2. TRANSMISSION SYSTEM
The transmission is a device that is connected
to the back of the engine and sends the power
from the engine to the drive wheels.
3. WHY TRANSMISSION NEEDED ?
1 TRANSMITTING POWER FROM
ENGINE TO THE WHEELS
2 TO MATCH THE LOAD REQUIREMENT
3 PROVIDING MECHANICAL
ADVANTAGE
4 A TRANSMISSION WORKS BY
ALLOWING THE ENGINE TO OPERATE
IN IT'S NARROW RANGE OF SPEEDS
WHILE OUTPUTTING A BROAD RANGE
OF SPEEDS.
4. CONSTRAINTS WE KEEP IN MIND WHILE
DESIGNING TRANSMISSION
1 SPACE 8 feasibility
2 POWER REQUIRED
3 POWER SOURCE
4 RANGE OF SPEED
5 WEIGHT
6 ECONOMIC
7 LINKS
A GEAR
B CHAIN
C SHAFT
7. DESIGNING
TRANSMISSION FOR
cycle
DESIGNING
TRANSMISSION FOR
bike
DESIGNING
TRANSMISSION FOR car
1 POWER REQUIRED
less Moderate 6-60 BHP Car 80-1000BHP
2 power source
manual driven Ic engine 100-500CC Ic engine 800-6000CC
3 weight
very less less 100- 200KG High 1000-6000kg
4 range of speed
low High High
5 links
chain ,sprocket Chain sprocket Gear train , cardan shaft
6 economic
less costly Moderate High cost
7 SPACE
LESS Less high
8 feasibility
chain sprocket Chain sprocket Gear train + drive shaft
8. 2 WHEEL
DRIVE
Two types
1 REAR
WHEEL DRIVE
2 FRONT
WHEEL DRIVE
9. 2 WHEEL DRIVE 4 WHEEL DRIVE
Advantages
1 less of a power loss
2 The production costs are
lower.
3The engine sitting over
the driving wheels gives
better traction.
4 simple construction
Disadvantage
vehicle is accelerated the
weight of the car shifts to
the rear and the front
wheels tend to scrabble for
grip.
Eg swift,maruti 800,indica
1 Improved traction
and handling
2 Able to transmit
torque to all
four wheel
3 Higher initial cost
and weight
Requires special
service and
maintenance
Eg DUSTER, trucks
10. COMPONENT OF TRANSMISSSION
SYSTEM
• CLUTCH
• GEAR BOX/TRANSMISSION
• CARDAN SHAFT
• DIFFERENTIAL
• WHEELS/TYRES
13. CLUTCH SYSTEM
CLUTCH IS THE CRUCIAL LINK BETWEEN THE
POWER PLANT (ENGINE) AND THE DRIVELINE
THE PURPOSE OF THE CLUTCH
• LINK OR DE-LINK(ENGAGE OR DIS-ENGAGE)
THE ENGINE FROM THE DRIVELINE, AS DESIRED
BY THE DRIVER
COMPONENTS OF CLUTCH
•CLUTCH ACTUATION MECHANISM
LINK TYPE
CABLE TYPE
HYDRAULIC TYPE
•CLUTCH PRESSURE PLATE
•CLUTCH DRIVEN PLATE
14.
15.
16. How does a clutch work
https://www.youtube.com/watch?v=pqF-aBtTBnY&
index=13&list=UUjDn0r-Jxfmh-
HR4id885yw
17. GEAR RATIO
•It is also known as its speed ratio, is the
ratio of the angular velocity of the input
gear to the angular velocity of the output
gear.
• The gear ratio can be calculated directly
from the numbers of teeth on the gears in
the gear train.
•This shows that a simple gear train with
two gears has the gear ratio R given by
18. GEAR BOX
•A gearbox is a mechanical
device utilized to increase
the output torque or change
the speed (RPM) of a motor.
•The motor's shaft is
attached to one end of the
gearbox and through the
internal configuration of
gears of a gearbox, provides
a given output torque and
speed determined by the
gear ratio.
19. HOW DOES A MANUAL
TRANSMISSION WORKS ??
https://www.youtube.com/watch?v=K53c
PGRE1Kk
27. Calculating final drive ratio ( If)
Let vmax. = maximum vehicle speed ( km/hr) at highest gear
ratio
Let highest gear ratio be 1:1 for the sake of convenience
( Nw)max . = max. rpm of wheel
(Ne )pmax. = rpm of engine at max. power
Vmax. = 2π * Rw * (Nw)max.*60 /1000
= 0.377 Rw * (Nw)max.
(Nw )max. = Vmax. / 0.377 Rw
As (Nw)max. will occur at (Ne)pmax ,
(Nw)max. = (Ne)pmax / ig*if
If = 7.4646 : 1 (Final drive ratio )
28. EQUATION OF MOTION FOR VEHICLE
1 ROLLING RESISTANCE
rolling resistance, sometimes called rolling friction or rolling
drag, is the force resisting the motion when a body (such as
a ball, tire, or wheel ) rolls on a surface
2 AERODYNAMIC DRAG
3 GRADING RESISTANCE
The force, due to gravity, that resists the movement of a vehicle
up a slope.
4 ACCELERATION RESISTANCE
Force experienced during acceleration due to inertial forces
29. 1. Rolling resistance R.R. (min.) = CR*mg
= 0.037*2943 = 108.9 N
R.R. ( max.) = 0.06*2943 = 176.58 N
2. Force on slope Fs = mg * sinɵ
= 2943 * sin (22.50)
= 1126.23 N
3. Force for acceleration
Force = mass * velocity max. / time
Fa = 300 * 16 / 8
= 600 N
Total tractive effort = R.R. + Fs + Fa
= 176.58 + 1126.23 + 600
= 1902.8 N
Total wheel torque = total tractive effort *wheel radius
=627.92 Nm
30. BAJA VEHICLE SPECIFICATION
DETERMINING THE BOTTOM GEAR RATIO
Bottom gear ratio
Ig = Tw/Tmax*if*nt
where
Tw = wheel torque
Tmax = maximum torque from
engine
Nt = transmission efficiency
Ig= 4.922:1
31. PROPELLER
SHAFT
• propeller shaft is a mechanical component for
transmitting torque and rotation, usually used to
connect other components of a drive train that
cannot be connected directly because of distance or
the need to allow for relative movement between
them
32. DIFFERENTIAL
• The differential is designed
to drive a pair of wheels
while allowing them to rotate
at different speeds.
•When cornering, the inner
wheel needs to travel a
shorter distance than the
outer wheel, so with no
differential, the result is the
inner wheel spinning and/or
the outer wheel dragging,
and this results in difficult
and unpredictable handling,
damage to tires and roads,
and strain on (or possible
failure of) the
entire drivetrain.