APROJECT REPORT ON

POWER TRANSMISSION SYSTEM FOR OCEAN WAVE ENERGY CONVERSION

SUBMITTED BY

1. SACHIN G. KUMKAR

2. PRASAD L. JAGTAP

3. VIPENDRA PANDEY

4. KARAN N. KUCKIAN

UNDER THE GUIDANCE OF

PROF. N. CHANDRAN

DEPARTMENT OF MECHANICAL ENGINEERING

SARASWATI COLLEGE OF ENGINEERING

KHARGHAR, NAVI MUMBAI-410 210

UNIVERSITY OF MUMBAI

2010-2011

SARASWATI COLLEGE OF ENGINEERING

DEPARTMENT OF MECHANICAL ENGINEERING

(AFFILIATED TO UNIVERSITY OF MUMBAI)

Kharghar, Navi Mumbai-410 210

CERTIFICATE

This is to certify that the following students

1. SACHIN G. KUMKAR

2. PRASAD L. JAGTAP

3. VIPENDRA PANDEY

4. KARAN N. KUCKIAN

have completed the project entitled “POWER TRANSMISSION

SYSTEM FOR OCEAN WAVE ENERGY CONVERSION” and duly submitted

the project report as fulfillment of the curriculum for ‘Bachelor of Engineering’

degree under University of Mumbai during the academic year 2010-2011.

(Mr. N. Chandran)

INTERNAL GUIDE EXTERNAL EXAMINER

(Mr. G. N. Thokal) (Dr. S. Jairam)

PROJECT CO-ORDINATOR PRINCIPAL

(Mr. S. N. Teli)

HOD (MECHANICAL)

Acknowledgement

We would like to express our deep regards and thanks to our honorable

principal Dr. S. Jairam for his continuous encouragement and support.

We would like to acknowledge Prof. S. N. Teli (HOD, Mechanical Dept.) and

all our staff members for co-operation and valuable guidance which they provided us to

complete our project.

We express our gratitude and sincere thanks to our project guide Prof. N.

Chandran. Our vocabulary does not have suitable words befitting to high standards of

knowledge and extreme sincerity, devotion and affection with which he has regularly

encouraged us to put our heart and soul in this work.

We want to extend our cordial thanks to workshop Superintendent Prof. T. Z.

Quazi for granting us permission to use the college workshop and all its facilities to full

extent without which our project could not be completed. We also thank the workshop

staff Mr.Vaibhav, Mr.Subhedar for their timely assistance. We sincerely acknowledge

Prof. G.N.Thokal for the guidance provided for completing the project report.

Our parents have been an endless source of support and inspiration throughout

the course of our study; it is indeed our great privilege to express our heartfelt gratitude

towards them.

SACHIN G. KUMKAR

PRASAD L. JAGTAP

VIPENDRA PANDEY

KARAN N. KUCKIAN

Abstract

This report is a summarized volume of various techniques, procedure and

fabrication method employed in the design and manufacturing of the power

transmission system for a float type ocean wave converter.

The important feature of this project is the unidirectional gearbox. This report

concentrates on the unidirectional gearbox, its principle, design, layout, functioning.

This type of gearbox employs a chain and sprocket arrangement for the unidirectional

motion of the output shaft regardless of the direction in which the input shaft rotates.

This report also gives an overview of the ocean wave energy conversion as a

whole, its components, layout and advantages to human life. Various important

formulae’s for extracting wave power have been included in this report.

We sincerely hope that all our efforts put forward in recording this project

report, bears fruitful to all our fellow students and guide them in the interesting field of

non-conventional energy sources.

Content

Acknowledgement i

Abstract ii

List of Figures iii

Fig. No. Particular Page No.

1.1 Block diagram Representation Of Wave Energy Conversion System 4

2.1 Wave generation 7

2.2 Forms of energy In Ocean Wave 7

2.3 Nomenclature Of a Wave 8

2.4 Wave Creation 9

2.5 Schematic Of Wave Power Generation Device 11

2.6 Pilot Plant Of Ocean Wave Energy Converter At Ratnagiri, Maharashtra 12

3.1 Schematic Of A Unidirection Gear Box. 17

3.2 The Working Model Of Uni-Directional Gearbox 18

4.1 Vertical & Horizontal Bending Moment Diagram 22

4.2 Schematic of side plate 35

5.1 Model of input shaft 38

5.2 Deformation in input shaft 39

5.3 Analysis of a solid shaft 39

5.4 Model of a Plate 41

5.5 Deformation in a plate 42

5.6 Analysis of a plate 42

5.7 Model of a Plate 2 44

5.8 Deformation of a Plate 2 45

5.9 Analysis of a Plate 2 45

List of Tables vii

Table No. Particular Page No.

2.1 Types of float designs & their parameters 13

4.1 Horizontal & vertical forces on pulley & sprocket 21

4.2 Bearing series 27

4.3 Comparison of different types of mechanical drives 29

4.4 selection of chain 32

5.1 Elemental quality of shaft 37

5.2 Properties of Material selected shaft1 37

5.3 Forces & moment acting on the shaft1 39

5.4 Elemental quality of side plate 1 40

5.6 Forces & moment acting on the Side plate 1 41

5.7 Elemental quality of side plate 2 43

5.8 Material properties of side plate 2 43

5.9 Forces & moment acting on the Side plate 2 44

Sr. No. INDEX Page No.

1. INTRODUCTION 1

1.1 Motivation 2

1.2 Ocean Wave Energy Conversion 4

1.3 Overview of Project 4

2. Literature Survey 6

2.1 Wave Energy Physics 7

2.2 Wave Creation 8

2.3 Wave Energy Formula 9

2.4 Wave Power Generation Device 10

2.5 Float system 13

2.6 Simulation Tank 14

3. Problem Definition 15

3.1 Scope of project 16

3.2 Concept of uni-directional gearbox 17

4. Design Calculation 19

4.1 Shaft Design 20

4.2 Bearing selection 26

4.3 Importance & features of chain drive In unidirectional gearbox

29

4.4 Chain Design 31

4.5 Side Plate Design 35

5. Analysis 36

5.1 Analysis of shaft 37

5.2 Analysis of side plate 40

6. Conclusion 46

7. Bibliography 47

8. APPENDIX 48

CHAPTER: 1

INTRODUCTION

1.1 Motivation

Today more than 80 per cent of the world’s electric power production comes

from fossil-fuelled plants.Future energy supply projections suggest that there will be

problems in matching supply and demand in the next century. Furthermore, since the

cost of primary energy will almost certainly rise, alternative forms of energy conversion

must obviously be investigated and developed as their supplementary or insurance

technologies.

