HYDRAULIC BOTTLE JACK
AKNOLEDGMENT
First of all, I would like to give my great and great thanks for my lord Jesus Crist.
Secondly, I would like to express my special thanks for my family for helping and support me.
And Instructor Abebe A. who gave us good opportunity to do this wonderful project on the topic
hydraulic bottle jack. He also help me in doing a lot of research and I came to know about so
many things I really thankful to mister Abebe A. thank you for everting that you helping me.
Thirdly, I would also like to thank all Mechanical stuff, who helped me a lot in finishing this
project within the limited time.
Finally, I would like to thanks our friends’ especially all my Mechanical student’s dorm friends.
And student Anatoli D. who helped me allow computer access.
Designed by Abenezer Tarekegn
HYDRAULIC BOTTLE JACK
Abstract
This project deals with design of hydraulic bottle jack with the help of hydraulic system. The
project deals also the working principle and application of hydraulic bottle jack. The working
principle of a hydraulic bottle jack is explained with the help of figure.
Consider the main cylinder and plunger, operating in two cylinders of different diameters, which
are interconnected at the bottom, through the tread, which is filled with some liquid. And then by
Appling small force on the plunger by using pump handle we can easily move up the car. And
also there is a bolt act as a valve I used to return the oil from the reservoir.
The application of Pascal’s law is also discussed in the project because of its main role in the
work principle of the hydraulic bottle jack.
Designed by Abenezer Tarekegn
HYDRAULIC BOTTLE JACK
NUMENCLETURE
σ c = compression stress.
σ y = yield stress.
Mb = Bending moment.
τ = shear stress.
V = volume of base.
P1 = Pressure on the large piston.
P2 = Pressure on the small piston.
g = gravity.
h1 = height of displaced volume on the left side.
h2 = height of displaced volume on the right side.
dp = diameter of the small piston.
w = given load.
σ all = allowable stress.
Designed by Abenezer Tarekegn
HYDRAULIC BOTTLE JACK
Contents
CHAPTER ONE..............................................................................................................................6
1
NTRODUCTION....................................................................................................................6
1.1
BACKGROUND..............................................................................................................6
1.2
INTRODUCTION............................................................................................................7
1.3
Classification of jack.........................................................................................................7
1.4
Advantage.........................................................................................................................8
1.5
Dis-advantage....................................................................................................................9
1.6
Problem Statement............................................................................................................9
1.7
Objective of the project.....................................................................................................9
1.7.1
General objective.......................................................................................................9
1.7.2
Specific objective.......................................................................................................9
1.8
Scope of the project...........................................................................................................9
1.9
Limitation........................................................................................................................10
1.10
Methodology of the project.........................................................................................10
CHAPTER TWO...........................................................................................................................13
2
LITERATURE REVIEW......................................................................................................13
2.1
Literature review.............................................................................................................13
CHAPTER THREE.......................................................................................................................15
3
DESIGN ANALYSIS............................................................................................................15
3.1
Component of hydraulic jack..........................................................................................15
3.1.1
Main cylinder (body)...............................................................................................15
3.1.2
Hydraulic press (piston)...........................................................................................16
3.1.3
Handling pump........................................................................................................17
3.1.4
Saddle (reservoir).....................................................................................................17
3.1.5
Basement..................................................................................................................17
3.2
Force Analysis.................................................................................................................18
3.2.1
Force analysis of piston...........................................................................................19
3.3
Geometric analysis..........................................................................................................20
3.4
Material selection............................................................................................................22
Designed by Abenezer Tarekegn
HYDRAULIC BOTTLE JACK
3.4.1
Material Selection for Piston Rod............................................................................22
Table 1:- Material Selection for Piston Rod..........................................................................22
3.4.2
Material Selection for Piston head...........................................................................23
3.4.3
Material selection for the cap..................................................................................23
3.4.4
Material selection for main cylinder........................................................................24
3.4.5
Material selection for pumping cylinder..................................................................25
3.4.6
Material Selection for handle...................................................................................25
3.4.7
Material Selection for plunger.................................................................................26
3.4.8
Material Selection for basement..............................................................................26
3.5
Stress Analysis................................................................................................................27
3.5.1
Stress analysis for piston rod...................................................................................27
3.5.2
Stress analysis for piston head.................................................................................31
3.5.3
Stress analysis for cup.............................................................................................32
3.5.4
Stress analysis for main cylinder.............................................................................34
3.5.5
Design of Telescopic cylinder.................................................................................37
3.5.6
Stress analysis for the reservoir cylinder.................................................................38
3.5.7
Stress analysis for pumping cylinder.......................................................................39
3.5.8
Stress analysis for Pump handle..............................................................................41
3.5.9
Stress analysis for plunger.......................................................................................42
3.5.10
Stress analysis for basement....................................................................................44
3.6
Size and form determination...........................................................................................44
CHAPTER FOUR.........................................................................................................................47
4
Conclusion and Recommendation.........................................................................................47
4.1
Conclusion:.....................................................................................................................47
4.2
Recommendation:...........................................................................................................47
Designed by Abenezer Tarekegn
HYDRAULIC BOTTLE JACK
CHAPTER ONE
1 NTRODUCTION
1.1 BACKGROUND
Jack is a machine element which used for lifting heavy loads by Appling small force. Jack is also
a mechanical device used for lifting huge body manually and automatically.
Before many years the automotive world become so closely associated with the word jack. Car
jack is mainly used to lift heavy load or apply a great force. Car jack work on the principle,
which a relative small force applied then with this force we can lift and support heavy load or
move massive object into a desired position.
In the repair and maintenance of automobiles (car), it is often necessary to raise an automobile to
change a tire or access the underside of the automobile. Accordingly, a variety of car jacks have
been developed for lifting an automobile from a ground surface. Available car jacks, however,
are typically manually operated and therefore require substantial laborious physical effort on the
part of the user.
A lifting jack was first design by Leonardo da Vinci in the late 1400 who demonstrated the use
of the screw jack for lifting load using the threaded warm gear that was supports in drive lifting
screw jack to move the load.
In the early 1880 frank henry sleeper design a lifting a jack which was also based on principle of
a ball bearing for supporting a load and transforming rotary motion in do translation motion. This
design patent was bought by author as more Norton leading to the first Norton jacks who were
produce in Boston’s.
Designed by Abenezer Tarekegn
HYDRAULIC BOTTLE JACK
In 1883 a Mississippi river boat captain named Josiah barret came up with an idea of the ratchet
jack which was based on the family liver and fulcrum principle. Manufacturing company took up
that chance and started the production of barrette jack. More recent screw jack designs have
concentrated on improved efficiency and durability.
1.2 INTRODUCTION
A car jack is a mechanical device which uses a screw thread or a hydraulic cylinder to lift heavy
loads or apply great linear forces. The hydraulic jack is one of the most important tools in
automotive repair. Hydraulic jacks are used to lift cars and hold heavy parts in place. They also
are used as key components in log-splitting machines and in presses used for straightening out
deformed metal rods. A hydraulic bottle jack is a tool device that is used to lift of a vehicle and
other heavy objects. It works on the principle of Pascal’s law. Jacks are portable hand operated
devices for raising and lowering loads through short distance.
Hydraulic have six main parts. These are the reservoir, pump, check, main cylinder,
piston, and release valve. The reservoir holds. A pump will draw the fluid up and then create
pressure on the down stroke as it pushes the fluid through. This valve allows the fluid to
leave the reservoir and enter the main cylinder. In the main cylinder, the piston is forced up
as the cylinder is filled with the fluid. When it is time to release the pressure and allow the
piston to return to its starting position, the release valve is opened.
A jack use for lifting, pulling, or forcing, consisting of a compact portable hydrostatic press, with
its pump and a reservoir containing a supply of liquid, as oil. It works by manually to lifting
heavy load and distributed widely in industrial place with wide application. Hydraulic bottle jack
works in vertical lifting heavy load based their standard. Each company has used in different
ways, so that hydraulic bottle jack can be used as need base, which applicable in heavy industries
and power equipment that require tremendous to operate. Hydraulic jack can be classified in to
three based on the application of the jack that are:-hydraulic service jack, session hydraulic jack
and hydraulic bottle jack.
1.3 Classification of jack
Classification of car jack are: -
Designed by Abenezer Tarekegn
HYDRAULIC BOTTLE JACK
1. Hydraulic jack
 Hydraulic bottle jack
 Hydraulic service jack
 Hydraulic scissor jack
2. Mechanical jack
 Single scissor jack
 Double scissor jack
 screw jack
Hydraulic jack
Hydraulic jack is use a fluid which is incompressible that is formed in to a cylinder by pumping
it inside oil will used since it is self-lubricated and stable when the pusher push back.it draw oil
out of the cylinder through a distance chuck valve in cylinder. The function valve ball is uniform
and the chamber open with each draw of the plunger.
Mechanical jack
Mechanical jack is a jack which use mechanical force used to lift heavy load or
apply a great force.
Jacks employ screw tread to apply very high linear force. A mechanical jack is a
device which is used to lift heavy equipment. The linear form of this mechanical
jack are car jack, floor jack or grange jack which lift vehicles. A mechanical jack
lifts the heavy load by using mechanical system to allow human to lift a vehicle by
manual force.
1.4 Advantage
The main advantage of a hydraulic jack is that it is: 
Easy to use, Easy to maintain, easy to carry.
Designed by Abenezer Tarekegn
HYDRAULIC BOTTLE JACK

