Project Report on Low Floor Part 1

8/3/2019 Project Report on Low Floor Part 1

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Project report

Ashok leyland

SUBMITTED BY:

PUNEET SHAH

B.Tech:- Third Year

MECHANICAL ENGINEERING

VIVEKANAND INSTITUTE OF TECHNOLOGY AND

SCIENCE GZB


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CONTENT

1) PREFACE

2) ACKNOWLEDGEMENT

3) CERTIFICATE

4) INTRODUCTION

5) HISTORY

6) PRODUCTS

7) LOW FLOOR BUSES

8) ENGINE

9) TURBOCHARGER

10)CRANK SHFT

11)GEARS

12)AUTOMATIC TRANSMISSION

13)BRAKE


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PREFACE

With the ongoing revolution in auto mobile where innovations are taking place at the blink of an

eye, it is impossible to keep the pace with the emerging trends.

Excellence is an attitude that the whole of the human race is born with. It is the

environment that makes sure that whether the result of this attitude is visible or otherwise. A well

planned, properly executed and evaluated project training helps a lot in inculcating a professional

attitude. It provides a linkage between the student and industry to develop an awareness of

industrial approach to problem solving, based on a broad understanding of process and mode of

operation of organization.

During this period, the students get the real, first experience for working in the actual

environment. Most of the theoretical knowledge that has been gained during the course of their

studies is put to test here. Apart from this, the students get an opportunity to learn the latest

technology, which immensely helps them in building their career.

Project training has become and important part in students curriculum as it not only

makes him aware of the working conditions of any industry, it also helps him in bridging the gap

that exists between and institution and an industry. The project training is of high importance in

helping him psychologically for the transformation.

I had the opportunity to have a real experience on many ventures, which increased my

sphere of knowledge to a great extent. I got a chance to learn many new technologies and was

also interfaced to many new machines.

ASHOK LEYLAND company also gives opportunity to students of many disciplines in helping

him/her prepare for the big jump. They conduct training for organization, which excel in their

own fields of operation.


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ACKNOWLEDGEMENT

I take this opportunity to express my sincere thanks and deep gratitude to all the members of theASHOK LEYLAND East Vinod Nagar Depot of D.T.C. All of them were extremely cooperative

and helping. They have been very supportive of my work with their encouragement and

criticism. I am deeply indebted to:

1. Mr. RAJPAL (managing head)

2. Mr. PANKAJ ( service engg.)

for allowing me to join their department and guiding me throughout the project.

PUNEET SHAH

VIVEKANAND INSTITUTE OF TECHNOLOGY AND SCIENCE

GHAZIABAD


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INTRODUCTION

Ashok Leyland (NSE: ASHOKLEY, BSE: 500477) is a commercial vehicle manufacturing

company based in Chennai, India. Founded in 1948, the company is one of India's leading

manufacturers of commercial vehicles, such as trucks and buses, as well as emergency and

military vehicles. Operating six plants, Ashok Leyland also makes spare parts and engines for

industrial and marine applications. It sells about 60,000 vehicles and about 7,000 engines

annually. It is the second largest commercial vehicle company in India in the medium and heavy

commercial vehicle (M&HCV) segment with a market share of 28% (200708). With passenger

transportation options ranging from 19 seaters to 80 seaters, Ashok Leyland is a market leader in

the bus segment. The company claims to carry over 60 million passengers a day, more people

than the entire Indian rail network. In the trucks segment Ashok Leyland primarily concentrateson the 16 ton to 25 ton range of trucks. However Ashok Leyland has presence in the entire truck

range starting from 7.5 tons to 49 tons. The joint venture announced with Nissan Motors of Japan

would improve its presence in the Light Commercial Vehicle (LCV) segment (


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HISHTORY

Following the independence of India, Pundit Jawaharlal Nehru, Indias first Prime Minister,

persuaded Mr Raghunandan Saran, an industrialist, to enter automotive manufacture. The

company began in 1948 as Ashok Motors, to assemble Austin cars. The company was renamed

and started manufacturing commercial vehicles in 1955 with equity participation by British

Leyland. Today the company is the flagship of the Hinduja Group, a British-based and Indian

originated transnational conglomerate.

Early products included the Leyland Comet bus which was a passenger body built on a truck

chassis, sold in large numbers to many operators, including Hyderabad Road Transport,

Ahmedabad Municipality, Travancore State Transport, Bombay State Transport and Delhi Road

Transport Authority. By 1963, the Comet was operated by every State Transport Undertaking in

India, and over 8,000 were in service. The Comet was soon joined in production by a version of

the Leyland Tiger.

In 1968, production of the Leyland Titan ceased in Britain, but was restarted by Ashok Leyland

in India. The Titan PD3 chassis was modified and a five speed heavy duty constant-mesh

gearbox utilized, together with the Ashok Leyland version of the O.680 engine. The Ashok

Leyland Titan was very successful, and continued in production for many years.

Over the years, Ashok Leyland vehicles have built a reputation for reliability and ruggedness.

This was mainly due to the product design legacy carried over from British Leyland.

Ashok Leyland had collaboration with the Japanese company Hino Motors from whom the

technology for the H-series engines was bought. Many indigenous versions of H-series engine

were developed with 4 and 6 cylinder and also conforming to BS2 and BS3 emission norms in

India. These engines proved to be extremely popular with the customers primarily for their

excellent fuel efficiency. Most current models of Ashok Leyland come with H-series engines.
http://en.wikipedia.org/wiki/Pandit_Jawaharlal_Nehruhttp://en.wikipedia.org/wiki/Pandit_Jawaharlal_Nehruhttp://en.wikipedia.org/w/index.php?title=Mr_Raghunandan_Saran&action=edit&redlink=1http://en.wikipedia.org/wiki/Ashok_Motorshttp://en.wikipedia.org/wiki/Austin_Motor_Companyhttp://en.wikipedia.org/wiki/British_Leylandhttp://en.wikipedia.org/wiki/British_Leylandhttp://en.wikipedia.org/wiki/Hinduja_Grouphttp://en.wikipedia.org/wiki/United_Kingdomhttp://en.wikipedia.org/w/index.php?title=Leyland_Comet&action=edit&redlink=1http://en.wikipedia.org/wiki/Leyland_Tiger_(front-engined)http://en.wikipedia.org/wiki/Leyland_Titan_(front_engined_double-decker)http://en.wikipedia.org/wiki/Hino_Motorshttp://en.wikipedia.org/wiki/File:MTC_orange_line_bus.jpghttp://en.wikipedia.org/wiki/Hino_Motorshttp://en.wikipedia.org/wiki/Leyland_Titan_(front_engined_double-decker)http://en.wikipedia.org/wiki/Leyland_Tiger_(front-engined)http://en.wikipedia.org/w/index.php?title=Leyland_Comet&action=edit&redlink=1http://en.wikipedia.org/wiki/United_Kingdomhttp://en.wikipedia.org/wiki/Hinduja_Grouphttp://en.wikipedia.org/wiki/British_Leylandhttp://en.wikipedia.org/wiki/British_Leylandhttp://en.wikipedia.org/wiki/Austin_Motor_Companyhttp://en.wikipedia.org/wiki/Ashok_Motorshttp://en.wikipedia.org/w/index.php?title=Mr_Raghunandan_Saran&action=edit&redlink=1http://en.wikipedia.org/wiki/Pandit_Jawaharlal_Nehru


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An Ashok Leyland bus run by the Chennai Metropolitan Transport Corporation

In 1987, the overseas holding by Land Rover Leyland International Holdings Limited (LRLIH)

was taken over by a joint venture between the Hinduja Group, the Non-Resident Indian

transnational group and IVECO Fiat SpA, part of the Fiat Group and Europe's leading truck

manufacturer. Ashok Leylands long-term plan to become a global player by benchmarking

global standards of technology and quality was soon firmed up. Access to international

technology and a US$200 million investment programme created a state-of-the-art

manufacturing base to roll out international class products. This resulted in Ashok Leyland

launching the 'Cargo' range of trucks based on European Ford Cargo trucks. These vehicles used

Iveco engines and for the first time had factory-fitted cabs. Though the Cargo trucks are no

longer in production and the use of Iveco engine was discontinued, the cab continues to be used

on the 'ecomet' range of trucks.

In the journey towards global standards of quality, Ashok Leyland reached a major milestone in

1993 when it became the first in India's automobile history to win the ISO 9002 certification.

The more comprehensive ISO 9001 certification came in 1994, QS 9000 in 1998 and ISO

14001 certification for all vehicle manufacturing units in 2002. In 2006, Ashok Leyland became

the first automobile company in India to receive the TS16949 Corporate Certification. Editors

note: This is part of a series of articles peeking into clean car industries and car manufacturers of

China, India, South Korea and Germany.

