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STIRLING ENGINE KITCHEN SMOKE REMOVER 1

1/6/2012

MACHINE COMPONENT DESIGN

BMCD3523

STIRLING ENGINE KITCHEN SMOKE REMOVER

FAKHRURAZI BIN AZIZ

B040910051

HALIMATON BASMATU BINTI ALI

B040910081

MOHD AZARUL SYAZARI BIN CHE AZIZ

B040910167

MOHD IDHAM KHALID BIN ABU HASAN

B040910094

NURUL NADIA BINTI ABDULLAH

B040910227

SYED ZULKARNAIN BIN SYED SAIDINB040910037

DUE DATE

1 JUNE 2012

LECTURE

SHAFIZAL BIN MAT

Bachelor of Mechanical Engineering (Thermal-Fluid), Faculty of Mechanical Engineering,

Universiti Teknikal Malaysia Melaka, Durian Tunggal, Melaka.


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List of Contents

List of Tables.....3

List of Figures............4

Abstract......5

Acknowledgement.6

Introduction.......7

Chapter 1 : Objective and Problem Statement 7-8

1.1.Objective.......71.2.Problem Statement...........8

Chapter 2 : Theory..8-12

Chapter 3 : Methodology..12-14

Chapter 4 : Conceptual design.15-19

4.1.Design 1...............................154.2.Design 2...............................164.3.Design 3..........................16-174.4.Weight Decision Matrix.......17-184.5.Pugh method.......................19

Chapter 5 : Detail design..19-26

Chapter 6 : Discussions and Design Analysis .....27-47

6.1.Analysis due to welding27-306.2.Analysis of shaft31-326.3.Bolt Analysis..32-356.4.Bearing analysis ...36-376.5.Bevel gear analysis38-406.6.Non-Permanent Joints. 40-456.7.Discussion..46-47

Chapter 7 : Conclusion...........................................47

References48


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List of Figures

Figure 1 Screw.........................................................................................................................10

Figure 2 strength of bolt.........................................................................................................11

Figure 3 Gear...........................................................................................................................12

Figure 4: Stirling Engine........................................................................................................12

Figure 5: Stirling Engine Parts..............................................................................................13

Figure 6: Parts involved in power generation......................................................................14

Figure 7: Electricity powered................................................................................................15

Figure 8 : Solar powered........................................................................................................16

Figure 9 : Stirling Engine powered.......................................................................................17

Figure 10 : Blade....................................................................................................................19

Figure 11 : Suction Tunnel.....................................................................................................20

Figure 12 : Gears and Shaft..................................................................................................20

Figure 13 : Bearing................................................................................................................21

Figure 14 : Stirling Engine.....................................................................................................21

Figure 15 : Stove including the stove cabinet.......................................................................22

Figure 16 : Final Rendering..................................................................................................22

Figure 17 : Engine Assembly.................................................................................................23

Figure 18 : Bill of Material....................................................................................................24

Figure 19 : 2D Drawing..........................................................................................................25

Figure 20 : 2D Drawing of Stove Assembly.........................................................................26

Figure 21 : welding part 1.....................................................................................................27

Figure 22 : Welding part 2....................................................................................................29

Figure 23 : shaft part..............................................................................................................31

Figure 24 : bolt part................................................................................................................32


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List of Tables

Table 1 : Table 11-2................................................................................................................36

Table 2 : Table 8-15................................................................................................................40

Table 3 : Table 8-11................................................................................................................41

Table 4 : table 8-1..................................................................................................................41

Table 5 : Table A-30...............................................................................................................42

Table 6 : Table 8-8..................................................................................................................44


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Abstract

In this project, stirling engine concept is being used for green technology aspect to run

the blade. Why the Stirling Engine being choose? It is because the sustainable type of energy

that has a lot more benefits than the conventional energy that uses electricity as the source.

But the main objective in this project is to analysis each parts of mechanical component that

being installed in this engine. The mechanism will be working by allowing compression and

expansion of air or other gas at different temperature levels such that there is a net conversion

of heat energy to mechanical work. Then the process will be transferred into mechanical part.

All of the parameter will be calculated according to the aspects that have been given. Whether

the dimension of the component is suitable for the system or not, is the factor safety is not

below then one or not? And many more aspect have been consider to build this sisten


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Acknowledgement

We owe a great many thanks to a great many people who helped and supported us

during the build this project, many thank to Sir. Shafizal Bin Mat who has given us a chance

to prove that we can do things on our own. He gave a positive perspective in life and sharing

his valuable time with giving us an information to finish this project. Although, the project is

quit challenging, but we can finish it on time.

