pgfs document

POWER GENERATION FROM SPEED BREAKER Dept. of MECH

AURORA’S TECHNOLOGICAL & MANAGEMENT ACADEMY 1

CHAPTER -1

INTRODUCTION

This project attempts to show how energy can be tapped and used at a commonly used

system-the road speed-breakers. The number of vehicles passing over the speed breaker in

roads is increasing day by day. 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. In this model we show that how we can generate a voltage from the busy

traffic. Conversion of the mechanical energy into electrical energy is widely used concept. It’s

a mechanism to generate power by converting the potential energy generated by a vehicle

going up on a speed breaker into rotational energy. We have used that simple concept to the

project.

The utilization of energy is an indication of the growth of a nation. For example,

World average per capita electricity consumption is 2730 kWh compared to Pakistan’s per

capita electricity consumption of 451 kWh. Pakistan has an installed electricity generation

capacity of 22,797MW. The average demand is 17,000MW and the shortfall is between 4,000

and 5,000MW. One might conclude that to be materially rich and prosperous, a human being

needs to consume more and more energy. Pakistan is facing serious energy crisis at this time.

Pakistan as third world developing country is lot affected by this energy crisis in the world.

The major issue is electric crisis which is known as load shedding Pakistan’s small

manufacturing markets are lot affected by the rise of energy prices.

By just placing a unit like the “Power Generation Unit from Speed Breakers”, so much

of energy can be tapped. This energy can be used for the lights on the either sides of the Roads

and thus much power that is consumed by these lights can be utilized to send power to these

villages.



CHAPTER -2

LITERATURE REVIEW

The energy crisis is any great bottleneck in the supply of energy resources to an

economy. The studies to sort out the energy crisis led to the idea of generating power using

speed breaker. Firstly, South African electrical crisis has made them implemented this method

to light up small villages of the highway. The idea is basic physics, to convert the kinetic

energy into electrical energy that gone wasted when the vehicle runs over speed-breaker. Since

then, a lot has been done in this field. An amateur innovator, Kanak Gogoi in Guwahati has

developed a similar contraption to generate power, when a vehicle passes over speed-breaker.

The idea has caught the eye of IIT-Guwahati, which funded the pilot project related to

generate electricity from speed-breakers. They has evaluated the machine and recommended

to the Assam government. Their work has provided the need to think on this alternative to

generate electricity on the large scale, as it proves to be a boon to the economy of the country.

This paper focuses on mechanism of electricity generation using speed breakers. There

are many methods to produce electricity using speed breakers like Roller, Rack-Pinion, Crank

shaft etc. This paper is based upon the project which has rack-pinion mechanism. We are

going to outline the significant studies devoted to this topic. Singh et al. discussed rack pinion

mechanism to generate electricity.

They proposed mechanism using chain sprocket and springs with rack pinion to

generate electricity. Vehicle was passed over that mechanism and then due to rack pinion there

was rotation in gears and shafts moved with chain sprocket movement. Dc power was

generated and was stored in a battery and then using an inverter they changed that dc in ac

power. Das et al. proposed mechanism in which electricity was produced by kinetic energy of

speed breaker. The basic principle was when a car passes over the jump or dome which is the

device use in place of jump the dome will go down due to weight of car while moving car

possess kinetic energy that kinetic energy will be converted into rotational energy with the

help of rack and pinion. A fly wheel was mounted on the shaft whose function was to make



energy uniform. That shaft is connected through a belt with dynamos. These dynamos were

used to convert mechanical energy in electrical energy. The power was generated in both

directions.

They used Zener diode to generate power in opposite direction too. Kaur et al.

discussed mechanism of power generation with speed breakers by using rack and pinion

technique. They made a dome like assembly to place under the speed breaker. When a car

passed over this dome the rack will convert linear motion into rotatory motion with the help of

pinion and pinion is connected to a shaft which will also rotate with the pinion.

A large gear was also connected to the shaft which will also move and it will move

with the same speed of pinion this gear is connected to another small gear using chain sprocket

arrangement this will rotate the small gear and small gear will complete more rotations as

compared to bigger one. A flywheel was mounted on the lower shaft whose function was to

regulate the fluctuation in the energy and to make the energy uniform, now this shaft was

connected to the generator using spur gear due to which the generator was rotated and the

electricity was produced. The project and mechanism which is explained in this paper is

continuity of the mechanism of power generation. In this paper electrical portion is modified

by using microcontroller and sinusoidal PWM inverter. Electrical circuitry is improved so that

there should be less power losses across the mechanism and more power can be collected at

the end.



CHAPTER -3

DEMONSTRATION OF THE PROJECT

3.1 WORKING PRINCIPLE:

The project is concerned with generation of electricity from speed breakers-like set up.

