TOM Project Report

PUMP JACK DESIGN FOR OIL EXTRACTION

Group Members

Jamal Ahmad 2010146

Farhad Jan 2010174

Umer Saleem 2010371

Ghulam Ishaq Khan Institute of Engineering and Technology

Ghulam Ishaq Khan Institute of Engineering and Technology Page 2

TABLE OF CONTENTS

1. Abstract 3

2. Introduction 4

2.1 Oil Pump Jack 4

2.2 Structure 5

3. ANALYSIS 6

3.1 Degree of Freedom 6

3.2 Grashof motion Analysis 6

3.3 Position Analysis 7

3.4 Velocity Analysis 8

3.5 Acceleration Analysis 9

3.6 Graphs for Velocity and Position of crank 10

4. CAD Model 12

4.1 Design 12

4.2 Analysis 15

5. Conclusion 19

Appendix A 20

Appendix B 21


1. ABSTRACT

We are designing a model of oil jack pump in our course project of ME-312 Theory of Machines,

as per the requirement of the course. The basic purpose of designing the oil jack pump is the

fact that it has a great importance in the petroleum industry. The mechanism is used in

extracting the oil from the ground. The report contains the analysis of the mechanism of the oil

jack pump. The analysis part contains the position analysis, velocity analysis and the

acceleration analysis. The report also includes the CAD models of the mechanism. The graphical

solution is also presented in the end. The project has given us the opportunity to completely

analyze the work of four bar linkages in the real world problems. The basic purpose of this

report and this project is to give an insight of the Oil Pump Jack to the viewer. We are really

thankful to our teacher, Dr. Shahid Parvez, who has been so helpful throughout the course. He

has also helped us in selecting the topic of our project by giving us the examples of four bar

linkage applications as well as helping us throughout till the completion of the project.


2. INTRODUCTION

2.1 Oil Pump Jack:

A pump jack, which has many names like nodding donkey, horsehead pump and sucker rod

pump (SRP), is the over ground mechanism for reciprocating motion of the piston pump in oil

well. This mechanism is used to take oil out of the ground if there is not enough pressure

generated by the vacuum to automatically lift liquid out of the ground. The oil pump jacks have

the capability of extracting 5 to 40 liters of oil in a single stroke depending on its size. They are

common in areas which are rich in oil.

As discussed, the oil pump jacks extract the oil from the ground, after which the oil is taken for

the fractional distillation. Thus, oil pump jacks are an important part of the petroleum industry.

The pump is worked by a motor which is attached to the crank of the mechanism.

Figure 2.1: An Oil Pump Jack in California (Retrieved from http://en.wikipedia.org/wiki/Pumpjack)


2.2 Structure:

Oil pump jack is a four bar mechanism which is mounted on a frame for support. The crank is

the shortest link which also has an actuator in the form of a constant speed motor. Usually

gears are applied to alter the speed of the stroke from that of the motor. The crank is attached

with the coupler which is further attached to the rocker. The crank revolves a complete 360

degrees while the rocker performs oscillatory motion about a pivot point. The rocker is

extended further from the pivot point. A complex motion is associated with the coupler link.

Figure 2.2: Structure of oil pump Jack (Retrieved from http://en.wikipedia.org/wiki/Pumpjack)

The other links attached are just to support the mechanism and provide the stability to the

structure. Different designs are available as per the requirement of the application, where the

oil pump jack is to be mounted. To general type of pump jacks are:

1) Above Ground

2) Down Hole

We will be designing and analyzing the above ground mechanism.


3. ANALYSIS

(ANALYTICAL APPROACH)

3.1 Degree of Freedom:

Firstly we will calculate the degree of freedom of the mechanism. The degree of freedom can

be defined as the number of inputs required to completely define the motion of the

mechanism. Oil Pump Jack is a four bar mechanism with all full joints. There are no half joints.

The mechanism mostly contains the pin joints. The formula used to calculate the mobility or the

degree of freedom is given as:

M = 3(L 1) 2J

Where;

M = Mobility

J = No. of joints

L = No. of links

In this mechanism, we have 4 links i.e. crank, rocker, coupler and ground and four joints. Thus;

J = 4

L = 4

Putting in the equation above;

M = 3(4 1) 2(4)

M = 3(3) 8 = 1

M = 1

3.2 Grashof motion Analysis:

The link lengths being used can roughly be approximated as:

Crank = Shortest link; Ground = Longest Link

Rocker = Link P Coupler = link Q

The other two links will be longer than crank but smaller than Ground link. According to the

Grashofs condition;


S + L < P + Q

We will be using the above equation to make sure that there is no toggle position in the

mechanism, as it is not required in the design. According to the design analysis, the grounded

link is the link adjacent to the shortest link, i.e. the ground. So the mechanism is a Crank Rocker

Mechanism, in which the crank will perform a full rotation and the other link pivoted to the

ground will oscillate.