We would have not finished this project without the support of our team mate whose

has encouragement each other to keep going and struggle to ensure this project was success.

And special gratitude to our classmate whose helped us in researching on different fields

concerning this project and giving a fresh idea that help us a lot to complete this project.


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Introduction

Nowadays, green technology is something that no longer alien to our daily life. We

can see how the scientist manipulated each type of energy to become new useful machinery

that can save our environment. From the light energy that can convert into electrical energy

by using solar panel, from the mechanical energy or also known as vibration energy also can

convert into electrical energy by using Piezoelectric, also from the wind, see waves, and many

more. But here we will focused on stirling engine that can convert onto mechanical energy.

Stirling Engine is one of the reversible thermodynamic cycle application, they work

based on compression and expansion cycling of air or other gas. They are also traditionally

know as an external combustion engine. They are widely can found in industry application

because of the high thermal efficiency, form a quiet and safe operation, ease of operation and

able to working with any form of thermal energy. The most efficient type of sterling engine is

the type that can handle the low temperature difference. Such as temperature between the

hand palm and the ambient temperature.

Advantage of applying this technology are, can operate with any type of heat source, it

is last longer than reciprocating engine type and also having the simple engine mechanisms. it

is also using the single-phase of working fluid that will reduce the explosion rate. lastly, they

also a flexible technology. For the disadvantage, it need huge size of engine to supply large

amount of power, and it will cost of a lot of money. Type of gas being used also need to be

considered, the gas should have a low heat capacity to produced high pressure.

Chapter 1 : Objective and Problem statement

1.1.Objective1.1.1. To design a kitchen smoke remover that uses sustainable energy as source of

energy

1.1.2. To analysis each part of mechanical component1.1.3. To apply the principles of mechanical component design in this project


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1.2.Problem statement

Based on the conventional kitchen smoke remover that being use nowadays, it

is using electricity as the source of energy to run the suction blade. It is not very

environmental friendly because electricity is not one of the sustainable energy.

Furthermore, consumers will be burdened with excessive electricity bills every

month. Now, from what we can see the earth will not allowing us to stick to one

source of energy, the available sources like coal, oil and other will diminish. And

now we need to design a new technology that will use sustainable energy that easy to

get in our daily life. It is our objective to change this type of energy to a more

sustainable energy as the alternative to a more environmental friendly energy.

Chapter 2: Theory

An Exhaust Smoke system was used to remove smoke that produces by kitchen. This

system was work based on stirling engine that placed on the kitchen. There are several part on

the system had been analyze. A small machine components are joined together to form a

larger machine part. The design of joint are important because it was critical part that ensure

that the system were able act with the force react on the system. A week of joint may spoil a

utility of the machine part.

Bolt was one of nonpermanent joint where it was temporary of joining the materials.

To ensure the joint that causing by bolt was safety, there was several analysis was done to

know the factor safety, preload recommendation for the type of bolt, preload stress and stress

the can be supported by the bolt. All the value of preload was used to calculate the load factor,

yielding factor that can cause by the bolt, and also the load factor guarding against joinseparation. The analysis was depending on the type of material of bolt and also the type of

bolt. A different type and material of bolt that used were giving a different value of safety

factor. A mass of part that was used the nonpermanent joint was mostly effected the safety

factor of the bolt were it was concern as force load that act on the joint. The total force that

acts on the plate was divided by the amount of the bolt that used on the plate. The calculations

of all the part of analysis on bolt are based on these equations.


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Torque necessary to achieve preload;

T = K Fi d (1)

Load factor;

nL = ( SP AtFi)/ C(Ptotal/N) (2)

Yielding factor safety;

nP = ( SP At)/ [C(Ptotal/N) + Fi] (3)

Load factor guarding against join separation;

no = Fi/[ (Ptotal/N)(1-C)] (4)

Welding was type of permanent joint where it cannot be dissemble without damaging

the components. The part that was weld is used molecular force to joint the component. The

permanent joints are preferred on the part that face with a high load and its was durability.

Advantage of this type of joint are high load bearing capacity, better distribution of stresses

through the material and also has higher yield strength of the combined structure. The two

plate of metal was melt at the bottom by using high temperature where the aid of filler

material a weld pool was created. The joint made permanent by reducing the work piece

temperature to the room temperature. There were several type of weld such as Gas welding

and also several type of joint such as butt joint, corner joint, edge joint, lap joint and also tee

joint. To ensure the type of weld and joint are safe for the structure, there were analysis that

used to calculate the factor safety of the weld. The depths of weld were the critical part in the

welding design. The type of force that acts on the welding are based on bending or torsional

force. Different types of weld were giving a different analysis. An equation that used onanalyze the welding to find the factor safety are:

Primary shear

= V/A (5)

Secondary shear bending

= Mc/I (6)


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Total shear,

= (2+ 2)1/2 (7)

Factor safety

Fs = Ssy/max (8)

Shaft is rotating member where it used to transmit power or motion. There was several

type of material that used for shaft. The shaft rotates due to the transmitting power from the

stirling engine that produce by the kitchen. The forces that involve are bending and torsional.

