AurOMOBILE ENGINEERING

1.22

It is installed between
Clutch
the engine and gearbox
plate
Diaphragm
spring
of an automobile. It is
while
disengaged Flywheel
wheel -Stcel cove
starting the engine, shift -Fork
the gears, idling the
engine or stopping the Clutch
Pressure pedal
vehicle. It is kept
plate Release
when we
engaged only'
want the vehicle in
bearing
condition. Figure 1.13 Clutch
moving
Typically a clutch
consists of a clutch fork. thrust bearing, diaphragm. cover, pressure plate, clutch plate, and

a flywheel as shown in figure 1.14.

The driving member consist of a cover which carries a cast iron pressure plate or
driving disc. the pressure springs (or diaphragm) and the releasing levers (or fork).

The entire

assembly is bolted to
the flywheel and
rotates with it all the
times. The fywheel
and the pressure plate
grip the driven
member between Diaphragm
them under the action
of the pressure
springs. The driven
member consists of a
disc or plate which is
free to slide
lengthwise on the
splines of the clutch
shaft, which drives the Cover
shaft through these Pressure Clutch Flywhecl
Clutch Thrust
splines. The clutch fork plate plate
bear1ng
disc carries friction
material on both Figure 1.14 Clutch Components
bearing surface.
FRAME BODY
AND IRANSMISSION SrsTEM
1.23
The operating mechanism consists of the foot
pedal, the
the rcleasc linkage, the release or throw
othearing,
lever and the
springs necessary to ensure
clutch.
proper operation of the
1.11.1 Functions of Clutch
(a) It permits engagement or
disengagements of a gear when the vehicle is
and the engine is running. stationary
(h) It transmits the engine power to the transmission system without jerk/shock while
setting the road wheels in motion.

(c) It permits engag1ng of gears when the vehicle is in motion without damaging the gear
wheels

1.11.2 Requirements of Cutch

(a) It should engage gradually to avoid jerks.
(b) It should be able to transmit maximum torque developed by the engine, i.e. free from
slip when engaged.
(c) It should be able to dissipate heat because during engagement rubbing causes heat
generation.
(d) It should be dynamically balanced especially in high speed clutches.
(e) It should be as small possible
that it occupy minimum space.
as so

(f) It should consume minimum physical effort at the time of engagement and
disengagement
(g) It should be designed so, that it can absorb the shocks of engaging and disengaging
at different speeds.
(h) It should have minimum inertia and should be made as light as possible so that it will
not contnue to rotate after it is
disengaged
(i) It should be noiseless when engaged

1.11.3 Principle of Clutch

Ihe clutch works on the principle of friction. When two friction surfaces are brought in

a c t with cach other and pressed they are united due to friction between them. If onc
revolved, the other will also revolve. The friction berveen the two surfaces depends
upon:
(a) The area of surtace.
(b) Pressure
applied upon them
 friction of the surface materials.
(c) Coefficient of
Flywheel
Clutch plate (B)
(driven member)
Flywheel (A)
(driving member) Clutch pedal
relcased

Engine
Clutch pedal
released
Clutch plate
Rear wheel

(a)

Clutch plate (B) Flywheel Release

Flywheel (A) bearing
Clutch pedal
pressedd

Engine ap JF
Clutch pedal Diaphragm
F spring
Rear pressed
wheel Clutch plate

b)

Figure 1.15 Principle of friction clutch (a) Clutch engaged, (b) Clutch disengaged
One surtace
The two surfaces canseparated and brought into contact when required.
be
is considered as driving member (A) and the other is considered as
driven member (B),
contact witn
the driving member is kept rotating. When the driven member is brought in
not revolve.
the driving member, it also starts rotating. And when it is separated, it does

1.11.4 Types of Clutch

Some types of clutches used in vehicles are given below:

Friction Clutch: It may be

(a) Single plate clutch
FRAME BODY AND
TRANSMISsION SYSTEM
(b) Multiplate clutch 1.25
(c) Cone clutch

