Rsrtc summer training report

Dept. of Mechanical engg.
S S College of Engineering, Udaipur
RAJASTHAN TECHNICAL UNIVERSITY
KOTA
A
Industrial Training Report
On
“Rajasthan Roadways”
SUBMITTED IN PARITIAL FULFILMENT OF THE REQUIREMENT FOR
THE AWARD OF THE DEGREE
OF
BACHELOR OF TECHNOLOGY
In
Mechanical Engineering
Session 2015-2016
Submitted To: Submitted By:
Dept. of MechanicalEngg. Chandan Kumar
Roll No. 12ECOME302
IV Year/ VII Sem.
Department of Mechanical Engineering
S S College of Engineering
S S Hills, Jhamar Kotda Road, Umarda, Udaipur (Raj.)

RAJSTHAN STATE ROAD TRANSPOT CORPORATION
CERTIFICATE
DATE-:15-07-2015
To whom it may concern
This is to be certify that Mr.-: Chandan kumar S/o shree
…Mithlesh jamadar student of S S College of
Engineering , Udaipur has successfully completed
summer training programme from 01 June 2015 to
15 July 2015 in depot workshop RSRTC, Udaipur.
I wish him every success in his future life with best
wishes.
Manager (operation)
RSRTC, Udaipur.

Acknowledgement
I would like to express our gratitude towards all the people who have contributed their
precious time and effort to help me. Without whom it would not have been possible for me to
understand and complete the training.
I would like to thank Mr. Kanhaiya Gautam, Head of Mechanical Department RSRTC, My
Training Co-coordinator Mr. Anand Sinha and my Guide Mr. Raunit Verma and Mr.
Kapil Lohar for their guidance, support, motivation and encouragement throughout. The
period this work was carried out. And I also thank Mr. Anil Chauhan, Head of Department
of Mechanical Engineering, S S College of engineering for this motivational support and
guidance for training.
Their readiness for consultation at all times, their educative comments, their concern and
assistance even with practical things have been invaluable.
.
CHANDAN KUMAR

Abstract
Rajasthan State Road Transport Corporation is also known as RSRTC, and has 1 million
passengers travel by its buses daily. RSRTC’s services are to all important places in
Rajasthan and adjoining states of Gujarat, Haryana, Punjab, Delhi, Uttar Pradesh, Himachal
pradesh, Madhya Pradesh and Maharashtra.
Today RSRTC has entered into 50th year of business, since its inception and is committed to
providing high quality bus services, consistently and constantly improving the services for
the satisfaction of the passenger’s.
To fulfill the commitment, RSRTC has incorporated ordinary, Express, Deluxe, A.G Gandhi
Rath, A.C., A.G Sleeper, Volvo-Mercedes, Volvo-Pantry, Volvo-LCD, Volvo-LCD-Pantry
bus services in fleet for all category of passengers.
It has 5,000 buses in its fleet and 56 depots across the state and 3 depots outside the state i.e.
Indore, Ahmadabad and Delhi.

CONTENT
Certificate I
Acknowledgement II
Abstract III
Contents
IV
Chapter 1
1.1 Introduction 1
1.2 History 2
Chapter 2
Tyre section
2.1 Type of tyre 3
2.2 Material properties and structure for tyres 5
Chapter 3
Dieselsection
3.1 Pump diesel supply 7
3.2 Oil leakage- Diesel leakage 7
3.3 Oil change of Engine- about Engine 8
3.4 F.I Pump Change- About Pump 9
3.5 Engine Change 10
Chapter 4
MechanicalHeavyWork
4.1 Body work 12
4.1.1 Welding & Repair of Body 12
4.1.2 Accidental Vehicle 14
4.1.3 Glass Work 14

4.2 Washing of Bus 16
Chapter 5
TransmissionSystem
5.1 Transmission System (Gear Box) 19
5.1.1 Functions of Transmission 20
5.1.2 Necessity of transmission 20
5.1.3 Types of Transmission 20
5.2 Sliding mesh type of gear box 21
5.3 Constant Mesh Gear Box 24
5.4 Synchromesh Gearbox 25
Chapter 6
Clutches
6.1 Clutches 27
6.1.1 Clutch System 27
6.1.2 System Components 28
6.2 Clutch Components – Flywheel 29
6.2.1 Flywheel Construction 30
6.2.2 Dual-mass Flywheel 30
6.3 Clutch Disc 31
6.3.1 Clutch Disc Construction 32
Chapter 7
Brakes

7.1 Brakes 33
7.1.1 Function of brakes 33
7.1.2 Classification of brakes 33
7.1.3 Requirement for good braking system 33
7.2 Types of Braking Systems 34
7.2.1 Brake system components 34
7.2.2 Brake Action 35
7.3 Brake Linings 36
7.3.1 Types of Linings 36
7.4 Disc and Drum Brakes 37