The shaft was rotate due to torsional and bending. To find the maximum shearing stress that

act on the shaft, equations below are used;

max = (9)

Screw was also one of the types of non permanent joint. The helical-thread screw was

undoubtably an extremely important mechanical invention. It was the basis of power screw,

which change angular motion to linear motion to transmit power or develop large forces and

threaded fastener. All the threads are made according to right-hand rule unless noted.

The thread geometry of metric M and MJ profiles is shown in figure below;

These assemblies may structural as a load bearing of component that subjected both shear and

tensile stresses.

Figure 4 Screw


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Torque for raising the load;

TR = ( ) (10)

Torque required lowering the load;

TR = ( ) (11)

One of machine element is bearing that constrain the relative motion between two or

more parts to only desired type of motion. It was manufactured to take pure radical loads,

pure thrust load, or a combination of the kinds of loads. It used to allow and also promote a

free linear movement or free rotation around a fixed axis.

In selecting a bearing for a given application, it is necessary to relate the desired load and life

requirements to the published catalog load rating corresponding to the catalog rating life.

Where;

FR(LR nR 60)

1/a

= FD(LD nD 60)

1/a

(12)Where;

FR = catalog rating

LR = rating life

nR = rating speed

FD = desired radial load

LD = desired life

nD = desired life

Figure 5 strength of bolt


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Gear is a rotating machine where it has cut teeth which mesh with another toothed part

in order to transmit torque. The gear that had working in tandem is known as transmission and

it can provide a mechanical advantage through the gear ratio.

Chapter 3 : Methodology

Energy Concept

A Stirling engine is a type of external combustion engine that uses the expansion and

compression of air in order to create a mechanical energy.

Figure 4: Stirling Engine

Figure 6 Gear


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Typical of heat engines, the general cycle consists of compressing cool gas, heating

the gas, expanding the hot gas, and finally cooling the gas before repeating the cycle. The

efficiency of the process has an upper limit set by the efficiency of the equivalent Carnot

cycle operating between the same hot and cold temperatures.

Advantages

-The Stirling engine is noted for its high efficiency compared to steam engines, quiet

operation, and the ease with which it can use almost any heat source. This compatibility with

alternative and renewable energy sources has become increasingly significant as the price of

conventional fuels rises, and also in light of concerns such as peak oil and climate change.

-This engine is currently exciting interest as the core component of micro combined heat and

power (CHP) units, in which it is more efficient and safer than a comparable steam engine.

Figure 5: Stirling Engine Parts

Cooling Compartment

Cool Piston

Heating

Compartment

Hot Piston


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Mechanism of Power Generation

Figure 6: Parts involved in power generation

1) When the stove is ignited, heat will be transmitted by the heat conduction coil to the

Stirling engine in order to generate heat.

2) When enough heat had been accumulated, the Stirling engine will start to operate and starts

to transmit rotational motion to the shaft.

3) The shaft will transmit the power towards the gear compartment.

4) Bearing that is being placed at the shaft will smooth the rotary motion.

4) In gear compartment, the gear will increase the rotational power of the shaft; hence we will

get more power.

5) From gear compartment, a small shaft will transmit the power towards the blade, and the

blade will spins.

6) When the blade spins, smoke from the stove will be sucked to the blade and out of the

kitchen.

Coil

Heat Conductor

Shaft

Gear

Blade


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Chapter 4 : Conceptual design

A concept design could be regarded as the initial proposed design for a particular

product. Usually several design drawings will be made in order to make the best choice from

the options that is given. It will make it easier for a design team to make assessment of the

potential design and make the right choice out of it.

For our design, we had come out with several concept designs that is designed based

on its type of energy used. Out of the three designs, we had chosen the best design that met

our design requirements.

4.1 Design 1

For this design, we used electricity as the source of energy. Electricity could also be

regarded as renewable energy as long as it is based on hydroelectric power. Hence it is

suitable with our energy requirement that requires us to use renewable energy. However,

electricity is not quite suitable due to the fact that it requires monthly bill cost and also some

of it is generated by coal power plant that is not a renewable energy. So, we decided to scrap

this idea.