Power generation in India today is mainly from hydroelectric and thermal

power plants. The present total installed capacity hardly meets the grid demand.

Uncertainty of the monsoon and problems of coal transport put a strong limitation on

expansion of present generation capacity. However, the increase in standard of living

and rapid industrial growth necessitates a high rate of growth of power supply. The

price of oil continues to be high in India. The present contribution of power generation

from nuclear plants is small, and the uncertainty in the protective measures against all

environmental hazards of such plants indicates that development of renewable energy

sources is important for India. [1]

As the demand for electricity is forecasted to increase, there is an urgent need

to find new methods to extract electric energy from renewable sources. Hence, the need

for renewable energy is fast-becoming essential in today's world energy market. The

world needs a source of energy that will last longer than our limited supply of fossil

fuels. Pollution is also an issue, and many environmentalist groups are pushing toward

more "earth-friendly" energy sources. Renewable electric energy supply is today one of

the highest priorities in many parts of the world.

The Kyoto declaration 1997 and the last agreement at Marrakech 2002 are

significant proof of this. One important renewable energy source is ocean energy.

Ocean waves represent a vast unexplored source of renewable energy.

Solar radiation, which sustains life on earth, is continuous and inexhaustible. It

has been estimated that about 1016W of solar energy reaches the earth. The ocean, which

covers nearly 71% of earth’s surface, acts as a natural collector of this energy. Thus, the

ocean has an enormous potential to supply energy in many different ways. The major

advantages of ocean energy are that it is renewable and continuous throughout the year,

is pollution free and has minimum health hazard. For remote islands, ocean energy will

be the most important form of alternative energy since it comes from the immediate

vicinity.

The incessant motion of the sea surface in the form of wind waves constitutes a

source of continuous energy. About 1.5% of the incoming energy from the sun is

converted to wind energy. Part of the energy from the winds is transferred to the sea

surface, resulting in generation of waves. This energy is carried to coastlines throughout

the world, where it is dissipated as the waves break. If this source can be tapped

properly and used economically, it can generate a sizeable portion of world energy

needs.

Extraction of energy from waves is more efficient than directly from wind,

since wave energy is concentrated through interaction of the wind and the free ocean

surface. The sea behaves like an immense energy collector whereby the wind energy,

transferred to the large sea surface, is stored as mechanical energy in waves. The inertia

of waves provides this short-time storage and partly smoothens the high variability of

the wind over time and space.

Wave energy has the potential to be a much larger resource than tidal power.

Unlike tidal current extraction, which works best in the small number of highly

favorable sites wave energy can be extracted in many places along a coastline as well as

offshore.

With the substantial resource potential, a wide variety of methods for extracting

energy has been developed. The different devices and systems not only employ different

techniques for “capturing” the wave energy, but also employ a large variety of different

methods for converting it to electricity (i.e., the “power take-off” system).

The above mentioned causes have thereby motivated our project i.e. ocean

wave energy conversion which is based on a float and pulley mechanism.

1.2 Ocean Wave Energy Conversion

Basic wave energy conversion can be stated as the force (or torque) produced

in a system by an incident wave causes relative motion between absorber and reaction

point, which acts directly coupled to electric generator. Block diagram representation of

the proposed wave energy conversion system is shown in fig.1.1 .It consists of energy

conversion device which converts ocean wave energy into mechanical or some useful

form of energy. Converted energy (in the form of mechanical shaft power) is again

converted into electrical energy by an electric generator. Generated energy is further

stored by using suitable storage device such as a battery.

Fig. 1.1 Block diagram representation of wave energyConversion system

Ocean wave energy is total sum of kinetic potential energy of moving water

blocks. Wave energy available at Indian Coasts is in the range of 5kW/m to 70kw/m.

Using this energy conversion device 1 kW energy can be easily extracted.

1.3 Overview of the Project

The Ocean wave energy conversion system is a real time project of Saraswati

College of Engineering. The system is less efficient and hence requires more research

for the wide scale application of this system in our country. India has a major potential

for harnessing energy from ocean; the coastline of India being 7515 km. Our project is a

part of this research that can make this system more efficient by testing this system in a

laboratory against various parameters.

The two important objectives of this project are-

1. Modelling of the ocean wave energy conversion system

2. Increase in efficiency of the system

OCEAN WAVE ENERG

Y

ENERGY CONVER

SION DEVICE(ABSORB

ER)

ELECTRIC

GENERATOR

ENERGY

STORAGE

DEVICE

The project is based on modeling of the following systems:-

1. Float system

2. Ocean wave simulation

3. Power transmission system

The scope of the system being vast, it has been divided into three sub-groups

based upon the above three modeling systems. Out of the above three sub-groups, our

group is responsible for the modeling of the power transmission system and increase

in efficiency of the same.

The power transmission system forms a very important part of the project.

The efficiency of the entire project is largely dependent on this system. This system

basically comprises of the rope and pulley system, the unidirectional gearbox, a

generator and a storage battery. The original project on the lines of which our project

is modeled consists of similar components except for the high speed gearbox and

uni-directional clutch. This is what makes our project different from the original work

which has been described in detail ahead.

CHAPTER: 2 LITERATURE

SURVEY

2.1 Wave Energy Physics

Fig. 2.1 Wave generation

Among different types of ocean waves, wind generated waves have the highest

energy concentration. Wind waves are derived from the winds as they blow across the

oceans. This energy transfer provides a natural storage of wind energy in the water near

the free surface. Once created, wind waves can travel thousands of kilometers with little

energy losses, unless they encounter head winds. Near the coastline, the wave energy

intensity decreases due to interaction with the seabed. Energy dissipation near shore can

be compensated by natural phenomena as refraction or reflection, leading to energy

concentration (“hot spots”).

Fig 2.2 Forms of energy in ocean wave

Ocean waves encompass two forms of energy: the kinetic energy of the water

particles that in general follow circular paths; and the potential energy of elevated water

particles. On the average, the kinetic energy in a linear wave equals its potential energy.

