rod and yoke connection
TRANSCRIPT
DESIGN & CONSTRUCTION OF ROD & YOKE CONNECTION
Supervised by
Engr. Md. Rasedul Islam
Lecturer,
Department of Mechanical Engineering,
KUET, Khulna- 9203
Submitted by Md. Abrar Amin
Roll: 1105007
Md. Asif Uddin
Roll: 1105008
Md. Hasan Ikbal
Roll: 1105010
Tanver Ahmed
Roll: 1105011
Md. Shahjahan Mahmud
Roll: 1105012
Khulna University of Engineering & Technology
Khulna-9203, Bangladesh.
Department of Mechanical Engineering
A report submitted to the department of Mechanical Engineering, Khulna University of
Engineering & Technology, in partial fulfillment of the requirements for the
Course No: ME 3118
ACKNOWLEDGEMENT
Authors want to express their gratefulness to Almighty Allah for His kindness and mercy to them,
giving them precious opportunity to be a part of this work and to carry out this project work.
The authors would like to express deep and sincere gratitude to their supervisor Md. Rasedul
Islam, Lecturer, Department of Mechanical Engineering, KUET, for his consultation and
discussion which were essential to carry out this work. His perpetual energy and enthusiasm in
research had motivated the authors through his advices a lot. In addition, he was always accessible
and willing to help them carry out this project.
They want to express their sincere gratitude to Dr. Mohammad Ariful Islam, Head, Department
of Mechanical Engineering, KUET, who gave them permission to work in machine shop, welding
shop and heat engine laboratory.
Also thanks to all the lab assistants who helped the authors in order to achieve the project goal.
“Authors”
I
Rod and yoke connection is a specific part of universal joint which allows for the range of
motion. The several stresses developed at the rod and yoke due to applied force is calculated.
In this project, a rod and yoke connection has been designed and constructed with locally
available materials in order to measure the stresses. All the calculations have been calculated
for the material AISI C1040, as annealed. But for unavailability of AISI C1040 we used mild
steel. This material is chosen for its better ductility rather than cast iron. For constructing the
final job we used several machining processes such as turning, facing, boring, slot cutting,
thread cutting, surface finishing, grinding etc. But the experimental final job is a dummy
constructional work. Finally it can be said that the stresses developed from the mathematical
calculation will must be satisfied for the designed calculation.
ABSTRACT
II
CONTENTS
Acknowledgement……………………………………………………………………………...I
Abstract……………………………………………………………………………………......II
List of Figure………………………………………………………........................................VI
Nomenclature...…………………….......................................................................................VII
CHAPTER-I: INTRODUCTION
1.1 Introduction………………………………………………………………………...............1
1.2 Objectives………………………………………………………………………………….2
CHAPTER-II: LITERATURE REVIEW
2.1 Historical Background…………………………..................................................................3
2.2 Rod…………………………………………………………………………………………4
2.3 Yoke………………………………………………………………………………………..4
2.4 Pin………………………………………………………………….....................................5
2.5 Rod and Yoke Connection…………………………………………………………………5
Page No.
III
CHAPTER-III: DESIGN
3.1 Mathematical Analysis………………………………………….........................................6
3.1.1 Approximation…………………………………………………………………...6
3.1.2 Problem…………………………………………………......................................6
3.1.3 Stress Analysis…………………………….……………......................................6
3.1.4 Solution…………………………………………………......................................8
3.1.5 Answer………………………………………………………………………….10
3.2 Rod Design……………………………………………………………………………….10
3.2.1 Dimension……………………………………………........................................10
3.2.2 Material…………………………………………………………………………11
3.3 Yoke Design………………………………………….......................................................11
3.3.1 Dimension……………………………………………........................................11
3.3.2 Material…………………………………………………………………………11
3.4 Pin Design...…………………………………………........................................................12
3.4.1 Dimension……………………………………………........................................12
3.4.2 Material…………………………………………………………………………12
3.5 Rod and Yoke Connection Design……………………………………………………….12
3.5.1 Dimension……………………………………………........................................13
3.5.2 Material…………………………………………………………………………13
IV
4.1 Construction…………………………………………………............................................14
4.1.1 Machining Process……………………………………………………………...14
4.1.1.1 Lathe machine…………………………………...................................14
4.1.1.2 Grinding machine…………………………………………………….14
4.1.1.3 Drilling machine………………………………...................................14
4.1.1.4 Internal Thread cutting……………………………………………….14
4.2 Final Constructed Job Figure……………………………………………………………..15
CHAPTER-V: DISCUSSION
5.1 Result and Discussion………………………………………….........................................16
V
CHAPTER-IV: CONSTRUCTION
CHAPTER-VI: CONCLUSION
6.1 Conclusion………………………………………………………………………………..17
6.2 Future recommendation…………………………………………………………………..17
References……………………………………………………………………………………18
LIST OF FIGURES
Figure
No.