3.3 Position Analysis:

As shown in the graphical analysis of the report, the lower extreme position of the rocker link

occurs at an angle of 2 = 45 degrees. The upper extreme position will occur at 2 = -135

degrees. Thus the position analysis is being done for the same position as it is of our interest.

The link lengths and other required parameters are given below: -

Crank = a = 5 in

Ground = d = 11 in

Coupler = b = 8 in

Rocker = c = 9 in

= 45

k = d/a

k = d/c

k = (a - b + c +d)/ 2ac

A = cos - k - k cos + k

B = -2sin

C = k + k - (k + 1) cos

Angle can be calculated by the following relations: -

k = d/b

k = (c - d - a - b)/ 2ab


D = cos - k + kcos +k

E = -2sin

F = k + (k - 1)cos + k

Angle can be calculated by the following relation: -

After putting the values in the above given formulas, the following results are deduced for a

specific value of =45.

Table 3.1

k k k k k A B C D E F

2.2 1.22 1.81 1.375 -1.612 -0.54 -1.41 2.44 -2.133 -1.41 0.85 42 99

This has also been shown in the graphical analysis of the mechanism.

3.4 Velocity Analysis:

As we have done the position analysis, we can now shift to the velocity analysis of the

mechanism. The velocity analysis includes the angular velocity of the links as well as the linear

velocity of the point of the interest. As our crank is mounted with the motor, the angular

velocity of the crank is known by using tachometer. We can place the values of the other

parameters in the following relations to get the angular velocities;

The value of as calculated from the tachometer is 102rev/min so,

= 1.7 rev/sec

The velocity of the link four is approximately equal to 0 rev/sec, which is in accordance with our

graphical analysis that it will be minimum at a crank angle of almost 45. The linear velocity of

the end point can be measured by the following formula;


Table 3.2

v

rev/sec rev/sec in/sec

-1.022 0.063 2.37

3.5 Acceleration Analysis:

The acceleration analysis can be performed as we have completed the velocity analysis. As the

angular velocity of the motor is constant so the angular acceleration of the crank will be 0

rev/sec. The acceleration of different links, at the extreme position, can be calculated by using

the following relations:

= 0rev/sec

A = c sin

B = b sin

C = asin + a cos + b cos - c cos

D =c cos

E = b cos

F = a cos - a sin - b sin + c sin

The following values are calculated from the above formulas;

Table 3.3

A B C D E F

0 8.58 5.35 16.6 -2.7 5.94 -15.93

And from the values in the table and the formulas given as under, the values of and are

calculated.

= 1.40 rev/sec

= 2.81 rev/sec


So, these values show the angular acceleration of the link 3 and 4 respectively, when the link 4

is in its lower position.

3.6 Graphs for Velocity and Position of crank:

The graphs for the complete revolution of the crank can be drawn by using the same above formulas. The chart shows the values of , , and for different values of the crank angle

.

Table 3.4

(deg) (rad) A B C D E F

0 0 -0.61 0 1.79 -1.4375 0 0.9625 78.58484 119.4502 -1.41551 -1.41531

20 0.34906585 -0.596732 -0.68404 1.923882 -1.58073 -0.68404 0.939885 60.61332 105.3568 -1.50491 -0.87316

40 0.698131701 -0.55853 -1.28558 2.309381 -1.99314 -1.28558 0.874767 45.00981 99.70973 -1.12394 -0.10063

60 1.047197551 -0.5 -1.73205 2.9 -2.625 -1.73205 0.775 34.00304 101.9787 -0.76602 0.446942

80 1.396263402 -0.428203 -1.96962 3.624501 -3.40009 -1.96962 0.652618 26.5096 109.262 -0.52268 0.765419

100 1.745329252 -0.351797 -1.96962 4.395499 -4.22491 -1.96962 0.522382 21.38069 119.3508 -0.35438 0.934823

120 2.094395102 -0.28 -1.73205 5.12 -5 -1.73205 0.4 18.00816 130.8073 -0.21471 1.001673

140 2.443460953 -0.22147 -1.28558 5.710619 -5.63186 -1.28558 0.300233 16.3239 142.5066 -0.05587 0.97286

160 2.792526803 -0.183268 -0.68404 6.096118 -6.04427 -0.68404 0.235115 16.90449 153.1882 0.18419 0.819423