The energy flux in a wave is proportional to the square of the amplitude and to the

period of the motion. The average power in long period, large amplitude waves

commonly exceeds 40-50 kW per meter width of oncoming wave. [5]

2.2 Wave Creation

Ocean waves are created by the wind. When the wind blows across a smooth

water surface, air particles from the wind grab the water molecules they touch. The

force or friction between the air and water stretches the water surface, resulting in small

ripples, known as capillary waves. Surface tension acts on these ripples to restore the

smooth surface and thereby waves are formed. As waves form, the surface becomes

rougher and it is easier for the wind to grip the roughened water surface and intensify

the waves. The highest part of the wave is called the crest and lowest part that is

depressed beneath the surface is called the trough. The overall vertical change in height

between the crest and the trough (= 2 x amplitude) is called the wave height. The

distance between two successive crests is the length of the wave or wavelength (L). The

time required for two successive crests or two successive troughs to pass a point in

space is called the period (T). The number of peaks (or troughs) that pass a fixed point

per second is the frequency.

Fig. 2.3 Nomenclature of a wave

The air moves faster at the wave crests (point A) than in the troughs (point B).

By the Bernoulli principle, this produces a pressure differential that tends to increase the

elevation difference between the crest and trough. The area over the ocean in which a

particular set of waves is developed depends on the size of the pressure fronts involved.

This area is called a “fetch.”

Fig.2.4 Wave creation

2.3 Wave Energy Formula

[4] Ocean waves are random in nature. The power available in random sea is

expressed as

P= 0.55×H2×T

Where,

H=significant wave height (defined as average of highest waves) in meters

T=zero crossing period in seconds.

The above formula states that wave power is proportional to the wave period

and to the square of the wave height. When the significant wave height is given in

meters, and the wave period in seconds, the result is the wave power in kilowatts (kW)

per meter of wave front length. From the above relation for a significant height of 2m

and a zero crossing period of 7 sec, the power is 15w/m of wave front.

For a sinusoidal wave of height H, the average energy E stored on a horizontal

square metre of the water surface is:

E=KE×H2

Where,

kE = r g / 8 = 1.25 kW-s/m2

r = mass density of sea water » 1020 kg/m3

g = acceleration of gravity » 9.8 m/s2

Half of this is potential energy due to the weight of the water lifted from wave

troughs to wave crests. The remaining half is kinetic energy due to the motion of the

water.

As the waves propagate, their energy is transported. The energy in the waves

travel with the group velocity cg. The individual waves travel faster - they are born on

the rear end of the group, and they die in the front end. On deep water this phase

velocity is twice, the group velocity.The energy transport velocity is the group velocity.

As a result, the wave energy flux, through a vertical plane of unit width perpendicular to

the wave propagation direction, is equal to:

P=E × Cg

Where,

Cg = group velocity (m/s)

On deep water the group velocity is cg = g T/4p

2.4 Wave Power Generation Device

The combination of forces due to the gravity, sea surface tension and wind

intensity are the main factors of origin of sea waves. While we know that wave power is

more energy dense than wind power for a large percentage of the year, we still do not

know how to calculate the power available from a wave. This is important for the

design process of a wave energy convertor. First, the power and forces acting on the

device should be assessed, and then the device may be sized for the desired energy

output. [2]

The main components of the ocean wave energy conversion device are:-

1. Float system

2. Rope and pulley system

3. Power transmission system (uni-directional gearbox, generator)

The wave energy conversion device consists of float, flexible ropes, pulleys,

unidirectional gearbox, counter weight, electric generator, storage battery and

supporting frame. Float and counter weight is connected to each other using flexible

rope. Rope is passed over pulley system as shown in fig.2.5, which shows weight of

float and bouncy force is balanced by counter weight. Counter weight is designed such

that float is always half immersed in the water. The float is displaced when an ocean

wave crest or trough strikes the float. When a wave crest strikes the float, it is raised

against the dead weight and this rotates the input shat of the generator on which a pulley

is mounted. When a wave trough appears, the float is lowered raising the dead weight

and thereby again rotating the input shaft of the generator.

Thus, the float is subjected to two types of movement, one is the horizontal

movement due to horizontal thrust and the second one is the vertical movement due to

the vertical thrust. Therefore, it is the prime requirement to measure these horizontal

and vertical movements of the float. By measuring the displacement of the float, we can

calculate the wave energy absorbed by the float by using the wave energy formula.

Pulley system is further connected to a unidirectional gearbox through

couplings. The unidirectional gearbox converts the to and fro motion of shaft to one

direction motion which is the prime requirement for generation of electrical energy via

electrical generator. The generator is further connected to storage battery or it can be

directly connected to electrical supply transport system.

Fig.2.6 Pilot plant of ocean wave energy converter at Ratnagiri, Maharashtra

2.5 Float system

The float is one of the prime requirements of the ocean wave converter. The

float receives the energy in the form of waves. The float is displaced when an ocean

wave crest or trough strikes the float. When a wave crest strikes the float, it is raised

against the dead weight and this rotates the input shat of the generator on which a pulley

is mounted. When a wave trough appears, the float is lowered raising the dead weight

and thereby again rotating the input shaft of the generator. Thus, the float is subjected to

two types of movement, one is the horizontal movement due to horizontal thrust and the

second one is the vertical movement due to the vertical thrust. Hence, the selection of

best design and material for a float is essential.

Table 2.1: Types of float designs & their parameters

FLOAT MASS VOLUME BOUYANCE FORCE

1.943 kg

(approx)

2.4856 × 10-3 m³

(approx)

-28.80 N

(approx)

1.856 kg

(approx)

2.37356 × 10-3 m³

(approx)

-37.16 N

(approx)

1.514kg

(approx)

1.9363 × 10-3 m³

(approx)

-38.11 N

(approx)

2.6 Wave generation tank

The figure below shows the varios components of the wave generation tank

along with there dimensions:

Fig.2.7 Dimensions and labelling of tank

Fig.2.8 Components of wave generation tank

Dimensions are as follows :

Length of tank : 6 feet

Width of tank : 2 feet

Height of tank : 2 feet

The wave generation tank used for the simulation is made of marine wood.

Why wood is selected as material?

1. It is light in weight hence easy for transportation.

2. It is cheaper compared to metal and plastic since their fabrication cost is much

higher.

3. Wood is easy to craft compared to metal and plastic.

4. Modifications can be easily done on wood hence proves a better option for our

experiment.