(d) Centrifugal clutch

(c) Semi-ccntrifugal clutch
(Hydraulic clutch
(g) Vacuum clutch

(h) Electromagnetic clutch

1.11.5
Requirements and Material of Clutch
Requirements and in material of clutch
plate are discussed below:
(a) Requirements of Clutch
Facing
) Good wearing properties
(i) Presence of good binder
(i) Cheaper
(iv) High cocfficient of friction.
(v) High resistance to heat.
(b) Types of Clutch Facing
G) Mill board type
(ü) Moulded type
(ii) Woven
Solid woven vanety
Laminated woven vanety.
(c) Common Clutch
Facing Material
) Leather
(i) Cork
(ii) Fabric
(iv) Asbestos
(v) Reybestos
(vi) Ferodo
(vin) Non asbestos clutch facing
 AUTOMOBLE ENGINEERING
1.26
Single Plate Clutch
1.11.6
clutch is Clutch plate
The single plate
autonmobiles
used in most Clutch
a quick Flywhecl cover
for producing
and
disengagement
pemitting change of

gears with minimum

Diaphragm
spring
effort. As shown in figure
1.16, clutch plate is hcld
To transmission
between the pressure

plate and fywheel Release

Clutch springs are bearing
provided circumferentially
provide avial force
and
to

the clutch in Pressure

keep plate
The
engaged position. The

pressure plate and clutch

mounted on a
(a)
plates are

hub which can shde over

Clutch
the clutch shaft. / plate
Most light vehicles use Clutch
a singie-plate clutch to
Flywheel cover

Diaphragm
transnit torque from spring fulcrum

the engine to the Diaphragm

transmission input shaft spring
(clutch shaft).
Input shaft
The fywheel is the
clutch driving member. Release
Crankshaft bearing
The clutch unit
mounted on the Release fork
flywheel's machined Pressure
rear face. so that the plate
unit rotates with the
flywheel. (b)
The clutch unit consists
of-a friction-type disc Figure 1.16 Single plate clutch (a) Disengaged
(clutch plate), with 2 condition, (b) Engaged condition
 BODY
AND TRANSMISSION SYSTEM
FRAME

friction facings and a central splincd hub

1.27

The lutch shaft passes through

center of the the
clutch plate
Its par splines cngage with the intcrnal
disc (clutch platc) splines of the central hub, on the friction
The clutch plate is

sandwichcd between the

machined surfaces of

the flywhecl and the

when the
pressure plate
is bolted
pressure plate
to the outer edge
of the
flywheel fac.

A pressure plate assembly,

consisting of a pressed steel
cover, a pressure plate with a
machined flat face, and a
Figure 1.17 Diaphragm spring
segmented diaphragm spring and
a release bearing and operating
fork.
.
The clamping force on the friction facings is provided by the diaphragm spring
When unloaded, it is a dished shape.
As the pressure plate cover tightens, diaphragm spring pivots
on its fulkrum
rings, and flattens out to exert a force on the pressure plate. and the clutch
plate
With engine rotation, torque can now be transmitted from the thywheel. through the
friction disc (clutch plate), to the central hub. and to the
transmission
When the clutch pedal is pressed, the movement is transfèrred
through the operating
mechanism, to the operating fork and the release beanng
Ihe release
bearing moves forward and pushes the center of the diaphragm spnng
towards the flywhee.
The diaphragm pivots on this fulcnum rings causing the outer edge to move in the
Opposite dircction and act on the pressure-plate retraction ehps
ne clutch plate disengages, and drive is no longer transmitted
torce and engae
CICasing the
pedal allows the diaphragm to -apply its clamp1ng
the clutch and drive is
restored.
dry x
EoAME BODY AND IRANSMISSION SYsTEM

