REVERSE GEAR MECHANISM IN TWO WHEELER FOR … · 2019-07-05 · operated reverse gear mechanism in two wheelers for physically challenged people’. International Research Journal

REVERSE GEAR MECHANISM IN TWO WHEELER FOR

HANDICAPPED PEOPLE

Sreehari K U

UG Student, Department of Mechanical Engineering,

MGM College of Engineering and Technology,

Pampakuda, Kerala, India.

Sibin Sunny




Joshua A J




Swaran Joseph




Febin M Suresh

Assistant Professor, Department of Mechanical Engineering,



Abstract At times when the front wheel goes into a trench it is very

difficult to take the wheel from parking. Even normal people

face much problem to take the vehicle out of the parking. In

case of handicapped people who drive two wheelers with

extra support wheels, face much problem to take the vehicle

out of parking by pushing the vehicle with leg like normal

people do. In order to take the vehicle out of parking, they

need others help or they should do it alone.

As a help to them we have created a gearbox which could

perform forward motion as well as reverse motion. It includes

the selection of a suitable reverse gear mechanism for two

wheelers. The fabrication process deals with designing

suitable gear wheels, and assembling it in the gearbox which

provides easy assembly and manufacturing at low cost. This

paper details the design and fabrication of a mechanism that

can provide reverse motion in two wheelers.

Keywords: gear box, reverse gear mechanism, gear wheel.

Introduction Disability in humans may be caused during birth which may

be of physical, cognitive, mental, emotional and

developmental. The disability in humans may be a physical

disability, sensory disability, and vision impairment, olfactory

and gustatory impairment. According to a survey conducted

by the National sample survey Organization conducted during

the period of July–December 2002, it was found that the

number of people having locomotion disability alone was

found to be 23,557 in the rural areas and 14099 in the urban

areas.

In human life transportation is playing very important role

from ancient time, due to transportation and communication

facilities we say that, world is coming closer and closer. Day

by day new vehicles with variety of models are coming into

market. Normal person i.e. person without any disability can

avail this vehicles easily. But in our society the number of

disabled persons is also considerable, some of them born with

disability, some get disabled due to accidents (road,

workplace, natural calamities, etc.), large number of persons

get disabled due to war activities and due to many other

factors. Depending upon the severity of disability, the

disabled persons can use the transportation facilities; persons

with lesser disability can use the facilities as it is for normal

persons, some persons are able to use the vehicles with little

bit modifications like retrofitted bikes and cars. There are

some utilities like wheelchairs, tricycles which are used by the

disabled persons. In some cases the disability is so severe that

person can’t move from one place to other place without help.

The persons with hand and leg disability are able to travel but

they are unable to use the vehicles for normal persons as it is.

So the vehicles are modified (customized vehicles) to make

them accessible to the disabled persons.

International Journal of Applied Engineering Research ISSN 0973-4562 Volume 14, Number 14, 2019 (Special Issue) © Research India Publications. http://www.ripublication.com

Page 1 of 4

Objective

The objective of this work is to identify suitable

method of reverse gear mechanism for the usage of

physically challenged people, provide more facilities

on two-wheeler to make more comfortable and

independent too.

Design of gear box was mostly the result of the

requirement specified by medical practitioners who

always insisted on transportation needs hence it

always lacked engineering/ergonomic approach. This

work intends to use the terminology for the

technology for the benefit of challenged people and

hence, two-wheeler with side car one of the largely

used product by these people

Nowadays, transformations are inseparable part of

the human life. Normal person can travel easily by

means of transportation such as bicycles, bikes, cars,

public transports etc. But for physically challenged

persons, travelling is not easy. Depending upon the

disability physically challenged person can avail

travelling such as tricycle, wheelchair, customized

vehicle like car, bike, buses etc.

But these means, off transportation are not easily

accessible for physically challenged persons due to

some difficulties. This project discusses these means

of transportation for physically challenged people.

Material selection

Table 1: Mechanical properties of EN19

Properties Metric

Tensile strength 655 MPa

Yield strength 415 MPa

Bulk modulus 140 GPa

Shear stress 165 MPa

Elastic modulus 200 GPa

Poisson’s ratio 0.28

The materials used for the manufacture of gears depend upon

the strength and service conditions like wear, noise etc. The

gears may be manufactured from metallic or non-metallic

materials. The metallic gears with cut teeth are commercially

obtainable in cast iron, steel and bronze.

The material of the bevel gear used is EN19 also called AISI

4140. AISI 4140 steel is a low alloy steel containing

chromium, molybdenum, and manganese. It is widely used

across numerous industries and is an excellent material choice

due to its toughness, high wear resistance, high fatigue

strength, and abrasion and impact resistance.

Clutch dog Outboard motors nearly all use a simple dog clutch type

mechanism for connecting the propeller to the engine. The

clutch dog is splined to the propeller shaft and allowed to

move fore and aft sufficiently to engage the teeth machined on

the side faces of forward and reverse gears. Both gears spin

freely on the propeller shaft and are rotating while ever the

engine is running. The dog clutch is moved to engage the

desired motion by a cross pin and shift rod inside the hollow

propeller shaft.

Figure 1: Typical outboard dog clutch shift system.

Design of gear and shaft Design of gear

As the rotation from engine needs to be transmitted to

perpendicular shaft we require pinion and bevel gears.