Chapter 1
1.1 Introduction
As per the syllabus an industrial training for B.TECH. Students are compulsory. So, I have
taken training at “Rajasthan Roadways”.
Present status
“.Today RSRTC has entered into 50th year of business, since its inception and is committed
to providing high quality bus services, consistently and constantly improving the services for
the satisfaction of the passengers .To fulfill the commitment, RSRTC has incorporated
Ordinary, Express, Deluxe, A.G. Gandhi Rath , A.C., A.G. Sleeper, Volvo-Mercedes, Volvo-
Pantry, Volvo-LCD, Volvo-LCD-Pantry bus services in fleet for all category of passengers. It
has 5,000 buses in its fleet and 56 depots across the state and 3 depots outside the state i.e.
Indore, Ahmedabad and Delhi. About 1 million passengers travel by its buses daily. RSRTC's
services are to all important places in Rajasthan and adjoining states of Gujarat, Haryana,
Punjab, Delhi, Uttar Pradesh, Himachal Pradesh, Madhya Pradesh and Maharashtra.
Fig 1.1 R.S.R.T.C BUS

1.2 History
The corporation has been established by Government of Rajasthan on 1 October 1964 under
the Road Transport Act 1950 with the objective of providing economic, adequate, punctual
and efficient services to the traveling public in the state.
Parent Department of Transport, Government of Rajasthan
Founded October 1, 1964; 50 years ago (1964-10-01)
Headquarters Jaipur, Rajasthan, India
Service area Rajasthan and neighboring states
Service type Low floor, Semi low floor, Mini bus, A/C
Stations 52 (Bus Depot) and 11 (Bus Stand)
Fleet 5000 (approx.)
Daily ridership 10,000,00 passengers per day approx.
Fuel type Diesel,
Chairman and Managing
Director
Bhaskar A. Sawant (IAS)
Website rsrtc.rajasthan.gov.in
Rajasthan State Road Transport Corporation Hindi RSRTC) is the largest provider of
intercity bus transportation in the Indian state Rajasthan.It is headquartered in Jaipur,
Rajasthan

Chapter 2
TYRE SECTION
Proper selection of tubes and flaps is essential to ensure proper performance of the tube-type
tyre. The tube - made of butyl rubber - is designed to maintain the air pressure in the tyre
while the flap protects the tube from chafing with the rim and prevents it from being pushed
under the bead toe. Fitting the tube and flap properly is an essential step in the process.
2.1 TYPES OF TYRE
1. TUBE TYRE
2. TUBELESS TYRE
Fig 2.1 construction comparison between radial tyre and bias tyre

Fig 2.2. - Tyre size detail
w/house
location
No. Itemno. Itemdescription
Tyre size Tube size Ply rating
Free state 1 11.00-20 1100/20 16
Free state 2 11.00-20 1000/20 14
Free state 3 14.00-20 1400/20 18
Free state 4 18.4-30 15/30 10
Free state 5 17.5-25 TUBLESS 16
Free state 6 315/80R22.5 TUBLESS 16
Free state 7 12R22.5 TUBLESS 16
Free state 8 195R14C TUBLESS 8
Free state 9 9.00-20 900/20 14
Free state 10 8.5R17.5 TUBLESS 10
Free state 11 7.00-16 700/16 10
Free state 12 225-70R15 TUBELESS 8
Free state 13 11R22.5 TUBELESS 16
Free state 14 155/80R13 TUBELESS NPR
Free state 15 185R14C TUBELESS 8
Free state 16 165/80R13 TUBELESS 8
Free state 17 215R15C TUBELESS 6
Free state 18 31-10.5R15 TUBELESS NPR
Free state 19 5.00R12 TUBELESS NPR
Free state 27 215/80R15 TUBELESS 8
Free state 28 205R16 TUBELESS NPR

2.2 Material properties and structure for tyres –:
Tyre – Carcass
Carcass (casing) is the strength element of the tyre. It transfers tensile, brake and
lateral forces to the tyre radial. It is formed of several layers (plies) of rubberized textile,
anchored at the wire rings of the beads. The textile (Fig. 1) is a fabric with the warp made of
threads of cotton, rayon, nylon, polyester, glass fiber, metallic fiber or carbon fiber, which
imparts mechanical strength to the tyre. The weft is rarely spaced and it serves only to
maintain a constant distance between the warp threads.
The fabric is rubberized by calendaring, and the calendared sheets are cut into pieces of
convenient length, under bias angles varying from 45o (standard diagonal ply tyre) to 90o
(radial ply tyre). The plies thus obtained are joined into a continuous band, and interleaved
with a textile lining in order to avoid self-adhesion during storage.
The composition of the rubber compound for carcass can be 70% NR + 30% SBR or PB. In
these compounds, SBR cannot be over 35% and PB over 30%.
The mechanical properties of the carcass depend also on the nature of the fabric
thread. To obtain the fabrics, the following types of threads or cords (2-3 yarned threads) are
employed:
a) Threads of rayon (a-cellulose)
The material is obtained from cellulose by reaction with sodium hydroxide and carbon
disulfide and regeneration (after spinning) with sulfuric acid. The chemical structure is as
follows:
Rayon threads are characterized by a very small deformation during tyre utilization and
they have a very good adhesion to rubber. In exchange, moisture absorption is higher than in
the case of synthetic fibers.
b) Polyamide threads
Polyamides 6 or 6, 6, i.e., the polyamide with the chemical structure -[NH-CO-(CH2)4-
CO-NH-(CH2)6]n-, are used. Polyamide threads possess higher breaking, fatigue and impact
strengths and moisture resistance and a lower density than cellulose. They display a larger
elongation under stress and a lower adhesion to rubber by comparison with rayon threads. All
these deficiencies can be partially corrected.
c) Polyamide (aromatic polyamide) threads
These polyamides contain aromatic rings in the molecule, which leads to remarkable

