal force

    or

    side

    wind

    gives

    rise

    to

    both

    side

    thrust

    and a

    bending

    rnoment.

    {fzi

    \tJ

  • 8/17/2019 AT6602 - Chassis Component Design

    8/14

    7.

    ?.i

    \,)

    Give

    the

    expression

    for

    c,

    Critical

    specd

    N.:

    '

    A

    hatch

    back

    vehicle

    engir

    gear

    ratio

    is

    3:1.

    If

    a prop.

    used,

    determine

    the

    insiri

    assunring

    a

    safe

    shear

    strcs

    Hint:

    Use

    formulas:

    p:1

    and

    r:

    ft

    IR

    9.

    Functions of

    final

    drive

    Changes

    the

    directio:

    o

    Bcvcl

    gears

    are

    user

    .

    Pinion-

    gear

    with

    less

    .

    Ring

    gear-

    gear

    with

    l0.Dcsign

    criteria

    of

    shaft

    cli:,

    .

    Full

    floating

    _

    same

    (,

    o

    Diamcter

    is

    uniformlr

    o

    Diameter

    is

    uniformlr

    :ulating

    critical

    specd

    of propellershaft.

    ry-@G

    develops

    3OkW

    at

    1450

    rpm

    and

    its

    bottom

    er

    shaft

    of

    38

    mm

    outside

    diameter

    is

    to

    be

    diameter

    of

    mild

    steel

    tube

    to

    be

    used,

    ,f

    56

    x

    103

    kpa

    for

    the

    mild

    steel.

    lI.

    tw

    )0'

    ;,

    ,ov/er

    to

    90

    degrce

    transmit

    power

    to

    90

    clegree

    umber

    of

    teeth

    rre

    number

    of

    teeth.

    rtitcr

    .

    .meter

    taryrng,

    more

    in

    wheel

    side

    I

    ,arying,

    same

    diameter

    at

    tooth

    encl.

  • 8/17/2019 AT6602 - Chassis Component Design

    9/14

    Lont

    il

    udrhul Tortior*

    t"

    WhaYr

    d,rb3onally OfPoxEl-

    ,|vont

    .fq\{ ovtv bumga

    ,ritmrrlfo.ylr.ou\

    ,

    t^r

    t,*o

    i

    lurisfrA

    r%

    offo.lri[-c.

    clr'rec

    h'on ,\o

    V^at

    i

    bolft

    &l

    .,lnar

    anct

    tfu

    c\oss-

    m.tmLrvt

    avc

    ggjojecfed

    h

    \ongiFudi'ral

    tovs{o't,

    ,

    rr:hir

    h

    ol-r'.l,t"ovF,r

    lt"q.

    Ch

    a"u*r'r.

    .

    PartB r/(.?')

    Unit

    1

    I

    LJ"

    1.

    Calculate

    the

    maxintunt

    bending

    moment

    and

    maximurn

    section

    rnodulus

    tbr

    the

    side

    member

    of

    a

    vehicle

    frame

    l-raving

    channcl

    section

    anci

    the

    following

    particulars

    are

    Wheel

    base

    :

    180

    cm,

    Overall

    length

    =

    360

    cni,

    Equal

    overhang

    on

    either

    side.

    ,270

    kgf

    acting

    45

    cnr

    in

    front

    of

    front

    axle

    ,180

    kgf

    acting

    45

    crn

    behind

    front

    axle,

    180

    kgf

    acting

    45

    cm

    in

    front

    of

    rear

    axle,

    67.5

    kgf

    acting

    45 cm

    behind

    the

    rear

    axle

    In

    addition,

    there

    is a

    uniformly

    distributed

    load

    of 1.75

    kgf/cm

    run

    o\/er

    entire

    length

    of

    the

    chassis.

    Assume

    dynamic

    stress

    is

    twice

    the

    static

    stress'

    Solution:

    Chassrs

    0prvcxlinq

    Condibions:.