1.29

Flywhcel
Clutch pedal

Fulcnum
Pressure Pin
plat

Spigot end

Beanrng
Clutch Spring Clutch
shaft
Plate
Fnction limng
Separator piate

Figure 1.19 Multiplate Clutch

The construction is similar to that of single
inthis case are in two
plate tvpe except that al the fnction plates
sets, i.e.. one set of plates sides n the grooves on the tlywheel
and the other one
slides on splines on the pressure plate hub. Altematve
to each set. plates belong
Theclutch plates are assembled and are timly
plate, by coil springs. These coil
pressed with the heip of pressure
sprung exert aial force. due to which there is contact
Detween the clutch plates, thwheel and the
pressure plate The tnetional surfaces on both
Sides of plates help transferring the moion tron twbei to the clutch shaft. This is
cngagcd position of clutch B operating the clutch pedal. the torce is enerted against
orce of diaphragm sprungs and cvntact berven the thywhoel. elutch plates and
PSsure plate is lost and no motion is transtèred trom tywheel to cluteh shaft. This is
SCngaged position for the clutch Presentlh most of the automobiles use multi-plate
clutches
 ENGINEERING
Flywheel
Scparator plates
(silver eolour)

Pressure plates
(silver colour)
Clutch plates
brown colour)

Figure 1.20 3D View of

multiplate clutch
In multiple wet clutch anumber of thin piates made of steel fitted
to the engine and
on gear shaft are made of
phosphor bronze. These are immersed in a both of oil, those
have grooved surfaces for fiow of oil and these
transfer of heat. These type of clutches
longer life than dry clutches due to betier dissipation of heat. have

8 9
8 9
19

17 16 15 13 12
4 10
List of parts of the clutch
housing
1.Bearing 6 Spring retaner 11.Clutch adjusting screw 16 Clutch drum
2. SpacerT 7. Clutch spring 12. Roller 17.Clutch housingB
3. SpacerT 8 Washer 13 Pressure plate 8 Cluch peg
4. Sceger Ing 9. Screw TC 14. Driven plae 19 Ball (2)
5. Bearing 10. Hexagon 5. Driving plate 20 Clutch operating rod
Figure 1.21 Multiplate Wet Clutch Assembly
FRAME AND TRANSMISSION SYSTEM

ln multiple dryclutch, d1ffercnt 1.31

plate These are uscd in
plates arc lined with
tractors or other friction lining used in case of
Advantages: Iight power engine vehicles. single
vehicles.
t can be used in
vehicles where the
Thc overall diameter space is limited
plate clutch
of the mult1plate clutch is
reduced when compared to single
1.11.8 Cone Clutch
Shown in figure I 18
is a cone clutch It Driven cone
consists of a male cone)
flywhecel Fly wheel
and a cone mounted
on the engine shaft Driving cone
and gear box shaft female cone) Pedal
respectively. The
Engine
shape of the inside of shaft Chutch
the flywheel is such shaft
that it accommodate
the male cone. The
surfaces of contact
are lined with the spnng
friction lining
(Asbestos. leather
etc.) -Fnction
hmng

Fnction hning

Sprung
Clutch pedal
Clutch
shaft

Engine Clutch coatrol

shatt Male
Female cOne
cone

Figure l.22 Cone clutch

 ENGINEERING
During the engagement
of clutch the driven member
is forced toward the driving
cone by the spring force.
Hence, the power IS
transmitted from the engine
to the driving cone, driving
cone to driven andcone
driven cone to the gear box
when the clutch is to be
disengaged the driven cone FN d, do
is to be pulled off by applying
force on the pedal and
contact surfaces are
separated hence no power is
transmitted to the clutch
shaft. Male cone
If the wedge angle is very less, it will Female cone
result in excessive wedge action and
fierce engagement, which results Figure 1.23 Geometry of Cone
difficulty in disengagement.
If wedge angle is too large it reduces the torque transmission capacity of clutch. Semi-
cone angle of 12°-16° are commonly used for effective torque transmission. The torque
transmitted by a cone clutch is given by

T = F22 2sina
where, d, and d, are inner and outer diameter of cone, a is the semi-cone angle

Advantages:
force as
Normal force acting on the friction surface is greater than the axial
compared to single plate clutch.
Less axial force is required to cngage the clutch.