180 3.141592654 -0.17 -2.5E-16 6.23 -6.1875 -2.5E-16 0.2125 20.99787 161.2402 0.535736 0.528123

200 3.490658504 -0.183268 0.68404 6.096118 -6.04427 0.68404 0.235115 29.33841 165.6221 0.868872 0.221123

220 3.839724354 -0.22147 1.285575 5.710619 -5.63186 1.285575 0.300233 40.77949 166.9622 1.052139 0.015484

240 4.188790205 -0.28 1.732051 5.12 -5 1.732051 0.4 53.57546 166.3746 1.105815 -0.11507

260 4.537856055 -0.351797 1.969616 4.395499 -4.22491 1.969616 0.522382 66.44704 164.4172 1.067492 -0.224

280 4.886921906 -0.428203 1.969616 3.624501 -3.40009 1.969616 0.652618 78.34913 161.1016 0.937036 -0.3519

300 5.235987756 -0.5 1.732051 2.9 -2.625 1.732051 0.775 87.99406 155.9697 0.672077 -0.54077

320 5.585053606 -0.55853 1.285575 2.309381 -1.99314 1.285575 0.874767 93.29956 147.9995 0.179546 -0.84313

340 5.934119457 -0.596732 0.68404 1.923882 -1.58073 0.68404 0.939885 90.97964 135.7231 -0.62247 -1.25361

360 6.283185307 -0.61 4.9E-16 1.79 -1.4375 4.9E-16 0.9625 78.58484 119.4502 -1.41551 -1.41531


The graph from the above data is plotted between crank angle and the angular velocity of

the link 4 i.e. . The graph shows that the velocity of the desired point becomes 0 rev/sec

instantaneously at two specific points which are approximately = 42 and 220.

Figure 3.1

-2

-1.5

-1

-0.5

0

0.5

1

1.5

0 50 100 150 200 250 300 350 400


4. CAD MODEL

(Design and Analysis)

4.1 Design

Following are the steps that lead to the design of the oil pump jack model. The images were

extracted from Creo 1.0.

Both Engineering drawings and Extruded models are shown below. The first image belongs to

the coupler.

Figure 4.1: Couplers Engineering Drawing

Figure 4.2: Couplers Extruded Model


Similarly, the engineering design and extruded model of the Crank are as follows:

Figure 4.3: Engineering Drawing of Crank

Figure 4.4: Extruded Model of Crank


The drawing and model of the Rocker is given below:

Figure 4.5: Engineering Drawing of Rocker

Figure 4.6: Rockers Extruded Model


And finally the assemblys engineering drawing and model is given below:

Figure 4.7: Engineering Drawing of the combined Assembly

Figure 4.8: Assembly View


4.2 Analysis

The following three images were taken from the motion analysis of the software. It shows the

progression and working mechanism of the pump jack.

Figure 4.9: Oil Pump Jack initial position

Figure 4.10: Oil Pump Jack after completing quarter of revolution


Figure 4.10: Oil Pump Jack after completing half a revolution

Further, the motion analysis was done for the rocker. The graph of the position as a function of

time is shown below:

Figure 4.11: Position Analysis of Rocker


The graph of the rockers velocity analysis is given below:

Figure 4.12: Velocity Analysis of Rocker

And finally the acceleration graph of the rocker is as follows:

Figure 4.13: Acceleration Analysis of Rocker


5. Conclusion

The report contains all the position, velocity and acceleration analysis. The CAD models are

attached with the email and the soft copy. Moreover the report also contains the graphical

analysis for position and instant centers. The physical model is made to give an idea to the

viewer that how a pump jack really works. The motion of the mechanism is visible in the CAD

model and the physical model as well. The analysis clearly shows that the rocker and the

desired point have 0 in/sec velocity at the extreme positions for which the crank angle is 42

and 99.


Appendix A

References

http://aoghs.org/technology/all-pumped-up-oil-production-technology/

http://en.wikipedia.org/wiki/Pumpjack

http://www.sjvgeology.org/old_stuff/pumpjacks.html

https://www.youtube.com/watch?v=5uJ_8lemzoo

http://weburbanist.com/2010/03/21/10-pimped-pump-jacks-give-the-nod-to-urban-oil-art/


Appendix B

Index

Acceleration 3, 9, 10, 18

Analysis 3, 6, 7, 8, 9, 12, 16, 17, 18

Coupler 5, 6, 7, 12

Crank 4, 5, 6, 7, 8, 10, 11, 13

Design 3, 5, 7, 12, 13

Grashof 6

Links 6, 8, 9

Position 3, 7, 8, 10, 17

Pump 3, 4, 5, 6, 12, 16, 17, 20

Rocker 5, 6, 7, 11, 14, 17, 18

Velocity 3, 8, 9, 11, 13, 18

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