5. Since marine wood is used there is no question of swelling of wood.

Components of tank .

Piston giude:

To guide the vertical motion of the piston

To achieve the constraint motion of the piston so that there is no

deflection while applying force on water surface.

Piston

It is used to get a uniform pressure distribution on the water surface.

Valve

It acts as aone way valve.

It is used to prevent the non-return motion of the water.

Variable Inclined plate

To vary the outlet discharge area of water from the water column.

With the help of variable inclined plate, we can obtain different wave

height and wave length.

Fixed angle plate

It is adjusted at a fixed angle of 600 as obtained in the calculations.

It directs the water coming from the water column.

The forced water takes the profile of the fixed angle plate and comes out

as a wave.

Variable sea shore angle plate

Its function is to minimize the back force of water striking thw tank

wall.

To examine the effect of back force of water on the float at different sea

shore angle.

Components of Mechanism :

Piston

Connecting rod

Crank

Dead weight

Bearing

Handle

Fig.2.9 Mechanism of simulation tank

CHAPTER 3: PROBLEM

DEFINITION

3.1 Scope of project

An ocean wave is a sum of a wave crest and a wave trough. The float is

displaced when an ocean wave crest or trough strikes the float. When a wave crest

strikes the float, it is raised against the dead weight which is connected to the other end

of the rope moving over the pulley. This movement of the rope along with the dead

weight rotates the pulley and thereby the shaft in a particular direction say anti-

clockwise .This rotates the input shat of the generator on which a pulley is mounted,

thereby producing electricity.

When a wave trough appears, the float is lowered raising the dead weight and

thereby again rotating the input shaft of the generator. Thus, in the ocean wave

converter, the input shaft on which the pulley is mounted rotates in both the direction.

However, for the continuous power generation at the generator a unidirectional motion

(rotation) of the output shaft is required. This problem gives a wide scope for our

project. This report mainly gives a solution to this problem. This can be achieved by

using a mechanism which converts the bi-directional motion of the shaft into uni-

directional motion. We have sought a solution by using a uni-directional gearbox

utilizing a chain and sprocket arrangement.

The Uni-directional gearbox converts bi-directional motion of a shaft in to

unidirectional motion of another shaft. It converts the alternative rotation into

continuous rotation with no significant loss in transmitted energy. This captured and

converted energy in the form of mechanical rotation could be used for further

utilization. This unidirectional gearbox is capable of converting any clockwise or anti-

clockwise directional rotation at its input shaft into continuous unidirectional rotation at

its output shaft. This process happens with no significant energy loss. 

3.2 Concept of Uni-directional gearbox

Fig 3.1 Schematic of a Uni-direction gear box.

Construction:-

This type of unidirectional gearbox consists of sprockets and chain which

convert the bi-directional motion of the input shaft into a uni-directional motion, which

is the prime necessity in a generator.

components of a unidirectional gearbox

1. Sprocket (6 NOs.)

2. Chain (2 NOS.)

3. Shaft on which sprockets are mounted (4 NOS.)

4. Bearings (8 NOS.)

5. Side Plate (2 NOS.)

Fig.3.2 The working model of uni-directional gearbox

Working: -

1. On the input shaft are mounted the pulley and the sprocket between the bearings.

2. When the pulley rotates in anticlockwise direction sprocket 1, 3 &4 rotates in

the same direction as that of the pulley (i.e. anticlockwise direction).

3. However the other three sprocket i.e. 2, 2'& 4 ' rotates in the clockwise direction.

4. It should be noted that 2'& 4 ' always rotates in the clockwise direction. This is

due to the free wheel mechanism in the sprocket.

5. When the input shaft rotates in the anticlockwise direction the free wheel

mechanism start acting in the sprocket 4.

6. When the shaft rotates in the clockwise direction the free wheel mechanism start

acting in the sprocket 2.

7. This mechanism gives uni-directional motion to the output shaft which is

connected to the generator irrespective of the direction of input rotation.

CHAPTER: 4 DESIGN

CALCULATION

4.1 Shaft Design

Velocity of float=V= 0.5 m/s

Diameter of pulley= Dpulley= 0.052m

V = π D pulley N

60

N = 60 × 0.5

π × 0.052 =183.64 rpm

Torque, Mt= force on pulley× radius of pulley

=75 × 0.026

=1.95 N-m

Power, P =2 π N Mt

60

= 2 π ×183.45 ×1.95

60 = 38W

Vertical and Horizontal Forces

Pulley at A

Weight of pulley = 2.34N

Weight of Dead wt. = 75 Cos 40=57.453N

Tension in rope = 75 Cos 40=57.453N

∴Vertical force on pulley

(FV) A = Wt. of pulley + Wt. of Dead weight.

+ Tension in rope

=2.34+ 57.34 + 57.453

∴ (FV) A =117.246 N

∴Horizontal force on pulley, (FH) A = 75 sin 40

∴ (FH) A =48.209 N

Sprocket at C

Weight of sprocket = 1.86 N

Diameter of sprocket=D sprocket = 65mm

T t

T s

=eμθ

T t

T s

=1.05 ……………{µ ( very less )=0.02θ=180o

( Tt – Ts) Dsprocket

2 = Mt

(1.05Ts – Ts ) 652

= 1.95×103

Tt = 1200 N

Ts = 1260 N

Resultant tension, Tc = Tt + Ts

= 1260+1200

= 2460N

Vertical force on sprocket

(F V)C = Tc sin 40 + W Sprocket

=2460× Sin50 +1.86

Horizontal force on sprocket

(FH)C = TC cos40

= 2460 cos40

Table 4.1 : Horizontal & vertical forces on pulley & sprocket

Forces Pulley A Sprocket C

Horizontal (FH)A=48.209 N (FH)C=1884.469N

Vertical (FV)A=117.246N (FV)C=1583.117 N

(FH)C = 1884.469 N

(F V)C = 1583.117 N

Fig 4.1 Vertical & horizontal bending moment diagram

Vertical Reaction

∑ M B=0

(117.246× 36 )+(V D ×103 )=(1583.117 ×33.5)

∑ FV =0

117.246 + 1583.117 - 473.91 = VB

Vertical Bending Moment

(MA)V = (MD) V = 0

(MB)V = 117.246 ×36 = 4220.856N-mm

(MC)V = (117.246× 69.5) – (1226.453× 33.5) = 32937.57 N-mm

Horizontal Reaction

∑ M B=0

(48.209 × 36 )+( H D ×103 )=(1884.469 ×33.5 )