Disadvantages:
it
If the cone angle is made smaller than 20°, then the clutch tends to bind and
becomes difficult to disengage the clutch.
CoAME BODY AND IRANSMISSION SYsTEM
1.33
A small amount or wear On the cone surtaccs
nOVement, for which it will be difficult to results in considerable amount of axial
allow.
The two shafts on which cone clutch
are mounted should be
strictly coaxial.
1.11.9 Semi-Centrifugal Clutch
w
vehicles, at high speed the clutch
the
force pressure plate, at the same timespring pressure is not considerable
more stiff enough to
engaging procesS will become tiring for the driver. spring can not be used as the
Lh makes use of centrifugal force to assist Thus this type of clutch is used
the spring force at
high speed.

Friction
ining Pressure
plate
Pressure
plate

B
Engine
shaft
Lever

Cover
Clutch Clutch
plate shaft
Lever

Clutch
- Fly whecl spring

Figure 1.24
Semi-centrifugal Clutch Figure 1.25 Semi-centrifugal Clutch lever
Fig
igure 1.24 shows a
semi-centrifugal clutch. It consists of three hinged and weighted
lever: arranged at
cqual intervals. Enlarged view of lever is shown in figure 1.25.
 Pressure plate clamping load
(% of maximum spring thrust)

Eombined-thrust
AME BoDY AND IRANSMISSION SYsTEM
1.35

Clutch plate (D)

G H

P
D
B
F A (ly weight)

Pressure plate (C)

L
Engine Clutch
shaft
shaft
Figure 1.27 Centrifugal Clutch
This makes the clutch
engaged. The force exerted by spring G
keps the -lutch
discngaged at low speed. The stop H limits the amount of
centrifugal torce. by limiting
the outward movement
of AA.
Disengaged Slip Fully engaged
phase phase phase

Clamping
thrust range
Take up
thrust
0 range
500 1000 500 2000 2500 3000
Engine spced, rpm
Figure 1.28 Centrifugal clutch characteristics
 AUTOMOBILE ENGINEERING
1.36
the spring pressure acts. while at high enginc spccds .the
engine specds only
At low
the sprng pressure. Thus smooth
the weight supplements and
force generated b
obtained under are ing conditions of load and SDcod
var
acceptable gear changes
Advantages:
control mechanism because it is automatic. which
This Npe of clutch require no

vehicle casier.
makes starting and drving the
last indefinitely as long as they are properly maintained
Centrifugal clutches will
less expensive than altemative clutches. It
is also easy to
Simple design and
nstall
when the output shaft is slowed or stopped abrunth
Prevents the engine from stalling
force.
therefore decreases the engine braking

Disadvantages:
slipping between driver and driven parts which causes loss of
It involves friction and
power

creates waste heat through slipping while it is engaged.

it

1.11.11 Electromagnetic Clutch

An electromagnetic clutch is a clutch that Is engaged and disengaged by an

actuator. The flywheel consists of winding and electric current is
electromagnetic
provided to it by battery or dinamo.
will attract the pressure
When electric current is supplied to the windings the flywheel
and the clutch forced between pressure plate and flywhel resultingin
plate is
plate
engagement of clutch. When supply
is cut off the electromagnetic field disappears,
force
is lost and clutch is disengaged by releasing the pressure plate due to the
contact

exerted by the springs

The gear lever consists of a clutch relcase switch.
The switch operation cuts off the
is
current thereby disengaging the clutch. When the
vehicle is stalling, the cngine specd
Therefore, three
lower and the dynamo output is low, the clutch is not firmly engaged.
shown in this figurc) which helps the
Springs are also provided on the pressure plate (not
clutch engaged fimly at low speeds also.
Ihe forces of the electromagnet can be regulated by means of on electrica
dal
resistance provided with acceleration system and controlled by accelcrator pcua
When speed is increased the accelerator pedal is pressed and the resistance gradually cu
ore
oft and thus electromagnetic force is increased and clutch transmission becomes nmo