Among many other goals, Ashok Leyland aims to expand its operations to penetrate intooverseas markets. Included in the companys plans is to acquire smaller car manufacturers in

China and in other developing countries. In October 2006, Ashok Leyland bought a majority

stake in the Czech based- Avia. Called Avia Ashok Leyland Motors s.r.o., this will give Ashok

Leyland a channel into the competitive European market. According to the company, in 2008 the

joint venture sold 518 LCVs in Europe despite tough economic conditions. Furthermore, the

company will expand its product offers into construction equipment, following a joint venture

with John Deere. Newly formed in June 2009, the John Deere partnership is a 50/50 split

between the companies. The company says negotiation is progressing on land acquisition, and

the production plans are in place. The venture is scheduled to start rolling out wheel loaders and

backhoe loaders in October 2010. Aside from the full expansion planned for the company, Ashok

Leyland is also paying close attention to the environment. In fact, they are one of the companies

showing the strongest commitment to environmental protection, utilizing eco-friendly processes

in theirvarious plants. Even as they thrust into different directions, Ashok Leyland maintains an
http://en.wikipedia.org/wiki/Metropolitan_Transport_Corporation_(Chennai)http://en.wikipedia.org/w/index.php?title=Land_Rover_Leyland_International_Holdings_Limited&action=edit&redlink=1http://en.wikipedia.org/wiki/IVECOhttp://en.wikipedia.org/wiki/Fiathttp://en.wikipedia.org/wiki/Ford_Cargohttp://en.wikipedia.org/wiki/ISO_9002http://en.wikipedia.org/wiki/ISO_9001http://en.wikipedia.org/w/index.php?title=QS_9000&action=edit&redlink=1http://en.wikipedia.org/wiki/ISO_14001http://en.wikipedia.org/wiki/ISO_14001http://en.wikipedia.org/wiki/TS16949http://en.wikipedia.org/wiki/Aviahttp://en.wikipedia.org/wiki/Aviahttp://en.wikipedia.org/wiki/TS16949http://en.wikipedia.org/wiki/ISO_14001http://en.wikipedia.org/wiki/ISO_14001http://en.wikipedia.org/w/index.php?title=QS_9000&action=edit&redlink=1http://en.wikipedia.org/wiki/ISO_9001http://en.wikipedia.org/wiki/ISO_9002http://en.wikipedia.org/wiki/Ford_Cargohttp://en.wikipedia.org/wiki/Fiathttp://en.wikipedia.org/wiki/IVECOhttp://en.wikipedia.org/w/index.php?title=Land_Rover_Leyland_International_Holdings_Limited&action=edit&redlink=1http://en.wikipedia.org/wiki/Metropolitan_Transport_Corporation_(Chennai)


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R&D group that aims to uncover ways to make their vehicles more fuel efficient and reduce

emissions.

In fact, even before laws were placed on car emissions, Ashok Leyland was already producing

low-emission vehicles. Back in 1997, they have already released buses with quiet engines and

low pollutant emission based on the CNG technology. In 2002 it developed the first hybrid

electric vehicle. Ashok Leyland has also launched a mobile emission clinic that operates on

highways and at entry points to New Delhi. The clinic checks vehicles for emission levels,

recommends remedies and offers tips on maintenance and care. This work will help generate

valuable data and garner insight that will guide further development.

When it comes to the development of environmentally friendly technologies, Ashok Leyland has

developed Hythane engines. In association with the Australian company Eden Energy, Ashok

Leyland successfully developed a 6-cylinder, 6-liter 92 kW BS-4 engine which uses Hythane (H-

CNG,) which is a blend of natural gas and around 20% of hydrogen. Hydrogen helps improve the

efficiency of the engine but the CNG aspect makes sure that emissions are at a controlled level.

A 4-cylinder 4-litre 63 KW engine is also being developed for H-CNG blend in a joint R&D

program with MNRE (Ministry of New and Renewable Energy) and Indian Oil Corporation.

The H-CNG concept is now in full swing, with more than 5,500 of the technologys vehicles

running around Delhi. The company is also already discussing the wide-scale use of Hythane

engines with the Indian government. Hythane engines may be expected in the near future, but

these may not be brought to the United States as yet. Ashok Leylands partnership with Nissan is

also focusing on vehicle, power train, and technology development listed under three joint

ventures. With impressive investment, the joint ventures will focus on producing trucks with

diesel engines that meet Euro 3 and Euro 4 emission standards.

In the coming years, Ashok Leyland also has some hybrid trucks and buses in store for its

market. The buses and trucks are set to feature a new electronic shift-by-wire transmission

technology as well as electronic-controlled engine management for greater fuel efficiency.

Ashok Leyland focuses on improving fuel efficiency without affecting automotive power and the

vehicles will have a 5% improvement on fuel efficiency. Ashok Leyland is also developing

electric batteries and bio-fuel modes.
http://en.wikipedia.org/w/index.php?title=Eden_Energy&action=edit&redlink=1http://en.wikipedia.org/w/index.php?title=Eden_Energy&action=edit&redlink=1


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CURRENT STATUS

Ashok Leyland is the second technology leader in the commercial vehicles sector ofIndia. The

history of the company has been punctuated by a number of technological innovations, which

have since become industry norms. It was the first to introduce multi-axled trucks, full air brakes

and a host of innovations like the rear engine and articulated buses in India. In 1997, the

company launched the countrys first CNG bus and in 2002, developed the first Hybrid Electric

Vehicle.

The company has also maintained its profitable track record for 60 years. The annual turnover of

the company was USD 1.4 billion in 2008-09. Selling 54,431 medium and heavy vehicles in2008-09, Ashok Leyland is India's largest exporter of medium and heavy duty trucks. It is also

one of the largest private sector employers in India - with about 12,000 employees working in 6

factories and offices spread over the length and breadth of India.

The company has increased its rated capacity to 105,000 vehicles per annum. Also further

investment plans including putting up two new plants - one in Uttarakhand in North India and a

bus body building unit in middle-east Asia are fast afoot. It already has a sizable presence in

African countries like Nigeria, Ghana, Egypt and South Africa.

Ashok Leyland has also entered into some significant partnerships, seizing growth opportunities

offered by diversification and globalization with Continental Corporation for automotive

infotronics; with Alteams in Finland for high pressure die casting and recently, with John Deere

for construction equipment.[3]

As part of this global strategy, the company acquired Czech Republic-based Avia's truck

business. The newly acquired company has been named Avia Ashok Leyland Motors s.r.o. This

gives Ashok Leyland a foothold in the highly competitive European truck market.

In 2010 Ashok Leyland acquired a 26% stake in the British bus manufacturer Optare, a company

based on the premises of a former British Leyland subsidiary C.H.Roe.

The Hinduja Group also bought out IVECO's indirect stake in Ashok Leyland in 2007. The

promoter shareholding now stands at 51%.
http://en.wikipedia.org/wiki/Indiahttp://en.wikipedia.org/wiki/USDhttp://en.wikipedia.org/wiki/Uttarakhandhttp://en.wikipedia.org/wiki/Ashok_Leyland#cite_note-2http://en.wikipedia.org/wiki/Ashok_Leyland#cite_note-2http://en.wikipedia.org/wiki/Ashok_Leyland#cite_note-2http://en.wikipedia.org/wiki/Czech_Republichttp://en.wikipedia.org/wiki/Aviahttp://en.wikipedia.org/wiki/Aviahttp://en.wikipedia.org/wiki/Czech_Republichttp://en.wikipedia.org/wiki/Ashok_Leyland#cite_note-2http://en.wikipedia.org/wiki/Uttarakhandhttp://en.wikipedia.org/wiki/USDhttp://en.wikipedia.org/wiki/India


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ACHIEVEMENT

Ashok Leyland buses carry 60 million passengers a day, more people than the entire Indian

rail network

Ashok Leyland has a near 85% market share in the Marine Diesel engines markets in India

In 2002, all the vehicle-manufacturing units of Ashok Leyland were ISO 14001 certified for

their Environmental Management System, making it the first Indian commercial vehicle

manufacture to do so.

In 2005, received the BS7799 Certification for its Information Security Management System

(ISMS), making it the first auto manufacturer in India to do so.

In 2006, received the ISO/TS 16949 Corporate Certification, making it the first auto

manufacturer in India to do so.

It is one of the leading suppliers of defence vehicles in the world and also the leading

supplier of logistics vehicles to the Indian Army.

It is the largest manufacturer of CNG buses in the world.


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PROJECT REPORT ON

LOW FLOOR MAINTAINANCE

Many low-floor buses are low-floor over only a part of the bus, with the rear section raised to

accommodate powertrain equipment. Van Hool has a series of "side-engine rear-drive" buses that

puts the engine off to one side of the cabin longitudinally, to maximize usable cabin space. The

Czech Irisbus Citelis - also in Skoda 24Tr trolleybus version - has 100% low floor with the

engine in a vertical cabinet at the rear of the bus.

Most bus manufacturers achieve a low floor height by making rear-engined rear-wheeldrive buses with independent front wheels, so that no axle is needed to pass under the floor of the

passenger compartment.