    1-h"

    d*3,

    -l

    tr-rrdrv

    tfa,rdrhg

    "{

    tfia

    t{t,rd

    b

    |,fr"

    0",

    no

    rroc"d'

    Thr

    mt1"

    I

    ood,'ng

    5ruoJrbnr'

    .

    Ci)

    vevlical hending:

    af

    ir:.

    end.r,

    by

    tfi"

    V{.hick*

    t-qpiymanY,

    (Yorrnd

    tfu

    raid.dlc

    Coolc&:ung

    a

    *tu,vx

    l**

    ix

    t"'lYott^a

    tJi\[.d

    ax/;,r

    antcl

    o-

    c'rr.r'3ht

    e#"al:ot1l

    l,l

    ii-

    Pdi*lngev,r

    ar,d

    /r^ggog,

    a5

    conrr-itvqf''d

    ,-{

    f

    Fa

    u:trarf

    barc,

    lffrn

    tfi-a

    *r'ctr

    m"Lrnbzvs

    crnd

    y.rav

    yaad

    oh^td.l

    afi

    crruf,orrphi{r Chq^tn'A

    }ra7rP2"1

    pviov

    dl

    (ondihbns

    t

    '"'

    Ll,ahv'u"

    ,rr. -{.rrtq

    D

    ,l

    Ci",al,r^X

    t**t_dt

    qx?€.rtr' nc{A

    tuu'

    lhcJ

    fnclq&.

    end*

    4

    tfu

    ,cl14v;a

    a\r

    o,Yr

    Suljrc{.ed

    h:

    vtvHca.(

    bmdLq

    (au-v{ng tftm

    f0

    '[ag

    f"'

    lt''r

    Cenfnal

    r.g'bn,

    LongRudinal

    torsbr.

  • 8/17/2019 AT6602 - Chassis Component Design

    10/14

    i0t,

    Y

    L.g:g

    B

    enctr.ng

    r

    fiu

    chct,vrr*

    n

    {xpo1r.d,

    G

    1a6.r*

    {r^.c&l

    ,Jorcn

    }f"a-t

    f\

    t

    -

    a,r-rl

    h

    t0.o

    chqmbrv

    -t

    lf,u

    rroao{,

    Aiclo

    Lopnd,

    celt-vr}ugaf

    "to*:'

    tr:hiic

    huvnin3

    a

    Covruv,

    ov

    (olli,sion

    qrith

    ,romr

    objccE.

    J(n

    ttr*^

    oppoA{^

    lt

    ry.

    i*"g

    S".*a-,,R^

    o

    Y{/$rtt

    o.

    bhdf",S

    rnornmr

    olrn

    or. w\t

    C-ha,ua'"r

    xd..rt

    ty\tmbru\

    .\o

    tLd-f

    &xthat+lt

    fvaru

    trnd.r

    {a

    ho..o

    i.

    &.".cho,.

    af

    tfur

    {wu.jor,-

    ' \ rvr'

    tlon?9nrq1

    LoZonging,l

    Honpnfal

    Lo1ensinq,,

    -

    .,r

    ,,

    .

    ,

    ,

    R

    ch4lh'A

    ly."*-

    d

    drr'"u

    {ovuravo(

    oy

    bacr

    uayc{

    J't

    Conhnuo\

    truLjutzd"

    b

    ohsl

    impcrl

    roihh

    yoacl

    obt{acLu>

    'fu^ch

    a'*

    pcl-

    liol+,

    yocrcl;'oint,

    Srrr.faca

    hrirnpa,

    a-rrct

    cqrM

    61.^6

    oif,sv

    urharl,r

    Pyodrrc,

    lfi-e popeiling

    t6vus[.

    fir,u.ton&ih,anr

    c

    6,r\At

    K,,,

    Pavcrl&logvaln,

    *hqp(

    lcnoron

    an

    t\

    lo7nrg

    ing'r.