The size of the jack so small and the overall weight of the jack is so light.

The strength of the jack is more compact and harder than other type of jack.

It is made to provide easy to lift heavy material like automobile.

It uses short period of time during in work.

There is no requirement of fuel, electricity or other power source to operate this jack.
1.5 Dis-advantage
Some dis advantage of car jack:

Require more energy to operate.

Some jack is not applicable due to its cost and limited application.

Cannot carry or support very heavy load or equipment.

They are not used on the uneven surface.
1.6 Problem Statement
Hydraulic bottle jack for lifting load with manual operation of 2 tone and for maximum and
minimum height of 180mm and 280mm respectively with detail drawing.
1.7 Objective of the project
1.7.1

General objective
The general objective of this design project is to design and modeling hydraulic bottle
jack.
1.7.2
Specific objective

To design the cup and the piston rode.

To design the main cylinder.

To design the telescopic cylinder and the reservoir.

To design the plunger and pumping cylinder.

To design the base, the handle.
Designed by Abenezer Tarekegn
HYDRAULIC BOTTLE JACK
1.8 Scope of the project
The project is to design the hydraulic bottle jack by using the given specification. To have the
ability maximum lifting capacity, maximum and minimum height to calculate force analysis and
using geometric analysis to determine the size and stress of the material selection compare to
design stress chuck the failure. Finally draw assemble drawing by calculation method of design
size.
1.9 Limitation
The main limitation I get to do this project is:

The lack of the capacity of lifting more than 2 tone.

The lack of the maximum lifting capacity more than 280mm.

The lack of excess knowledge about design.