The load acted upon the speed breaker -setup is there by transmitted to rack and pinion

arrangements. Here the reciprocating motion of the speed-breaker is converted into rotary

motion using the rack and pinion arrangement. The axis of the pinion is coupled with the

sprocket arrangement. The sprocket arrangement is made of two sprockets. One of larger size

and the other of smaller size (free wheel). Both the sprockets are connected by means of a

chain which serves in transmitting power from the larger sprocket to the smaller sprocket.

As the power is transmitted from the larger sprocket to the smaller sprocket, the speed

that is available at the larger sprocket is relatively multiplied at the rotation of the smaller

sprocket. The axis of the smaller sprocket is coupled to a fly wheel. The fly wheel is coupled

to the shaft at axis of the smaller sprocket. Hence the speed that has been multiplied at the

smaller sprocket wheel is passed on to this flywheel of larger dimension. The smaller sprocket

is coupled to the larger fly wheel. So as the larger fly wheel rotates at the multiplied speed of

the smaller sprocket, the smaller sprocket following the larger sprocket still multiplies the

speed to more intensity. Hence, although the speed due to the rotary motion achieved at the

larger sprocket wheel is less, as the power is transmitted to fly wheel, finally the speed is

multiplied to a higher speed.

This speed which is sufficient to rotate shaft connected to generator. The rotor (shaft)

rotates the generator. The generator produces the DC current. This DC current is now sent to

the storage battery where it is stored during the day time. This current is then utilized in the

night time for lighting purposes on the either sides of the road to a considerable distance.



3.2 BLOCK DIAGRAM:

Fig 3.1 Block diagram of construction

Fig. 3.2 Output of project



CHAPTER -4

MODELING, SIMULATION AND RESULTS

4.1 FABRICATION DETAILS:

The frame structure for the total unit is fabricated using L-Angle frames and ordinary

frames. These frames are made of mild steel. They are held to proper dimensions are attached

to form a unit with the help of welding. Then the bearings which are of standard make are kept

in place with the irrespective shafts through them and are welded to the frame structure.

The shafts are also made of mild steel. Hinges are used to move the speed breaker

arrangement by welding it to the frame structure. These hinges are responsible for the

movement of the speed breaker in an up and down motion. A rack which is made up of mild

steel is welded to the speed breaker arrangement. A pinion which is also made up of mild steel

and which has Thirty six teeth is fitted on the shaft initially, and welded. This pinion tooth is

exactly made to mate with the teeth of the rack.

A bicycle sprocket and chain arrangement of standard make is fitted with the larger

sprocket on the top shaft and its smaller sprocket on the bottom shaft. The sprocket wheels are

welded to the shafts. A fly wheel that is made of cast iron is machined suitably to the precise

dimensions in a lathe and is placed on the shaft with its axis coinciding with the axis of the

shaft and is welded. A special stand arrangement is made to seat the 12v DC generator using

frames. A 12v DC generator is placed within the seat and is held firm using bolts and nuts.

4.2 FABRICATION MODEL SHOWING INNER PARTS:

Wires are connected to the terminals of the DC generator and its other ends are

connected to a Lead-Acid battery. Another wire is taken from these points on the battery and

its other ends are connected to the Positive and negative terminal of an inverter. An output

wire from the inverter is sent to the light.



4.3 MATERIALS USED:

RACK-MILD STEEL

PINION-MILD IRON

SPROCKET WHEELS-MILD STEEL

CHAIN-MILD STEEL

SPUR GEARS-CAST IRON

SPRINGS-MILD STEEL

SHAFT -MILD STEEL

SPEED BREAKER -MILD STEEL

4.4 SPECIFICATIONS:

Generator - 12v DC generator

Battery - lead acid battery

Inverter - 250 w AC inverter



CHAPTER -5

EQUIPMENT REQUIRED

5.1 Rack and Pinion Gears:

The rack and pinion used to convert between rotary and translator motion. The rack is

the flat toothed part, while the pinion is the gear. Rack and pinion can convert rotary to linear

of from linear to rotary motion.

Fig. 5.1 Pinion

Fig.5.2 Rack & Pinion Mechanism



5.2 Ball Bearings:

A roller-element bearing is a bearing which carries a load by placing round elements

between the two pieces. The relative motion of the pieces causes the round elements to roll

(tumble) with little sliding. They reduce the friction and transmit the motion effectively.

Fig. 5.3 Ball bearing

5.3 Spur Gear:

It is a positive power transmission device with definite velocity ratio. It is preferred for

adjusting some linear misalignment. It should have high wear and tear, shock-absorbing

capacity.