    3'

    A

    chassis

    side member

    is 4.gm

    long

    measurecr

    from

    the

    position

    of

    the

    front

    axre,

    the

    wheer

    base

    is

    3.6m

    ancr

    trre

    rear

    overhang

    is

    l.2rn.

    The

    frame

    can

    be

    consicrered

    as

    a

    beam

    simprl,

    supported

    at

    the

    positions

    of

    2'

    A

    semi-ellipticar

    raminated

    spring

    to

    cany

    a

    load

    of

    300

    kg

    consists

    of

    7

    leaves

    and

    6.5

    cm

    wide

    and

    2

    orire

    reaves

    are

    extending

    fuil

    length.

    The

    spring

    is

    to

    be

    t

    I0

    cm

    in

    rength

    and

    attached

    to

    the

    axre

    by

    two

    u

    borts

    g

    cm

    apart.

    The

    leaf

    is

    to

    be

    made

    of

    siricon_nanganese

    steel.

    Assume

    the

    allowabre

    stress

    on

    fuil

    rength

    reaf

    to

    be

    3500

    kgflcm2.

    Determine

    the

    thickness

    of

    the

    leaf

    if

    the

    diameter

    of

    the

    eye

    is

    t]s

    .r.

    AIso

    determine

    the

    radius

    to

    rvhich

    the

    leaf

    to

    be

    initiaily

    bent

    assuming

    modulus

    of

    lasticity

    F,:2.1

    *

    106

    kgf/cm2.

    L6'loral

    bendlng.

    Lc,zenglng,

  • 8/17/2019 AT6602 - Chassis Component Design

    11/14

    [

    *or't*inq

    r-romaflt

    :

    +

    t,

    k' ,At

    c

    : .'>

    ht

    Rt

    D

    :

    -t-t.sx49xq1l

    :

    -l-1'tl8'-rs

    r'tet'n

    a':

    l-j

    &:

    W

    cr

    R

    :

    -l'l.sxqo

    xQo/**615;x46

    :

    -lDt3ao

    Nq\

    ffi

    f3l

    W

    Ab E

    :

    *l'1'5613-t,(95

    -Srs(9o't^Rof,45

    :lol'-5

    Ntnn

    fl:, 2

    fl'

    ^

    rkiro'.,qxttr9

    *'g1-'uxtc

    W;

    N+k

    F

    :

    -t'T'stx:5

    \2'35

    -6zsnlte

    +5tle"l

    5xr]t

    *l{ou'Ki'

    la'

    t

    the front

    arld

    rear axles.

    It carries

    a

    point

    load

    of lOkN

    ancl

    30kN

    at 0.6m

    '(lJ,

    and

    2.4

    m respectively

    from the

    fiont

    axle and

    another

    point

    load

    of

    2kN

    at

    the rear

    end.

    Calculate the values

    of

    the reaction

    at the

    front

    and

    rear

    axles.

    So\lLtion

    '.

    Tor<

    \n1

    fflsroonr

    RoF'l80

    -

    l1'5xzlo

    -

    lScO

    x

    l.?5

    "-ltOCr4:s

    +

    2'IoO

    x4t

    :L)

    l

    go

    Ro :

    11.

    5

    ialo

    (

    2: -'

    '.t'5.1qo€o

    t6-?s

    x

    z)5

    tle

    oor'rar

    +t

    *q:o

    r

    4C

    i a

    'to{f

    x45-

    h

    =

    B"ltg'15N

    )

    \s

    rr.r-,\/ld

    .- - - i L-

    R6

    {'R,5,

    =

    ;;'

    *'*oo+lgc']o

    haloo

    1-t-t'5'r36c>

    :,,

    =)RB:

    8t5

    b-'rt_I-

    g-r

    ^t"11'5'rlbo

    Ra

    1Rr*

    :

    k-I9

    l-l€clo+l(oo

    tzlo

    :)RB

    :

    815

    {"'xS

    N

    r-rw^.r'r'z*,.vzw

    4.

    A

    leaf spring

    has

    an overall length

    of

    1.1

    m

    and

    sustains a

    load

    of

    70

    kN

    at

    its

    center.

