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Design and Development of Road Speed Breaker for The Generation of Electricity

Project SupervisorProf. Dr . Syed Amjad Ahmed

Prof. Dr. Ahmed ShafiMr .Yasir Javaid

Presented ByM.Bilal Awan

Osama ShakeelM.Asim JameelAdnan Mushtaq

M.Umair Manzoor

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Table of contents

Objective. Introduction Basic principle Types of Speed Breaker Working Model What we achieved Future Scope

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Objectives

• To use a non–conventional source of energy to generate electricity

• To generate electricity at low cost• To tap a readily available source of energy• To reduce load on the national grid

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Why this project?

According to TEPA power consumption of street lights in Lahore is 15-20MW.

Currently we have 1500MW shortfall of electricity with a maximum of 6000MW in summer.

A large number of speed breaker are present in Pakistan on major roads and toll plazas

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Introduction

A large amount of energy is wasted at the speed breakers through the dissipation of heat and also through friction, every time a vehicle passes over it. There is great possibility of tapping this energy and generating power by making the speed-breaker as a power generation unit. The generated power can be used for the lamps, near the speed breakers and resulting in saving a lot of energy which is spent on street lights.

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Basic Principle

Law of conservation of energy.Simple energy conversion from Mechanical

to Electrical.To generate electricity using the vehicle

weight (potential energy) as input

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Types of Speed breaker Mechanism

Possible using 3 different mechanisms:

I. Roller mechanism

II. Crank-shaft mechanism

III. Rack- Pinion mechanism

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Roller mechanism

Top view

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Roller Mechanism

Side view

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Problems

• Generation of electricity depends upon the velocity of the car

• Maintenance will be very difficult

• Maximum velocity of the roller will be low.

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Crankshaft mechanism

• The crankshaft is a mechanism that transforms linear movement into rotary movement and vice versa.

• Whenever the vehicle going on the speed breaker the speed breaker goes downwards . So, the potential energy is converted into kinetic energy of the crank shaft

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Crankshaft Mechanism

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Problems

• Crank-shafts are required to be mounted on bearings which creates balancing problem leading to mechanical vibrations which in turn damage the bearings.

• Secondly any occurrence of variable load leads to balancing problem.

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Rack and Pinion

• A rack and pinion gears system is composed of two gears. The normal round gear is the pinion gear and the straight or flat gear is the rack.

• The rack has teeth cut into it and they mesh with the teeth of the pinion gear.

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Working of rack and pinion

• The rack and pinion is used to convert between rotary and linear motion. Rack and pinion can convert from rotary to linear of from linear to rotary.

• The diameter of the gear determines the speed that the rack moves as the pinion turns.

• Rack and pinions are commonly used in the steering system of cars to convert the rotary motion of the steering wheel to the side to side motion in the wheels04/11/2023

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RACK- PINION

• Rack-Pinion assembly gives good mounting convenience

• Maximum gear losses– 3 to 5%• Efficiency– 95%

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Block diagram

Gear DrivesRack pinion and chain sprocket arrangement

Speed Breaker Arrangement

Street LightsInverter and Battery Generator

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Working model

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Components

• Rack and pinion• Sprocket and chain• DC Generator• Flywheel• Spring

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Design and Calculations

• The system is designed for a maximum load of 50kg. Assuming no loss in energy conversion from potential to kinetic the max output energy in 1 sec that is available theoretically

PE=mgh

M= mass of the car

G= acceleration of gravity

H=height of the rack moved by car

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Maximum Power Output

. 50*9.81*0.3 147P E W

120

NPf

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Where

f= frequency of the alternating current in Hz

P= no. of poles of the electric generator

N= RPM of the electricity generator

• To generate a 50 Hz voltage we can use a 2 pole or 4 pole generators.

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For 2 pole generator

• Rpm required is

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For 4 pole generator

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• So will be using 2 pole DC generators . We need to design the length of the rack and gear box with a gear ratio accordingly

• Length of rack= 13inch• Pitch of rack teeth’s=1/8inch • Number of teeth’s on rack =104

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Gear box

First shaft• Number of teeth on pinion on first shaft attach

to rack=10 • Pinion to rack ratio=10 means it will give us

10 rpm on the first shaft.• Number of teeth of the sprocket on the first

shaft= 74

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Second shaft

• Number of teeth of the small sprocket on the 2nd shaft= 18

• Large sprocket to small sprocket ratio=4.11• It will give 4.11*10=41 rpm on the second

shaft• Number of teeth of the gear on the 2nd

shaft=120

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Third shaft

• Number of teeth of the gear on the 3rd shaft=10

• Gear ratio=12• It will give 41*12=492 rpm on the 3rdshaft• Number of teeth of the gear on the 3rd

shaft=60

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Generator shaft

• Number of teeth of the gear attach to generator shaft=15

• Gear ratio=4• So generator shaft will rotate at 492*4=1968

Rpm .

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DC generator

• Installed capacity of generator=180W• Max. theoretical output=147W• Output=47W• Efficiency=47/147=32% (without assuming losses)

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Springs

• Helical Compression Spring is being used.

• Material is Alloy steels such as chrome .

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Design and Calculations

F=kx

x=deflection of spring=0.26

K=Stiffnes of spring

K=mg/x = 50*9.81/.26 = 1.6 KN/m

Lf=24 inch = 609.6 mm

Lf=Free length of spring

Number of turns=n=40

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Design and Calculations

• P= Lf / n-1 = 609.6 / 39 = 15 mm

• Lf=(n*d)+x+(0.15x)

=(40*d)+254+(0.15*254)

d = (609.6 – 254 – 38.1 ) / 40 = 8 mm

Where d= Wire dia

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Design and Calculations

K = Gd^4 / 8D^3 n

Where G=70 GPa

D = 82 mm = 3 inch

Where D= Dia of the Spring

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Flywheel

• Material used for manufacturing of flywheel is cast iron

• Kinetic energy of fly wheel, E = ½ I 2

E=200 J m= 8 kg Since I = m k2, E = ½ I k22

K=4.7 inch

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I = moment of inertia of fly wheel about the axis.

m = mass of fly wheel in Kg

k = radius of gyration of fly wheel in meters

= mean angular speed in rad/sec.

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What We Achieved

• Although we got less electrical output, we have successfully explained our idea of generating electricity from speed breaker.

• This is a immediate solution to energy crisis in Pakistan.

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Future Scope

• Such speed breakers can be designed for heavy vehicles, thus increasing input torque and ultimately output of generator.

• More suitable and compact mechanisms to enhance efficiency

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Advantages

• Low budget electricity production • Less floor area • No obstruction to traffic • Easy maintenance • Suitable at parking of multiplexes, malls, toll

booths, signals, etc. • Uses: Charging batteries and using them to

light up the streets, etc

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Advantages

• Pollution free power generation.• Simple construction, mature technology, and

easy maintenance.• No manual work necessary during generation.• Energy available all year round.• No fuel transportation problem.• No consumption of any fossil fuel which is

nonrenewable source of energy.

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Disadvantages

• Selecting suitable generator. • Selection of springs. • Achieving proper balance of speed and torque. • It gives low electric output • It can get rusted in rainy season

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Conclusion

• In order to overcome energy crisis, third world countries like Pakistan should implement such projects to share a burden of National Grid.

• Such a mechanism will save a lot of electricity, of power plants which is wasted in illuminating the street light.

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Conclusion

• Conventional sources of energy like coal, Natural gas and oil are depleting very fast and by the turn of century man will have to depend upon non conventional sources of energy for power generation.

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Questions?