ngd
 AND TRANSMISSION SYsTEM
FRAME
Bo, 1.37

Windings
-Pressure plate

-Friction linings

Engine Clutch Plate

shaft
Clutch shaft

Splines

Fly wheel- Spings

Figure 1.29 Electromagnetic Clutch

Advantages:
No
linkage are required to control its engagement.
Eliminates wear and tear of starters and contact points
Low starting torque and less HP motors can be used
One motor can drive different mechanism simultancously or individually, through

number of clutches
Disadvantages:
High initial cost.
s important to select the right tvpe o f magnet with correct magnetic tlux density
to
transfer the required torque.
1.38 AUTOMOBILE ENGINEERING
Clutch operating temperature is limited byv the tempCrature rating of the insuati.
tion of
the magnetic coil

1.11.12 Vacuum Clutch

The vacuum clutch is operated by the vacuum existing in the engine manifold sha
figure 1.30. It is the mechanism of a vacuum chutch. It consists of a vacuum cvlinder
piston, solenoid. reservoir and a non retum value. The solenoid switch is located at
gear knob lever which is operateod with the help of a battery. the switch is operated w the
the driver holds the lever to change gears.
when

Batter Switch in the

gear lever
To inlet manifold
Solenoid
Piston
Vent
Non-Retum To clutch
Valve Reservoir

Valve Vacuum Vent

cylinder
Figure 1.30 Mechanism of vacuum clutch
When the throttle is wide opened. the pressure in the inlet manifold decreases due to
which the non retum value closes, isolating the reservoir from the manifold. Thus a
vacuum exists in the reservoir all the time.

In normal operation. the switch in the gear lever remains off, the solenoid operated
value remains in its bottom position. In this position the atmospheric pressure acts on botn
SIdes of the vacuum cylinder, because the vacuum cylinder is open, so also atmosphere
through a vent. When the driver holds the lever to change the gear, the switch is closcd
energizing the solenoid which pulls the valve up. This connects one side of vacuum
cylinder to the reservoir. Due to the difference of pressure on the vacuum cylinderpiston
It moves. '1his movement of the is transmitted by a linkage to the clutch, causing
piston
it todisengage. When the driver is not operating the gear lever, the switch is opcn a
the clutch remains
engaged due to force of springs
Advantages:
No blecding is required.
Low initial as well as maintenance cost.
 AND
IRANSMISSION SYSTEM
BoDY 1.39
FRAM
1.11.13 Hydraulic Clutches

ydraulic clutch uscs pressurized incompressible oil instead of mechanical cables to

cngage or disengage.

Accumulator
=
Oil
reservoir

Pump
Piston
Slave rod
Fork

Control
valve
Cylinder Clutch
Pivot shaft
ball
Flywheel
Clutch
Release
plate
beanng
Diaphgram
sping

Figure 1.31 Hydraulic Clutches

Working: Above figure shows the mechanism of a hydraulic clutch It consists of a
ynnder With piston, control valve. pump, accumulator and oil reserv oir The piston is
conected to the clutch by a linkage. The pump is operated by the engine itself. The oil
Tom the reservoir is pumped into the accumulator tank The accumulator tank is

cOnnccted to the cylinder through the control valhe The control valve is electrically
controlled by switch in the gear lever
a

When the driver holds the gear lever to change the gears., the switeh is operated to
open the control
valve adnmitting the oil under pressure to the cylinder. Duc to u c ou
r e , the piston moves causing the clutch to be discngaged The force of the moving

ctuates the piston in the skave eslinder and forees the slave rod outwards against
Cutch fork. When the slave rod extends, pressure is applied to one end of the elutch
lork

Causes the fork to rotate on the pivot ball and forces the release bearing along
forvard and pushes the center
SSiOn unput shat. The release bearing moves
 AuTOMOBILE ENGINEERING
1.40
towards the tlywheel causing the
outer cdge to move

of the diaphragm spring clips.