∑ FV =0

48.209 + 1884.469 – 596 = HB

Horizontal Bending Moment

(MA)H = (MD) H = 0

(MB)H = 48.209 ×36 = 1735.524 N-mm

(MC)H= (48.209 × 69.5) – (1336.678 ×33.5) = 41428.187 N-mm

VD = 473.91 N

VB = 1226.453 N

HD = 596 N

HB = 1336.678 N

Resultant Bending Moment

(Mb ) B = √ ( M B )H

2+( M B )v

2 = 4563.734 N-mm

(Mb)C = √ ( M C )H2+( M C )v

2 = 52926.158 N-mm

Thus from BMD, the critical point is at point C

Mb= (Mb) C = 52926.158 N-mm

Mt =1.95×103 N-mm

Material Selection

Shaft material: - C-50………………………………….. P . S . G1.9

[6 ]

σyt = 380 N/mm2

Allowable stress: -

σt =σ yt

FOS = 95 N/mm2…………………..F.O.S = 4 (assume)

τ=0.5 σ t …………………………… (as per Maximum Shear Stress Theory))

¿47.5 N /mm2

Combined fatigue and shock load factor………………P . S . G

7.21

( Kb , Kt - revolving shaft and assuming minor shock load factor)

Kb= 2, Kt = 1.5

Equivalent Bending Moment

(M ¿¿b)e=12 [( M b Kb )+√(M b Kb)

2+(M t K t)2 ]¿

= 12

[ (52926.158 × 2 )+√ (52926.158 × 2 )2+ (1.95× 103 ×1.5 )2 ] = 105.872 ×103 N-mm

Equivalent twisting Moment

Te =√(M b Kb)2+(M t K t)

2

=√ (52926.158 ×2 )2+(1.95×103 ×1.5 )2

=105.892 ×103 N-mm

Diameter of shaft

1) Based on maximum normal stress

d = 3√ 32M be

π (σ¿¿ t)¿

=3√ 32 ×105.872 ×103

π × 95

d = 22.474mm

2) Based on maximum shear stress

d = 3√ 16 T eπ (τ )

= 3√ 16 × 105.892× 103

π × 47.5

d =22.475

Taking greater value

i.e. d =22.475

∴Standardizing the shaft diameter,

d = 25mm

Optimizing shaft design

Table 4.2:- Effect of variation in shaft dia. on various parameter

Component Solid shaftHollow shaft with I.D. = 10

Hollow shaft with I.D. = 12

Hollow shaft with I.D. = 13

Material C-50 C-50 C-50 C-50Area[m2]

0.016 0.021 0.022 0.022

Volume[m3]

9.8574 x 10-5 8.5646x 10-5 7.9955 x 10-5 7.6723 x 10-5

Density[Kg/m3]

7860 7860 7860 7860

Mass[Kg]

0.775 0.673 0.628 0.603

Graph 4.1: Shaft dia. Vs Mass of shaft

We know that, hollow shaft are stronger per kg of material and they can be forged on a mandrel, thus making the material more homogeneous than in case of solid shaft. Therefore, instead of solid shaft for same strength, we can use hollow shaft which will reduce material and overall system weight. This reduces the cost of the system.

4.2 Bearing Selection

Load on bearing : For B

Radial load (Fr) = 1.226 KN

Axial load (Fa) =1.336 KN

For D

Radial load (Fr) = 0.473 KN

Axial load (Fa) =0.596 KN

Bearing speed : N=185rpm

Expected Life in hours : Lhr =17520

Probability of survival : P07= 93%

Temperature factor : Kt =1

Type of bearing : Ball bearing

Expected life of bearing in million revolutions (mr) for 93% probability of survival:

L07 = Lhr× N × 60

106

=17520×185×60/106

=194.47 mr

Life of bearing expected for 90% of probability of survival:

L07L10 = { ln(1/ P 07)

ln(1/ P 10)}1/b

Where,

P07=0.93, P10=0.90

b=1.34 ……………….. (For ball bearing P.S.G. /4.2)

L10=256.853 mr

Fixing bearing series based on excessive radial load factor:

Pe= [V × X × Fr × Kr ] S × Kt

Pe= equivalent load

V= Ring rotation factor,

If outer race is fixed, V=1

If outer race is moving, V=1.2

S=service factor =1.2… (Assuming medium shock load )

X=Radial load factor =1

Kr=Excessive radial load factor

If Fa/Fr < 0.3, then Kr =1.2

If 0.3 < Fa/Fr >0.5, then Kr =1.3

If Fa/Fr > 0.5, then Kr=1.5

Pe= [1×1×1.226×1.5]1×1.2

Pe = 2.206 KN

Dynamic capacity (C):

C = (L10)1/K× Pe

K= 3 ………………………… (For ball bearing P.S.G. /4.2)

C = (267.45)1/3×2.206

=15.5017 kN (1550 kg-f)

Selection of suitable bearing series:

Table 4.3: Bearing series

Series I.D. (mm) C0 (kgf) C (kgf) Max. RPM

6305 25 1040 1660 10000

6306 30 1460 2200 10000

6207 35 1370 2000 10000

6009 45 1270 1630 10000

Based on economical criteria and safety condition, selecting

Bearing Series 6305

Dynamic capacity (C) =1660 Kg-f

Static capacity (Co) =1040 Kg-f

Checking for the actual bearing life :

Equivalent load on bearing

Pe = [(V × X × Fr) + (Y×Fa)] S × Kt

To find X and Y:

For bearing at D, F aC o

=596

10400 =0.057

∴ e = 0.27

F a

V × F r=

596473.91

=1.2526 >

∴ X=0.56 , Y=1.6,

Pe = [(1 × 0.56 ×473.91) + (1.6×596)] 1.2 × 1

= 1462.78 N

Life of bearing for 90% probability of survival

L10= ( 166001462 .78 )

3

= 1461 mr > expected life

Hence, Bearing is Safe.

RESULT:

Selecting the bearing series 6305 on dynamic load carrying capacity of 1.660 kN

for 93% probability of survival and then checked it so that whether its L10 life is more

or less from the expected life.

Hence, it is a safe condition.