Figure 7: Electricity powered


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Figure 9 : Stirling Engine powered

4.4.Weight Decision MatrixObjective Tree For The Design Of A Kitchen Smoke Remover

KITCHEN SMOKE REMOVER

COST QUALITY IN SERVICE

ROI Mfg. Cost Reparability Durability Reliability maintenance Safety


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O1 = 1.0

O11 = 0.5 O12 = 0.5

O111 = 0.3 O112 = 0.4 O113 = 0.3 O121 = 0.4 O122 = 0.3 O123 = 0.3 O124 = 0.3

Weighted Decision Matrix

Decision

Criterion

Weight

Factor

Unit

s Electric Stirling engine Solar

Score Rating Score Rating Score Rating

maintenance 0.15 RM 8 1.20 6 0.90 4 0.60

Manufacturingcost

0.20 RM 7 1.40 7 1.40 5 1.00

Reparability 0.15 EXP 5 0.75 9 1.35 8 1.20

Durability 0.20 EXP 6 1.20 8 1.60 8 1.60

Reliability 0.15 EXP 5 0.75 9 1.35 8 1.20

ROI 0.15 HR 5 0.75 7 1.05 4 0.6

Safety 0.20 EXP 8 1.60 5 1.00 7 1.40

7.65 8.65 7.60


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4.5.Pugh methodNumber criteria solar datum Stirling

engine

1 maintenance - +

2 Manufacturing cost - +

3 Reparability + -

4 Durability - +

5 Reliability + -

6 ROI - -

7 Safety - -

plus 2 3

minus 5 4

Chapter 5 : Detail design

Figure 10 : Blade


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Figure 11 : Suction Tunnel

Figure 12 : Gears and Shaft


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Figure 13 : Bearing

Figure 14 : Stirling Engine


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Figure 15 : Stove including the stove cabinet

Final Rendering

Figure 16 : Final Rendering


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Figure 17 : Engine Assembly


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Figure 18 : Bill of Material


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Figure 19 : 2D Drawing


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Figure 20 : 2D Drawing of Stove Assembly


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Chapter 6: Design analysis and Discussions

ANALYSIS OF EACH PART

6.1.Analysis due to welding

part 1

Due to bending force;

By assuming Sy = 300MPa,

Force =250kNh = 8

Primary shear, = V/A, where V = shear force

Secondary shear bending, = Mc/I, where I = 0,707hIu

Total shear, = (2+ 2)1/2

From table 9-2 (pg 488; shigleys)

N0 6; throat area, A = 1.414h (b + d)

Figure 21 : welding part 1


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Location of G,= d/2

X = b/2

Unit second moment of area, Iu =

Calculation;

A = 1.414h (b + d)

= 1.414 (8) (780 + 379.814) = 13119.82 mm2

X = b/2 = 780/2 = 390mm

= d/2 = 379.814/2 = 189.91mm

Iu = = 3 = V/A= (250x 103)/ 13119.82 = 19.06N/mm2

I = 0.707hIu= 0.707(8) (65392793.8) = 369.8616x106

mm4

= Mc/I = 250 x103(550)(189.91)/ 369.8616 x106 = 70.60N/mm2

max= (2+ 2)1/2 = (70.602 + 19.062)1/2 = 73.13N/mm2

Ssy = 0.577Sy = 0.577(300) = 173.1 MPa

Factor safety = Ssy/max = 173.1 / 73.13 = 2.37

Explanation;

Based on the calculation that had done based on the dimension from the solid work

drawing, the value of factor safety are 2.37.Its was due to the dimension of the welding

process where the depth of welding between the plate to the and the exhaust smoke casing are

8mm. Amount of area that are weld are 13119.82mm2 . The forces that attract on the welding

are bending force. By assuming the value of distortion-energy criterion, the stresses are

300MPa where the stresses allowable are 173.1 MPa. Due to the calculation that had done the

value of maximum stress are 73.13MPa. The factor safety is based on the allowable stress

over maximum stress where it was 2.37. The depths of weld in this system are safe. The value

of factor safety shown that the weld between plate and the exhaust smoke casing are safe.