For smaller buses, such as midibuses, the low-floor capability is achieved by placing the front

wheels ahead of the entrance. One of the last types of buses to gain low-floor accessibility as

standard was the minibus, where a similar front-wheel arrangement allows around 12 seats and a

wheelchair space to be accommodated in very small low-floor minibuses, such as the Optare

Alero and Hino Poncho.

Accessibility was previously achieved in paratransit type applications, which use small vehicles

with the fitment of special lifts. The inception of small low-floor buses has allowed the

development of several accessible demand-responsive transport schemes using standard 'off-the-

shelf' buses.

Low-floor buses usually include an area without seating (or seating that folds up) next to at least

one of the doors, where wheelchairs andperambulators can be parked. This is sometimes not the

only purpose of this area, though, as many operators employ larger standee areas for high

occupancy at peak times. Despite the space existing, operators may also insist that only one or

two wheelchairs or pushchairs can be accommodated unfolded, due to space/safety concerns.

An interesting implementation of the low floor design exists in Australia, where Custom Coaches

makes a "Hybrid" variant of its CB60 bodywork. These buses combine a smaller low floor area

with a small underfloor bin for some luggage. Whilst these buses do not provide a full amount of

luggage space, they can be used to house more luggage than what can be held inside the bus

itself. Another drawback is the arrangement means the section ofthe bus that is at kerb height is
http://en.wikipedia.org/wiki/Powertrainhttp://en.wikipedia.org/wiki/Van_Hoolhttp://en.wikipedia.org/wiki/Irisbus_Citelishttp://en.wikipedia.org/wiki/Bus_manufacturerhttp://en.wikipedia.org/wiki/Rear-engine_designhttp://en.wikipedia.org/wiki/Rear-wheel_drivehttp://en.wikipedia.org/wiki/Rear-wheel_drivehttp://en.wikipedia.org/wiki/Axlehttp://en.wikipedia.org/wiki/Midibushttp://en.wikipedia.org/wiki/Minibushttp://en.wikipedia.org/wiki/Minibus#Low_floor_minibuseshttp://en.wikipedia.org/wiki/Optare_Alerohttp://en.wikipedia.org/wiki/Optare_Alerohttp://en.wikipedia.org/wiki/Hino_Ponchohttp://en.wikipedia.org/wiki/Paratransithttp://en.wikipedia.org/wiki/Demand-responsive_transporthttp://en.wikipedia.org/wiki/Wheelchairhttp://en.wikipedia.org/wiki/Baby_transporthttp://en.wikipedia.org/wiki/Baby_transporthttp://en.wikipedia.org/wiki/Wheelchairhttp://en.wikipedia.org/wiki/Demand-responsive_transporthttp://en.wikipedia.org/wiki/Paratransithttp://en.wikipedia.org/wiki/Hino_Ponchohttp://en.wikipedia.org/wiki/Optare_Alerohttp://en.wikipedia.org/wiki/Optare_Alerohttp://en.wikipedia.org/wiki/Minibus#Low_floor_minibuseshttp://en.wikipedia.org/wiki/Minibushttp://en.wikipedia.org/wiki/Midibushttp://en.wikipedia.org/wiki/Axlehttp://en.wikipedia.org/wiki/Rear-wheel_drivehttp://en.wikipedia.org/wiki/Rear-wheel_drivehttp://en.wikipedia.org/wiki/Rear-engine_designhttp://en.wikipedia.org/wiki/Bus_manufacturerhttp://en.wikipedia.org/wiki/Irisbus_Citelishttp://en.wikipedia.org/wiki/Van_Hoolhttp://en.wikipedia.org/wiki/Powertrain


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very short-consisting of enough space to house the wheelchair area and then rising up, to

accommodate the luggage bin. These buses also lack the ability to have a centre door.

A disadvantage of the low floor is accommodating the bus's own wheels. With the low floor, the

wheels protrude into the passenger cabin, and need to be contained in wheel pockets of waist

height, and this occupies space which would otherwise be used for seating. Seating layout for a

low-floor bus therefore requires careful design.[1]

Low floors can be complemented by a hydraulic or pneumatic 'kneeling device', which can be

used when the bus is not in motion, tilting it or lowering it at the front axle even further, often

down to normal kerb height. Depending on how close to the kerb the bus is parked and

wheelchair design, this can allow wheelchair users to board unaided. Though such technology

has been available and in use on high-floor buses since the 1970s, it is of significant utility on

low-floor vehicles only where it enables less-mobile passengers to board and leave the vehicle

without help from others. Many vehicles are also equipped with wheel-chair lifts, or ramps

which, when combined with a low floor, can provide a nearly level entry.

DELHI

With the introduction of Bus Rapid Transit (BRT) and the development of dedicated corridors

for the service, bus service is set to improve.[5]TheDelhi Transport Corporation (DTC) has

started introducing air-conditioned buses and brand new low-floor buses (with floor height of

400 mm (15.75 in) and even higher on one third area as against 230 mm (9.06 in) available

internationally) on city streets to replace the conventional buses.[6]A revamp plan is underway to

improve bus-shelters in the city and to integrate GPS systems in DTC buses and bus stops so as

to provide reliable information about bus arrivals. The Delhi Government decided to expedite

this process and procured 6,600 low floor buses for the DTC before commonwealth games in

2010.
http://en.wikipedia.org/wiki/Low-floor_bus#cite_note-0http://en.wikipedia.org/wiki/Low-floor_bus#cite_note-0http://en.wikipedia.org/wiki/Low-floor_bus#cite_note-0http://en.wikipedia.org/wiki/Hydraulicshttp://en.wikipedia.org/wiki/Pneumatichttp://en.wikipedia.org/wiki/Curb_(road)http://en.wikipedia.org/wiki/Low-floor_bus#cite_note-indiaexpress-4http://en.wikipedia.org/wiki/Low-floor_bus#cite_note-indiaexpress-4http://en.wikipedia.org/wiki/Low-floor_bus#cite_note-indiaexpress-4http://en.wikipedia.org/wiki/Delhi_Transport_Corporationhttp://en.wikipedia.org/wiki/Low-floor_bus#cite_note-the_hindu-5http://en.wikipedia.org/wiki/Low-floor_bus#cite_note-the_hindu-5http://en.wikipedia.org/wiki/Low-floor_bus#cite_note-the_hindu-5http://en.wikipedia.org/wiki/2010_Commonwealth_Gameshttp://en.wikipedia.org/wiki/2010_Commonwealth_Gameshttp://en.wikipedia.org/wiki/Low-floor_bus#cite_note-the_hindu-5http://en.wikipedia.org/wiki/Delhi_Transport_Corporationhttp://en.wikipedia.org/wiki/Low-floor_bus#cite_note-indiaexpress-4http://en.wikipedia.org/wiki/Curb_(road)http://en.wikipedia.org/wiki/Pneumatichttp://en.wikipedia.org/wiki/Hydraulicshttp://en.wikipedia.org/wiki/Low-floor_bus#cite_note-0


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4 stroke IC engine

The internal combustion engine is an engine in which the combustion of a fuel (normally

a fossil fuel) occurs with an oxidizer (usually air) in a combustion chamber. In an internalcombustion engine, the expansion of the high-temperature and -pressure gases produced by

combustion applies direct force to some component of the engine, such as pistons, turbine

blades, or a nozzle. This force moves the component over a distance, generating useful

mechanical energy.

As their name implies, four-stroke internal combustion engines have four basic steps that repeat

with every two revolutions of the engine:

(1) Intake stroke (2) Compression stroke (3) Power stroke and (4) Exhaust stroke

1. Intake stroke: The first stroke of the IC engine is also known as the suction stroke because the

piston moves to the maximum volume position (downward direction in the cylinder). The inlet

valve opens as a result of piston movement, and the vaporized fuel mixture enters the

combustion chamber. The inlet valve closes at the end of this stroke.

2. Compression stroke: In this stroke, both valves are closed and the piston starts its movement to

the minimum volume position (upward direction in the cylinder) and compresses the fuel

mixture. During the compression process, pressure, temperature and the density of the fuel

mixture increases.

3. Power stroke: When the piston reaches the minimum volume position, the spark plug ignites

the fuel mixture and burns. The fuel produces power that is transmitted to the crank shaft

mechanism.

4. Exhaust stroke: In the end of the power stroke, the exhaust valve opens. During this stroke, the

piston starts its movement in the minimum volume position. The open exhaust valve allows the

exhaust gases to escape the cylinder. At the end of this stroke, the exhaust valve closes, the inlet

valve opens, and the sequence repeats in the next cycle. Four stroke engines require two

revolutions.

