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