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Part 2

Due to bending force;

By assuming Sy = 300MPa,

Force =250kN

h = 12

Primary shear, = V/A, where V = shear force

Secondary shear bending, = Mc/I, where I = 0,707hIu

Total shear, = (2+ 2)1/2

From table 9-2 (pg 488; shigleys)

N0 6; throat area, A = 1.414h (b + d)

Location of G,= d/2

X = b/2

Unit second moment of area, Iu =

Calculation;

A = 1.414h (b + d)

= 1.414 (12) (780 + 50) = 14083.44 mm2

Figure 22 : Welding part 2


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X = b/2 = 780/2 = 390mm

= d/2 = 50/2 = 25mm

Iu =

= 3 = V/A= (250x 103)/ 14083.44= 17.75N/mm2

I = 0.707hIu= 0.707(12) (2987500) = 25.34595x106

mm4

= Mc/I = 250 x103(252.447)(25)/ 25.34595x106 = 62.25N/mm2

max= (2+ 2)1/2 = (17.752 + 62.252)1/2 = 64.73N/mm2

Ssy = 0.577Sy = 0.577(300) = 173.1 MPa

Factor safety = Ssy/max = 173.1 / 64.73 = 2.67

Explanation;

Based on the calculation that had done based on the dimension from the solid work

drawing, the value of factor safety is 2.67. The depth weld between the plate of the exhaust

smoke casing and plate of shaft are 12mm. The depth welding of the part are greater compare

the depth welding between the plate and the exhaust smoke casing because it was critical partcompare with that. Its because, when the system was running based on the stirling engine

process, the shaft was rotating and that may causing a vibration on the part. The vibrations

were giving a more force on the weld. So, the weld should be greater to circumvent the

system from broken. The amounts of area that are weld are about 14083.44mm2. The forces

that attract on the welding were due to bending force. By assuming the value of distortion-

energy criterion, the stresses are 300MPa where the stresses allowable are 173.1 MPa. The

values of maximum stress that are act at the weld are 64.73MPa. The factor safety is based on

the allowable stress over maximum stress where it was 2.67. The depths of weld in this

system are safe. Its also greater than the value of safety factor of plate and the exhaust smoke

casing are safe.


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6.2.Analysis of shaft

Assuming N=500rpm

Power, P = 20kW

Sy= 300MPa

Mass gear = 0.5 kg

Given( from drawing)

L = 1210mm

d = 30mm

Calculation;

Ssy = 0.577sy = 0.577(300) = 173.1MPa

Bending moment, M = P x L

Wgear = 0.5(9.81) = 4.905 N

P= Wgear= 4.905 N

M= P x L = 4.905(1210) = 5935.05 Nmm

From power,P = T

T = P/ , where = 2N/60

= 2(500)/ 60 = 52.36 rad/s

so, T = 20x103 / 52.36 = 381.97097Nm = 381970.97Nmm

max =

max =

= 72.06 MPa

thus; factor safety = Ssy/max = 173.1/ 72.06 = 2.40

Figure 23 : shaft part


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Explanation;

Shaft is rotating member where it used to transmit power or motion. The material of shaft that

used is steel. The rotating of the shaft are about 500rpm that transmit power about 20 kW. The

mass of the gear that was placed at the shaft are 0.5kg and the value of distortion-energy

criterion, the stresses are 300MPa where the stresses allowable are 173.1 MPa. The length of

the shaft are 1210mm. the length of shaft was greater because it was placed from the stirling

engine at the kitchen and transmit the power to the gear and the rotation of the gear were

move the fan blade on the exhaust smoke. From the analysis that had done, the force that act

on the shaft are bending moment and torque. The diameters of shaft are about 30mm. from

the amount of power that transmit by the shaft, the value of a torque were find that are about

381970.97 Nmm. The bending moment those acts on the shaft are about 5935.05 Nmm. The

maximum shear stress that had calculated based on the equation is 72.06 MPa. Due to the

factor safety calculation, the amount of safety factor of this system is 2.40. This was shown

the type and diameter of shaft was suitable to used in these system that are not exceed to 1.

6.3.Bolt Analysis

Type of material : steel

Type of bolt : Hex Head (upset)

Mass : 20kg

Area : 10 x 40 = 400mm2

Angle = 900C = 1.57 rad

Times, t = 1sec

K = 0.18 (lubricated)N = 3( total bolt)

Figure 24 : bolt part


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From table 8.8 (pg 130:shigleys)

Poisson Ratio : 0.291

Elastic Modulus : 207 Gpa

A : 0.78715

B : 0.62873

From table 8.9 (pg 433)

*Psi = lbf/in2

*Sp ( minimum Proof Strength)

SAE Grade No: 5 (material: Medium carbon, Q & T)

Minimum Proof Strength : 85 kpsi = 586.05 MPa

Minimun Tensile Strength : 120 kpsi = 827.37 MPa

Minimum Yield Strength : 92 kpsi = 634.32 MPa

By assumming Length of screw, L : 30mm

d : 9.53mm

From table 8.7( pg 426)