Title:
Page No.
2.1 Rod 4
2.1 Yoke 4
2.3 Pin 5
2.4 Rod and Yoke connection 5
3.1.2 Problem solution fig. 6
3.1.4 FIGURE AF-1
8
3.2 Designed 3D rod 10
3.3 Designed 3D yoke
11
3.4 Designed 3D pin
12
3.5(a) Designed 3D rod and yoke connection
12
3.5(b) Solid work Design
13
4.2 Experimental Final Job of Rod & Yoke Connection 15
VI
Symbols Description
a Thickness of the rod
b Thickness of yoke leg
c Diameter of the hole
d Yoke width
D Diameter of the rod
F Load
A Stress Area
𝑆𝑠 Shear Stress
𝑆y Yield Strength
𝑆𝑢 Ultimate Strength
S𝑑 Design Stress
BHN Brinell Hardness Number
𝑁 Factor of Safety
NOMENCLATURE
VII
CHAPTER-I
INTRODUCTION
1.1 Introduction:
A rod and yoke connection which is similar named as clevis fastener is a three-piece
fastener system consisting of a yoke, pin, and rod or tang. The yoke is a U-shaped piece that has
holes at the end of the rod to accept the pin. The pin is similar to a bolt but is only partially threaded
or unthreaded with a cross-hole for a split pin. The rod is a piece that fits in the space within the
yoke and is held in place by the pin. The combination of a simple yoke fitted with a pin is
commonly called a shackle, although a yoke and pin is only one of the many forms a shackle may
take.
There are two main types of pins threaded and unthreaded. Unthreaded pins have a domed head at
one end and a cross-hole at the other end. A cotter pin or split pin is used to keep the clevis pin in
place. Threaded pins have a partially threaded shank on one end and a formed head on the other.
The form head has a lip, which acts as a stop when threading the pin into the shackle, and a
flattened tab with a cross-hole. The flattened tab allows for easy installation of the pin and the
cross-hole allows the pin to be moused.
The several use of rod and yoke connection are as follows:-
a) Rod and yoke connections are used in a wide variety of fasteners.
b) It is used in farming equipment and sailboat rigging.
c) Automotive, aircraft and construction industries.
d) They are also widely used to attach control surfaces and other accessories to servo controls
in airworthy model aircraft. As a part of a fastener, a rod and yoke provides a method of
allowing rotation in some axes while restricting rotation in others.
e) In many industries like textile machines CNC machines paper industry, pneumatic
cylinder, hydraulic cylinder, automation, printing machines, packing machines, hydro
press, machine tools, robots, laser cutting machines, special purpose machines.
1.2 Objectives:
a) To make a design for constructing rod and connection.
b) To construct a rod and yoke connection.
c) To know the function of rod and yoke connection.
d) To know the application of rod and yoke connection.
e) To calculate different types of stresses developed for applying load.
CHAPTER-II
LITERATURE REVIEW
2.1 Historical Background:
(Historical Terms) (In the ancient world) a symbolic reconstruction of a yoke, consisting of
two upright spears with a third lashed across them,
under which conquered enemies were compelled to march, especially in Rome. At early yoke
was used as a crossbar with two U-
shaped pieces that encircle the necks of a pair of oxen or other draft animals working together.
Any of various emblems of subjugation, such as a structure made of two upright spears with
third laid across them, under which conquered enemies
of ancient Rome were forced to march in subjection.The condition of being subjugated by or
as if by a conqueror; subjugation or bondage; 14th century Russia under the Tartar
yoke; the yoke of drug addiction. Pin is a small thin piece of metal with a point at one end,
especially used for temporarily holding pieces together.
A rod that joins two particular moving parts in an engine, especially one joining the piston to
the crank-shaft in a motor vehicle.
The rod or link for transmitting motion and force between a rotating and a reciprocating
part, as between a piston and a crankshaft. [1830–40].