Lack of Experian’s in design.
1.10 Methodology of the project
This project has generally two stages. The first stage is analysis of the project by using the
geometric analysis, material selection, force analysis, stress analysis and as well as the detail
drawing. The second one is the presentation of the project. The project design is focus on the
design of hydraulic bottle jack which is different parameters such as force, stress, strain etc. are
calculated by numerical method.
In my project I use the knowledge of strength, mechanics, mathematics and engineering drawing.
To finish this project I use secondary source such as: some previous projects, internet etc.
Designed by Abenezer Tarekegn
HYDRAULIC BOTTLE JACK
Methodology flow chart
Designed by Abenezer Tarekegn
HYDRAULIC BOTTLE JACK
aim or need
mechanism selecton
workng principle
force analaysis
giometric analaysis
material selection
form and size determination
stress analaysis
result and discusion
conclusion
recomendation
reference
detail drawing
Part drawing
Assembly drawing
Designed by Abenezer Tarekegn
HYDRAULIC BOTTLE JACK
CHAPTER TWO
2 LITERATURE REVIEW
2.1 Literature review
Hydraulic bottle jack is a device used to lift heavy load. The device itself is light compact and
portable but it has a capable of everting great force. The device pushes liquid against the piston
pressure built in the jack container. The jack is based on the Pascal’s law that the pressure of the
liquid in the container is the same at all points. The jack is uses compressible fluid which is
forced in to a cylinder by plunger oil is usually used for the liquid because it is self-lubricating
and has stability compared with other liquid through another valve through in to a cylinder.
The section bar present in the jack open at each draw of the plunger. The discharge valve which
is outside the jack opens when oil is pushed in to a cylinder. The pressure of the liquid enables
the device to lift heavy load. Hydraulic bottle jack is typically used for shop work rather than as
an emergency jack to be carried with the vehicles. Use of jack not designed for a specific vehicle
require more than the usual core in selecting ground conditions. The jacking point on the vehicle
and to ensure stability when the jack is extended. Hydraulic jack is often used to lift elevator in
low and medium rise building.
Leonardo, he was Italian genius (1452-1519) who first emphasized the direct study of nature in
its many aspects. He was the first correctly formulated the basic principle of hydraulic known as
continuously the velocity of flow varies inversely with the cross sectional area of the stream.
Novel London, he expressed that this hydraulic bottle jack is an ideal choose for vertical lifting
and pressing cars, trucks trailers etc. it’s equipped with a caring handle for easy transport. the
hydraulic bottle jack mode of painted cast has study construction. The heavy duty bottle jack is
stable and durable for long term service life. The bottle jack feature compact and design it offer
maximum lifting capacity of 2 tones thus tacking the weight of your shoulder with easy safety
valve of bottle jack enable you to repels the car access or rise and perform routine main finance
more safely and efficiently.
Designed by Abenezer Tarekegn
HYDRAULIC BOTTLE JACK
Simon Stevin he was Dutch hydraulic engineer (1548-1620) who made essential contribution for
hydraulic. He showed that the force exerted by the liquid on the base of liquid column exerting
from the base to the free surface that this force doesn’t depend on the shape of the vessel become
known as hydraulic paradox.
Richard Dudgeon, a Scottish machinist who emigrated to the U.S., invented the hydraulic jack.
He set up a machinist's shop in New York City. The hydraulic jack is just one of the many
significant inventions of Dudgeon. In 1851, he was given a patent for the invention. The U.S.
Postal Service issued a stamp in his honor recognizing his contribution to industrial
advancement.
And here I would like to design to have good capacity of lifting height and lifting load and I
reduce the component with to have a good performance and to reduce the cost.
Designed by Abenezer Tarekegn
HYDRAULIC BOTTLE JACK
CHAPTER THREE
3 DESIGN ANALYSIS
3.1 Component of hydraulic jack
The basic components of a hydraulic bottle jack are:
Main cylinder (Body)

Hydraulic press (piston)

Handling pump

Saddle (reservoir)

Basement

Valve(bolt use as valve)
We will explain the operation of these systems briefly, so you will know the purpose of each
component and can better understand how hydraulics is used in the operation of these systems.
3.1.1
Main cylinder (body)
The main body of the hydraulic bottle jack is containing the whole system of lifting mechanism,
which is a cylindrical bottle shape. Its selected material is steel.
Fig 1:- main cylinder of the jack
Designed by Abenezer Tarekegn
HYDRAULIC BOTTLE JACK
The stroke of the piston in the suction pump covers a long distance, the length of the pump
cylinder. When the jack fluid is forced into the main cylinder, it presses the ram piston upward,
which does the lifting.
3.1.2
Hydraulic press (piston)
The hydraulic press consists of two cylinders of different diameter. One of the cylinders is of
large diameter (large piston) and contains a ram, while the other cylinder is of smaller diameter
(small piston) and contains a plunger. The two cylinders are connected by a pipe.
Even if you install a hydraulic piston must always consider the requirement and the available
space. The installation must be such that it does not consume much space, when the industry
meets the full requirement as well.
Large piston
small piton
Fig 2:- hydraulic press (piston)
The large piston or the reciprocating shaft is one of the parts of the completed hydraulic jack,
which assembled on the top of the main body. It reciprocates up and down direction during
manual hydraulic press. When the lifting load acts in downward and pumping pressure of the
liquid acts in upward direction on the piston, the radial forces and compression stresses can be
produced.
Designed by Abenezer Tarekegn
HYDRAULIC BOTTLE JACK
3.1.3
Handling pump
A hydraulic air pump is a type of pump that makes use of air pressure as the means of efficiently
pumping oil or some other type of hydraulic fluid. The pump can be utilized with a variety of
hydraulic equipment, including motors, presses, pullers and rams.
Fig 3:- handling pump
The source power applied on this handling pump, which socked or attached with the handle
sleeve. It used to press the liquid in downward direction and has their dimension based on the
applied power.
3.1.4
Saddle (reservoir)
It is the supporter of the lifting load, which connects the top of the piston. The upward and
downward limitation of the reciprocating shaft controlled by the saddle.
Fig 4:- saddle of the jack
3.1.5
Basement
It is the supporter off the whole components of the hydraulic bottle jack, which has their standard
strength based on the load applied and supporter part. It will be better to designed in rectangular.
Designed by Abenezer Tarekegn
HYDRAULIC BOTTLE JACK
Fig 5:- basement or support
3.2 Force Analysis
Determination of number of telescope
Here I am going to analyze the number ram or telescope depend on the maximum and minimum
lifting height. From the given data: 
Minimum lifting height = 180mm