Properties:
High tensile strength and modulus;
Dimensional stability;
Heat endurance;
Good chemical stability;
High degree of crystallinity.
The lower adhesion to rubber can be corrected by using special adhesives. An example of
aromatic polyamide with industrial application is the one obtained from p-phenylenediamine
and terephthalic acid.
d) Polyester threads
Poly (ethylene terephthalate) (see structure below) is used frequently.
It displays the following characteristics:
Hydrophobic and moisture resistant;
High degree of crystallinity;
Small elongation under stress;
The low adhesion to rubber can be corrected with special adhesives.
e) Metallic threads
They are used for obtaining the plies for radial tyres or to manufacture the fabrics for
breaker. They are made of special steel which contains: 0.4-0.7% MN; 0.15-0.30% Si; min.
0.65% C; max. 0.03% S; max. 0.03% P and traces of Cu, Ni, Cr.
The advantages of the metallic threads over the organic ones are: high breaking
strength, resistance to high temperatures, high elongation modulus and high thermal
conductivity.
The following disadvantages can be mentioned as well:
Higher density;
Low fatigue strength (cyclic stress);
Much higher corrosion.

Chapter 3
DIESEL SECTION
3.1 Pump dieselsupply
KNOCKING – DAMAGE OF VEHICLE
First some basics
In diesel engines, first air is taken in when piston is moving down from TDC to BDC. And
during the compression cycle the fuel is injected at high pressure. Due to high compression
ratio, the fuel ignites and explodes to give the power stroke.
This is a kind of heterogeneous combustion because the mixture concentration varies from
low to high throughout the combustion chamber.
Now the requirement of this combustion model is that, the highly atomized fuel should start
burning as soon as it is sprayed in the cylinder, producing heat and thus preparing the
chamber for combustion of incoming mixture. The objective is to burn the incoming fuel to
get a long power stroke. But, if the fuel sprayed initially is not able to mix properly due to
variety of reasons, it keeps on concentrating in the combustion chamber.
This increases the concentration of fuel in the chamber and at some point the large quantity of
fuel ignites sending pulses throughout the chamber. This leads to knocking.
3.2 Oil leakage- Diesel leakage
Pay close attention to leaks from your automobile's engine. Running a vehicle that’s
drastically low on a vital fluid can cause severe damage. After you find the source of the leak,
the following information will help you decide whether you can handle it yourself or you
need professional help.
If water is getting into your vehicle’s passenger compartment, check the rubber
gaskets and weather-stripping around the windows, doors, and sunroof.

Fig 3.1 – Oil leakage
3.3 Oil change of Engine- about Engine
Diesel oil change is a regular part of the maintenance required of your diesel vehicle.
Just like a car or truck that runs on gas, diesel engines require the proper lubrication to keep
them in good working order. A synthetic diesel oil change, under the right conditions, can
last a very long time without needing to be drained. Am soil and Mobil 1 are two synthetic
diesel options to look into, but you should never forgo changing your diesel oil just because
you think you can. Consulting with your mechanic is a good idea if you have questions about
how long your synthetic oil will last. There are some basics to a diesel oil change that every
diesel owner should know. Things like cost, drain intervals and brand options are important
to have in mind when you go to get your oil changed. Knowing how to do it yourself helps
too.
In our country Ashok Leyland and Telco are leading Bus manufacturers and their
recommendations
Ashok Leyland with Hino engine
1. for long distance 32,000 kms
2. Local usage 24,000 kms

Telco with Cummins engine
1. Every 18,000 kms.
Eiche Motors
Every 18,000 kms.
Fig 3.2 Oil change
3.4 F.I Pump Change- About Pump
An Injection Pump is the device that pumps diesel (as the fuel) into the cylinders of a diesel
engine. Traditionally, the injection pump is driven indirectly from the crankshaft by gears,
chains or a toothed belt (often the timing belt) that also drives the camshaft. It rotates at half
crankshaft speed in a conventional four-stroke diesel engine. Its timing is such that the fuel is
injected only very slightly before top dead center of that cylinder's compression stroke. It is
also common for the pump belt on gasoline engines to be driven directly from the camshaft.
In some systems injection pressures can be as high as 200 MPa (30,000 PSI).