4.3 Importance Of Chain Drive In Unidirectional Gearbox [8]

Table 4.4: Comparison of different types of mechanical drives

Type Roller ChainTooth

BeltV Belt Spur Gear

Synchronization

Transmission Efficiency

Anti-Shock

Noise/Vibration

Surrounding ConditionAvoid Water,

Dust

Avoid Heat, Oil,

Water, Dust

Avoid Heat,

Oil, Water,

Dust

Avoid Water, Dust

Space Saving

(High Speed/ Low Load)

Space Saving

(Low Speed/ High Load) Compact Heavy Pulley Wider Pulley Less Durability Due

to Less Engagement

LubricationRequired No Lube No Lube Required

Layout Flexibility

Excess Load onto Bearing

Excellent Good Fair Poor

Generally, under the same transmission conditions, the cost of toothed belts

and pulleys is much higher than the cost of chains and sprockets.

Features of Chain Drives:

1. Speed reduction/increase of up to seven to one can be easily accommodated.

2. Chain can accommodate long shaft-center distances (less than 4 m), and is more

versatile.

3. It is possible to use chain with multiple shafts or drives with both sides of the

chain.

4. Standardization of chains under the American National Standards Institute (ANSI),

the International Standardization Organization (ISO), and the Japanese Industrial

Standards (JIS) allow ease of selection.

5. It is easy to cut and connect chains.

6. The sprocket diameter for a chain system may be smaller than a belt pulley, while

transmitting the same torque.

7. Sprockets are subject to less wear than gears because sprockets distribute the

loading over their many teeth.

4.4 Chain Design

Power to be transmitted, N = 0.97KW

Input speed n1 =210rpm

Velocity ratio, i =2

Service factor

KS =K1 × K2 × K3 × K4 ×K5× K6 ………………………. P . S . G.

7.76

K1, load factor =1

K2, distance regulation factor =1

K3, center distance factor =1

K4, position of sprocket factor =1

K5, lubrication factor =1

K6, rating factor =1

KS = 1×1×1×1×1×1 =1

Number of teeth on driver & driven

Since i =2

Z1 = 16 , Z2 =32

Selection of pitch (P)

Since n=210 rpm …….(200 < rpm < 500 )

Hence selecting pitch P =12.7

Pitch circle diameter of sprocket (p.c.d)

d1 =

P

sin (180Z1

) = 12.7

sin (18016 ) = 65.09 mm

d2 =

P

sin (180Z2

) = 12.7

sin (18032 ) =129.56 mm.

Speed of chain (V1)

V1= πdN

60,000 m/sec.

= π × 65.09× 210

60,000

= 0.715 m/sec.

Power transmitted on basis of Breaking Load (Q) ....…………….. P . S . G.

7.77

N=Q ×V 1

102 ×n × K S

Q=102 × N ×n × K S

V 1

Q=102 ×0.97 ×7.8 × 10.715

= 1079.34 kg-f

Chain selection Based on breaking load ………………………P . S . G.

7.71

Table 4.5 : selection of chain

Chain No. Pitch

Roller

Dia.

Max.

Transverse

Pitch

Bearing

areaWt/Length

Breaking

Load

Iso/din Rolonp Dr Pt A w Q

mm. mm. mm. cm2 Kg-f Kg-f

08A-1 R40 12.7 7.95 11.7 0.44 0.69 1410

Check for bearing stress

σbr =Allowable bearing pressure

= 3.15 kg-f/mm2 ……………………………………………………P . S . G.

7.75

Induced Bearing stress(σ)

σ ¿102× ks × N

A × V

σ=102 ×1 × 0.970.44 ×0.715

=314.49 kg-f/cm2

= 314.49×10-2 kg-f/mm2

= 3.1449 kg-f/mm2

Since σ < [σ br]

∴Design is Safe.

Lp =2a + (Z2+Z1

2 ) +(Z2−Z1

2π )2

ap

Where LP , length of continuous chain in multiple of pitches

aP ,approximate center distance in multiple of pitches

ap = a0

p

where a0 ,assumed center distance (a0 = 90mm )

ap = 90

12.7 = 7.086

Lp = (2×7.086) + ( 32+162 ) +( 32−16

2 π )2

7.086

Lp = 14.17 + 24 + 0.162 = 39.087

Corrected to even no. ∴ Lp = 40

Exact center distance (a)

a = ( e+√e2−8m4 )× pitc h

e = LP −( Z1+Z2

2 ) = 40 −( 32+16

2 )e =16 (assume e=16)

m = (Z2−Z1

2 π )2

=( 32−162π )

2

= 6.48 ( m = constant)

a =( 16+√162 –8 × 6.484 ) × pitch

= 7.57×12.7

a = 96.16 mm

L = LP × P (L = chain length) = 40 × 12.7 = 508 mm

Actual factor of safety [n]…………………………………………P . S . G.

7.78

[n¿= Q

∑ p

Q=1410 kg-f

∑ P = Pt+ Pc+ Ps

Where,

Pt = Tangential load

¿102× N × KS

V=102× 0.97 ×1

0.715 = 138.37 kg-f

Pc = Centrifugal load

¿ w × v2

g ¿ 0.69× 0.7152

9.8 = 0.035 kg-f

Ps = load due to sagging

= k × w × a =4 × 0.69 ×90 × 10-3 = 0.248 kg-f.

Where,K= coefficient of sag,w= weight per meter length,

a= center distance in meter.

P =Pt +Pc +Ps

P =138.37+ 0.035+ 0.2484 = 138.66 kg-f

∴[n] ¿Q

∑ P = 141038.66 = 10.16

As [n] > 7.8 (min f. o. s ) ……….. Safe condition.

Effect of no. of sprocket teeth on the output shaft on various parameters of Uni- Direction gear box

1. No. Of teeth on sprocket of input shaft = 16 ( Fixed)

2. No. Of teeth on sprocket of ideal shaft = 16 ( Fixed)

3. Speed of input sprocket = 180 rpm.

4. Tension in the chain = 1200 N.

Table 4.6 :- Effect of no. of teeth of sprocket on various parameter of Uni- Direction gear box

Graph 4.2. Graph showing effect of decrease in no. of t teeth on the output shaft speed & power

Therefore, selecting sprocket with 8 teeth on the output shaft to increase the output speed, torque & power.