Based on drawing l : 10mm

LT = 2d + 6mm, L 125mm, d 48mm

Length of unthreaded portion in grip : ld = L -LT

Length of threaded portion in grip: lt = l - ld

Area of unthreaded portion : Ad= d/ 4

Area of thereaded portion : At from table 8.1

Fastener stiffness : kb=

From table 8.1(pg 412)

Nominal Major Diameter, D : 14mm

Pitch, p : 2mm

Tensile-stress Area, At : 125 mm2

Minor-Diameter Area, Ar : 116mm2

Equations that was used: (8.23) (pg 429)C =

(pg 436)

Fp = At Sp


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Fi = 0.90 Fp (permenent connection)

i = Fi/ At

b = Fb/ At = (CP+ Fi) / At

T = K Fi d

nL = ( SP AtFi)/ C(Ptotal/N)

nP = ( SP At)/ [C(Ptotal/N) + Fi]

no = Fi/[ (Ptotal/N)(1-C)]

Calculations :

LT = 2(9.53) + 6mm = 25.06 mm

ld = 3025 = 5mm

lt = 105 = 5mm

Ad = = 71.33 mm2Bolt stiffness;

kb = = 1.8802 x 1012 Mpa

Members stiffness;

km/ (207x 106)(9.53) = (0.78715) exp [(0.62873)(9.53)/10 )]

km = 1.7092 x 109

Mpa

Stiffness constant;

C = (1.8802 x 1012) / (1.8802 x 1012 + 1.7092 x 109 ) = 0.9991

Proof load;

Fp = 125 (856.05 Nmm2) =107.01 kN

Preload recommandation;

Fi = 0.90 (107.01 kN) = 96.31 kN

Preload stress;

i = Fi/ At = 96.31 x103 / 125 = 770.45 N/mm2

Stress under the service ;

b = Fb/ At = (CP+ Fi) / At

Fp = ma, a = x/t2

X= r = 4.77 (1.57) = 7.4889mm

a = 7.4889 / 12 = 7.4889 mm/s


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Fp = 20 (7.4889) = 149.778 N

P = Fp/A = 149.778 / 400 = 0.37 Pa

b = [(0.9991)(0.37) + 96.31)/ 125] = 0.7734N/mm2

Torque necessary to achieve preload;

T = K Fi d = 0.18 (96.31x 103) (9.53) = 162.21 kNmm

Load factor;

nL = ( SP AtFi)/ C(Ptotal/N)

nL = ( 856.05(125)96.31x103) / 0.9991(0.37/3) = 86.804x103

Yielding factor safety;

nP = ( SP At)/ [C(Ptotal/N) + Fi]

nP = ( 856.05(125))/ [0.9991(0.37/3) + 96.31x103] = 1.11

Load factor guarding against join separation;

no = Fi/[ (Ptotal/N)(1-C)]

no = 96.31x103 / [(0.37/3)(1-0.9991)] = 867.66x106

Explanation;

Bolt are the types of nonpermanent joints.On this system the material that used are

steel and the bolt are Hex Head (upset) type. The mass of this system is about 20 kg. The plate

that used is not much heavy where it was suitable for the system. The areas that are involved

with bolt are 400mm2. The major of the bolt are 14mm and the fastener diameter of the bolt is

9.53mm. From all the specification on the system, there are several tables had been refer to

find the accurate value of torque, load factor, yielding factor safety and also the load factor

guarding against join separation. Due to the bolt that had used on the system, the value of

preload and service load stresses are respectively ten percent less than the proof strength.Therefore the types of bolt are suitable applied at this system where the torque that was

applied at the bolt is only about 162.21 kNmm. Based on the theoretical calculation, the

yielding factor of safety that guarding against the static stress exceeding the proof strength

that is about 1.11. Based on the factor safety that is not exceeding 1, the bolt was suitable for

this system. The fillets of the bolt are the point of stress concentration. This type of bolt can

stand with the vibration that produces by the shafts that are including the different frequency.

The bolt was also durable for this system.


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6.4.Bearing analysis

Given:

02-series deep groove ball bearing :-

Desired load = 1.2kN

Desired life LD = 30 000h

Desired speed nD = 400 rpm

Ball bearing; a = 3

Application factor, af = 1.2

The rating life is revolutions.( based on the SKF manufactured )

= 10755.371 N= 10.75 kN

So from the Table 11-2, we obtain;

Table 7 : Table 11-2

The new C10 =12.7 kN

Bore = 20 mmOD = 47 mm

*


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Based on the SKF manufactured :-

X0 = 0.02

= 4.459

b = 1.483

so from the data above

( - X0 ) = 4.439

XD= = = 720

From the new C10,Based on the equation Reliability, R

( * )R < 0.90

For the ball bearing decision making we choose 02-series, deep groove ball bearing on our

product. First we assume the desired load for the ball bearing is about 1.2kN as a load that

will be apply to the ball bearing. Then we assume the desired life for that material is 30 000h.