Fig-3.3 F.I PUMP
3.5 Engine Change
An engine swap is the process of removing a bus's original engine and replacing it
with another.
This is done either because of failure, or to install a different engine, usually one that
is more modern and so more efficient, this may make it more powerful and or economical.
Older engines may have a shortage of spare parts and so a modern replacement may be more
easily and cheaply maintained. Swapping to a diesel engine for improved fuel economy is a
long established practice, with modern high efficiency and torque diesel engines this does not
necessarily mean a reduction in performance associated with older diesel engine swaps. For
the particular application of off-road vehicles the high torque at low speed of turbo diesels
combined with good fuel economy makes these conversions particularly effective. Older non-
electronic fuel injection diesels were well known for their reliability especially in wet
conditions.
An engine swap can either be to another engine intended to work in the car by the
manufacturer, or one totally different. The former is much simpler than the latter. Fitting an
engine into a car that was never intended to accept it may require much work – modifying the
car to fit the engine, modifying the engine to fit the car, and building custom engine mounts
and transmission bell housing adaptors to interface them along with a custom built driveshaft.
Some small businesses build conversion kits for engine swaps, such as the Fiat Twin cam into
a Morris Minor or similar.

Swapping the engine may have implications on the cars safety, performance, handling and
reliability. The new engine may be lighter or heavier than the existing one which affects the
amount of weight over the nearest axle and the overall weight of the car - this can adversely
affect the car's ride, handling and braking ability. Existing brakes, transmission and
suspension components may be inadequate to handle the increased weight and/or power of
the new engine with either upgrades being required or premature wear and failure being
likely.
Fig –3.4 Engine Change

Chapter 4
MECHANICAL HEAVY WORK
4.1 BODY WORK
It includes – WELDING & REPAIR OF BODY, ACCIDENTAL VECIHLE, GLASS
WORK ETC.
4.1.1 Welding & Repair of Body
Welding is a fabrication or sculptural process that joins materials, usually metals or
thermoplastics, by causing fusion, which is distinct from lower temperature metal-joining
techniques such as brazing and soldering, which do not melt the base metal. In addition to
melting the base metal, a filler material is often added to the joint to form a pool of molten
material (the weld pool) that cools to form a joint that can be as strong as the base material.
Pressure may also be used in conjunction with heat, or by itself, to produce a weld.
Some of the best known welding methods include:
 Shielded metal arc welding (SMAW) - also known as "stick welding", uses an
electrode that has flux, the protectant for the puddle, around it. The electrode holder
holds the electrode as it slowly melts away. Slag protects the weld puddle from
atmospheric contamination.
 Gas tungsten arc welding (GTAW) - also known as TIG (tungsten, inert gas), uses a
non-consumable tungsten electrode to produce the weld. The weld area is protected
from atmospheric contamination by an inert shielding gas such as Argon or Helium.
 Gas metal arc welding (GMAW) - commonly termed MIG (metal, inert gas), uses a
wire feeding gun that feeds wire at an adjustable speed and flows an argon-based
shielding gas or a mix of argon and carbon dioxide (CO2) over the weld puddle to
protect it from atmospheric contamination.
 Flux-cored arc welding (FCAW) - almost identical to MIG welding except it uses a
special tubular wire filled with flux; it can be used with or without shielding gas,
depending on the filler.
 Submerged arc welding (SAW) - uses an automatically fed consumable electrode and
a blanket of granular fusible flux. The molten weld and the arc zone are protected
from atmospheric contamination by being "submerged" under the flux blanket.
 Electro slag welding (ESW) - a highly productive, single pass welding process for
thicker materials between 1 inch (25 mm) and 12 inches (300 mm) in a vertical or
close to vertical position.
Many different energy sources can be used for welding, including a gas flame, an electric arc,
a laser, an electron beam, friction, and ultrasound. While often an industrial process, welding
may be performed in many different environments, including in open air, under water, and in
outer space. Welding is a hazardous undertaking and precautions are required to avoid burns,
electric shock, vision damage, inhalation of poisonous gases and fumes, and exposure to
intense ultraviolet radiation.

Until the end of the 19th century, the only welding process was forge welding, which
blacksmiths had used for centuries to join iron and steel by heating and hammering. Arc
welding and ox fuel welding were among the first processes to develop late in the century,
and electric resistance welding followed soon after. Welding technology advanced quickly
during the early 20th century as World War I and World War II drove the demand for reliable
and inexpensive joining methods. Following the wars, several modern welding techniques
were developed, including manual methods like SMAW, now one of the most popular
welding methods, as well as semi-automatic and automatic processes such as GMAW, SAW,
FCAW and ESW. Developments continued with the invention of laser beam welding,
electron beam welding, magnetic pulse welding (MPW), and friction stir welding in the latter
half of the century. Today, the science continues to advance. Robot welding is commonplace
in industrial settings, and researchers continue to develop new welding methods and gain
greater understanding of weld quality.
Fig 4.1.1- Welding