Sr. No. No. of teeth on O/P sprocket P.C.D. Of

sprocket(m)

O/P Shaft speed(rpm)

Torque(N-m)

Power(W)

1 16 0.0659 180 39.06 738.2

2 12 0.049 240 29.4 740.9

3 10 0.041 288 24.66 745.7

4 8 0.0371 360 22.26 841.4

4.5 Side Plate Design

Fig.4.2 schematic of side plate

Material Selection:-

Cast Iron (MEEHANITE CASTING) GE50 (flake graphite / pearlitic)…....... PSG1.3

Yield strength (σ yt ¿= 140 N/ mm2.Assume F.O.S =7.

Tensile stress, σ t= σ yt

F . O.S .=140

7=20N/mm2.

Shear Stress, τ=0.5 ×σ yt

F . O. S .=0.5 ×

1407

=10 N/mm2

A] Tearing Failure in plate section 1-1

σt = LoadArea

=W max .

(195−47)×12= 1814.08316

(195−47)×12 = 1.021 N/mm2

B] Shearing Failure in plate section 1-1

τ = Load

Shear Area

=W max.

2× 45 ×12=1814.08316

2× 45 ×12 = 1.68 N/mm2.

C] Tearing Failure in plate section 2-2

σt = LoadArea

=W max .

(295−94)×12= 1814.08316

(295−94)×12 = 0.75 N/mm2.

∴ Hence, Design is Safe

CHAPTER: 5 ANALYSIS OF SHAFT

5.1 Analysis of Shaft

MESH: Entity Size

Nodes 416Element 1228

ELEMENT TYPE:

Connectivity Statistics

TE4 1228 (100.00%)

ELEMENT QUALITY: Table 5.1 : Elemental quality of shaft

Criterion Good Poor Bad Worst Average

Stretch1226

(99.84% )2

( 0.16% )0

( 0.00% )0.278

0.568

Aspect Ratio1196

(97.39% )32

( 2.61% )0

( 0.00% )5.813 2.218

MATERIAL:Table 5.2 : Properties of Material selected shaft 1

Material Steel

Young’s Modulus 2×1011 N/m2

Poisson's ratio 0.266

Density 7860kg/m3

Coefficient of thermal expansion 1.17×10-5 /K deg

Yield strength 2.5×108 N/m2

STATIC CASE:

Fig.5.1 Model of input shaft 1

STRUCTURE COMPUTATION:

Number of nodes : 416 Number of elements : 1228Number of D.O.F. : 0Number of Contact relations : 0 Number of Kinematic relations : 0

LOAD COMPUTATION:Applied load resultant: Fx = 4. 610e-008 N Fy = -1. 933e+003 N Fz = -1. 700e+003 N Mx = 3. 842e+001 N-m My = -1. 450e-007 N-m Mz = 1. 659e-007 N-m

Table 5.3 : Forces & moment acting on the shaft

Components Applied Forces Reactions ResidualRelative

Magnitude Error

Fx (N) 4.61×10-8 -4.698×10-18 2.0188×10-12 6.5414×10-15

Fy (N) -1.9327×103 1.9327×103 1.5916 ×10-12 5.1572×10-15

Fz (N) -1.7004×103 1.7004×103 1.3870× 10-11 4.4941×10-14

Mx (N-m) 3.84×101 -3.8415×101 -5.187×10 -13 1.6427×10-14

My (N-m) -1.45×107 1.4500×10-7 -1.391 ×10-13 4.4074×10-15

Mz (N-m) 1.6594×107 -1.6594×10-7 8.928 × 10-14 2.8281×10-15

STATIC CASE SOLUTION - DEFORMED MESH:

Fig. 5.2 Deformation in a shaft

STATIC CASE SOLUTION - VON MISES STRESS (NODAL VALUES):

Fig. 5.3 Analysis of a solid shaft

5.2 Analysis of Side Plate 1

MESH:

Entity Size

Nodes 588

Elements 1437

ELEMENT TYPE:

Connectivity Statistics

TE4 1437 (100%)

ELEMENT QUALITY:

Table 5.4: Elemental quality of side plate 1

Criterion Good Poor Bad Worst Average

Stretch1437

(100%)0 (0.00%) 0 (0.00%) 0.429 0.591

Aspect

ratio

1437

(100%)0 (0.00%) 0 (0.00%) 2.647 2.161

MATERIAL:

Table 5.5: Material properties of side plate 1

Material Iron

Young’s modulus 1.2× 1011 N/m2

Poisson’s ratio 0.291

Density 7870 kg/ m2

Coefficient of thermal conductivity 1.21 ×10-5 /kdeg

Yield strength 3.1×108 N/ m2

STATIC CASE:

Fig. 5.4 Model of a Plate

STRUCTURE COMPUTATION:Number of nodes : 588Number of elements : 1437Number of D.O.F. : 1764Number of contact relation : 0Number of kinematic relations : 0 Linear tetrahedron : 1437

LOAD COMPUTATION: Applied load resultant:Fx= -4.459 × 10-8 NFy = -5.347 × 103 N Fz = -4.906 × 103 NMx = 8.688 × 102 N-mMy = 2.943 × 101 N-mMz = -3.208 × 101 N-m

Table 5.6: Forces & moment acting on the Side plate 1

ComponentsApplied Forces

Reactions ResidualRelative

Magnitude Error

Fx (N) 4.4587×10-9 -4.4605×10-8 -1.7792×10-11 2.0716×10-14

Fy (N) -5.3467×103 5.3467×103 -3.5470×10-11 4.1299×10-14

Fz (N) -4.9058×103 4.9058×103 -2.0009×10-11 2.3297×10-14

Mx (N-m) 8.6884×102 -8.6884×102 6.4801×10 -12 2.5150×10-14

My (N-m) 2.9435×101 -2.9435×101 -3.1797×10-12 1.2341×10-14

Mz (N-m) -3.2080×100 3.2080×101 4.6185× 10-13 1.7925×10-15

STATIC CASE SOLUTION - DEFORMED MESH

Fig. 5.5 Deformation in a plate

STATIC CASE SOLUTION - VON MISES STRESS (NODAL VALUES)

Fig. 5.6 Analysis of a plate

5.3 Analysis of Second Side Plate 2

MESH:

Entity Size

Nodes 588

Elements 1437

ELEMENT TYPE

Connectivity Statistics

TE4 1437 (100%)