For this ball bearing we put it as a shaft for the fan and we assume it as 400rpm . it is how fast

if the fan rotate as 400rpm and give the bearing force to rotate. Every bearing that we created

is based from 2 manufactured that is Timken manufactured and SKF manufactured. For the

ball bearing we use is we decide from the SKF manufactured. For SKF manufactured we need

to refer its own rating life for the every purchase of manufactured. For the ball bearing the

value for a is 3.


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6.5.Bevel gear analysis

All the units calculation are in mm units.

Given:

Bevel Gear

N = 400 rpm

Transmit power, H = 40 kW

Solution

The pitch angles are

= 35o =32o

The pitch-line velocity corresponding to the average pitch radius is

V = 1.6755

Therefore the transmitted load is

Which act in the positive z-direction


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Where Wr is in x-direction and Wa is in y-direction

In preparing to take sum of the moments about bearing D, define the position vector from D

to G.

We shall also required a vector from D to C;

Then, summing moments about D gives;\

-------------------1When we replace the details in equation 1 become equation 2.

After the two cross products are taken, the equation become ------

2

From which

T = 5037.30 N.m ---------------3

Now sum the forces to zero. Thus

FD + FC + W = 0

when the details are inserted, Equation 4 becomes

--------4


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Find we see that = 460459 N, and so

+

+

k

Then, from Equation

FD = ( 668i - 9605.57k ) N

In determining shaft and bearing loads for bevel-gear applications, the usual to use the

tangential or transmitted load that would occur if all the forces were concentrated at the

midpoint of the tooth. Here we prepared the picture the bevel gears dimension and the force

distribution for every part of critical point of the bevel gears. The force transmitted to the

bevel gears and it calculated by vector methods. In the bevel gears we have tangential force

Wt, radial force W r, and axial force W a. All the three forces Wt ,Wr, and Wa are at right

angles to each other and can be used to determine the bearing loads by using the methods of

statics.

6.6. Non-Permanent Joints.

1. Tightening torque, T = KFid


Torque factor,K= 0.20

Preload, Fi = 0.75 Fp


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Proof load, Fp = At Sp

From Table 8-11;


For M12, Sp = 310 MPa

From table 8-1;

Table 10 : table 8-1

For M12 and Course-Pitch series, At = 84.3 mm2


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Proof load, Fp = At Sp

Fp = (84.3)(310)

Fp = 26133 MPa.mm2

Preload, Fi = 0.75 Fp

Fi = 0.75(26133)

Fi = 19600 MPa.mm2

Therefore;

Tightening torque, T = KFid

T = (0.2)(19600)(8)

T = 31360 N.m

2. Factor safety guarding against yielding.Bolt length, L = l + H

given;

l = 20mm

From table A-30

Table 11 : Table A-30

Height, H = 7.76 mm

Therefore;


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Bolt length, L = 20 + 7.76

= 27.76 mm 28 mm ( From table A-17)

Treaded length, LT = 2d + 6

LT = 2(8) + 6

LT = 22 mm

Length of unthreaded portion in grip, ld= L - LT

ld= 28 - 22

ld= 6 mm

Length of threaded portion in grip, lt= l - ld

lt= 20 - 6lt= 14 mm

Area unthreaded portion, Ad =

Ad =

Ad = 16 mm2

Fastener stiffness: kb = , E = 207 GPa ( Table 8-8 for steel)kb =

kb = 7.252x10

11

Member stiffness, km = AEd exp (Bd /l )


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From table 8-8;


A= 0.78715

B= 0.62873

E= 207 GPa

Member stiffness, km = AEd exp (Bd /l )

km = (0.78715)( 207 G)( 0.62873)( 0.62873x8/ 20)

km = 1.6763x1012

Stiffness constant of the joint, C =

C =

C = 0.3020

Resultant bolt load, FB = Pb + Fi = CP + Fi , P = 50KPa / 5 = 10KPa

= (0.3020)(10x103) + 19600 MPa

= 22620 N

Resultant load on connected member, Fm = Pm + Fi = (1-C)P - Fi

= (1-0.3020)(10x103) - 19600

= -12620 N

Factor Safety for tension in members, n =

, Ssy = 340 MPa


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=

= 149.70 MPa

Therefore, n =

= 2.27

Factor Safety for bolt, n =

=

= 200 MPa

n =

n = 1.7

In order to find the value of resultant bolt load, FB and resultant load on the connected

members, Fm, first step is identify several parameters required. The purpose of finding

the resultant load is to determine the factor safety. First is need to find the tightening

torque,T where the value that were obtained from the calculation is 31360 N.m.