The concept of the rod and yoke connection is come from based on the design of universal
joint, which have been in use since antiquity. One anticipation of the universal joint was its use
by the Ancient Greeks on ballistae. The first person known to have suggested its use for
transmitting motive power was Gerolamo Cardano, an Italian mathematician, in 1545,
although it is unclear whether he produced a working model. In Europe, the device is often
called the Cardan joint or Cardan shaft. Christopher Polhem of Sweden later reinvented it,
giving rise to the name Polhemsknut in Swedish.
The first known application of the rod and yoke with together occurred in China more than
2,000 years ago.
2.2 Rod: A rod is a bar which is connected with the yoke by a cross screw and nut at each end
for tightening them. Rod or link for transmitting motion and force
between a rotating and a reciprocating part, as between a piston and a crankshaft.
2.3 Yoke:
Yoke is a clamp or vise that holds a machine part in place or controls its movement or that holds
two such parts together. A crosshead of relatively thick cross section, that secures two or more
components so that they move together.
2.4 Pin:
A yoke is a "U" shaped part located at the end of a straight metal rod.
With a hole on each side of the U, this coupling allows a cross-
shaped bar, called a joiner or rod to fit and rotate within.
Figure 2.2: Rod
Pin is an instrument used for connecting the
rod with the yoke.
Figure 2.4: Pin
It is a semi-circular clamp or vise that holds a machine part in place or controls its
movements or that holds two such parts together.
A crosshead that transmits the drive of an opposed piston engine from the upper
of a pair of linked pistons to the crankshaft through a connecting rod.
Figure 2.3: Yoke
2.5 Rod and Yoke Connection:
Figure 2.5: Rod and Yoke connection
A rod and yoke is the specific part of a
universal joint that allows for the
range of motion. U joints are common
place in vehicle drive shafts. A rod and
yoke connection is a two straight rods
coupled so they may move in any
direction.
CHAPTER-III
DESIGN
3.1 Mathematical Analysis:
3.1.1 Approximation: For solving problem material is considered AISI C1040, annealed.
But for actual mild steel is chosen for availability.
3.1.2 Problem:
For the connection shown below, let a=1 in, b=3 5⁄ in, c=1 2⁄ in, d= 8 5⁄ in, D=4 5⁄ in. The material
is C1040, annealed (see Fig. AF 1). (a) For a load 7500 lb, compute the various tensile,
compressive and shear stresses. Determine the factor of safety based on (b) ultimate strength, (c)
yield strength. ……[1]
3.1.3 Stress Analysis:
Before solving the problem for designing the rod & yoke connection stress analysis is necessary.
Consider, the material is AISI C1040, as annealed. The first step in a design problem is to decide
upon the design stresses.
There are three stresses developed in rod & yoke connection. These are:
Figure 3.1.2: Problem solution fig.
(a)Tensile stress:
Tensile stress developed in yoke and in rod.
(b) Compressive stress:
Compressive stress developed between pin & yoke and between pin & rod.
(c) Shearing stress:
Shearing stress is developed between rod & yoke.
3.1.4 Solution:
(All the equations are taken from the book “DESIGN OF MACHINE ELEMENTS” 4thedition, by
Virgil Moring Faires)
Figure 3.1.4: FIGURE AF-1
Tensile stresses:
Tensile stress in yoke 𝐹
𝐴=
𝐹
2(𝑑−𝑐)𝑏=
7.5
2×(8
5−1
2)×
3
5
= 5.68 ksi
Tensile stress in rod 𝐹
𝐴 =
𝐹
(𝑑−𝑐)𝑎=
7.5
(8
5−1
2)×1
= 6.82 ksi
Compressive Stress:
Between pin & yoke 𝐹
𝐴=
𝐹
2×𝑏×𝑐=
7.5
2×3
5×1
2
= 12.5 ksi
Between pin & rod 𝐹
𝐴=
𝐹
𝑐×𝑎=
7.51
2×1
= 15 ksi
Shear Stress:
𝑆𝑠 =𝐹
𝐴=
𝐹
𝜋𝑐2
4×2
= 7.5 (𝜋
4(1
2)2 × 2)⁄ = 6.28 ksi
From Fig. AF – 1 (page-572, Virgil) AISI C1040, annealed
𝑆y = 48 ksi
Ss = 500(BHN)
BHN=159
Ss = 500×159= 500 × 159 =795000= 79.5 ksi
(b) Factor of safety based on ultimate strength
S𝑑 =𝑆𝑢
𝑁
or, N=𝑆𝑢
𝑆𝑑=79.5
15= 5.30
(b) Factor of safety based on yield strength
𝑆𝑑 =𝑆𝘺
𝑁
or, N=𝑆𝘺
𝑁=48
15 = 3.2
3.1.5 Answer:
(a) Tensile stress in yoke 5.68 ksi
Tensile stress in rod 6.82 ksi
Compressive Stresses between pin & yoke 12.5 ksi,
& between pin & rod 15 ksi
Shear Stress between rod & yoke.6.28 ksi
(b) Factor of safety based on ultimate strength 5.30
Factor of safety based on yield strength 3.2
3.2 Rod Design:
Figure 3.2: Designed 3D rod
3.2.1 Dimension:
a =1 in
D=4 5⁄ in
3.2.2 Material: We choose AISI C1040 annealed material for completing our rod
design.