Maximum lifting height = 280mm
I am going to analyze the change of lifting height from the above given lifting value.
∆ H L = HL max - HL min
∆ H L = 280mm – 180mm
∆ H L = 100mm
Where: - ∆ H L = change of lifting height.
HL max = maximum lifting height.
HL min = minimum lifting height.
It is obvious that the telescope length should be less than 140mm by considering the cup and the
base. Assume height of base = 30mm and length of cup = 10mm.
H max = maximum lifting height – height of base – length of cup
H max = 280mm – 30mm – 10mm
H max = 240mm
H min = minimum lifting height – height of base – length of cup
Designed by Abenezer Tarekegn
HYDRAULIC BOTTLE JACK
H min= 180mm – 30mm – 10mm
H min = 140mm
Now I am going to find the number of ram using the following equation.
N=
H max−H min
H min
Where: - N = number of ram
N=
240 mm−140 mm
140 mm
N = 0.714
The number of ram could not be expressed in point. So approximate to the highest number. So
hear conclude that for the given minimum and maximum lifting height.
N=1
Since N = 1; so I use piston rather than ram or telescope because there is no different between
the ram and the piston.
3.2.1
Force analysis of piston
It is obvious that the applied force on the piston is equal to the maximum design weight or lifted
weight. Since compressive load is distributed equally in the piston. But hear the given car load is
2000N so to gate the one leg load I multiply by 40%.
Therefore: m = 2000kg × 40%
m = 800kg
To gate the force use newton’s 2nd laws equations: F=m×g
F = 800kg × 9.81
F = 7848N
Designed by Abenezer Tarekegn
HYDRAULIC BOTTLE JACK
3.3 Geometric analysis
Fig 6:- geometry of hydraulic bottle jack.
Geometric Analysis deals with the; determination of the lifting height, overall dimensions of the
part of the maximum and minimum lifting height.
The maximum lifting height, H max = 450mm
The minimum lifting height, H min =120mm
Then find the lifting height of hydraulic bottle jack is given by:ΔH = H max - H min
ΔH = 280mm – 180mm
ΔH = 100mm
Designed by Abenezer Tarekegn
HYDRAULIC BOTTLE JACK
Assumptions
Once again consider the above sketch of the given jack. The head thickness of the piston rod
actually these parameters should have to be determined after design analysis of the piston cap
but we can assume some standard value to the thickness since it may help to find the other
parameters.

Let the thickness be, tp = 20mm.

Diameter of piston dp = 20mm.

The thickness of the base and its components is the height of the jack below the bottom
part of the reservoir cylinder but the minimum value of these parameters be, tb = 30mm.

Diameter of cup, dc = 15mm.

And assume q is equal to one half of h2 and q = 40mm.
Now h1, h2 and h3 (at labeled in the sketch) can be found as follows:
From the given the minimum left height of the jack is; H min=180mm.
H min = h1 + h2 + tp
180 = h1 + 80 +20
h1 = 80mm
From the above calculation, the lifting height of the jack is; ΔH = 100mm.
ΔH = h3 – tp
100 = h3 – 20
h3 = 120mm
From the assumption, q is the half of h2, so:h2 = 2 ×40mm
h2 = 80mm.
Designed by Abenezer Tarekegn
HYDRAULIC BOTTLE JACK
3.4 Material selection
3.4.1
Material Selection for Piston Rod
Table 1:- Material Selection for Piston Rod
Cast iron
Mild steel
Carbon steel
Stainless steel
Compressive stress (crushing)




Stiffness (buckling)




Good surface finish.




Cheap & available in the market




From the above material I select mild steel because mild steel (Ni350C40 steel) full fil the
property that I went.
Table 2:- material property of mild steel. [3]
Material Selected
mild steel
Yield strength
1035Mpa
Shear strength
620Mpa
Modulus of elasticity
207Mpa
The material I selected for the solid piston rod is mild steel because, it has the following
property;
High strength, harden ability and resistance.

High compressive strength to support the load.

High creep and wear resistance with good surface finishes.

Relatively low cost to the other grades of steel.
3.4.2
Material Selection for Piston head
I was selected the material for the head such that the piston rod and its head are the same
material thus, we can use the previous mechanical properties of the piston material.
Designed by Abenezer Tarekegn
HYDRAULIC BOTTLE JACK
Table 3:- material property of mild steel. [3]
3.4.3
Material Selected
mild steel
Yield strength
1035Mpa
Shear strength
620Mpa
Modulus of elasticity
207M
Material selection for the cap
Since the cap is in directing contact the load it has to be stiff, hard enough and should not be
easily failing due to the direct high compressive stress. The material for the cup and the piston
rod is the same, so I use for cup is the previous material Ni350C40 steel.
Table 4:- material property of mild steel. [3]
3.4.4
Material Selected
mild steel
Yield strength
1035Mpa
Shear strength
620Mpa
Modulus of elasticity
207Mp
Material selection for main cylinder
Table 5:- material selection for main cylinder.
Cast iron
Mild steel
Carbon steel
Stainless steel
strength & ductility




Tensile & radial stress resistance




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HYDRAULIC BOTTLE JACK
Stiffness (buckling)




Good surface finish.




Cheap & Local availability




And due to the following two reasons I select the stainless steel, with mechanical properties
given below, as cylinder materials the reasons are:
 Manufacturing feasibility
 Local availability
Table 6:- material property of Stainless Steel. [3]
3.4.5
Material Selected
Stainless Steel
Yield strength
520Mpa
Ultimate strength
860Mpa
Shear strength
150Mpa
Modulus of elasticity
190GPa
Material selection for pumping cylinder
The material that we select for the pumping cylinder satisfies the following selection criteria’s.