    The spring

    has

    3

    lull

    length

    leaves

    and

    15

    graduated

    leaves

    witlr

    a center band of

    100 mm

    wide.

    All the leaves

    are

    stressed

    to

    420

    N/mm2. When

    fully

    loaded, the

    ratio

    of total

    spring

    depth to

    r.vidth

    is

    2.

    Determine

    i.

    Tliickness

    and

    rvidth

    of

    the leaf.

    clboLr-t-

    ?,

    dfilRr'o

    x?]:

    +l'1

    .5 xQoxQr:

    'tr't5Yzz5

    Zz

  • 8/17/2019 AT6602 - Chassis Component Design

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    4. Following

    data are related

    to

    a cone

    clutch:

    Maximum

    contact

    surface radius

    :

    140

    mm,

    maximum

    contact

    surface

    radius

    :

    125

    mm, semi cone angle

    :20

    deg,

    coefficient

    of

    friction

    :0.25,

    allowable normal

    pressure

    :

    137.34

    kpa.

    E,stimate

    the

    axial

    load and

    power

    transmitted

    at

    1000

    rpnr

    5.,

    A

    torque

    of 350

    Nm is transmitted

    through

    a

    col1e

    clutch

    having

    a

    rlean

    diarneter

    of

    300 mm

    and

    a

    semi

    cone

    angle

    of

    15

    deg.

    The maximum

    normal

    pressure

    at

    the

    mean radius

    is

    150

    KN/m2.

    The

    coefficient

    of

    friction

    is 0.3. Calculate

    the

    width

    of the

    contact

    surface.

    Also find the

    axial force to

    engage the

    clutch.

    The clutch

    of a motor

    car

    has

    to

    transmit

    73.6 kW

    at

    3600 rpm.

    It

    is

    a

    single

    plate

    type, both

    sides being effective

    friction

    materiai

    yields

    a

    coefficientof

    friction

    of

    0.25

    and

    the

    axialpressure

    is

    limited

    to

    83

    kpa

    of

    plate

    area.-If the

    intemal

    diametet

    of theplate

    is

    to be75Yo

    of,

    the

    external

    diameter,

    determine

    the

    minirrrum

    dimensions

    of

    the clutch

    plate.

    (a)

    An

    autornobile is fitted

    with a

    single

    plate

    clutch

    to

    transmit

    22.1kW

    at

    2100 rprn. The

    total axial

    load

    on

    the clutch plate

    is

    1422.5

    N.

    The

    outside

    diameter of

    the friction

    surface is

    250

    mqr'

    both

    the

    sides

    of

    the

    plates

    are effective and the co-efficient

    of friction

    betlveen

    the

    contact

    surfaces

    is

    0.35.

    Assuming

    uniform

    'rate

    of

    wear

    condition,

    calculate

    the

    inner

    diameter of

    the friction

    surface.

    The

    rotating

    part

    is

    attached

    to

    drivenparts ofthe clutch are initially

    at rest having

    moment

    ofinertia

    of

    20.7

    N m'

    .

    Assrming the

    acceleration

    of

    the machine

    is uniform.

    Calculate

    the

    time

    lapse

    before the

    engine attains full

    speed

    of

    2l00rpm

    if the clutch

    is

    suddenly

    engaged.

    A single

    plate

    clutch, effective

    on

    both

    sides,

    is

    required

    to transmit

    25

    kW

    at 3000 rpm.

    Determine

    the

    outer

    andinnerdiarletersoffriction

    surface

    if the coefficient of friction

    is 0.255,

    ratio

    of

    diameters

    is 1.25

    and

    the

    maximum

    pressure

    is

    not

    to

    exceed

    0.1

    N/mm'

    .

    Find

    out the

    axial

    thrust to be

    provided

    by

    springs. Assume plate

    rvear

    unifonn

    rvear

    for

    the

    design.