Many engines overlap these steps in time; jet engines do all steps simultaneously at different

parts of the engines.
http://en.wikipedia.org/wiki/Enginehttp://en.wikipedia.org/wiki/Combustionhttp://en.wikipedia.org/wiki/Fuelhttp://en.wikipedia.org/wiki/Fossil_fuelhttp://en.wikipedia.org/wiki/Combustion_chamberhttp://en.wikipedia.org/wiki/Temperaturehttp://en.wikipedia.org/wiki/Pressurehttp://en.wikipedia.org/wiki/Forcehttp://en.wikipedia.org/wiki/Pistonhttp://en.wikipedia.org/wiki/Turbine_bladehttp://en.wikipedia.org/wiki/Turbine_bladehttp://en.wikipedia.org/wiki/Propulsive_nozzlehttp://en.wikipedia.org/wiki/Energyhttp://en.wikipedia.org/wiki/Energyhttp://en.wikipedia.org/wiki/Propulsive_nozzlehttp://en.wikipedia.org/wiki/Turbine_bladehttp://en.wikipedia.org/wiki/Turbine_bladehttp://en.wikipedia.org/wiki/Pistonhttp://en.wikipedia.org/wiki/Forcehttp://en.wikipedia.org/wiki/Pressurehttp://en.wikipedia.org/wiki/Temperaturehttp://en.wikipedia.org/wiki/Combustion_chamberhttp://en.wikipedia.org/wiki/Fossil_fuelhttp://en.wikipedia.org/wiki/Fuelhttp://en.wikipedia.org/wiki/Combustionhttp://en.wikipedia.org/wiki/Engine


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Turbo charger

A turbocharger, or turbo (colloquialism), is a centrifugal compressor powered by

a turbine which is driven by an engine's exhaust gases. Its benefit lies with the compressorincreasing the pressure of air entering the engine (forced induction) thus resulting in greater

performance (for either, or both, power and efficiency). They are popularly used with internal

combustion engines (e.g. four-stroke engines like Otto cycles and Diesel cycles).

HISTORY

Forced induction dates from the late 19th century, when Gottlieb Daimler patented the technique

of using a gear-driven pump to force air into an internal combustion engine in 1885.[3]The

turbocharger was invented by Swiss engineer Alfred Bchi, who received a patent in 1905 for

using a compressor driven by exhaust gasses to force air into a piston engine.[4]During the First

World War French engineer Auguste Rateau fitted turbochargers to Renault engines powering

various French fighters with some success.[5]In 1918, General Electric engineerSanford

Alexander Moss attached a turbo to a V12Libertyaircraft engine. The engine was tested at Pikes

Peakin Colorado at 14,000 feet (4,300 m) to demonstrate that it could eliminate the power loss

usually experienced in internal combustion engines as a result of reduced air pressure and densityat high altitude.[5]General Electric called the systemturbosupercharging.[6]

Turbochargers were first used in production aircraft engines such as the Napier Lioness[7]in the

1920s, although they were less common than engine-driven centrifugal superchargers. Ships and

locomotives equipped with turbocharged Diesel engines began appearing in the 1920s. In theaviation world, turbochargers were most widely used by the United States, who led the world in

the technology due to General Electric's early start. During World War II, notable examples of

US aircraft with turbochargers include the B-17 Flying Fortress, B-24 Liberator, P-38

Lightning and P-47 Thunderbolt. The technology was also used in experimental fittings by a
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number of other manufacturers, notably a variety ofFocke-Wulf Fw 190models, but the need for

advanced high-temperature metals in the turbine kept them out of widespread use.

OPERATING PRINCIPAL

All naturally aspirated Otto and diesel cycle engines rely on the downward stroke of a piston to

create a low-pressure area (less than atmospheric pressure) above the piston in order to draw air

through the intake system. With the rare exception of tuned induction systems, most engines

cannot inhale their full displacement of atmospheric density air. The measure of this loss or

inefficiency in four stroke engines is called volumetric efficiency. If the density of the intake air

above the piston is equal to atmospheric, then the engine would have 100% volumetric

efficiency. Unfortunately, most engines fail to achieve this level of performance.

The objective of a turbocharger, just as that of a supercharger, is to improve an

engine's volumetric efficiency by increasing the intake density. The compressor draws in

ambient air and compresses it before it enters into the intake manifold at increased pressure. This

results in a greater mass of air entering the cylinders on each intake stroke. The power needed to

spin the centrifugal compressor is derived from the high pressure and temperature of the engine's

exhaust gases. The turbine converts the engine exhaust's potential pressure energy and kinetic

velocity energy into rotational power, which is in turn used to drive the compressor.

A turbocharger may also be used to increase fuel efficiency without any attempt to increase

power. It does this by recovering waste energy in the exhaust and feeding it back into the engine

intake. By using this otherwise wasted energy to increase the mass of air it becomes easier to

ensure that all fuel is burned before being vented at the start of the exhaust stage. The increased

temperature from the higher pressure gives a higher Carnot efficiency.
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CRANKSHAFT

The crankshaft, sometimes casually abbreviated tocrank, is the part of an engine which

translates reciprocating linear pistonmotion into rotation. To convert the reciprocating motioninto rotation, the crankshaft has "crank throws" or "crankpins", additional bearing surfaces

whose axis is offset from that of the crank, to which the "big ends" of the connecting rods from

each cylinder attach.

It typically connects to a flywheel, to reduce the pulsation characteristic of the four-stroke cycle,

and sometimes a torsional or vibrational damper at the opposite end, to reduce

the torsion vibrations often caused along the length of the crankshaft by the cylinders farthest

from the output end acting on the torsional elasticity of the metal.

HISTORY

A Roman iron crankshaft of yet unknown purpose dating to the 2nd century AD was excavated

in Augusta Raurica, Switzerland. The 82.5 cm long piece has fitted to one end a 15 cm long

bronze handle, the other handle being lost.[2][1]

Roman Hierapolis sawmill from the 3rd century AD, the earliest known machine to combine a

crank with a connecting rod.[3]

The earliest evidence, anywhere in the world, for a crank and connecting rod in a machineappears in the late Roman Hierapolis sawmill from the 3rd century AD and two Roman

stone sawmills atGerasa, Roman Syria, and Ephesus, Asia Minor (both 6th century AD).[3]On

the pediment of the Hierapolis mill, a waterwheel fed by a mill race is shown powering via

a gear train two frame sawswhich cut rectangular blocks by the way of some kind of connecting

rods and, through mechanical necessity, cranks. The accompanying inscription is in Greek.[4]

The crank and connecting rod mechanisms of the other two archaeologically attested sawmills

worked without a gear train.[5][6]In ancient literature, we find a reference to the workings of

water-powered marble saws close to Trier, now Germany, by the late 4th century
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poetAusonius;[3]about the same time, these mill types seem also to be indicated by the Christian

saint Gregory of Nyssa from Anatolia, demonstrating a diversified use of water-power in many

parts of the Roman Empire.[7]The three finds push back the date of the invention of the crankand connecting rod back by a full millennium;[3]for the first time, all essential components of the

much later steam engine were assembled by one technological culture.

CONSTRUCTION

Crankshafts can be monolithic (made in a single piece) or assembled from several pieces.

Monolithic crankshafts are most common, but some smaller and larger engines use assembled

crankshafts.

Forging and castingCrankshafts can be forged from a steel bar usually through roll forging or cast in ductile steel.

Today more and more manufacturers tend to favor the use of forged crankshafts due to their

lighter weight, more compact dimensions and better inherent dampening. With forged

crankshafts, vanadium microalloyed steels are mostly used as these steels can be air cooled after

reaching high strengths without additional heat treatment, with exception to the surface

hardening of the bearing surfaces. The low alloy content also makes the material cheaper than

high alloy steels. Carbon steels are also used, but these require additional heat treatment to reach

the desired properties. Iron crankshafts are today mostly found in cheaper production engines

(such as those found in the Ford Focus diesel engines) where the loads are lower. Some engines

also use cast iron crankshafts for low output versions while the more expensive high output

version use forged steel.

Machining

Crankshafts can also be machined out of a billet, often using a bar of high quality vacuum

remelted steel. Even though the fiber flow (local inhomogeneities of the material's chemical

composition generated during casting) doesnt follow the shape of the crankshaft (which is

undesirable), this is usually not a problem since higher quality steels which normally are difficult

to forge can be used. These crankshafts tend to be very expensive due to the large amount of

material removal which needs to be done by using lathes and milling machines, the high material

cost and the additional heat treatment required. However, since no expensive tooling is required,this production method allows small production runs of crankshafts to be made without high

costs.

Fatigue strength

The fatigue strength of crankshafts is usually increased by using a radius at the ends of each

main and crankpin bearing. The radius itself reduces the stress in these critical areas, but since

the radius in most cases are rolled, this also leaves some compressive residual stress in the

surface which prevents cracks from forming.
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Hardening

Most production crankshafts use induction hardened bearing surfaces since that method gives

good results with low costs. It also allows the crankshaft to be reground without having to redothe hardening. But high performance crankshafts, billet crankshafts in particular, tend to

use nitridization instead. Nitridization is slower and thereby more costly, and in addition it puts

certain demands on the alloying metals in the steel, in order to be able to create stable nitrides.The advantage with nitridization is that it can be done at low temperatures, it produces a veryhard surface and the process will leave some compressive residual stress in the surface which is

good for the fatigue properties of the crankshaft. The low temperature during treatment is

advantageous in that it doesnt have any negative effects on the steel, such as annealing. With

crankshafts that operate on roller bearings, the use ofcarburizationtends to be favored due to thehigh Hertzian contact stresses in such an application. Like nitriding, carburization also leaves

some compressive residual stresses in the surface.