Before the value factor safety can be determine, the value of member stiffness, Km and

Kb must be calculate. The value of Km obtained is 1.6763x1012 and the value of Kb is

7.252x1011. By substituting into the equation, the value of stiffness constant of the

joint, C can be determine and only then the value of the resultant bolt and the resultant

load on the connected members can be determine. The value that were obtained for FB

is 22620 N and the value for Fm is -12620 N. After that we can determine the stressconcentration and then the factor safety. The value for the factor safety for tension in

members is 2.27 which is guaranteed safe because it is in range. Meanwhile, the factor

safety for bolt is 1.7. Even though it is out of safety range a little bit, but some

observation has been made by surfing the internet where it is found that there are

several companies that considered this kind of values is still in safety zone. Therefore,

it can be conclude that this fastener is suitable for this application.


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6.7.Discussion

After one semester of teaching and learning of Mechanical Component Design, this

report is mainly about designing a product for Machine component Design subject. For this

project, the application of stirling engine is used in order to complete the project.

In this project, there are several factors that need to be considered. Factors that need to

be considered are based on the parts of the design. Most parts must be calculated in order to

ensure that the product meet the safety requirements. Each part of the design must be

calculated to ensure that the product was safe to use. By considering the load of force that act

on the system, the shear stress and factor safety can be calculated. The factor safety of the part

must be greater than one. It was been calculate by referring the dimension of drawing for each

component n solid work. If the factor safety that get was less than one, there are several part

will be considered. That is change the dimension, change the material and also change the

position.

Due to welding part, there was bending and torsional force that act on the bending.

The basic of torsional and bending force are based on type of welding. The areas of welding

also give some effect on the force that act on the plate. In this project, there were two plates

that were involved with welding. Meanwhile, bolt analysis was based on the type of material

that was used and the type of head that used on the machine screw. The stiffnesss and the

bolt strength had been calculated based on the material and type of bolt that used in this

system.

Shaft was the rotating cylinder that used to rotate the gear and provide the torque to

rotate the blade to remove the hot air from the building to the environment. Shaft was the

most important part where it was the main part of transmitted the power from the stirling

engine through the gear to moving the blade. The other part that used in this system is gear.The type of gear that used in this system is bevel gear. The force analysis was used to

determining shaft and bearing loads for the bevel gear application that was to used tangential

and also transmitted load. The pitch of bevel gears is measured at the large end of tooth, and

both the circular pitch and the pitch diameter are calculated.

Screw was non-permanent joint that used in this system. The total amount that used

was 10 pieces. Screw is among the important component as it holds bigger components

together. Screw is used because it is cheap. Besides that, the calculation of the resultanceforce that acting on the fastener or bolt and the resulting force that acting on the members also


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been calculated. From the force that were obtained, the factor safety of the part can be

calculated and the result that were obtained shown that the design is in safety range. On the

other hand, bearing is used to smoothen any rotations in the system. The type of bearing used

is ball bearing. Only one bearing is used in the design.

However, there were also some problems that need to overcome in order to ensure that

this design is successfully done. One of the problems are the design is of the stirling engine

itself. A precise consideration needs to be done in order to make sure the stirling engine is

applicable to the application. First is how to make it functioning. To be functioning the blade

must be connected to the stirling engine and to overcome it, shaft was introduced to the

system where it connect blade to the engine. Since there is a different in angle between the

position of the engine and the blade, therefore, the bevel gear was applied to the shaft of the

blade and the stirling engine.

Chapter 7 : Conclusion

Throughout this project, there is a lot of input were gained, especially for a better

understanding in what have been learn in previous class. The knowledge and theory that

Mr.Shafizal taught in class is obviously were strengthen much more after completing this

project. And for this project, it can be conclude that, based on the calculation that been made

the product which is the Smoke Kitchen Remover functioning according to plan and most

importantly it is safe to be use in daily life. To be precise, the best design has been selected by

using the method of Weighting Matrix and Pugh Method. Besides that, instead of using an

electric current to run the stirling engine, the usage of heat from the stove to run the engine.

So that, the daily electricity consume can be reduced and of course it is an important element

that must be considered nowadays. Asides that, this project required a presentation by videomontage, which is a good added value, since it is the first time student of 3 BMCT been

exposed to that approach of presentation. On top of that, this project is extremely good for

better understanding in Mechanical Engineering Design subject and of course, credit should

be given to the lecturer, Mr.Shafizal Bin Mat for giving out this assignment at the first place.


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