Fig. 5.4 Spur gear



5.4 Flywheel:

The primary function of flywheel is to act as an energy accumulator. It reduces the

fluctuations in speed. It absorbs the energy when demand is less and releases the same when it

is required.

Fig. 5.5 Flywheel

5.5 Shaft:

It is a rotating element, which is used to transmit power from one place to another

place. It supports the rotating elements like gears and flywheels. It must have high torsional

rigidity and lateral rigidity.

Fig. 5.6 Shaft



5.6 Generator:

It is a device, which converts mechanical energy into electrical energy. The generator

uses rotating coils of wire and magnetic fields to convert mechanical rotation into a pulsing

direct electric current through “Faraday”s law of electromagnetic induction”.

Fig. 5.7 Generator

5.7 Lead acid battery:

Lead-acid batteries are the most common in PV systems because their initial cost is

lower and because they are readily available nearly everywhere in the world. There are many

different sizes and designs of lead-acid batteries, but the most important designation is that

they are deep cycle batteries. Lead-acid batteries are available in both wet-cell (requires

maintenance) and sealed no-maintenance versions. AGM and Gel-cell deep-cycle batteries are

also popular because they are maintenance free and they last a lot longer.

Lead acid batteries are reliable and cost effective with an exceptionally long life. The

Lead acid batteries have high reliability because of their ability to withstand overcharge, over

discharge vibration and shock. The use of special sealing techniques ensures that our batteries

are leak proof and non-spill able. Other critical features include the ability to withstand

relatively deeper discharge, faster recovery and more chances of survival if subjected to

overcharge.



Lead acid batteries are manufactured/ tested using CAD (Computer Aided Design).

These batteries are used in Inverter & UPS Systems and have the proven ability to perform

under extreme conditions. The batteries have electrolyte volume, use PE Separators and are

sealed in sturdy containers, which give them excellent protection against leakage and

corrosion.

Features:

Manufactured/tested using CAD

Electrolyte volume

PE Separators

Protection against leakage

Fig. 5.8 Lead acid battery

5.8 Battery connections:

Lead-acid batteries are normally available in blocks of 2V, 6V or 12V. In most cases,

to generate the necessary operating voltage and the capacity of the batteries for the Solar

Inverter, many batteries have to be connected together in parallel and/or in series. Following

three examples are shown:



a) Parallel Connection:

Fig. 5.9 Parallel connection

b) Series Connection:

Fig. 5.10 Series connection



c) Parallel-Series Connection:

Fig. 5.11 Parallel-Series Connection



CHAPTER -6

RACK, PINION AND SPROCKET

6.1 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.

A rack and pinion is a type of linear actuator that comprises a pair of gears which

convert rotational motion into linear motion. The circular pinion engages teeth on a linear

"gear" bar which is called the “rack“.

Fig. 6.1 Rack and Pinion mechanism

Rotational motion applied to the pinion will cause the rack to move to the side, up to

the limit of its travel.

For example, in a rack railway, the rotation of a pinion mounted on a locomotive or a

railcar engages a rack between the rails and pulls a train along a steep slope.



The rack and pinion is also used to convert between rotary and linear motion. The rack

is the flat, toothed part, and the pinion is the gear. Rack and pinion can convert from

rotary to linear of from linear to rotary motion.

It converts the linear motion of the speed breaker into the circular motion needed to

turn the shaft.

6.2 SPROCKET:

A sprocket or sprocket-wheel is a profiled wheel with teeth or cogs that mesh with a

chain, trackor other perforated or indented material. The name "sprocket" applies generally to

any wheel upon which are radial projections that engage a chain passing over it. It is

distinguished from a gear in that sprockets are never meshed together directly, and differs

from a pulley in that sprockets have teeth and pulleys are smooth. The word "sprockets" may

also be used to refer to the teeth on the wheel.

Sprockets are used in bicycles, motorcycles, cars, tracked vehicles, chainsaws and

other machinery either to transmit rotary motion between two shafts where gears are

unsuitable or to impart linear motion to a track, tape etc. Perhaps the most common form of

sprocket may be found in the bicycle, in which the pedal shaft carries a large sprocket-wheel,

which drives a chain, which, in turn, drives a small sprocket on the axle of the rear wheel.

Early automobiles were also largely driven by sprocket and chain mechanism, a practice

largely copied from bicycles.

Sprockets are of various designs, a maximum of efficiency being claimed for each by

its originator. Sprockets typically do not have a flange. Some sprockets used with timing belts

have flanges to keep the timing belt centered. Sprockets and chains are also used for power

transmission from one shaft to another where slippage is not admissible, sprocket chains being

used instead of belts or ropes and sprocket-wheels instead of pulleys. They can be run at high

speed and some forms of chain are so constructed as to be noiseless even at high speed.