ELEMENT QUALITY

Table 5.7: Elemental quality of side plate 2

CRITERION Good Poor Bad Worst Average

Stretch1437

(100%)0 (0.00%) 0 (0.00%) 0.429 0.591

Aspect ratio 1437(100%) 0 (0.00%) 0 (0.00%) 2.647 2.161

MATERIAL

Table 5.8: Material properties of side plate 2

Material Iron

Young’s modulus 1.2× 1011 N/m2

Poission’s ratio 0.291

Density 7870 kg/ m2

Coefficient of thermal conductivity 1.21 ×10-5 /kdeg

Yield strength 3.1×108 N/ m2

STATIC CASE:

Fig. 5.7 Model of a Plate 2

STRUCTURE COMPUTATION Number of nodes : 588Numberof elements : 1437Number of D.O.F. : 1764Number of contact relation : 0Number of kinematic relations : 0 Linear tetrahedron : 1437

LOAD COMPUTATION Applied load resultant:Fx= -1.048 × 10-9 NFy = -1.422 × 103 N Fz = -1.788 × 103 NMx = 2.654 × 102 N-mMy = 1.073 × 101 N-mMz = -8.53 × 100 N-m

Table 5.9 : Forces & moment acting on the Side plate 2

Components Applied Forces Reactions ResidualRelative

Magnitude Error

Fx (N) -1.0477×10-9 1.0477×10-9 5.3788×10-12 1.7851×10-14

Fy (N) -1.4217×103 1.4217×103 -7.9581×10-12 2.6412×10-14

Fz (N) -1.7880×103 1.7880×103 -7.7307×10-12 2.5657×10-14

Mx (N-m) 2.6539×102 -2.6539×102 1.8190×10 -12 2.0123×10-14

My (N-m) 1.0728×101 -1.0728×101 -1.0676×10-12 1.1811×10-15

Mz (N-m) -8.5304×100 8.5304×100 9.700 × 10-14 1.0808×10-15

STATIC CASE SOLUTION - DEFORMED MESH

Fig. 5.8 Deformation of a Plate 2

STATIC CASE SOLUTION - VON MISES STRESS (NODAL VALUES)

Fig. 5.9 Analysis of a Plate 2

6. COST ESTIMATION OF ENTIRE PROJECT

Sr. No. Component Material Volumem3

DensityKg/m3

Mass Cost

1 Side Plate MS 0.002229672 7860 17.52 876.261

2 Shaft MS 0.000779106 7860 6.5 390

Bearing Cost

Quantity of bearing = 8 Nos.

Cost per bearing = Rs. 90/-

Total cost of bearing = Rs. 720/-

Cost of chain & sprocket

Cost of chain = Rs. 130/-

Cost of Sprocket= Rs. 330/-

Others (including nuts & bolts) = Rs. 200/-

Total cost of gear box unit = Rs. 2,646.26/-

7. CONCLUSION

1. The power transmission system (i.e. Uni direction gear box ) fabricated in

laboratory by using chain & sprocket mechanism gives an output of 9.196 W.

This brings the efficiency of the system to 24.2 % .

Input power = 38 W.

Output power = 9.196 W.

∴ηsytem=Out put power¿ put power

¿ 9.19638

=0.242=24.2 %

2. In the Uni- direction gearbox, reduction in the no. of teeth on output sprocket

increases the speed of output shaft and power available at output.

3. Reduction in shaft diameter contributes to the reduction in the net weight of the

system thereby increasing efficiency of system.

8. SCOPE OF THE PROJECT

1. The size of system can be reduced, by reducing various parameter like shaft

diameter, no. of teeth on sprocket, so that efficiency can be increased.

2. Analysis of chain sprocket mechanism can be done to check for any failure.

3. Uni -direction gear box also can be made by using other technique like worm

and worm wheel type.

BIBLIOGRAPHY

1. Energy from sea waves-the Indian wave energy programme- M.Ravindran and

Paul Mario Koola, CURRENT SCIENCE,VOL. 60,NO.12,25 JUNE 1991

2. Wave Energy Generation Device: Design, Development, and Implementation-

S. G. Kanitkar, J.G. Kori, Suhas Deshmukh, S. N. Teli.

3. Ocean Wave Energy Conversion-Jennifer Vining

4. Ocean Wave Energy Overview and Research at Oregon State University- Ted

K.A. Brekken, Annette Von Jouanne, Hai Yue Han.

5. Ocean Energy Conversion in Europe,Centre for Renewable Energy

Sources,2006

6. P.S.G. design data

7. Machine design-v.b.bhandari

WEBSITES

1. http://chain-guide.com/basics/1-chain-basics.html

2. http://www.urbanhart.com/shopsite/rope_rollers.html

3. http://www.definition-of.com/OCEW">OCEW</a>

4. http://www.oceanpowertechnologies.com/projects.htm4.

5. http://www.oceanpowertechnologies .com

6. http:// www.enchantedlearning.com/subjects/ocean/Waves.shtml

7. http://www.wavesenergy.com/links.html

8. http://www.oceanpowermagazine.net/2010/03/01/india-studies-feasibility-of-

over- 100-megawatts-of-tidal-energy-projects.

SOFTWARES USED

1. CATIA V5R17

2. AUTOCAD 2010

3. MICROSOFT OFFICE 2010

APPENDIX

NOMENCLATURE

H Significant wave height

T Zero crossing period in sec.

E Energy stored in a horizontal square metre of the water surface.

P Wave energy flux

Cg Group Velocity of wave(m/s)

V Velocity of float (m/s)

Mt Torque on the shaft

Tt Tension on tight side of chain

Ts Tension on slack side of chain

Tc Resultant tension

θ Angle of wrap of the chain

Kb, Kt Combined fatigue and shock load factor.

( M b )e Equivalent bending moment

( M t )e Equivalent twisting moment

d Shaft diameter

Fr radial Load

Fa Axial load

N Bearing speed

Lhr Expected life in hrs.

Kt Temperature Factor

Pe Equivalent load

V Ring rotation Factor

Kr Excessive radial load factor

C Dynamic capacity

Co Static capacity

Ks Service factor for chain design

Z1, Z2 No. of teeth on driver & driven sprocket

N Power transmitted

Q Breaking load

Lp Length of continuous chain

ap Approximate centre distance between the sprocket

a Exact centre distance

*********************************