Availability.

Corrosion resistance and chemical stability.

Manufacturing feasibility.
Table 7:- material property of Stainless Steel. [3]
Material Selected
Stainless Steel
Yield strength
515Mpa
Designed by Abenezer Tarekegn
HYDRAULIC BOTTLE JACK
3.4.6
Shear strength
320Mpa
Modulus of elasticity
207GPa
Material Selection for handle
The handle should have to fulfill the following criteria’s:

Should be hard.

Should be not brittle.

Good resistance to corrosion and rust (for long working life).

Ease of manufacturability.
Therefor the selected material is:
Table 8:- material property of Mild steel. [3]
3.4.7
Material Selected
Mild steel
Yield strength
1035Mpa
Shear strength
620Mpa
Modulus of elasticity
207Mpa
Material Selection for plunger
Mostly piston rods are made of high tensile materials finished and hardened with chromium
plating to provide resistance of corrosion. Stainless steel is also used as a rod material due to its
excellent anti-corrosive property.
We have the following material selected as piston rod material:
Table 9:- material property of Mild steel. [3]
Material Selected
Mild steel
Yield strength
1035Mpa
Shear strength
620Mpa
Modulus of elasticity
207Mpa
Designed by Abenezer Tarekegn
HYDRAULIC BOTTLE JACK
We have selected this material due to the reason:

High compressive strength to support the load.

Due to its appreciable hardness.

Give good surface finish.

Relatively low cost to other grades of steel.
3.4.8
Material Selection for basement
Considering carbon content, machinability corrosion resistance strength we have selected
mild still for base material. Its property tabulated below;
Table 10:- material property of Cast iron. [3]
Material Selected
Cast iron
Yield strength
294.8Mpa
tensile strength
394.0Mpa
HB
111
Modulus of elasticity
207GPa
3.5 Stress Analysis
3.5.1
Stress analysis for piston rod
The piston rod design of a hydraulic cylinder is highly stressed and therefore it should be able to
resist the bending and the compressive force that it may encounter during it operation without
Designed by Abenezer Tarekegn
HYDRAULIC BOTTLE JACK
buckling. The piston should design in such a way that it is able to support a given load without
experiencing a sudden change in its configuration of the piston rod (ram).
The height of the piston rod including its head and cup is
hp (piston height) = h3 + q
hp = 80 + 40
hp = 120mm
This total height have to be completely occupied by the piston so that all the oil in the
main cylinder will return back to the reservoir when the load is lowered thus to satisfy this total
height of the piston should be adjusted, that hp = 115mm.
Fig 7: - piston rod with head and cup.
The piston rod may fail in two ways:

Failure due to compressive stress (crushing).