6.3 DRIVE ARRANGEMENTS:

Relative position of sprockets in drives should receive careful consideration.

Satisfactory operation can be secured with the centerline of the drive at any angle to the

horizontal, if proper consideration is given. Certain arrangements require less attention and

care than others are, therefore, less apt to cause trouble. Various arrangements are illustrated

in the diagrams. The direction of rotation of the drive sprocket is indicated.

6.4 BEST ARRANGEMENTS:

Arrangements considered good practice are illustrated in Figs. 1, 2, 3, and 4. The

direction of rotation of the drive sprockets in Figs. 1 and 4 can be reversed.

Fig. 6.2 Direction of rotation of the drive sprockets



6.5 OTHER ACCEPTABLE ARRANGEMENTS:

If none of the above arrangements can be followed, an attempt should be made to use

an arrangement as illustrated in Figs. 5, 6, and 7.

Fig. 6.3 Other acceptable arrangements

When the large sprocket is directly above the small sprocket a drive cannot operate

with much chain slack. As the chain wears, shaft-center distance must be adjusted or an idler

be placed against the outside of the slack strand (near the small sprocket) to adjust slack and

keep the chain in proper contact with the small sprocket. With the drive slightly inclined, less

care will be required, because the weight of the slack chain strand helps to maintain better

contact between the chain and the sprockets.

Where center distances is short, or drives nearly horizontal, the slack should be in the

bottom strand, especially where take-up adjustment is limited, rather than an accumulation of

slack in the top strand may allow the chain to be pinched between the sprockets. When small

sprockets are used on horizontal drives, it is better to have the slack strand on the bottom,

rather than on the top. Otherwise, with the appreciable amount of slack, the strands may strike

each other.



6.6 LEAST RECOMMENDED ARRANGEMENTS:

Fig. 6.4 Least recommended arrangements

American sprocket manufacturers have adopted 4 specific types of sprocket.

Construction styles as American Standards. In addition to the standard sprockets,

Special sprockets may be available in the same styles.

Style A -Flat sprocket with no hub extension either side.

Style B -Sprocket with hub extension one side.

Style C -Sprocket with hub extension both sides.

Style D -Sprocket with a detachable bolt on hub attached to a plate.



6.7 SPROCKET DIMENSIONAL SPECIFICATIONS:

i) Bottom Diameter (B.D.):

The diameter of a circle tangent to the bottoms of the tooth spaces.

ii) Caliper Diameter:

Since the bottom diameter of a sprocket with odd number of teeth cannot be measured

directly, caliper diameters are the measurement across the tooth spaces nearly opposite.

iii) Pitch Diameter (P.D.):

The diameter across to the pitch circle which is the circle Followed by the centers of

the chain pins as the sprocket revolves in mesh with the chain.

PD=PITCH/SIN (180/Nt)

iv) Outside Diameter (O.D.):

The measurement from the tip of the sprocket tooth across to the corresponding point

directly across the sprocket. It is comparatively unimportant as the tooth length is not vital to

proper meshing with the chain. The outside diameter may vary depending on type of cutter

used.

OD = (Pitch) (.6 + COT [180 / Nt])

v) Hub Diameter (HOD):

That distance across the hub from one side to another. This diameter must not exceed

the calculated diameter of the inside of the chain side bars.

vi) Maximum Sprocket:

Maximum Sprocket Bore is determined by the required Bore hub wall thickness for

proper strength. Allowance must be made for keyway and setscrews.



vii) Face Width:

Face width is limited in its maximum dimension to allow proper clearance to provide

for chain engagement and disengagement. The minimum width is limited to provide the proper

strength to carry the imposed loads.

viii) Length thru Bore:

Length Thru Bore (or L.T.B.) must be sufficient to allow (LTB) a long enough key to

withstand the torque transmitted by the shaft. This also assures stability of the sprocket on the

shaft.



CHAPTER -7

CHAIN DRIVES, WHEELS AND SPRINGS

Chain drives are a means of transmitting power like gears, shafts and belt drives

Characteristics

High axial stiffness

Low bending stiffness

High efficiency

Relatively cheap

History and development

First belt drives: China c100 BC

First chain drives: Roman c200 AD

Leonardo Davinci sketch of leaf type chain c1500 AD –many similarities to modern chains.

Galle chains: 19thcentury first mass produced roller chains (no bushes).

Hans Renold (Switzerland) 1880–invented modern bush roller chain

Fig. 7.1 Chain drive mechanism



7.1 BUSH ROLLER CHAINS:

Parts of a bush roller chain,

Fig. 7.2 Parts of a bush roller chain



Terminology:

Manufacture bushes and pins, cold drawn, cropped, Turned/ground, case hardened,

ground Again and shot penned. Side-plates are stamped from plate.