Counterweights

Some expensive, high performance crankshafts also use heavy-metal counterweights to make the

crankshaft more compact. The heavy-metal used is most often a tungsten alloy but depleteduranium has also been used. A cheaper option is to use lead, but compared with tungsten its

density is much lower.

Stress on crankshafts

The shaft is subjected to various forces but generally needs to be analysed in two positions.

Firstly, failure may occur at the position of maximum bending; this may be at the centre of the

crank or at either end. In such a condition the failure is due to bending and the pressure in the

cylinder is maximal. Second, the crank may fail due to twisting, so the conrod needs to bechecked for shear at the position of maximal twisting. The pressure at this position is the

maximal pressure, but only a fraction of maximal pressure.
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GEAR

A gear is a rotating machine part having cut teeth, or cogs, which mesh with another toothed part

in order to transmit torque. Two or more gears working in tandem are called atransmissionandcan produce a mechanical advantage through a gear ratio and thus may be considered a simple

machine. Geared devices can change the speed, torque, and direction of a power source. The

most common situation is for a gear to mesh with another gear, however a gear can also mesh a

non-rotating toothed part, called a rack, thereby producing translation instead of rotation.

The gears in a transmission are analogous to the wheels in a pulley. An advantage of gears is that

the teeth of a gear prevent slipping.

When two gears of unequal number of teeth are combined a mechanical advantage is produced,

with both the rotational speeds and the torques of the two gears differing in a simple relationship.

In transmissions which offer multiple gear ratios, such as bicycles and cars, the term gear, as

infirst gear, refers to a gear ratio rather than an actual physical gear. The term is used to describesimilar devices even when gear ratio is continuous rather than discrete, or when the device does

not actually contain any gears, as in a continuously variable transmission.

Transmission

A machine consists of a power source and a power transmission system, which provides

controlled application of the power. Merriam-Webster defines transmission as: an assembly of

parts including the speed-changing gears and the propeller shaft by which the power istransmitted from an engine to a live axle.[1]Often transmission refers simply to the gearbox that

uses gearsand gear trains to provide speed and torque conversions from a rotating power source

to another device.

In British English the term transmission refers to the whole drive train, including gearbox,

clutch, prop shaft (for rear-wheel drive), differential and final drive shafts. In American English,

however, the distinction is made that a gearbox is any device which converts speed and torque,

whereas a transmission is a type of gearbox that can be "shifted" to dynamically change the

speed:torque ratio, such as in a vehicle.

The most common use is in motor vehicles, where the transmission adapts the output of

the internal combustion engine to the drive wheels. Such engines need to operate at a relativelyhigh rotational speed, which is inappropriate for starting, stopping, and slower travel. The

transmission reduces the higher engine speed to the slower wheel speed, increasing torque in theprocess. Transmissions are also used on pedal bicycles, fixed machines, and anywhere else

rotational speed and torque needs to be adapted.

Often, a transmission will have multiple gear ratios (or simply "gears"), with the ability to switch

between them as speed varies. This switching may be done manually (by the operator), or
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automatically. Directional (forward and reverse) control may also be provided. Single-ratio

transmissions also exist, which simply change the speed and torque (and sometimes direction) of

motor output.

In motor vehicle applications, the transmission will generally be connected to the crankshaft of

the engine. The output of the transmission is transmitted via driveshaft to one or

moredifferentials, which in turn drive the wheels. While a differential may also provide gearreduction, its primary purpose is to change the direction of rotation.

Conventional gear/belt transmissions are not the only mechanism for speed/torque adaptation.

Alternative mechanisms include torque converters and power transformation (e.g., diesel-electric

transmission, hydraulic drive system, etc.). Hybrid configurations also exist.

AUTOMATIC TRANSMISSION

Most modern North American and Australian and many larger, high specification European andJapanese cars have an automatic transmission that will select an appropriate gear ratio without

any operator intervention. They primarily use hydraulics to select gears, depending on pressure

exerted by fluid within the transmission assembly. Rather than using a clutch to engage the

transmission, a fluid flywheel, or torque converter is placed in between the engine andtransmission. It is possible for the driver to control the number of gears in use or select reverse,

though precise control of which gear is in use may or may not be possible.

Automatic transmissions are easy to use. However, in the past, automatic transmissions of this

type have had a number of problems; they were complex and expensive, sometimes had

reliability problems (which sometimes caused more expenses in repair), have often been lessfuel-efficient than their manual counterparts (due to "slippage" in the torque converter), and

their shift time was slower than a manual making them uncompetitive for racing. With the

advancement of modern automatic transmissions this has changed.

Attempts to improve the fuel efficiency of automatic transmissions include the use oftorque

converters which lock up beyond a certain speed, or in the higher gear ratios, eliminating power

loss, and overdrive gears which automatically actuate above certain speeds; in older

transmissions both technologies could sometimes become intrusive, when conditions are such

that they repeatedly cut in and out as speed and such load factors as grade or wind vary slightly.

Current computerized transmissions possess very complex programming to both maximize fuel

efficiency and eliminate any intrusiveness.

For certain applications, the slippage inherent in automatic transmissions can be advantageous;for instance, in drag racing, the automatic transmission allows the car to be stopped with the

engine at a high rpm (the "stall speed") to allow for a very quick launch when the brakes are

released; in fact, a common modification is to increase the stall speed of the transmission. This is

even more advantageous for turbocharged engines, where the turbocharger needs to be keptspinning at high rpm by a large flow of exhaust in order to keep the boost pressure up and

eliminate the turbo lag that occurs when the engine is idling and the throttle is suddenly opened.
http://en.wikipedia.org/wiki/Crankshafthttp://en.wikipedia.org/wiki/Driveshafthttp://en.wikipedia.org/wiki/Differential_(mechanical_device)http://en.wikipedia.org/wiki/Torque_converterhttp://en.wikipedia.org/wiki/Diesel-electric_transmissionhttp://en.wikipedia.org/wiki/Diesel-electric_transmissionhttp://en.wikipedia.org/wiki/Hydraulic_drive_systemhttp://en.wikipedia.org/wiki/Automatic_transmissionhttp://en.wikipedia.org/wiki/Hydraulicshttp://en.wikipedia.org/wiki/Pressurehttp://en.wikipedia.org/wiki/Clutchhttp://en.wikipedia.org/wiki/Torque_converterhttp://en.wikipedia.org/wiki/Shift_Timehttp://en.wikipedia.org/wiki/Torque_converterhttp://en.wikipedia.org/wiki/Torque_converterhttp://en.wikipedia.org/wiki/Drag_racinghttp://en.wikipedia.org/wiki/Stall_speed#.E2.80.9CStall_speed.E2.80.9Dhttp://en.wikipedia.org/wiki/Turbochargehttp://en.wikipedia.org/w/index.php?title=Boost_pressure&action=edit&redlink=1http://en.wikipedia.org/wiki/Turbo_laghttp://en.wikipedia.org/wiki/Turbo_laghttp://en.wikipedia.org/w/index.php?title=Boost_pressure&action=edit&redlink=1http://en.wikipedia.org/wiki/Turbochargehttp://en.wikipedia.org/wiki/Stall_speed#.E2.80.9CStall_speed.E2.80.9Dhttp://en.wikipedia.org/wiki/Drag_racinghttp://en.wikipedia.org/wiki/Torque_converterhttp://en.wikipedia.org/wiki/Torque_converterhttp://en.wikipedia.org/wiki/Shift_Timehttp://en.wikipedia.org/wiki/Torque_converterhttp://en.wikipedia.org/wiki/Clutchhttp://en.wikipedia.org/wiki/Pressurehttp://en.wikipedia.org/wiki/Hydraulicshttp://en.wikipedia.org/wiki/Automatic_transmissionhttp://en.wikipedia.org/wiki/Hydraulic_drive_systemhttp://en.wikipedia.org/wiki/Diesel-electric_transmissionhttp://en.wikipedia.org/wiki/Diesel-electric_transmissionhttp://en.wikipedia.org/wiki/Torque_converterhttp://en.wikipedia.org/wiki/Differential_(mechanical_device)http://en.wikipedia.org/wiki/Driveshafthttp://en.wikipedia.org/wiki/Crankshaft


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TORQUE CONVERTER

In modern usage, a torque converter is generally a type ofhydrodynamic fluid coupling that is

used to transfer rotating power from a prime mover, such as an internal combustion

engine or electric motor, to a rotating driven load. The torque converter normally takes the place

of a mechanical clutch in a vehicle with an automatic transmission, allowing the load to beseparated from the power source. It is usually located between the engine's flywheel and the

transmission.