Failure due to instability (buckling).
The cross section of the rod or critical loading should be calculated after considering
whether it is stressed rod or column. This consideration could be checked by the following
Designed by Abenezer Tarekegn
HYDRAULIC BOTTLE JACK
approach.
If the length of the rod to least cross actuation dimension ratio is less than or equals to 11.
Then the piston rod is considered as stressed otherwise considered as a column.
Mathematically,
L
≤ 11, for short column.
D
L
≥ 11, for long column.
D
Also since the piston is round shape ‘D’ can be substituted by; k×√ 12
K = √(
I
)
A
Where:
K = slenderness ratio.
I (moment inertia) =
πd ⁴
64
A (Area of piston) =
π d2
4
Substitute values:L
L
L
≤ 11,→ ≤ 11(√ 12),→ ≤ 40,
K × √ 12
K
K
√
π d4
d
=
2
4
πd
64
4
( ( ))
K=
d
4
Therefore, take dp = 20mm (from geometry analysis) and L = hp = 115mm.
Designed by Abenezer Tarekegn
HYDRAULIC BOTTLE JACK
115
≤ 40, → 23 ≤ 40, short column type.
20/4
Thus, the piston is short and will fail due to compressive stress Crushing and Buckling.
Design for Crushing
Assumed diameter dp = 20mm
Maximum load w = 7848N
Tack factor of safety f.c = 4.5
Next find the allowable stress and then find the design load (force); it must be greater than or
equal to the working load.
σ all =
σy =
σ y 1035
=
= 230Mpa
f .c
4.5
Wcr
Wcr
, → 230Mpa =
2
π d /4
π ¿ 202 /4
Wcr = 72.2KN
This is greater than that of working load, Wcr > W → 72.2KN > 7848N, the design is safe.
Design for Buckling
First find the length of piston without length of cup head.
Lpwc = 120mm – tc
Lpwc = 120mm – 20mm
Lpwc = 100mm
Where:
Lpwc = length of piston without length of cup head.
Wcr = working load.
Assume considered a solid short column then considering J.B Johnson’s equations for
buckling we have:
Designed by Abenezer Tarekegn
HYDRAULIC BOTTLE JACK
Wcr = Acr*σ y (1 - σ y/(4*c¿ π 2*E*(Lpwc/K)2))
Where:
Acr = π×
dp2
202
,→ π×
4
4
Acr = 314.15mm2
K=
dp 20
=
= 5mm
4
4
Lpwc 100
=
= 20mm
K
5
σ y = 1035Mpa
c = 2, for one fixed end and other pivoted.
E = 207Gpa
Substitute numerical value
Wcr = 314.15mm2×1035Mpa (
1035 Mpa
) = 51.475
4 × 2× π 2 ×207 Gpa ×(20)2
This is greater than that of working load, Wcr > W,→> 7848N, the design is safe.
3.5.2
Stress analysis for piston head
The head of the piston is taken as a uniform circular flat plate. The pressure of the oil acts upon
the plate uniformly.
Where:
thead = thickness of head.
dhead = diameter of head and Assume the diameter of head is 37mm.
Designed by Abenezer Tarekegn
HYDRAULIC BOTTLE JACK
Fig 8: - piston head.
σ all =
P=
σy
1035
=
= 79.61Mpa
f .c
13
7848
w
=
= 8.75Mpa
A π (35)2 / 4
thead = 0.433× dp√ ¿all)
thead = 0.433× 20√ ¿Mpa)
thead = 2.87mm ≈ 5mm
3.5.3
Stress analysis for cup
The cap of the piston is subjected to high compressive stress of the load. Now considering
shearing of the cap at the joint with the piston rod I have.
The next task is determining the diameter of the cap.
Designed by Abenezer Tarekegn
HYDRAULIC BOTTLE JACK
Fig 9: - cup
Then find the Total Tearing area of the cap:
𝐴𝑡𝑒𝑎𝑟=4×𝑡𝑝× (2× √ ¿ -
dp 2
)
4
𝐴𝑡𝑒𝑎𝑟 = 8×20𝑚𝑚× √ ¿ -
202
)
4
𝐴𝑡𝑒𝑎𝑟 = 80mm×√ (dc2 - 202)
Next by using allowable shear find dc
𝜏𝑎𝑙𝑙 =
7848 N
w
→
Atear
80 mm ×√ (dc 2−20 2)
8.32Mpa =
7848 N
80 mm ×√ (dc 2−20 2)
dc = 23.21mm≈ 32mm
τ all =
w
w
=
As π dc 2 /4
Designed by Abenezer Tarekegn
HYDRAULIC BOTTLE JACK
τ all =
7848
2
π (32) /4
τ all = 9.75Mpa
Where:
τ all – allowable sheer stress.
τ allcr = working allowable sheer stress.
w = given load.
As = sheering area equal with
dp = Diameter of the piston
tp = height of the cup.
Find the factor of safety:
τ allcr =
τ y 620 Mpa
=
f .c
4.5
τ allcr = 137.78Mpa
The working allowable sheer stress is greater than allowable sheer stress.→ 137.78Mpa >
9.75 Mpa, therefore this indicates that the thickness assumed (tp) is safe.
Also consider crushing stress of each extended rectangular shapes on the upper surface of the cap
we have the following analysis:
Thus the compression stress is:
σc =
w
Ac
Where:
σ c – Compressive sheer stress.
W – Given load.
Ac – critical area.
Designed by Abenezer Tarekegn
HYDRAULIC BOTTLE JACK
w = width of structure on the upper surface of the cap.
Let we need n such structure on the upper surface of the cap to minimize sliding of the loading.
Figure - rectangular geometry shapes at the profile of the cap. Let these are 5 in number.
Assume there will be 5 square shaped extended surfaces.
𝜎𝑐 =
𝜎𝑐 =
w
σy
=
w ∗n f . c
2
7848 1035 MPa
=
4.5
w2 ×5
w = 2.61mm≈ 3mm
3.5.4
Stress analysis for main cylinder
In hydraulic cylinder design the wall thickness it is closed so that the stress at the working
pressure (P) is less than the yield strength of the wall. Stress over the selection of the walls
cannot be assumed to be uniformly distributed. The walls develop both tangential and radial
stresses with values which depend up on the radius.
First find the thickness and pressure of the walls by using lame’s equation as follows. The
cylinder is subjected to for radial and tangential stress (𝜎𝑟 & 𝜎𝑡) respectively.
Fig 10:- main cylinder.
σr=
p ri2
ro2
1−
×
(
), and
ro2−ri2
ri2
Designed by Abenezer Tarekegn
HYDRAULIC BOTTLE JACK
σt =
p ri2
ro2
×
(1+ 2 )
ro2−ri2
ri
Now we can select different approaches (maximum normal stress theory, maximum shear stress
theory or maximum strain theory) to evaluate the failure of the cylinder.
Considering the maximum tangential stress and follow the maximum strain theory we get the