Assembly Pins and bushes are press-fitted into appropriate side plates.

Fig 7.3 Assembling of sprocket and chain drive

7.2 CHAIN DRIVE DESIGN:

Chain length and center distance:

Chain must contain even integer number of links

• Hence cannot pick an arbitrary center distance and chain pitch

• Nearest chain lengths (in pitches) for a contemplated center distance, CC, are calculated by

empirical formulae like (for a two sprocket system:

Where N1and N2 is the numbers of teeth on sprockets and P is the chain pitch.



The result of which should be ROUNDED UP to the next even number to calculate the

actual center separation CA:

Inertial force in chain:

In addition to the tension required to transmit power, chain tension also provides

centripetal force to move links around sprockets

The extra inertial force, Fcf, is given by:

7.3 VIBRATION:

Chain between sprockets can vibrate like a string

Fig. 7.4 Chain drive between two sprockets



Basic equation for natural frequency, fn, of taught string

Where F is the tension, m is the mass per unit length, L is the length and k is the mode number

For tight side of chain there are typically ranges of resonant frequencies given by:

Where,

Fc is the tight span tension (excluding inertial contribution)

7.4 AVOIDING VIBRATION:

To avoid the chain resonating, need to avoid having sources of excitation with

frequencies near possible resonant frequencies

Obvious source is impact of sprocket teeth on chain

Frequency of these occurs at:

Where ω is the sprocket rotation speed and N is the number of teeth.



7.5 CHAIN TYPES:

i) Transmission chains:

Chains to transmit rotary power between shafts

Bush roller chains are transmission chains

For more power capacity, multi-strand transmission chains are used

Fig. 7.5 Duplex chain

ii) Conveyor chain:

Rollers sit proud of links and can roll along supporting surface.

Can be used for transporting materials, as roller scan support weight.

Can also be used just to support weight of chain if transmitting power over long

distances.



Fig. 7.6 Conveyor chain

iii) Inverted tooth (or silent) chain:

Sprocket teeth mesh with shaped links instead of rollers on chain

Joints between links use rolling rather than sliding contact

Profile of links are more like in volute gear teeth Overall effect is to reduce noise

Fig. 7.7 Inverted tooth chain

iv) Leaf (or lifting) chain:

Designed for lifting rather (than power transmission)

Do not have to mesh with sprockets, hence no rollers

Therefore can narrower than roller chain with equivalent strength

Example: fork-lift truck



Fig. 7.8 Leaf chain

7.6 CHAIN FAILURES:

i) Failures caused by poor selection:

Overload

Failure of side plates due to cyclic load fatigue

Failure of bush or roller due to impact fatigue

Above failures can still occur due to poor installation or maintenance

Misalignment

Incorrect or failed lubrication system

ii) Generation of Electricity through Speed Breaker Mechanism:

If correct chain is selected, installed and maintained the overall life is determined by

wear

Causes and effects of chain wear

Caused by material removal as chain components slide relative to each other

Effect of wear is to cause the chain to gradually elongate



Fig. 7.9 Failure in chain drive

As pitch increases, chain sits at larger and large radius on sprockets

Limit is when chain jumps over sprocket teeth

Empirical extension limits are

2 % for sprockets with less than 200 teeth

200/N % for sprockets with more than 200 teeth

iii) Wear life:

Typically 15,000 hours for any power, chain or sprocket size if correctly selected installed and

maintain



7.7 FREE WHEEL:

A freewheels consists of either a single sprocket or a set of sprockets mounted on a

body which contains an internal ratcheting mechanism and mounts on a threaded hub.

i) Mechanics:

The simplest freewheel device consists of two saw-toothed, spring-loaded discs

pressing against each other with the toothed sides together, somewhat like a ratchet. Rotating

in one direction, the saw teeth of the drive disc lock with the teeth of the driven disc, making it

rotate at the same speed. If the drive disc slows down or stops rotating, the teeth of the driven

disc slip over the drive disc teeth and continue rotating, producing a characteristic clicking

sound proportionate to the speed difference of the driven gear relative to that of the (slower)

driving gear.

A more sophisticated and rugged design has spring-loaded steel rollers inside a driven

cylinder. Rotating in one direction, the rollers lock with the cylinder making it rotate in

unison. Rotating slower, or in the other direction, the steel rollers just slip inside the cylinder.

ii) Advantages:

Free wheel mechanism acts as an automatic clutch, making it possible to change gears

in a manual gearbox, either up- or downshifting, without depressing the clutch pedal, limiting

the use of the manual clutch to starting from standstill or stopping.

iii) Disadvantages:

The major disadvantage of the multiple sprocket freewheel design is that the drive-side

bearing is located inboard of the free wheel, and as sprockets were added over time, moved the

bearing farther from the drive-side axle support. This resulted in more flexing stress is placed

on the axle which can bend or even break.