The key characteristic of a torque converter is its ability to multiply torque when there is a

substantial difference between input and output rotational speed, thus providing the equivalent ofa reduction gear. Some of these devices are also equipped with a temporary locking mechanism

which rigidly binds the engine to the transmission when their speeds are nearly equal, to avoid

slippage and a resulting loss of efficiency.

By far the most common form of torque converter in automobile transmissions is the device

described here. However, in the 1920s there was also the pendulum-based Constantinesco torque

converter. There are also mechanical designs for continuously variable transmissions and these

also have the ability to multiply torque, e.g. the Variomatic with expanding pulleys and a belt

drive.
http://en.wikipedia.org/wiki/Fluid_couplinghttp://en.wiktionary.org/wiki/prime_moverhttp://en.wikipedia.org/wiki/Internal_combustion_enginehttp://en.wikipedia.org/wiki/Internal_combustion_enginehttp://en.wikipedia.org/wiki/Electric_motorhttp://en.wikipedia.org/wiki/Clutchhttp://en.wikipedia.org/wiki/Transmission_(mechanics)http://en.wikipedia.org/wiki/Constantinesco_torque_converterhttp://en.wikipedia.org/wiki/Constantinesco_torque_converterhttp://en.wikipedia.org/wiki/Continuously_variable_transmissionhttp://en.wikipedia.org/wiki/Variomatichttp://en.wikipedia.org/wiki/Variomatichttp://en.wikipedia.org/wiki/Continuously_variable_transmissionhttp://en.wikipedia.org/wiki/Constantinesco_torque_converterhttp://en.wikipedia.org/wiki/Constantinesco_torque_converterhttp://en.wikipedia.org/wiki/Transmission_(mechanics)http://en.wikipedia.org/wiki/Clutchhttp://en.wikipedia.org/wiki/Electric_motorhttp://en.wikipedia.org/wiki/Internal_combustion_enginehttp://en.wikipedia.org/wiki/Internal_combustion_enginehttp://en.wiktionary.org/wiki/prime_moverhttp://en.wikipedia.org/wiki/Fluid_coupling


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TORQUE CONVERTER ELEMENTS

A fluid coupling is a two element drive that is incapable of multiplying torque, while a torque

converter has at least one extra elementthe statorwhich alters the drive's characteristics

during periods of high slippage, producing an increase in output torque.

In a torque converter there are at least three rotating elements: the impeller, which is

mechanically driven by the prime mover; the turbine, which drives the load; and the stator,

which is interposed between the impeller and turbine so that it can alter oil flow returning from

the turbine to the impeller. The classic torque converter design dictates that the stator be

prevented from rotating under any condition, hence the term stator. In practice, however, the

stator is mounted on an overrunning clutch, which prevents the stator from counter-rotating with

respect to the prime mover but allows forward rotation.

Modifications to the basic three element design have been periodically incorporated, especiallyin applications where higher than normal torque multiplication is required. Most commonly,

these have taken the form of multiple turbines and stators, each set being designed to produce

differing amounts of torque multiplication. For example, the BuickDynaflow automatic

transmission was a non-shifting design and, under normal conditions, relied solely upon theconverter to multiply torque. The Dynaflow used a five element converter to produce the wide

range of torque multiplication needed to propel a heavy vehicle.

Although not strictly a part of classic torque converter design, many automotive converters

include a lock-up clutch to improve cruising power transmission efficiency and reduce heat. Theapplication of the clutch locks the turbine to the impeller, causing all power transmission to be

mechanical, thus eliminating losses associated with fluid drive.

OPERATIONAL PHASES

A torque converter has three stages of operation:

Stall. The prime mover is applying power to the impeller but the turbine cannot rotate. For

example, in an automobile, this stage of operation would occur when the driver has placedthe transmission in gear but is preventing the vehicle from moving by continuing to apply

the brakes. At stall, the torque converter can produce maximum torque multiplication if

sufficient input power is applied (the resulting multiplication is called the stall ratio). The
http://en.wikipedia.org/wiki/Fluid_couplinghttp://en.wiktionary.org/wiki/prime_moverhttp://en.wikipedia.org/wiki/Structural_loadhttp://en.wikipedia.org/wiki/Overrunning_clutchhttp://en.wikipedia.org/wiki/Buickhttp://en.wikipedia.org/wiki/Dynaflowhttp://en.wikipedia.org/wiki/Dynaflowhttp://en.wikipedia.org/w/index.php?title=Lock-up_clutch&action=edit&redlink=1http://en.wikipedia.org/wiki/Transmission_(mechanics)http://en.wikipedia.org/wiki/Brakehttp://en.wikipedia.org/wiki/Brakehttp://en.wikipedia.org/wiki/Transmission_(mechanics)http://en.wikipedia.org/w/index.php?title=Lock-up_clutch&action=edit&redlink=1http://en.wikipedia.org/wiki/Dynaflowhttp://en.wikipedia.org/wiki/Dynaflowhttp://en.wikipedia.org/wiki/Buickhttp://en.wikipedia.org/wiki/Overrunning_clutchhttp://en.wikipedia.org/wiki/Structural_loadhttp://en.wiktionary.org/wiki/prime_moverhttp://en.wikipedia.org/wiki/Fluid_coupling


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stall phase actually lasts for a brief period when the load (e.g., vehicle) initially starts to

move, as there will be a very large difference between pump and turbine speed.

Acceleration. The load is accelerating but there still is a relatively large difference between

impeller and turbine speed. Under this condition, the converter will produce torque

multiplication that is less than what could be achieved under stall conditions. The amount of

multiplication will depend upon the actual difference between pump and turbine speed, as

well as various other design factors.

Coupling. The turbine has reached approximately 90 percent of the speed of the impeller.Torque multiplication has essentially ceased and the torque converter is behaving in a

manner similar to a simple fluid coupling. In modern automotive applications, it is usually at

this stage of operation where the lock-up clutch is applied, a procedure that tends toimprove fuel efficiency
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BRAKE

A brake is a mechanical device which inhibits motion. Its opposite component is a clutch. The

rest of this article is dedicated to various types of vehicular brakes.

Most commonly brakes use friction to convert kinetic energy into heat, though other methods of

energy conversion may be employed. For example regenerative braking converts much of the

energy to electrical energy, which may be stored for later use. Other methods convert kinetic

energy into potential energy in such stored forms as pressurized air or pressurized oil. Eddy

current brakes use magnetic fields to convert kinetic energy into electric current in the brake

disc, fin, or rail, which is converted into heat. Still other braking methods even transform kinetic

energy into different forms, for example by transferring the energy to a rotating flywheel.

Brakes are generally applied to rotating axles or wheels, but may also take other forms such asthe surface of a moving fluid (flaps deployed into water or air). Some vehicles use a combination

of braking mechanisms, such as drag racing cars with both wheel brakes and a parachute, or

airplanes with both wheel brakes and drag flaps raised into the air during landing.

Since kinetic energy increases quadratically with velocity (K= mv2 / 2), an object traveling at 10meters per second has 100 times as much energy as one traveling at 1 meter per second, and

consequently the theoretical braking distance, when braking at the traction limit, is 100 times as

long. In practice, fast vehicles usually have significant air drag, and energy lost to air drag rises

quickly with speed.

Almost all wheeled vehicles have a brake of some sort. Even baggage carts and shoppingcarts may have them for use on a moving ramp. Most fixed-wing aircraft are fitted with wheel

brakes on the undercarriage. Some aircraft also feature air brakes designed to reduce their speed

in flight. Notable examples include gliders and some World War II-era aircraft, primarily

some fighter aircraft and many dive bombers of the era. These allow the aircraft to maintain a

safe speed in a steep descent. The Saab B 17 dive bomber used the deployed undercarriage as an

air brake.

Friction brakes on automobiles store braking heat in the drum brake or disc brake while brakingthen conduct it to the air gradually. When traveling downhill some vehicles can use their engines

to brake.