retraction Now the clute
on the pressure-plate
direction and act
opposite and dnve is no longer
transmitted
the flywhcl.
disengages with
the switch is opencd which closos
the driver leaves the gear lever. th
As soon as
decreascs on the piston.
and piston moves ba ack A
oil pressurc also
control valve. Then This causcs the fork to rotate in on
slave rod also moves back. pposite
piston moves back. back and diaphragm spring flattens out to.
also c o m e s Cxen
direction and release bearing and the clutch plate is engagcd with
outer edge of the pressure
plate. h
a force on the

fywheel
Advantages:
vbration and wear ot the linkages are climinated
Complicated clutch linkages.
volume than other type of clutches
Deliver a higher torque per unit

Smooth engagement

It provide fast response times

Chart for Clutch
1.11.14 Troubleshooting
causes and remedies is given in
The troubleshooting chart
for clutch giving complaints,
table 13
Clutch
Table 1.3 Troubleshooting Chart for
Remedies
S.No.Complaint Causes the lining and
Clutch slips. 1.e.. Oil on the lining because of Replace
1. corect leaks
when the clutch leaks in engine seal or

IS engaged. there gearbox to

IS lack of firm Too small clearance of Adjust the clearance
lash of
the required back
contact between clutch
the flywheel. pedal
fnction
Install a new
pressure plate Worn out facing
and diven plate plate of
Install a new set
Weak clutch springs
springs
the
Clutch fails to Excessive clutch clearance Properly adjust
clearance
disengage Clean the splined
shaft
Friction plate not moving they
and hub and see that
frecly on splined shaft
move freely
on the
Friction plate Replace the facing
friction plate
 I R A N S M I S .
TEM
AND
BODY
FRAME

Clutch grabs, i.c., Scorcd contact surfaces 141

3.
the hub of the
flywhecl or pressure plateof Face the surfaces
friction plate warpcd them smooth to make
them smooth
binds on the
clutch shaft.
Warpcd friction plate
Straighten or
friction plate replace the
Relcasc levers not
placcd evenly Adjust the
levers properly
4. Clutch is noisy Clutch pedal bush is
dry The bush
should be
Clutch relcase bea1ng IS lubricated
The
without grease and is dry bcaring should be
filled with grease
Torsion spring is
damaged. Replace the torsion
Pilot bearing is sping
Clutch
damaged. Replace the pilot beanng
5. judder or Rivets are loose
The whole
vibration. facing should
be replaced
Clutch facings are wom out
The facings should be
replaced
Splined clutch shaft is bent Tr to straighten the
shatt. othenvise the shart
should be replaced

1.12 Fluid Coupling

uid
coupling is a hydraulic unit that replaces a clutch in a semi or
tully automae si s
ransnits eng1ne torque to a transmission svstem It is a myor part ot >
iywheel assembly. It is also
called a fluid tlvheel or tluid drive act1ng as at d
n this
drive, the power flows through a tluid instead ot thrugn a
device.
1.12.1 Construction
t
O a pump generall known as impeller or dn ng n
CTaly known as rotor or driven menmber both enelosad suiti
ot
e r and the rotor are bowl shaped and have large mmber
Tigure 1.32. The impeller is suitably connseted
to tne
connected to transmission shaft. Oil is filled in the tluid ouphng
p l u g is provided which blows off and drains out nt t

sustained overloading
 TaANSASIos Srs
Bo0YAND
FaAME 143
es centrifugal force acts on he od betoon fe
vans of de mplir d to whc
s ol is thrown into the furbne As a rosull of di e tub f o d o mo F
133 shos, he simplifiod diagras ofa d f T e angpo
from the crankshalft to the tran i shaf Thotic sp
t r a n s m i t t o d

tran almos al to dhat of mpeller oly nder de bet opertig ounditim

becomes
b
ccncy of the fad coupling s hghet Bat oly t spd s l d
impeller The lag of the turbune beld fhe pums kmo as ip
1.12.3 Characteristics
Shown in figure 134 is the varation f percngs ig wd the m l e s d The

percntage slip is defined as 100 whe Mmd

a e sps of dam
and driven members respectivcly
For low cngine spocdbelow 600 pm
perag slig s 00 ht m ch s
disengaged With the mcrease m speod from 600-000 ip am d The
percentage slip falls rapidly to about 10, besand wch the sig du gr oa
small valuc of about 27% at about 3000 pm