4.1.2 ACCIDENTALVEHICLE
Accidentmanagement isthe centralizedhandlingof amotorist’sclaimfollowingaroad
trafficcollision.Itisacost-effective intermediaryservice whichassistsdriversingettingbackonthe
road quicklyandinmanagingthe claimsprocessalone.Whilstitissignificantlymore cost-effective
for the innocentmotorist,the service costssignificantlymore asa result - a cost borne by the insurer
of the 'at-fault'driver.
The term encompasses a whole host of services; which may include 24-hour vehicle
recovery, damage assessment, replacement car provision, arrangement of vehicle repairs,
liaising with insurers, uninsured loss recovery, determining fault, personal injury assistance
and help with paperwork.
It is a particularly useful service for vehicle fleet operators, who need to keep downtime to a
minimum. An outsourced accident management service can save managers time and
administration costs.
4.1.3 Glass Work:
When car companies run ads on television touting their vehicle's new safety features, they
rarely mention the car's windshield or the surrounding windows, but the glass surrounding
you in those vehicles has been designed and manufactured with your safety in mind.
Although automotive glass looks the same as any other type of glass, it functions very
differently.
In most homes, the windows in each room are made from a standard type of glass that will
shatter into large shards when it breaks. With the exception of a sliding glass door or front
door, these home windows don't receive the same amount of strain that an automotive
window does. A car, on the other hand, will encounter many potholes, rocks and fender
benders in its lifetime. Because of this, automotive glass is manufactured into two different
types of safety glass to protect both the structure of the vehicle and the occupants inside. The
first type of glass is called laminated glass, which is for the windshield. The second type of
glass is known as tempered glass, which is used for the vehicle's side and back windows.
Later on, we'll learn how glass makers insert a thin layer of film between two layers of glass
and fuse them together through heat and pressure to make laminated glass. We'll also take a
look at how tempered glass gains its strength through a process of heating and rapid cooling.
Without these different styles of manufacturing and strengthening, automotive glass would be
little more than a simple barrier between us and the elements outside.
Laminated and tempered glass each have different functions, but together, they keep you
inside the vehicle in an accident, shield you from flying sharp glass, retain the roof's rigidity
in a rollover and allow the side air bag to protect you when it's deployed. Let's go on to the
next page and learn when these types of glass were first used and why.

Fig 4.1.2 Glass Work

4.2 Washing of Bus
Surface run-off from washing areas can contain high levels of pollutants such as:
 detergents
 oil and fuel
 suspended solids
 grease
 .antifreeze.
You must not allow run-off to enter surface water drains, surface waters or ground waters.
This will cause pollution and you could be prosecuted.
You should only wash vehicles in defined areas where the wash water and any rainfall run-
off can be contained.
If possible, direct the surface run-off from your vehicle washing area to an on-site treatment
system. You may be able to reuse the water. This will reduce your water use and your impact
on the environment. You can also discharge surface run-off directly to a foul sewer or
combined sewer. Contact your water and sewerage company or authority to find out if you
need authorization before you discharge run-off to a sewer. You must comply with any
conditions of your authorization.
Alternatively, you can collect your run-off in a sealed unit and send it to an authorized
disposal site. Check that anyone who takes your waste away from your site is a registered
waste carrier.
You can use sustainable drainage systems (SUDS) to drain run-off from washing areas.
SUDS slow and hold back run-off from a site, so that pollutants can be broken down
naturally. In Scotland you must use SUDS to drain run-off from all new built-up areas, such
as yards.
Using water from surface waters or ground waters
If you use (abstract) water from surface water or ground waters for cleaning vehicles, you
may need an authorization or license from your environmental regulator.
Good practice; Use water efficiently
Use vehicle washing facilities and equipment that filter and reuse water, or set up a wash
water recycling system.
Use trigger-operated spray guns. Make sure they have an automatic water supply cut-off.
Treat waste water from vehicle cleaning
Use collection systems to prevent contaminated water entering surface water drains, surface
waters or ground waters, or draining onto the land.

Use settlement lagoons or suitable absorbent material such as flocculent to remove suspended
solids such as mud and silt. Before using flocculent, contact your water and Sewerage
Company or authority to make sure that you can still discharge to the sewer.
Use catch pots or silt traps on drains, and ensure that they are in place during cleaning. Empty
them at regular intervals.
Remove oil, grease, petrol and diesel from wash water by passing it slowly through an
appropriately sized oil separator. An oil separator will not work effectively if:
 it is too small
 the speed of flow is too great
 It is poorly maintained.
Ensure that any discharge containing detergent cannot run to the oil separator, as this will
stop it working.
If you use detergents, use a recycling system with no discharge or ensure that any run-off
containing detergents is collected in a sealed unit. Contact your local water and Sewerage
Company or authority for guidance on how to dispose of any of these materials to the foul
sewer.
Cleaning chemicals
Minimize the amount of cleaning chemicals you use.
If you use detergents, choose biodegradable and phosphate-free products as they are less
harmful to the environment.
Only carry out cleaning in a designated impermeable area that is isolated from the
surrounding area by a roll-over bund, raised kern, ramps or stepped access, for example.
Store all cleaning chemicals safely and in an area where you can contain spills. This should
be within a secondary containment system (SCS) such as:
 an impermeable bounded area
 a bounded pallet or spill pallet
 A bounded storage unit.
Train your staff
Train all staff to follow your vehicle cleaning procedures. Display details of the procedures in
the work area so staff can check them easily.