When the brake pedal of a modern vehicle with hydraulic brakes is pushed, ultimatelya piston pushes the brake pad against the brake disc which slows the wheel down. On the brakedrum it is similar as the cylinder pushes the brake shoes against the drum which also slows the

wheel down.
http://en.wikipedia.org/wiki/Mechanical_devicehttp://en.wikipedia.org/wiki/Clutchhttp://en.wikipedia.org/wiki/Frictionhttp://en.wikipedia.org/wiki/Kinetic_energyhttp://en.wikipedia.org/wiki/Heathttp://en.wikipedia.org/wiki/Regenerative_brakinghttp://en.wikipedia.org/wiki/Electrical_energyhttp://en.wikipedia.org/wiki/Kinetic_energyhttp://en.wikipedia.org/wiki/Kinetic_energyhttp://en.wikipedia.org/wiki/Potential_energyhttp://en.wikipedia.org/wiki/Compressed_air_energy_storagehttp://en.wikipedia.org/wiki/Eddy_current_brakeshttp://en.wikipedia.org/wiki/Eddy_current_brakeshttp://en.wikipedia.org/wiki/Kinetic_energyhttp://en.wikipedia.org/wiki/Kinetic_energyhttp://en.wikipedia.org/wiki/Quadratic_functionhttp://en.wikipedia.org/wiki/Velocityhttp://en.wikipedia.org/wiki/Braking_distancehttp://en.wikipedia.org/wiki/Wheelhttp://en.wikipedia.org/wiki/Vehiclehttp://en.wikipedia.org/wiki/Baggage_carthttp://en.wikipedia.org/wiki/Shopping_carthttp://en.wikipedia.org/wiki/Shopping_carthttp://en.wikipedia.org/wiki/Moving_ramphttp://en.wikipedia.org/wiki/Fixed-wing_aircrafthttp://en.wikipedia.org/wiki/Undercarriagehttp://en.wikipedia.org/wiki/Air_brake_(aircraft)http://en.wikipedia.org/wiki/Glider_aircrafthttp://en.wikipedia.org/wiki/World_War_IIhttp://en.wikipedia.org/wiki/Fighter_aircrafthttp://en.wikipedia.org/wiki/Dive_bombershttp://en.wikipedia.org/wiki/Saab_17http://en.wikipedia.org/wiki/Dive_bomberhttp://en.wikipedia.org/wiki/Vehicle_brake#Friction_brakehttp://en.wikipedia.org/wiki/Automobilehttp://en.wikipedia.org/wiki/Drum_brakehttp://en.wikipedia.org/wiki/Disc_brakehttp://en.wikipedia.org/wiki/Airhttp://en.wikipedia.org/wiki/Engine_brakinghttp://en.wikipedia.org/wiki/Engine_brakinghttp://en.wikipedia.org/wiki/Automobile_pedalhttp://en.wikipedia.org/wiki/Hydraulic_brakehttp://en.wikipedia.org/wiki/Pistonhttp://en.wikipedia.org/wiki/Brake_padhttp://en.wikipedia.org/wiki/Disc_brakehttp://en.wikipedia.org/wiki/Brake_drumhttp://en.wikipedia.org/wiki/Brake_drumhttp://en.wikipedia.org/wiki/Brake_shoehttp://en.wikipedia.org/wiki/Brake_shoehttp://en.wikipedia.org/wiki/Brake_drumhttp://en.wikipedia.org/wiki/Brake_drumhttp://en.wikipedia.org/wiki/Disc_brakehttp://en.wikipedia.org/wiki/Brake_padhttp://en.wikipedia.org/wiki/Pistonhttp://en.wikipedia.org/wiki/Hydraulic_brakehttp://en.wikipedia.org/wiki/Automobile_pedalhttp://en.wikipedia.org/wiki/Engine_brakinghttp://en.wikipedia.org/wiki/Engine_brakinghttp://en.wikipedia.org/wiki/Airhttp://en.wikipedia.org/wiki/Disc_brakehttp://en.wikipedia.org/wiki/Drum_brakehttp://en.wikipedia.org/wiki/Automobilehttp://en.wikipedia.org/wiki/Vehicle_brake#Friction_brakehttp://en.wikipedia.org/wiki/Dive_bomberhttp://en.wikipedia.org/wiki/Saab_17http://en.wikipedia.org/wiki/Dive_bombershttp://en.wikipedia.org/wiki/Fighter_aircrafthttp://en.wikipedia.org/wiki/World_War_IIhttp://en.wikipedia.org/wiki/Glider_aircrafthttp://en.wikipedia.org/wiki/Air_brake_(aircraft)http://en.wikipedia.org/wiki/Undercarriagehttp://en.wikipedia.org/wiki/Fixed-wing_aircrafthttp://en.wikipedia.org/wiki/Moving_ramphttp://en.wikipedia.org/wiki/Shopping_carthttp://en.wikipedia.org/wiki/Shopping_carthttp://en.wikipedia.org/wiki/Baggage_carthttp://en.wikipedia.org/wiki/Vehiclehttp://en.wikipedia.org/wiki/Wheelhttp://en.wikipedia.org/wiki/Braking_distancehttp://en.wikipedia.org/wiki/Velocityhttp://en.wikipedia.org/wiki/Quadratic_functionhttp://en.wikipedia.org/wiki/Kinetic_energyhttp://en.wikipedia.org/wiki/Kinetic_energyhttp://en.wikipedia.org/wiki/Eddy_current_brakeshttp://en.wikipedia.org/wiki/Eddy_current_brakeshttp://en.wikipedia.org/wiki/Compressed_air_energy_storagehttp://en.wikipedia.org/wiki/Potential_energyhttp://en.wikipedia.org/wiki/Kinetic_energyhttp://en.wikipedia.org/wiki/Kinetic_energyhttp://en.wikipedia.org/wiki/Electrical_energyhttp://en.wikipedia.org/wiki/Regenerative_brakinghttp://en.wikipedia.org/wiki/Heathttp://en.wikipedia.org/wiki/Kinetic_energyhttp://en.wikipedia.org/wiki/Frictionhttp://en.wikipedia.org/wiki/Clutchhttp://en.wikipedia.org/wiki/Mechanical_device


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Frictional brakes are most common and can be divided broadly into "shoe" or "pad" brakes,

using an explicit wear surface, and hydrodynamic brakes, such as parachutes, which use friction

in a working fluid and do not explicitly wear.Typically the term "friction brake" is used to mean

pad/shoe brakes and excludes hydrodynamic brakes, even though hydrodynamic brakes use

friction.

Friction (pad/shoe) brakes are often rotating devices with a stationary pad and a rotating wear

surface. Common configurations include shoes that contract to rub on the outside of a rotating

drum, such as a band brake; a rotating drum with shoes that expand to rub the inside of a drum,

commonly called a "drum brake", although other drum configurations are possible; and pads that

pinch a rotating disc, commonly called a "disc brake". Other brake configurations are used, but

less often. For example, PCC trolley brakes include a flat shoe which is clamped to the rail with

an electromagnet; the Murphy brake pinches a rotating drum, and the Ausco Lambert disc

brake uses a hollow disc (two parallel discs with a structural bridge) with shoes that sit between

the disc surfaces and expand laterally.

DISC BRAKE

The disc brake or disk brake is a device for slowing or stopping the rotation of a wheel while it

is in motion.

A brake disc (or rotorin American English) is usually made ofcast iron, but may in some cases

be made of composites such as reinforced carboncarbon or ceramic matrix composites. This isconnected to the wheel and/or the axle. To stop the wheel, friction material in the form ofbrakepads (mounted on a device called a brake caliper) is forced

mechanically, hydraulically, pneumatically or electromagnetically against both sides of the

disc. Friction causes the disc and attached wheel to slow or stop. Brakes convert motion to heat,

and if the brakes get too hot, they become less effective, a phenomenon known as brake fade.
http://en.wikipedia.org/wiki/Band_brakehttp://en.wikipedia.org/wiki/Drum_brakehttp://en.wikipedia.org/wiki/Disc_brakehttp://en.wikipedia.org/wiki/PCC_trolleyhttp://en.wikipedia.org/wiki/Murphy_brakehttp://en.wikipedia.org/wiki/Ausco_Lambert_disc_brakehttp://en.wikipedia.org/wiki/Ausco_Lambert_disc_brakehttp://en.wikipedia.org/wiki/Brakehttp://en.wikipedia.org/wiki/Cast_ironhttp://en.wikipedia.org/wiki/Reinforced_carbon%E2%80%93carbonhttp://en.wikipedia.org/wiki/Reinforced_carbon%E2%80%93carbonhttp://en.wikipedia.org/wiki/Reinforced_carbon%E2%80%93carbonhttp://en.wikipedia.org/wiki/Ceramic_matrix_compositehttp://en.wikipedia.org/wiki/Axlehttp://en.wikipedia.org/wiki/Brake_padhttp://en.wikipedia.org/wiki/Brake_padhttp://en.wikipedia.org/wiki/Hydraulicshttp://en.wikipedia.org/wiki/Pneumaticshttp://en.wikipedia.org/wiki/Electromagnethttp://en.wikipedia.org/wiki/Frictionhttp://en.wikipedia.org/wiki/Brake_fadehttp://en.wikipedia.org/wiki/Brake_fadehttp://en.wikipedia.org/wiki/Frictionhttp://en.wikipedia.org/wiki/Electromagnethttp://en.wikipedia.org/wiki/Pneumaticshttp://en.wikipedia.org/wiki/Hydraulicshttp://en.wikipedia.org/wiki/Brake_padhttp://en.wikipedia.org/wiki/Brake_padhttp://en.wikipedia.org/wiki/Axlehttp://en.wikipedia.org/wiki/Ceramic_matrix_compositehttp://en.wikipedia.org/wiki/Reinforced_carbon%E2%80%93carbonhttp://en.wikipedia.org/wiki/Cast_ironhttp://en.wikipedia.org/wiki/Brakehttp://en.wikipedia.org/wiki/Ausco_Lambert_disc_brakehttp://en.wikipedia.org/wiki/Ausco_Lambert_disc_brakehttp://en.wikipedia.org/wiki/Murphy_brakehttp://en.wikipedia.org/wiki/PCC_trolleyhttp://en.wikipedia.org/wiki/Disc_brakehttp://en.wikipedia.org/wiki/Drum_brakehttp://en.wikipedia.org/wiki/Band_brake


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HISTORY

Disc-style brakes development and use began in England in the 1890s. The first caliper-type

automobile disc brake was patented by Frederick William Lanchester in his Birmingham,UK factory in 1902 and used successfully on Lanchester cars. However, the limited choice of

metals in this period, meant that he had to use copper as the braking medium acting on the disc.