3.3 Yoke Design:
Figure 3.3: Designed 3D yoke
3.3.1 Dimension:
b=3 5⁄ in
c=1 2⁄ in
d=85 ⁄ in
3.3.2 Material:
We choose AISI C1040 annealed material for completing our yoke design.
3.4 Pin Design:
Figure 3.4: Designed 3D pin
3.4.1 Dimension:
c=1 2⁄ in
3.4.2 Material:
We choose AISI C1040 annealed material for completing our yoke design.
3.5 Rod and yoke connection Design:
Figure 3.5(a): Designed 3D rod and yoke connection
3.5.1 Dimension:
a =1 in
b=3 5⁄ in
c=1 2⁄ in
d=85 ⁄ in
D=4 5⁄ in
3.5.2 Material:
We choose AISI C1040 annealed material for completing our rod and yoke connection
design.
Figure 3.5(b): Solid work Design
CHAPTER-IV
CONSTRUCTION
4.1 Construction:
In our project work we have used mild steel material as specimen. It is a ductile material which
shows more strength rather than cast iron. It can carry more stress than brittle materials.
4.1.1 Machining Process: For constructing this job several machines & machining
processes has been used……………[7]
These are as follows:-
4.1.1.1 Lathe machine: Lathe machine has been used for facing, turning, boring.
4.1.1.2 Grinding machine: Grinding machine has been used for surfacing.
4.1.1.3 Drilling machine: Drilling machine has been used for drilling & boring.
4.1.1.4 Internal Thread cutting: Internal die has been used for internal thread
cutting.
4.2 Final Constructed Job Figure:
Figure 4.2: Experimental Final Job of Rod & Yoke Connection
CHAPTER-V
DISCUSSION
5.1 Result and Discussion:
For mathematical analysis we have used the material C1040, annealed but in practical it is not
available in Bangladesh that’s why the construction work could not be done by this material. We
used mild steel for our dummy constructional work as a result the design which is developed for
several stresses on the job could not satisfy the calculated values. But it is sure that if the material
was C1040 annealed it must satisfy the stresses developed for it.
CHAPTER-IV
MATHEMATICAL ANALYSIS
CHAPTER-VI
CONCLUSION
6.1 Conclusion:
By performing this project we had learnt the design of a rod and yoke connection, analysis of a
rod and yoke connection, safety factor of it & the safe arrangement of it.
This work led to several conclusions:
(a) Annealed material was chosen for increasing ductility because it can carry more stress than
brittle materials.
(b) For calculating factor of safety the design stress which is taken is the highest stress.
(c) In several sectors of mechanical engineering there are various joints. One of them rod & yoke
connection has great importance which is discussed before.
6.2 Future recommendation:
In future it will be helpful for us to choose the right U-joint shape connection among various types
of connections. It also be helpful for us to research about it and related experimental project work.
REFERENCES
REFERENCES
[1] Faires Virgil Moring, “Design of Machine Elements”, 4th Edition.
[2] Jadon, Vijay Kumar, “Analysis and Design of Machine Elements”, 3rd Edition.
[3] Bhandari, V.B, “Design of Machine Element”, 3rd Edition.
[4] Shingley, Joshep, & Mischke Charles, “Standard Handbook of Machine Design”, 3rd
Edition.
[5] Childs Peter R. N., “Mechanical Design”, Second edition.
[6] Khurmi, R.S., Gupta, J.K., “A Textbook of Machine Design”, 4th Edition.
[7] Jain, R.K., “Production Technology”, 6th Edition.
[8] http://homepages.cae.wisc.edu/~me349/resources/engineering_terms.pdf
[9]http://www.norelem.com/xs_db/DOKUMENT_DB/www/NORELEM/DataSheet/en/27/27
615_Datasheet_16484--en.pdf