Fig 4.2 – Bus Washing

Chapter 5
TRANSMISSION SYSTEM
The mechanism which transmits the power developed by engine to drive the
automobile is known as transmission system OR power train. The complete transmission
system consists of engine, a clutch, a gear box, propeller shaft, rear axial and differential and
rear wheels and tyres.
5.1 TRANSMISSIONSYSTEM (GEAR BOX):
Gear box: Necessity for gear ratios in transmission, Synchronous gear boxes, 3, 4 and 5
speed gear boxes, Free Wheeling mechanism, Planetary gears systems, over drives, fluid
coupling and torque converters, Epicyclical gear box, principle of automatic transmission,
calculation of gear ratios.
Automotive Gears: Gears play an important role in trucks, car, buses, motor bikes and even
geared cycles. These gears control speed and include gears like ring and pinion, spiral gear,
hypoid gear, hydraulic gears, reduction gearbox.
Fig.5.1 Transmissionsystem
Depending on the size of the vehicles, the size of the gears also varies. There are low gears
covering a shorter distance and are useful when speed is low. There are high gears also with
larger number of teeth.

5.1.1 Functions of Transmission:
* To provide the high torque at the time of starting, hill climbing, accelerating and pulling a
load since high tractive effort is needed
* It permits engine crankshaft to revolve at high speed, while the wheels turn at slower
speeds
*Variable torque by set of gears
*Vehicle speed can be changed keeping engine speed same with certain limit
*The transmission also provides a neutral position so that the engine and the road wheels are
disconnected even with the clutch in the engaged position
* A means to back the car by reversing the direction of rotation of the drive is also provided
by the transmission
5.1.2 Necessityof transmission:
* Variation of resistance to the vehicle motion at various speeds
* Variation of tractive effort of the vehicle available at various speeds
5.1.3 Types of Transmission:
 Manual Transmission
*Sliding Mesh Gear box
*Constant Mesh Gear box
*Synchromesh Gear box
 Automatic Transmission
o Over drive (semi-automatic)
*Fluid drive or Fluid coupling
o Fully automatic
*Epicyclical gear box
*Free Wheeling unit
*Torque Convertor

5.2 Sliding mesh type of gearbox :
Fig.5.2 sliding mesh gear box in neutral position
The figure is of sliding mesh gear box in neutral position. It comprises of input shaft with a
gear (Transmission drive gear), main transmission shaft which is splined and gear are
mounted on it, and a lay shaft (counter shaft) with 2 or 3 or move gears which remains in
connected position with the shaft. Speed change lever (which is shown in figure of gear shift
mechanism) is used the change the gears. Drive gear on the lay shaft is constantly meshed
with drive gear of input shaft. On the splines of main transmission shaft two gears are
mounted which can slide on the splines of the main transmission shaft with the help of shift
lever. A reverse idler gear on the shaft is meshed constantly with the counter (lay) shaft
reverse gear. Gear can be connected to their counter parts on the lay shaft.
When gear are in neutral position, Engine is giving power to crankshaft which in turn
revolves input shaft, the drive gear of input shaft which is constantly meshed with drive gear
of lay shaft also revolves .Due to the revolutions of drive gear of lay shaft. Counter (lay) shaft
rotates in opposite direction to that of input shaft .But no gear of lay shaft are meshed with
gears on the main transmission shaft, hence main transmission shaft will not revolve. The
vehicle will remain as it is.
When vehicle is on first gear, the speed change lever is used to move the larger gear on the
splines of main shaft to mesh it with lower or first gear on the lay shaft the direction of
rotation of the main shaft is same as that of input shaft because gear on counter shaft is
meshed with the gear on the main shaft.

Fig.5.3 Gear in 1st position
Similarly, when the gear is change to 2nd or 3rd the large gear is demised from the first or
lower gear. Smaller gear on the transmission shaft is meshed with the second gear on the
counter shaft with the help of speed change lever. Then vehicle is on 2nd gear.
Fig-5.4 Gear in 2nd position

Fig .5.5 Gear in 3rd position
To make the vehicle move on 4th or top gear, use speed change lever to dames the second
gear and connect the transmission shaft with the input shaft. The vehicle will run on top gear.
Fig 5.6 Gear in 4th position

Fig-5.7 Gear in Reverse position
5.3 ConstantMesh Gear Box:
In constant mesh gear box, all the gear on the counter shaft and all the gears on main
transmission shaft are in constant mesh with one another. And all the gear on lay shaft are
rigidly fixed with it. Two dog clutches are mounted on the splines of the main shaft, one
between the on input shaft and second gear and other one between low and reverse gear.
These two dog clutches are free to slide on the main shaft and can also rotates with it.When
the right hand dog clutch is slides to right by speed change lever, it meshes with the reverse
gear and vehicle will move in reverse direction. When the same dog clutch is made to slide
towards left by speed change lever than the vehicle will run on first gear.
Fig-5.8 Constant mesh Gear Box
Similarly when left hand dog clutch is made to slide towards left and right, the dog clutch meshes