7.8 FLYWHEEL:

A flywheel is a rotating mechanical device that is used to store rotational energy.

Flywheels have a significant moment of inertia and thus resist changes in rotational speed. The



amount of energy stored in a flywheel is proportional to the square of its rotational speed.

Energy is transferred to a flywheel by applying torque to it, thereby increasing its rotational

speed, and hence its stored energy. Conversely, a flywheel releases stored energy by applying

torque to a mechanical load, thereby decreasing its rotational speed.

Fig. 7.10 Flywheel

Energy Stored in a Flywheel:

A flywheel is shown in Fig. when a flywheel absorbs energy its speed increases and

when it gives up energy its speed decreases.

Let m= Mass of the flywheel in kg,

k = Radius of gyration of the fly wheel in meters,

I = Mass moment of inertia of the flywheel about the axis of rotation in kgm2=m.k2,

N1and N2= Maximum and minimum speeds during the cycle in r.p.m,

ω1and ω2= Maximum and minimum angular speeds during the cycle in rad / s,

N= Mean speed during the cycle in r.p.m.



The radius of gyration (k) may be taken equal to the mean radius of the rim (R),

because the thickness of rim is very small as compared to the diameter of rim. Therefore

substituting k= R in equation (ii), we have

Δ E=m.R2.ω2.CS= m.v2.CS (v= ω.R)

From this expression, the mass of the flywheel rim may be determined.

Notes:

1. In the above expression, only the mass moment of inertia of the rim is considered and the

mass moment of inertia of the hub and arms is neglected. This is due to the fact that the major

portion of weight of the flywheel is in the rim and a small portion is in the hub and arms. Also

the hub and arms are nearer to the axis of rotation, therefore the moment of inertia of the hub

and arms is very small.



2. The density of cast iron may be taken as 7260 kg / m3and for cast steel; it may taken as

7800 kg / m3.

3. The mass of the flywheel rim is given by

m= Volume × Density = 2 πR× A× ρ

Fig. 7.11 Inner view of flywheel

From this expression, we may find the value of the cross-sectional area of the rim.

Assuming the cross-section of the rim to be rectangular, then

A=b× t

Where b= Width of the rim, and

t = Thickness of the rim.

Knowing the ratio of b/t which is usually taken as 2, we may find the width and

thickness of rim.



When the flywheel is to be used as a pulley, then the width of rim should be taken 20

to 40 mm greater than the width of belt.

7.9 SPRINGS:

A spring is defined as an elastic body, whose function is to distort when loaded and to

recover its original shape when the load is removed. The various important applications of

springs are as follows:

1. To cushion, absorb or control energy due to either shock or vibration as in car springs,

railway buffers, air-craft landing gears, shock absorbers and vibration dampers.

2. To apply forces, as in brakes, clutches and spring loaded valves.

3. To control motion by maintaining contact between two elements as in cams and followers.

4. To measure forces, as in spring balances and engine indicators.

5. To store energy, as in watches, toys, etc.

Types of springs:

Though there are many types of the springs, yet the following, according to their

shape, are important from the subject point of view.

i) Helical springs:

The helical springs are made up of a wire coiled in the form of a helix and are

primarily intended for compressive or tensile loads. The cross-section of the wire from which

the spring is made may be circular, square or rectangular. The two forms of helical springs are

compression helical spring as shown in Fig.(a) and tension helical spring as shown in Fig.(b).

Advantages:

(a) These are easy to manufacture.

(b) These are available in wide range.

(c) These are reliable.

(d) These have constant spring rate.



Fig. 7.12 Helical spring

ii) Conical and volute springs:

The conical and volute springs, as shown in Fig. are used in special applications

where a telescoping spring or a spring with a spring rate that increases with the load is desired.

The conical spring, as shown in Fig.(a), is wound with a uniform pitch whereas the volute

springs, as shown in Fig. (b), are wound in the form of parabolic with constant pitch and lead

angles. The springs may be made either partially or completely telescoping. This characteristic

is sometimes utilized in vibration problems where springs are used to support a body that has a

varying mass.

Fig. 7.13 Conical and Volute spring



iii) Torsion springs:

These springs may be of helical or spiral type as shown in Fig. The helical type may be

used only in applications where the load tends to wind up the spring and are used in various

electrical mechanisms. The spiral type is also used where the load tends to increase the

number of coils and when made of flat strip are used in watches and clocks.

The major stresses produced in torsion springs are tensile and compressive due to

bending.