100

80
sp
60

40
onib s l g y

20

S00 1000 1500 2 250 3000 350

lngeticr speod pun-
Figure 14 Fluid Ewhecl Characteristics
perccntage slip at any cngine spood, howcvcr depends upon the torquc being
aisiutlod, this curve is based on assumpoa that cngine cxrts Tull torqac at cvery
As
percentage slip represcots the loss of cncrgy and coscqacty ncrcasod tuci
SLnption the engine should noe be run at a speed betwccn 60u and 1000 rpm Ths
tion is similar to a shppung chutch n case of ordinary tncton tch
142 AutOMOBuE ENGINEERNG

Enginesh (transmission shaf

dming shait) driven shall

Casng
Radial
peller vanes
(pump Turbine (rotor)
Figure 1.32 Flid Coupling

1122 Operating Principle

Thereis mcchan e c t i o n betwcen the impeller and the rotor (i.e, the
dng and den ) nd the power is trnsmitod by virtue of the fluid filled in the
The dng s i o d to mginc crankshaft, when the crankshaft rotates, the
peilier lso otates

Devg Diven
membe
pcler) rotar)
Impeller Rotor

Input
Transmission shaft
shaft

Output
Bearin shaft

Radial
vanes

Figure 1.33 Fluid Coupling

 AUTOMOBILE ENGINEERING
1.44

Advantages:
Smooth transmission of power
from engine to gears.
No wear on moving parts
Elimination of clutch pedal.
Damping of torsional
vibrations of the crankshaft.
During braking or coming down a hill the transmission shocks are absorbed by th

fluid.
No maintenance necessary except oil level.
C a r can stop in gear and move off also by pressing pedal only
Disadvantages: It is generally used with epicyclic gearbox only. It can not be used wit
ordinary crash type gear box the to difficulty while changing gears.

Review Questions
Q.1 Explain the term automobile. What are its major components?
What is transmission system? Why it is necessary in a vehicle?
Explain briefly the various types of chassis with the
help of suitable diagrams.
Give classification on frame and various loads acting on it.
Write short notes on frames.
Q.6 Describe the principle of clutch? Discuss various
Q.7 requirements of clutch.
Wth the help of a neat sketch, explain the construction and working of a single plate u
clutch.
Q.8 Where and why do we use
multiplate clutches? Explain the working of multiplate u
clutch.
Q.9
Differentiate betwcen:
) Single and multiplate clutch
Q.10 What are the (ii) Dry and wet clutch.
main components of friction clutch?
Q.11
SCioe the principle of electromagnetic clutch. State
Q.12 Write short notes its advantages and
alsauv
tages
on
) Semi-centrifugal clutch
Q.13 i) Centrifugal clutch.
Explain with the help of neat
coupling. sketches, the construction and of a flu
Q.14 operating pncip
What is chassis? Give classificatign
Q.15 Whot nf chargi
 AUTOMOBILE ENGINEERING
1.44

Advantages:
from engine to gears.
Smooth transmission of power
No wear on moving parts.
Elimination of clutch pedal.
vibrations of the crankshaft
Damping of torsional
hill the transmission shocks are absorbed bv the
During braking or coming down the
a

fluid
No maintenance necessary except oil level
Car can stop in gear and move off also by pressing pedal only.
Disadvantages: It is used with epicyclic gearbox only. It can not be used with
generally
ordinary crash type gear box the to difficulty while changing gears.

Review Questions