We selected a pinion of 13 teeth which has a diameter of 4.0

cm.

Teeth, T1 = 13

Diameter, D1 = 4.0 cm

Rotations per minute, N1 = 5100

We require shaft rotation of 3400 times per minute,

So, N2 = 3400

Hence the requirement of designing a bevel gear.

Using gear ratio formula:

D1/D2 = N2/N1 = T1 /T2

ie, 4/D2 = 3400/5100 = 13 /T2

D2 = (5100/3400) * 4.0

= 7.0 cm

T2 = (5100/3400) * 13 = 23

So a bevel gear of 7.0 cm diameter with 23 teeth is required.


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Design of shaft

Length of shaft = (clearance space + double the thickness of

gear + distance between side frame to

wheel + thickness of frame)

= ( 3 + 3.5 + 3 + 10 )

= 19.5 cm

1 Kg = 1000g = 9.81 N

1 g = 9.81 * 10-3 N

Weight of bevel gear = 210g = 2.06 N

Weight of wheel = 3000 g = 29.5 N

Figure 2: Free body diagram.

RA + RB = (2.06 +2.06 + 29.5) = 33.62 N

(RA * 9.5) + (-2.06 * 6.5) + (-2.06 * 3) + (29.5 * 10) = 0

(9.5RA – 13.39 – 6.18 + 295) = 0

Therefore, RA = -28.9 N

RB = 62.52 N

Shear force diagram

Figure 3: Shear force diagram

Bending moment diagram

Figure 4: Bending moment diagram

Maximum bending moment = (29.5 * 10) = 295 Ncm.

M = 295 Ncm = 295*10-2 Nm.

P = (2π*N*T)/60

55000 = (2*3.14*5400*T)/60

ie, T = 97.31 Nm.

T equivalent = (M2 + T2)1/2 = (2.952 + 97.312)1/2

= 97.35 Nm

We selected material EN19, which has a shear stress in the

range 150 MPa to 180 MPa.

Here we took the shear stress as 165 MPa.

= 16 T/ πd3

165*106 = (16*97.35)/(3.14*d3)

Solving we get,

d = 14.43*10-3m

= 14.43 mm

Standardizing the diameter with reference to data hand book

by K.Mahadevan, design of shaft – page no: 57 – Table 3.5(a).

Thus, d = 16 mm.

3D modeling

Figure 5: Top view


Page 3 of 4

Figure 6: ISO view

Working

The rotation from the engine is transmitted to the rear wheel

as in vehicles, from there it is transmitted to the shaft carrying

the clutch dog assembly through the shaft. On pushing the

clutch dog to either sides the direction of rotation changes.

This rotation is further transmitted to the shaft to which tyre

are connected with the help of bevel gear by central shaft

carrying the pinions. Thus both forward and backward motion

based on positioning of dog clutch is possible.

Conclusion The design and fabrication of this mechanism was a

successful one. We used an outboard engine, and alterations

were made which could be manufactured in industrial level in

future. It didn’t face any kind of difficulties in producing the

required reverse motion. Implementing this mechanism to

handicapped vehicle would be a greater help to them. This

work has provided us an excellent opportunity and experience,

to use our limited knowledge. We gained a lot of practical

knowledge regarding, planning, purchasing, assembling and

machining while doing this work. We are proud that we have

completed the work with the limited time successfully. The

reverse mechanism is working well with satisfactory

conditions.

Future Scope of Work

This mechanism can be made more flexible such that this

could make reverse motion possible in all two wheelers on

easy and immediate assembly. Thus could be implemented in

large application levels.

References

[1] Aadya B. Son, et al.; ‘Design and fabrication of hand

operated reverse gear mechanism in two wheelers for

physically challenged people’. International Research

Journal of Engineering and Technology. Volume V,

Issue IV, ISSN 2395-0056, April 2018.

[2] Dukeshwar Padoti, et al.; ‘Fabrication of reverse gear

system in two wheeler’. International Journal for

Scientific Research and Development. ISSN 2321-

0613.

[3] Arun Vashishth, et al.; ‘An intelligent wheel chair for

the physically disabled’. International Journal of

Research in Advent Technology.Special Issue 4. ISSN

2321-9637, February 2017.

[4] H.Shah, et al.; ‘Design and development of vehicle for

differently abled people’. International Journal of

Mechanical and Production Engineering. ISSN 2301-

2092. Volume 5, Issue 6, June 2017.

[5] Kasi Samir.P, et al.; ‘Design and fabrication of reverse

gear system for handicapped person vehicle’. Journal of

Advances in Science and Technology. ISSN: 2230-

9659. Volume 13, Issue 1, March 2017.

[6] Ahmed Ansari, et al.; ‘Design and fabrication of

reverse gear box’. International Journal of Recent

Trends in Engineering and Research. ISSN 2455-1457.

April 2017.

[7] Sorathiya Mehul, et al.; ‘Design and implementation of

tricycle for handicapped person’. International Journal

of Advance Engineering and Research Development.

ISSN: 2348-4470. April 2017.

[8] E.S.Esakkiraj, et al.; ‘Modification of the two wheeler

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International Journal of Innovative Research in

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8753. Volume 4, Issue 3, March 2015.


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Documents

REVERSE GEAR MECHANISM IN TWO WHEELER FOR … · 2019-07-05 · operated reverse gear mechanism in two wheelers for physically challenged people’. International Research Journal