With gear on input shaft (clutch) and second gear respectively.
5.4 Synchromesh Gearbox:
*Similar to constant mesh type, because all the gears on the main shaft are in constant mesh
with corresponding gears on the lay shaft.
*The gears on the main shaft are free to rotate on it and that on the lay shaft are fixed to it.
* Avoids the necessity of double declutching.
*The parts which ultimately are to be engaged are first brought into frictional contact which
equalizes their speed, after which these may be engaged smoothly
Fig-5.8 SynchromeshGearbox
*A: engine shaft.
*Gears B, C, D, E are free on the main shaft and always mesh with corresponding gears on
lay shaft.
*Members F1 and F2 are free to slide on splines on the main shaft.
*G1 and G2 are ring shaped members having internal teeth fit onto the external teeth on
members F1 and F2 respectively.
* K1 and K2 are dog teeth on B and D respectively fit onto the teeth of G1 and G2.
*S1 and S2 are the forks.
*T1 and T2 is the ball supported by springs.

*M1, M2, N1, N2, P1, P2, R1, R2 are the frictional surfaces.
*T1 and T2 tend to prevent sliding of members G1 (G2) on F1 (F2).
*When force applied on G1 (G2) through forks S1 (S2) exceeds a certain value, the balls are
overcome and member G1 (G2) slides over F1 (F2).
*There are usually six of these balls symmetrically paced circumferentially in one
synchromesh device.
Engagementofdirect gearin Synchromesh Gearbox
Cones M1 and M2 mate to equalize speeds. Member G1 pushed further to engage with dog k1.
*For direct gear, member G1 and hence member F1 is slid towards left till cones M1 and M2
rub and friction makes their speed equal.
*Further pushing the member G1 to left cause it to override the balls and get engaged with
dog’s k1.
*So the drive to the main shaft is direct from B via F1 and the splines.
*Similarly for the second gear the members F1 and G1 are slid to the right so that finally the
internal teeth on G1 are engaged with L1.
* Then the drive to main shaft will be from B via U1, U2, C, F1 and splines.
*For first gear, G2 and F2 are moved towards left
*The drive will be from B via U1, U3, D, F2 and splines to the main shaft.
*For reverse,G2 and F2 are slid towards right.
*In this case the drive will be from B via U1, U4, U5, E, F2 and splines to the main shaft.

Chapter 6
CLUTCHES
6.1 Clutches:
• Purpose To connect and disconnect engine power flow to the transmission at the
wheel of the driver.
Fig-6.1 Transmission System
6.1.1 Clutch System:
*Clutch systems are used to disengage the engine from the road
*When the clutch pedal is depressed, the clutch (and transmission) is disengaged from the
engine
* With your foot off of the pedal, the clutch is engaged to the engine.
*The pressure plate holds the clutch against the flywheel, allowing power to travel through
the clutch to the input shaft of the transmission...
* The engine power will transfer through the clutch to the road

Fig-6.2 Clutch system
6.1.2 System Components:
Flywheel: Transfers engine power to the clutch
Input shaft: Transfers power from clutch to the transmission
Clutch Disk (clutch): Splined to input shaft; transfers power from engine to the input shaft
Pressure Plate Assembly: Spring pressure tightly holds the clutch to the flywheel.
Release bearing (throw-out bearing): Connected through linkage or hydraulics to the clutch
pedal; provides a way for the pressure plate to release pressure on the clutch
Pilot bearing (bushing): Mounted in the tail of the crankshaft. Stabilizes the input shaft. Not
always used for FWD.
Clutch Fork (if applicable): Slides the release bearing into and away from the pressure plate
assembly.
Clutch Linkage (or hydraulic plumbing): Allows the driver to operate the clutch fork
Clutch (bell-housing) Housing: Encloses the clutch assembly

Fig -6.3 Clutch component
6.2 Clutch Components – Flywheel:
*Mounted on the rear of the crankshaft
*Acts as balancer for engine
*Adds inertia to the rotating crankshaft
*Provides a surface for the clutch to contact
*Usually surrounded by a ring gear for electric starter operation
Fig -6.4 Flywheel

6.2.1 Flywheel Construction:
*Usually constructed of nodular cast iron which has a high graphite content
*The graphite helps lubricate engagement of the clutch
*May also be constructed from cold rolled steel
Fig 6.5 Flywheel Construction
6.2.2 Dual-mass Flywheel:
*The flywheel hub and clutch mating area are two separate components
*Springs are used to dampen engine and clutch engagement oscillation.
Fig -6.6 Dual-mass Flywheel

*Projects from the front of the transmission
*Usually has a pilot which rides in a bearing or bushing in the end of the crankshaft
*The clutch disc is splined to the clutch shaft.
6.3 Clutch Disc:
*Is squeezed between the flywheel and the pressure plate
*Transmits power from the engine crankshaft to the transmission input shaft.
Fig -6.7 Clutch Disc
Rigid - used primarily for industrial/racing applications.
Flexible - most common, everything from grandma’s cruiser to street/strip racing.
Hub flange - in direct contact with the input shaft
Friction ring - in direct contact with the flywheel/pressure plate.
Clutch facing - friction material.
Marcel springs - facing dampener.
Torsional springs - further dampening for clutch application.
Stop pins - limits the torsional spring’s travel.
Rivets -fastens the facing material to marcel (springs).