Fig. 7.14 Torsion spring

iv) Laminated or leaf springs:

The laminated or leaf spring (also known as flat spring or carriage spring) consists of a

number of flat plates (known as leaves) of varying lengths held together by means of clamps

and bolts, as shown in Fig. These are mostly used in automobiles.

The major stresses produced in leaf springs are tensile and compressive stresses.



Fig. 7.15 Laminated or leaf springs & Disc or Bellevile springs



Values of allowable shear stress, Modulus of elasticity and Modulus of rigidity for

various spring materials.

Table 7.1 Values of allowable shear stress, Modulus of elasticity and

Modulus of rigidity for various spring materials



Standard Size of Spring Wire:

Standard wire gauge (SWG) number and corresponding diameter of spring wire.

Table 7.2 Standard Size of Spring Wire



CHAPTER -8

DESIGN PARAMETERS, LIMITATIONS, ADVANTAGES AND

DISADVANTAGES

8.1 OUTPUT POWER CALCULATIONS:

Let us consider,

The mass of a vehicle moving over the speed breaker=10Kg (Approximately)

Height of speed brake=10 cm

Work done=Force x Distance

Here,

Force = Weight of the Body

=10Kg x 9.81

=98.1N

Distance traveled by the body = Height of the speed brake

=10 cm

Output power = Work done/Sec

= (89.1x 0.10)/60



=0.1485Watts (For One pushing force)

Power developed for 1vehicle passing over the speed breaker arrangement for one minute

= 0.1485watts

Power developed for 60 minutes (1 hr) =8.91watts

Power developed for 24hours=213.84watts

Velocity Ratio of Chain Drives:

The velocity ratio of a chain drive is given by

..=1/2=2/1

N1= Speed of rotation of smaller sprocket in r.p.m.,

N2= Speed of rotation of larger sprocket in r.p.m.,

T1= Number of teeth on the smaller sprocket, and

T2= Number of teeth on the larger sprocket.

..=1/2=2/1

.. =3619 =1.894

Experimentally,

Revolution:

Revolution of shaft by one push:

Using tachometer, 100 rpm =1.666rps



Torque:

Torque produce in push

ߨ60/2×=

0.851 = 1.666ߨ60/2×0.148=

8.2 DESIGN SPECIFICATIONS:

SHAFT (DIA) = 65 mm

Diameter of flywheel= 540 mm

Thickness of flywheel= 20 mm

8.3 SPROCKET WHEEL AND CHAIN:

No of teeth on large sprocket=36

No of teeth on small sprocket=19

Dia of large sprocket=460 mm

Dia of small sprocket= 230 mm

Length of chain =1620 mm

Optimum center distance = 560 mm



8.4 SPRINGS SPUR GEARS:

i) SPRINGS:

Diameter of wire = 2mm

Mean dia of coil = 12 mm

Free length of spring = 300mm

ii) SPUR GEARS:

No of Teeth On Rack = 36

Rack Length= 230mm

No of Teeth On Pinion =36

Diameter Of Pinion Gear =270mm

Thickness of pinion gear=20mm

Length of speed breaker=290mm

Width of speed breaker=220mm

Height of speed breaker=130mm

8.5 COST ANALYSIS:

i) Cost:

It is defined as the amount of expenditure occurred in bringing out a product.

Cost is expressed along with the atom viscose of bicycle axle Rs.15/-per axle cost of bearing

Rs.150/.Bearing.



ii) Cost of Elements:

The different cost is placed in three categories.

Material Cost

Labor Cost

Other Expenses

iii) Material Cost:

It is the cost on the material, which is converted into product. This is of two types, they

are Direct material cost and indirect material cost.

a) Direct Material Cost

It is cost of all those materials which when worked upon become the integral part of

the product. For example lathe bed casting when machined, heat treated and grounded

becomes a lathe bed.

b) Indirect Material Cost

All those materials, which are consumed during manufacturing for processing a

product, but do not become part of product. For example electric energy, cutting oil, grease,

water and cotton waste.

iv) Prime Cost

This is also known as direct cost. Prime Cost = direct material cost + direct labor cost

and expenses

v) Factory Cost

This is also known as factory cost. Factory cost = prime cost + factory expenses.

vi) Office Cost

This is also known as production office cost = factory cost + administrative expenses +

all and the expenses.



vii) Total Office

This is also known as selling cost. Total cost = office cost + selling and distribution

expenses

Selling price of product

Selling cost = total cost + profit loss

viii) Brake Even Chart:

This is graphical illustration to show loss and profit region. This type is deciding the no

of units to be made at which three is neither any loss nor any profit. It is arrived it following.

ix) Fixed Cost:

This is the cost, independent of product. This cost is three even if the product is nil.

x) Labor cost

It is the labor which converts raw material into product which tools and machines and

hence the cost over the labor

xi) Direct Labor cost

All the labors are working on the machines and material who can be identified with the

product, are called direct labor and hence cost over them. For example, a lathe operator, a

milling man.

xii) Indirect labor cost

All the labors that help in manufacturing cycle but cannot be identified directly with a

particular product and hence cost over them. For example, Sweepers, gate keepers, rigors,

store keepers etc.

xiii) Other expenses

All those expenses not covered under labor and material cost fall under this category.

