regenerative braking in conventional cars1

7/31/2019 Regenerative Braking in Conventional Cars1

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REGENERATIVE BRAKING IN CONVENTIONAL

CARS

SUBMITTED BY

N.CHANDRASEKARAN

M.ERIC AMIT

V.KARTHIKEYAKANDAVEL

GUIDE

Mr. T. SUTHAKAR M.S.,

SENIOR LECTURER.


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ABSTRACT

When the brake is applied most of the energy of the car is

dissipated as heat. Had we retrieved, it can be used for some

other useful purpose. In regenerative braking, this energy is

retrieved by an alternator which is stored in a battery. But,

nowadays, the regenerative braking technique is applied only inHybrid cars. Our objective is to incorporate the same in

conventional cars. The methodology adopted for doing this is

storing the energy in an energy storing device and retrieving it.

The conventional car we have taken is Ambassador 1.5 E2 DSL

model.


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WHY REGENERATIVE BRAKING?

When the brake is applied, vehicles kinetic energy is dissipatedas heat leads to wastage of engine output.

In city driving, about 30 percent of a typical car's engine output is

lost.

In this, some percentage of dissipating energy can be utilizedeffectively to charge the storage battery.

Thus engines net efficiency can be improved.


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REGENERATIVE BRAKING

However, it is not a perpetual motion machine.

Energy is still lost through the friction between road surface and

other components in the system.


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REGENERATIVE BRAKING

Working

When a hybrid electric vehicle is approaching a stop, it does not

create friction and useless heat in order to slow down. Instead it

reverses its electric motor turning it into an electric generator,

creating electricity which is fed to a battery.


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AIM OF OUR PROJECT

Generally, Regenerative braking is used only in hybrid cars, our

aim is to incorporate the same in conventional cars.


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BASIC IDEA

Basic idea is taken from the toy car which stores energy in the

spiral spring during backward pull and retrieving it to make it

move forward.

Using this idea, with a modification in an additional gearbox, theenergy which is going to be lost during braking can be stored in a

spiral spring.

Again from this spiral spring, retrieve the energy using fly wheel.


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GEAR ARRANGEMENT OF TOY CAR


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GEAR DETAILS

GEAR 1GREEN GEAR 2PINK

GEAR 3BROWN

GEAR 4BLUE

GEAR 5RED

POWER TRANSMISSION:-

INPUT :- GEAR 4 GEAR 3 GEAR 2 GEAR 1

OUTPUT:- GEAR 1 GEAR 5 GEAR 3 GEAR 4


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MODIFICATION IN GEAR BOX

In the existing gear arrangement, both the input and output are

from the same shaft. We are going to modify the geararrangement in such a way that input and output are from

different shafts.


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PROPOSED DESIGN


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DEMERITS OF SPRING

In the toy car spring is used as energy storing device for storing

and retrieving it. But it has the following demerits,

No Reliability.

Spring constant will vary in due course of time due to its fatigueness, leads to variation in amount of energy stored.


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FINAL DESIGN


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WORKING

The working procedure is,

When the pedal is pressed, the conical clutch which is running

on the splined shaft engaged with the first pair (free to rotate),

so that the power is transmitted to the first gear pair. Since the

size of the flywheel is large for high torque, the objective ofkeeping gear pair is just to transmit the power to parallel shaft

which is offset.

The second gear in the first shaft is rigidly fixed to the shaft. So

this will transmit the power to its pair when the brake is

pressed.


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WORKING

Similarly, there is one more gear pair of speed ratio 1, is usedto get an offset power transmission.

The gear in the third shaft is attached with a free wheel, so thatthe power is transmitted in only one direction.

In the third shaft, a flywheel is rigidly fixed. This will takeenergy and start rotating when the brake is pressed. Once thebrake is released, the conical clutch disengages the first pair.Hence the first pair is stop transmitting power. But due to theinertia of the flywheel, it continues to rotate. This power will nottransfer back because of the freewheel coupling between third

shaft and last gear. The retrieved energy is taken from the third shaft.


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TABLE

SINO

Speed (rpm) Energy retrieved (J) % Energy retrieved

1 500 1058.24 10.48

2 1000 4232.96 10.47

3 1500 9524.17 10.484 2000 16931.85 10.48

5 2500 26456.02 10.47

6 3000 38096.67 10.47

7 3500 51853.80 10.47

8 4000 67724.85 10.46


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GRAPHS

Speed Vs % Energy retrieved

10

10.1

10.2

10.3

10.4

10.5

10.6

10.7

10.8

10.9

11

0 2000 4000 6000

Speed (rpm)

%E

nergyretriev

ed

Series1


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GRAPHS

Speed Vs Energy retrieved

0

10000

20000

30000

40000

50000

60000

70000

80000

0 2000 4000 6000

Speed (rpm)

Energyretrie

ved(J)

Series1


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RESULTS

GEAR DIMENSIONS:

Center distance = 7.8 cm

Face width = 3 cm

Module = 3 mm

Pitch circle diameter of gear = 78 mm

Pitch circle diameter of pinion = 78 mm

Addendum = 3 mm

Dedendum = 3.75 mm

Tip circle diameter of pinion = 84 mm

Tip circle diameter of gear = 84 mm

Clearance = 0.75 mm

Tooth thickness = 4.7124 mm

Fillet radius = 1.2 mm


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RESULTS

FLYWHEEL DIMENSIONS:

Outer diameter of the fly wheel = 0.23 m

Radius of gyration of the fly wheel = 0.0823 m

Width of the fly wheel = 0.19 m

Thickness of the rim = 0.115 m

SHAFT DIMENSIONS:

Diameter of shaft 1 = 2 cm




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CONCLUSION

Thus for the Regenerative Braking arrangement proposed,

theoretical calculations are performed. Also the characteristics of

the arrangement with flywheel are studied using the following

graphs,

Speed (rpm) Vs Percentage Energy retrieved and

Speed (rpm) Vs Energy retrieved (J)

From the graph it is inferred that Percentage Energy retrieved is

almost constant also the energy retrieved by the flywheel is

gradually increasing for increasing speeds.


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REFERENCES

Automotive Mechanics

by William H. Crouse and Donald L. Anglin,

Tenth edition, Tata McGraw-Hill Publishing Company Limited.

Gear Engineering by Merritt (HE), Pitman Publishing company,London.

Gear Handbook by Darle W. Dudley, Mc-Grawhill company

Machine Design by T.V. Sundararajamoorthy, N. Shanmugam,Anuradha Publications.

Theory of Machines by R.S. Khurmi and J.K. Gupta, S. Chand & Co

Ltd, India.

Design Data by Faculty of Mechanical Engineering, PSG College ofTechnology, published by Kalaikathir Achchagam.


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THANK YOU

regenerative braking in conventional cars1

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