following equation called Bernie’s equation.
t=
d1
× ¿ – 1)
2
Find the known values:
𝜎𝑡 =
σy
520 Mpa
=
= 115.16Mpa
f .c
4.5
P=
7848 N
w
=
= 6.9Mpa
A 2 π ×(38)2 /4
Tack, d1 = 45.
𝜇 = 0.3, for small metal.
Then the value of the main cylinder thickness is:t=
45 mm
× ¿ – 1)
2
t = 1.6mm ≈ 5mm
Threads on the main cylinder
The main cylinder is screwed into the base to 0.05h1 depth the over plate is also screwed on the
upper part of the cylinder to a depth of r, thus the main cylinder is threaded in the both its ends.
Threads on the outer surface can be made on lathe machine of the cylinder is prepared by
casting. Standard selected M-82 and core diameter is 45mm.
Length of threaded part on the cylinder “L” is
𝐿=0.05×ℎ1,→ L = 0.05×80mm,→ L = 4mm
Designed by Abenezer Tarekegn
HYDRAULIC BOTTLE JACK
The lower part is subjected to compression stress due to radial stress in the cylinders.
presure force
p× A 2
σy
=
=
crushing force π × A 1 ×n
f .c
𝜎𝑐 =
Let as find the unknown parameters
𝜎𝑐 =
σy
520 Mpa
=
= 115.56Mpa
f .c
4.5
2
π d 22 π ×(36)
A2 =
=
= 1017.87mm2
4
4
A1 =
2
π d 12 π ×(45)
=
= 1590.43mm2
4
4
7848 N
F
P=
= π ×(20)2 = 24.98Mpa ≈25Mpa
Ap
4
Substitute numerical values
𝜎𝑐 =
25 Mpa × 1134.11mm 2
= 115.56Mpa
π × 1017.87 mm 2× n
n→ 0.076 ≈ 1
The pitch thread length is
Pitch =
L 5
= =5
A 1
Thread length for the upper thread
If there is excess fluid in the reservoir and the mechanic pumps more than maximum number of
strokes, shearing of threads many occurs.
𝜏𝑎𝑙𝑙 =
σ
150 Mpa
=
= 33.34Mpa
f .c
4.5
𝜏𝑎𝑙𝑙 =
W
circufrantial area of core
Designed by Abenezer Tarekegn
HYDRAULIC BOTTLE JACK
𝜏𝑎𝑙𝑙 =
7848 N
)
¿¿
33.34Mpa = 7848 N
¿¿
n = 2.09 ≈ 3
Thread length r is:r = pitch × 𝑛
r = 5 × 3, → 15mm.
3.5.5
Design of Telescopic cylinder
The telescopic cylinders are evaluated in the same way as the main cylinder since both are
subjected to the same internal pressure.
Fig 11: - telescopic cylinder.
The objective of the design analysis is to find the thickness of the telescopic cylinder based on
the Bernie’s equation the analysis is the same with the previous design of the main cylinder, the
only parameter changed here are the diameter and the tangential stress that is d2 = 36mm and
factor of safety f.c = 2.5.
Designed by Abenezer Tarekegn
HYDRAULIC BOTTLE JACK
t=
d2
׿ – 1)
2
Find the known values:
𝜎𝑡 = =
P=
σy
520 Mpa
=
= 115.56Mpa
f .c
4.5
7848 N
w
=
= 7.71Mpa
A 2 π ×(36)2 / 4
𝜇 = 0.3, for small metal.
t=
36
× ¿ – 1)
2
t = 1.27mm ≈ 2mm
Where:
𝜎𝑡 = tangential stress.
Pi = Initial pressure.
3.5.6
Stress analysis for the reservoir cylinder
The oil that fills the main cylinder and the telescopic cylinder comes from the reservoir cylinder
thus we can find the diameter of the reservoir cylinder considering volume relationships.
Fig 12: - reservoir.
Also the reservoir can fill only up to the oil feeder hole, thus only portion of the reservoir
cylinder below the oil feeder hole is considered. Let the oil feeder hole is located at ‘T’ mm unit
Designed by Abenezer Tarekegn
HYDRAULIC BOTTLE JACK
below that height (upper) level of the reservoir, also let the portion of the reservoir above the oil
feeder hole be 15% of the total volume thus:
𝑇=0.15 ×h1= 0.15 ×80mm = 12mm
Where;
Vr = Volume of reservoir.
h1 = height and diameter of reservoir.
T = oil feeder hole.
From the geometry analysis square reservoir, so the height of reservoir is equal to the diameter of
the reservoir h1= 80mm.
Vr = area of reservoir × height of reservoir
Vr = π ¿ ¿¿ ¿ × h1
Vr = π ¿ ¿¿ ¿ × 80mm
Vr = 100530.96mm3
As I have explained above the reservoir just only stress the oil and its thickness is independent of
the load since the pressurized fluid (oil) is preventing from going the safe just select the
thickness of reservoir tr =5mm and the tread on the reservoir is the same as the tread on the
cylinder is 5mm.
3.5.7
Stress analysis for pumping cylinder
The pumping cylinder is subjected to be the tangential and radial stresses.
Designed by Abenezer Tarekegn
HYDRAULIC BOTTLE JACK
Fig 13: - telescopic cylinder.
da 2 × Pi
dao2
× (1 +
𝜎𝑡=
)
(dao 2−dai 2)
(2 r )2
Where:
𝑑𝐴− Inner diameter.
𝑑𝐴𝑜−Outer diameter.
𝑃𝑖− Fluid pressure.
r - Point of maximum pressure.
And tack the height of pumping cylinder, hpc = 50mm.
The maximum pressure occurs at:
r=
da
2
Thus;
𝜎𝑡=Pi ×
dao2 + dai2
dao2−dai2
𝑑𝐴=25mm & Pi=25𝑀𝑃𝑎
Designed by Abenezer Tarekegn
HYDRAULIC BOTTLE JACK
𝜎𝑡 =
σy
515 Mpa
=
= 206𝑀𝑃𝑎
f .c
2.5
Substitute numerical value:
dao2 +(25 mm)2
𝜎𝑡 = 25𝑀𝑃𝑎 ×
2 = 206𝑀𝑃𝑎
(dao 2−( 25 mm ) )
dao = 28.24mm
Thus thickness of the cylinder is
𝑡A =
𝑡A =
dao−da
2
28.24 mm−25 mm
2
𝑡A = 1.62mm ≈ 2mm, it is very thick so I tack 5mm.
Threads on the pumping cylinder
The pumping cylinder is screwed into the base to 0.05 of the height of pumping cylinder.
Threads on the outer surface can be made on lathe machine of the cylinder is prepared by
casting. Standard selected M-82 and core diameter is 26mm.
Length of threaded part on the cylinder “L” is
𝐿=0.05 × hpc,→ L = 0.05×50mm,→ L = 2.5mm
Tack the pitch length and the tread length is that previously calculated in the main cylinder.
3.5.8
Stress analysis for Pump handle
Generally the force distribution over the handle can be represented as follows:
Fig 14: - pump handle.
Designed by Abenezer Tarekegn
HYDRAULIC BOTTLE JACK
The cross sectional area of the handle is assumed to be constant. As it easily can be seen the
handle is subjected to bending force and it should be designed for bending strength.