6.3.1 Clutch Disc Construction:
*Facing manufactured with frictional material
*(may contain asbestos)
*Other surface materials include:
Paper-based
Ceramic
Cotton
Brass

Chapter 7
BRAKES
7.1 Brakes:
When an acceleration pedal of a vehicle is pressed, heat energy of fuel is converted into
kinetic energy with the help of engine which develops a force at the tyre rod surface. To stop
the vehicle, we have to apply brakes. Brakes decelerate the vehicle, which ultimately stop the
vehicle. Reverse of acceleration is braking.
Generally the braking system used in automobile is hydraulic in nature. When the foot
brake pedal is pressed the fluid flows through brake tube which ultimately reaches to the
braking mechanism at the wheels. The mechanism apply brakes at the rotating parts of the
wheel to stop the vehicle.
7.1.1 Functionof brakes:
1. To stop a vehicle, whenever required.
2. To convert the kinetic energy of vehicle into heat energy and to dissipate the heat
energy.
3. Using hand lever hold the vehicle stationary, even when driver is not present.
4. To control the vehicle when climbing on a slope.
7.1.2 Classificationof brakes:
1. Nature of operation
Mechanical Brake
Hydraulic Brake
Vacuum Brake
Air Brake
Electric Brake
Vacuum & hydraulic Brake
2. Nature of application
Service Brake
Parking Brake
3. Nature of braking for
Double acting Brake
Single acting Brake.
4. Power Brake

7.1.3 Requirementfor goodbraking system:
Maximum retarding force should be developed by brake.
Deceleration should be uniform.
Wear of brake component should not affect brake performance.
Vehicle system other than braking system should not be affected due to braking operation.
Assembly of braking system should be light in weight.
Provision for secondary braking system should be there if the main braking system fail
secondary brakes can be used.
7.2Types ofBraking Systems:
 Service brakes. It’s the primary braking system using a pedal connected to a
hydraulic system causing it to operate.
 Parking brakes. It’s mechanically applied by a lever or pedal
Fig 7.1 Braking System

7.2.1 Brake systemcomponents :
Fig 7.2 Brake System Component
Friction is the resistance to motion between two objects in contact with each other.
• Dry friction (Brakes)
• Greasy Friction (Wheel bearings)
• Viscoubearings) s (Crank main
• Friction varies with the roughness of the surfaces.
• Kinetic (Motion) Friction
• Static (Rest) Friction
7.2.2 Brake Action:
When the Brake pedal is pressed, brake fluid travels from Master
Cylinder to the Caliper or Wheel cylinder, pushing the pistons out.
In turn this action pushes the shoes against the drum or
The pads against the rotor

Fig 7.3 Brake Action
7.3 Brake Linings:
 These are the friction materials that a vehicle uses.
 They can be bonded (glued), riveted, and injection molded to the backing pad or
shoes.
Fig 7.4 Brake Lining
7.3.1 Types of Linings:
• Asbestos
• Organic
• Semi-metallic
• Ceramic
• Carbon/Kevlar

Asbestos- these have phased out, very hazardous to breathe the dust.
Organic- mixture of asbestos and organic materials with a resin binder
Semi-metallic- organic mixed with metal shavings, last longer and very good at dissipating
heat.
Ceramic- low dust output, provide exceptional braking performance
Carbon/Kevlar- Motor sports application, not used on road vehicles because of cost and they
take time to warm up.
7.4 Disc and Drum Brakes:
 Disc brakes are found on almost all vehicles now.
 Older cars and trucks had a combination of disc and drum brakes.
 At one time vehicles came with drum brakes only (1970 and older)
Disc brake consists of metal disc or rotor with flat, lined shoes or pads. These pads rub
against the rotating disc to apply brakes. Brake shoes or pads are held in calipers with one or
more pistons. When pedal is pressed hydraulic pressure pushes the piston outwards. This
results in rubbing of pads with the disc.Due to the frictional force at the point of contact the
vehicle slowdown or stops.
Fig 7.5 (a) Disk Brake 7.5 (b) Drum Brake
In brake drum the break assembly at each wheel is enclosed by a metal brake drum. Brake
shoe having T-section and curve expand outwards. These brakes shoes are riveted with the
brake lining and synthetic adhesive is used to the attach the brake lining to the brake shoes.
Brake assembly is attached to steering knuckle and axle housing.

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