They are also of two types.



xiv) Direct expenses

All those expense, which can be assigned to a particular job, are placed in this

category. This will include the following.

Expenses incurred in preparing design, drawing and process sheet.

Cost of jobs, fixtures is any made / hired for the job.

Patterns used for the mold.

Any consultation fee paid for the job.

xv) Indirect expenses

All other expenses left out for above. They make a major part of the cost. These

expenses are of following type.

xvi) Factory Expenses

This is also known as “factory over heads”, factory on cost on work on cost.

Administrative expenses

Selling expenses

Distribution expenses

R & D expenses

Selling price of product, it can be calculated as follows:

xvii) Selling price of pipe bending machine:

Prime Cost:

Prime cost = material cost + labor cost + other cost.

=Rs,4500/.

Bearing, cutting tool, screw etc. = Rs500/.

Material cost = Rs3500.

Labor cost = 15hrs (no of machine operators * Rs50 per hour)



= 15 hour (5* Rs50 per hour)

= 500Rs.

Other expenses:

= manufacturing process (painting + machines and energy consumed)

Other expenses = 500 + 15hours 10Rs/hour

= 650/-

Factory Cost:

Factory cost = prime cost + factory expenses

= 4500 + 500 = Rs5000.

Total cost:

Total cost = office cost + selling cost and distribution cost =Rs 10150.

Selling cost:

Selling cost = total cost + profit lose.

= 10150 + (10 % * total cost)

= 10150 + (10 * 10150/100)= Rs.11155

By adding the general sales taxes = selling cost + 16% = 11155+ 16%

= Rs. 12939

Selling Cost = Rs. 12939



8.6 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 non-renewable source of energy.

Uninterrupted power generation during day and night.

Maximum utilization of energy.

Load to the piston cylinder arrangement is freely got by movement of vehicles.

No fuel storage is required.

It will work with light weight and heavy vehicle.

8.7 DISADVANTAGES:

We have to check mechanism from time to time.

It can get rusted in rainy season.

May not work with light weight vehicles.

Less power obtained.



CHAPTER -9

CONCLUSION

"Electricity plays a very important role in our life”. Due to population explosion, the

current power generation has become insufficient to fulfill our requirements. In this project we

discover technology to generate electricity from speed breakers in which the system used is

reliable and this technique will help conserve our natural resources. In coming days, this will

prove a great boon to the world, since it will save a lot of electricity of power plants that gets

wasted in illuminating the street lights. As the conventional sources are depleting very fast, it’s

high time to think of alternative resources. We got to save the power gained from the

conventional sources for efficient use. So this idea not only provides alternative but also adds

to the economy of the country.

In coming days, this will prove a great boon to the world, since it will save a lot of

electricity of power plants that gets wasted in illuminating the street lights. As the

conventional sources are depleting very fast, then it’s time to think of alternatives. We got to

save the power gained from the conventional sources for efficient use. So this idea not only

provides alternative but also adds to the economy of the country. Now, vehicular traffic in big

cities is more, causing a problem to human being. But this vehicular traffic can be utilized for

power generation by means of new technique called “power hump”. It has advantage that it

does not utilize any external source. Now the time has come to put forte these types of

innovative ideas, and researches should be done to upgrade their implication.

This technology is still in the stage of development. In future it is used to generate the

power throughout the year. Power generation is not affected by environmental conditions. It is

pollution free technique for generation of electricity. Suitable at parking of multiplexes, malls,

toll booths, signals, etc. Used charging batteries and using them to light up the streets, etc.

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.



REFERENCES

1. Department of Mechanical Engineering Queen’s Building, University of Bristol, Bristol,

BS8 1TR, UK

2. A Textbook of Design of Machine elements “2” by R.S. KHURMI AND J.K.GUPTA.

3. Automobile Engineering, Kirpal Singh.

4. Automobile Engineering, S.M.Pandey & K.K. Shah.

5. Shigley Tata McGraw hills (Machine Design).

6. Generation of Electricity through Speed Breaker Mechanism.

7. “Every speed breaker is now a source of power”, IPCBEE vol.1, 2011.