    A

    multi disc clutch

    is

    to transmit

    l0

    kW

    at

    800

    rpm. Thc ratio

    of

    inner radius

    is andthe outerradius

    is 1.75.

    The

    coefficient

    of expected

    friction

    inside

    oil

    is

    0.1.

    Find the

    inner

    and

    outer radius and axial

    force

    assuming uniform

    intensity

    of

    pressure

    of

    0.15 N/mm2

    rQ;;

    Unit

    3

    1.

    2.

    3.

    4.

  • 8/17/2019 AT6602 - Chassis Component Design

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  • 8/17/2019 AT6602 - Chassis Component Design

    14/14

    1.

    teeth..

    Determine

    the suitable

    number of

    teeth

    of

    the

    different

    gears

    and

    f(B t

    find

    out

    the

    distance

    between

    the

    main

    and layshafts.

    '

    \--"

    Unit

    5

    Sketch

    the

    arrangement

    of a six

    speed

    gear

    box.

    The minirnum

    and

    maximum

    speeds

    required

    are

    around

    460 and

    1400 rpm. The

    drive

    speed

    is

    1440rpm.

    Construct

    speed diagram

    of

    the

    gear

    box

    and

    obtain

    various

    reduction

    ratios.

    Use

    standard

    output

    speed

    and

    standard

    step

    ratio.

    Calculate

    number

    of

    teeth

    on

    each

    gear.

    An

    automobile

    engine

    develops

    28

    kW

    at 1500

    rprn and its bottom

    gear

    ratio

    is 3.06:

    1.

    If

    a

    propeller

    shaft

    of

    40

    mm outside

    diameter

    is

    to

    be

    used,

    determine

    the

    inside

    diameter

    of

    the

    shaft,

    dssuming

    a safe

    shear

    .stress

    of

    55 N/mm2.

    If

    the

    length of

    the

    propeller

    shaft

    is L54m,

    find

    the

    critical

    speed

    of the

    shaft.

    An

    automobile

    engine

    develops

    33.75

    kW

    at 1500 rpm

    and

    its

    bottorn

    gear

    ratio

    is

    3.06:1.

    If

    a

    propeller

    shaft

    of

    40 mm outside

    diarneter

    is

    to

    be

    usecl.

    Determine

    the

    inner

    diameter

    of

    the

    shaft,

    assuming

    a

    safe

    shear

    stress

    of

    56 N/mm2.

    If

    the

    length

    of

    the

    propeller

    shaft

    is

    1.54

    m,

    find

    the

    critical

    speed

    of

    the

    shaft.

    Also

    ascertain

    whether the

    critical

    speed

    is

    sufficient

    to

    avoid

    whirling.

    An

    automobile

    engine

    develops

    a

    maximum

    torque of

    162

    Nm.

    The low

    gear

    ratio

    of

    transmission

    is

    2.75,

    rvhile the back

    axle

    ratio

    is 4.25.

    The

    effective

    wheels

    radius

    is 0.325m

    and

    the

    co-efficient

    of

    friction

    betrveen

    the

    tyre

    and

    the

    road

    surface

    is 0.6.

    If the

    permissible shear

    stress

    is

    32373

    X

    104

    Pa,

    determine

    the

    maximum shaft

    diameter

    assutning

    that

    the

    load

    is

    nearly

    torsional.

    What

    is maximum

    load

    permissible on each

    rvheel?

    5.

    A centrifugal

    clutch

    is

    to

    transmit

    25.8

    kW at

    750 rprn

    rvhen engaged

    at

    75

    percent of

    the

    running

    speed.

    The inside

    diarneter

    is 0.36

    m

    and

    the radial

    distance

    of

    the center

    of

    gravity

    of

    each shoe

    from

    the

    shaft

    axis

    is 0.15

    m.

    Assuming

    Ir:0.3,

    determine

    the

    necessary

    u'eight

    of

    each

    shoe,

    length

    and

    breadth

    of

    the above

    clutch.

    2.

    -1

    .

    4.