The poor state of the roads at this time, no more than dusty, rough tracks, meant that the copper

wore quickly making the disc brake system non-viable (as recorded in The Lanchester Legacy).

It took another half century for his innovation to be widely adopted.

Modern-style disc brakes first appeared on the low-volume 1949 Crosley Hotshot, although they

had to be discontinued in 1950 due to design problems.[1] Chrysler's Imperial also offered a type

of disc brake from 1949 through 1953, though in this instance they were enclosed with dual

internal-expanding, full-circle pressure plates. Reliable modern disc brakes were developed in

the UK by Dunlop and first appeared in 1953 on the Jaguar C-Type racing car. The 1955 CitronDS featuring powered inboard front disc brakes was the first French application of this

technology, while the 1956 Triumph TR3 was the first English production car to feature modern

disc brakes.[2]The first production car to have disc brakes at all 4 wheels was the Austin-Healey

100S in 1954.[3]The first British company to market a production saloon (US: sedan) fitted withdisc brakes to all four wheels was Jensen Motors with the introduction of a Deluxe version of

the Jensen 541 with Dunlop disc brakes.[4]The first German production car with disc brakes was

the 1961 Mercedes-Benz 220SE coupe featuring British-built Girling units on the front.[5][6]The

next American production automobile equipped with caliper-type disc brakes was the 1963model year Studebaker Avanti[7](the Bendix system optional on some of the other Studebaker

models[8]). Front disc brakes became standard equipment in 1965 on the Rambler Marlin[9](the

Bendix units were optional on all American Motors "senior" platformmodels[10]), the FordThunderbird,[11]and the Lincoln Continental.[12]A four-wheel disc brake system was alsointroduced in 1965 on the Chevrolet Corvette Stingray.[13]

Compared to drum brakes, disc brakes offer better stopping performance, because the disc is

more readily cooled. As a consequence discs are less prone to the "brake fade" caused when

brake components overheat; and disc brakes recover more quickly from immersion (wet brakes

are less effective). Most drum brake designs have at least one leading shoe, which gives a servo-

effect; see leading/trailing drum brake. By contrast, a disc brake has no self-servo effect and its

braking force is always proportional to the pressure placed on the brake pad by the braking

system via any brake servo, braking pedal or lever, this tends to give the driver better "feel" to

avoid impending lockup. Drums are also prone to "bell mouthing", and trap worn lining materialwithin the assembly, both causes of various braking problems.

Many early implementations for automobiles located the brakes on the inboard side of

the driveshaft, near the differential, but most brakes today are located inside the road wheels. (Aninboard location reduces the unsprung weight and eliminates a source of heat transfer to the

tires.)
http://en.wikipedia.org/wiki/Frederick_William_Lanchesterhttp://en.wikipedia.org/wiki/Birmingham,_UKhttp://en.wikipedia.org/wiki/Birmingham,_UKhttp://en.wikipedia.org/wiki/Crosleyhttp://en.wikipedia.org/wiki/Disc_brake#cite_note-Crosley-0http://en.wikipedia.org/wiki/Disc_brake#cite_note-Crosley-0http://en.wikipedia.org/wiki/Chrysler_Imperial#1949.E2.80.931954http://en.wikipedia.org/wiki/United_Kingdomhttp://en.wikipedia.org/wiki/Dunlop_Rubberhttp://en.wikipedia.org/wiki/Jaguar_C-Typehttp://en.wikipedia.org/wiki/Citro%C3%ABn_DShttp://en.wikipedia.org/wiki/Citro%C3%ABn_DShttp://en.wikipedia.org/wiki/Triumph_TR3http://en.wikipedia.org/wiki/Englandhttp://en.wikipedia.org/wiki/Disc_brake#cite_note-AutoLemon-1http://en.wikipedia.org/wiki/Disc_brake#cite_note-AutoLemon-1http://en.wikipedia.org/wiki/Disc_brake#cite_note-AutoLemon-1http://en.wikipedia.org/wiki/Austin-Healey_100http://en.wikipedia.org/wiki/Austin-Healey_100http://en.wikipedia.org/wiki/Disc_brake#cite_note-2http://en.wikipedia.org/wiki/Disc_brake#cite_note-2http://en.wikipedia.org/wiki/Disc_brake#cite_note-2http://en.wikipedia.org/wiki/Jensen_Motorshttp://en.wikipedia.org/wiki/Jensen_541http://en.wikipedia.org/wiki/Disc_brake#cite_note-3http://en.wikipedia.org/wiki/Disc_brake#cite_note-3http://en.wikipedia.org/wiki/Disc_brake#cite_note-3http://en.wikipedia.org/wiki/Mercedes-Benzhttp://en.wikipedia.org/wiki/Disc_brake#cite_note-4http://en.wikipedia.org/wiki/Disc_brake#cite_note-4http://en.wikipedia.org/wiki/Disc_brake#cite_note-4http://en.wikipedia.org/wiki/Studebaker_Avantihttp://en.wikipedia.org/wiki/Studebaker_Avantihttp://en.wikipedia.org/wiki/Studebaker_Avantihttp://en.wikipedia.org/wiki/Bendix_Corporationhttp://en.wikipedia.org/wiki/Disc_brake#cite_note-7http://en.wikipedia.org/wiki/Disc_brake#cite_note-7http://en.wikipedia.org/wiki/Disc_brake#cite_note-7http://en.wikipedia.org/wiki/Rambler_Marlinhttp://en.wikipedia.org/wiki/Rambler_Marlinhttp://en.wikipedia.org/wiki/Rambler_Marlinhttp://en.wikipedia.org/wiki/American_Motorshttp://en.wikipedia.org/wiki/Automobile_platformhttp://en.wikipedia.org/wiki/Disc_brake#cite_note-whatsnewAMC-9http://en.wikipedia.org/wiki/Disc_brake#cite_note-whatsnewAMC-9http://en.wikipedia.org/wiki/Ford_Thunderbird_(fourth_generation)http://en.wikipedia.org/wiki/Ford_Thunderbird_(fourth_generation)http://en.wikipedia.org/wiki/Disc_brake#cite_note-10http://en.wikipedia.org/wiki/Disc_brake#cite_note-10http://en.wikipedia.org/wiki/Disc_brake#cite_note-10http://en.wikipedia.org/wiki/Lincoln_Continentalhttp://en.wikipedia.org/wiki/Disc_brake#cite_note-11http://en.wikipedia.org/wiki/Disc_brake#cite_note-11http://en.wikipedia.org/wiki/Disc_brake#cite_note-11http://en.wikipedia.org/wiki/Chevrolet_Corvette_(second_generation-C2)http://en.wikipedia.org/wiki/Disc_brake#cite_note-12http://en.wikipedia.org/wiki/Disc_brake#cite_note-12http://en.wikipedia.org/wiki/Disc_brake#cite_note-12http://en.wikipedia.org/wiki/Drum_brakehttp://en.wikipedia.org/wiki/Brake_fadehttp://en.wikipedia.org/wiki/Leading/trailing_drum_brakehttp://en.wikipedia.org/wiki/Inboard_brakehttp://en.wikipedia.org/wiki/Driveshafthttp://en.wikipedia.org/wiki/Differential_(mechanics)http://en.wikipedia.org/wiki/Unsprung_weighthttp://en.wikipedia.org/wiki/Unsprung_weighthttp://en.wikipedia.org/wiki/Differential_(mechanics)http://en.wikipedia.org/wiki/Driveshafthttp://en.wikipedia.org/wiki/Inboard_brakehttp://en.wikipedia.org/wiki/Leading/trailing_drum_brakehttp://en.wikipedia.org/wiki/Brake_fadehttp://en.wikipedia.org/wiki/Drum_brakehttp://en.wikipedia.org/wiki/Disc_brake#cite_note-12http://en.wikipedia.org/wiki/Chevrolet_Corvette_(second_generation-C2)http://en.wikipedia.org/wiki/D

Project Report on Low Floor Part 1

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Transcript of Project Report on Low Floor Part 1