The BMD and SFD are presented as follows:
Fig 15: - Diagram of pump handle.
The bending moment diagram shows that the maximum bending occurs at the pump. Thus the
strength equation is:
Mb=σ aii × Z
Where,
Mb = moment of maximum bending.
𝜎all = allowable bending stress.
Z = Modules section of the handle.
The modulus of section of circular cross section is, since the handle is hallow:
Z=
π
do ⁴−di⁴
×
32
do
Also we can express Z by using thickness of the handle:
Designed by Abenezer Tarekegn
HYDRAULIC BOTTLE JACK
Z=
Z=
π
do ⁴−(do−2× thandle) ⁴
×
32
do
π
(24) ⁴−(24−2× thandle) ⁴
×
32
24
From the BMD maximum bending value is 259KN.mm, also take f.c = 3.5 thus,
𝜎all =
1035 mpa
= 295.71mpa
3.5
Then, substitute numerical value:
130KN.mm = σ all × Z
130KN.mm = 295.71Mpa ×
π
(24) ⁴−(24−2× thandle) ⁴
×
32
24
thandle = 1.07mm ≈ 5mm
3.5.9
Stress analysis for plunger
Forces on the plunger are compression forces due to shear force in the hole. If the length of hpl is
larger relative to its diameter then the force may cause buckling and tack hpl 65mm. Let me take
factor of safety is 3.
Fig 16: - plunger pump.
Now find the plunger head thickness (tph) by using the following equations. First find the
allowable stress. And take dpl = 15mm and pmax = 100Mpa also dhole = 10mm.
σ all =
1035 Mpa
= 345Mpa
3
Designed by Abenezer Tarekegn
HYDRAULIC BOTTLE JACK
t ph=0.433 ×d pl ×
t ph=0 .433× 15 ×
√
√
p max
σ all
100 Mpa
345 Mpa
t ph=3.49 ≈5 mm
Where:
σ all = allowable stress.
σ wall = working allowable stress.
tph = thickness of plunger head.
dpl = diameter of plunger.
σ wall =
100 Mpa
2
A=π (15) /4
σ wal = 0.5658Mpa
The working stress σ wal is less than the allowable stress σ all → σ wal < σ all, so the diameter for the
plunger I was assumed is safe.
3.5.10 Stress analysis for basement
The thickness of the base is found using the following formula:
Let factor of safety be taken 2.5
Thus,
σ all =
σy 294.98 Mpa
=
= 118Mpa
f .c
2.5
σ all =
W
Area
118Mpa =
7848 N
Area
Area = 66.5m2 ≈ 66500mm2
Designed by Abenezer Tarekegn
HYDRAULIC BOTTLE JACK
So the area up to 66500mm2 is safe for the jack but I went the area to be 195mm by 100mm in
order to have good proportionality. And from the geometric analysis the assumed height of base
is 30mm.
Area = 195mm×100mm, → 19500mm2
Volume of base = 195mm ×100mm × 30mm
Volume of base = 585000mm3.
3.6 Size and form determination
Piston Rod with cup and head:
Table 11:- Piston Rod with cup and head:
Material
Height of piston
Diameter of piston
Thickness of cup
Diameter of cup
Diameter of head
Height od head
Mild steel
120mm
10mm
20mm
16mm
17.5mm
18mm
Main cylinder and pump cylinder:
Table 12:- Main cylinder and pump cylinder:
Material
Height of main cylinder
Diameter of main cylinder
Thickness of both
Height of pump cylinder
Diameter of pump cylinder
Stainless steel
80mm
45mm
5mm
60mm
26mm
Telescopic cylinder:
Table 13:- Telescopic cylinder:
Material
Height
Diameter
Thickness
Stainless steel
80mm
36mm
2mm
Reservoir cylinder:
Designed by Abenezer Tarekegn
HYDRAULIC BOTTLE JACK
Table 14:- Table of reservoir cylinder:
Material
Height
Diameter
Thickness
Stainless steel
80mm
80mm
5mm
Plunger pump:
Table 15:- Table of plunger pump:
Material
Mild steel
Height
65mm
Diameter
10mm
Hole on the top
6mm
Head thickness
4mm
Head diameter
24mm
Base:
Table 16:- Table of base:
Material
Height
Length
Cast iron
30mm
195mm
Width
100mm
Designed by Abenezer Tarekegn
HYDRAULIC BOTTLE JACK
CHAPTER FOUR
4 Conclusion and Recommendation
4.1
Conclusion:
The Hydraulic Bottle Jack is successfully designed so that it with stand all the mechanical stress
acting on it. The jack is analyzed under various conditions of operation. All forces are carried
according to strength and geometry analysis. The jack also can carry the external load with the
help of internal fluid at working conditions. The stresses in above-mentioned conditions are
found out and thickness of various parts is selected such that the stresses produced in each
member are within the maximum allowable range. Proper selection of working fluid during
maintenance is stated and replacing also presented this minimizes the effect of corrosion which is
a problem that makes the jack will be fail. Also the maximum lifting range for maintenance is
achieved. All the selected have been successfully verified and hence the design of the jack is
safe.
4.2
Recommendation:
The design progress was decent, but the given time to finish the design was very short compared
to the hugeness of the design. So, I recommended for the future the time allowed should be
enough to finish the design.
Designed by Abenezer Tarekegn
HYDRAULIC BOTTLE JACK
Appendix
Table17:- O-ring Standard [4]
Designed by Abenezer Tarekegn
HYDRAULIC BOTTLE JACK
Table 18:- Standard Pin [4]
Designed by Abenezer Tarekegn
HYDRAULIC BOTTLE JACK
Designed by Abenezer Tarekegn
HYDRAULIC BOTTLE JACK
Reference
1. How Hydraulic Jacks Work, http://www.thomasnet.com/articles/materials/
2. Pdf about Hydraulic bottle Jacks, http://www.sci-hub.tw/
3. Gupta, R. K. &. J., 2005. Theory of Machines.
4. R.s khurmi and j.k gupta theory of machine
5. Ashby, M. F., 2005. Material Selection in Mechanical Design.
6. Bhandari, V. B., 2010. Design of Machine Elements. Third Edition ed.
7. Marshek, R. C. J. &. K. M., 2012. Fundamental of Machine Design Components. Fifth
Edition ed. s.l.: john Wiley & Sons Inc.
Designed by Abenezer Tarekegn