Acknowledgement

I have taken efforts in this project. However, it would not have been possible without the kind
support and help of my teacher and friends. I would like to extend my sincere thanks to all of
them. I am highly indebted to my teacher Ato Mulugeta H. for his guidance, encouragement
and constant supervision in completing the project.

I would like to express my gratitude towards my friend specially sinner mechanical

engineering students for their kind co-operation and for providing necessary information
regarding to the project which help me in completion of this project. I would like to express
my special gratitude and thanks to industry persons for giving me such attention and time.

My thanks and appreciations also go to my colleague in developing the project and people
who have willingly helped me out with their abilities."
Abstract

A jack is a device that uses force to lift heavy loads. The primary mechanism with which force
is applied varies, depending on the specific type of jack, but is typically a screw thread or a
hydraulic cylinder. Jacks can be categorized based on the type of force they employ:
mechanical or hydraulic. Mechanical jacks, such as car jacks and house jacks, lift heavy
equipment and are rated based on lifting capacity (for example, the number of tons they can
lift). Hydraulic jack tends to be stronger and can lift heavier loads higher, and include bottle
jacks and floor jacks. hydraulic jacks depend on force generated by pressure. Essentially, if
two cylinders (a large and a small one) are connected and force is applied to one cylinder,
equal pressure is generated in both cylinders. However, because one cylinder has a larger
area, the force the larger cylinder produces will be higher, although the pressure in the two
cylinders will remain the same, hydraulic jacks depend on this basic principle to lift heavy
loads.
 TABLE OF CONTENT
Title Page number

Chapter one: Back ground ……………………………………………………………………………….. 1

1.1. Introduction ……………………………………………………………………………….. 1

1.2. Main component of hydraulic bottle jack …………………………………… 1
1.3. Working principle ………………………………………………………………………… 2
1.4. Literature review ……………………………………………………………………………. 2
1.4.1. Manually operated pump ……………………………………………………… 2
1.4.2. Valves …………………………………………………………………………………….. 2
1.4.3. Rams (Actuating pump) ……………………………………………………………. 3
1.4.4. Reservoir ………………………………………………………………………………….. 3
1.5. Alternatives ……………………………………………………………………………………. 6
1.5.1. Hydraulic bottle jack with single lifting ………………………………………. 6
1.5.2. Telescopic hydraulic bottle jack ………………………………………………… 6
1.5.3. Dual speed hydraulic bottle jack ……………………………………………….. 6
1.6. Decision matrix …………………………………………………………………………………. 8

Chapter two: Geometry analysis …………………………………………………………………………… 9

Chapter three: Force analysis ………………………………………………………………………………… 11

3.1. Handle ……………………………………………………………………………………………….. 11-12

3.2. Ram rods and plunger rod …………………………………………………………………..12-13
3.3. Extension screw ………………………………………………………………………………….14
3.4. Valve springs ………………………………………………………………………………………. 15

Chapter four: Strength analysis and material selection ……………………………………………. 16

4.1. Hallow ram rod …………………………………………………………………………………….. 17-19

4.2. Solid ram rod ………………………………………………………………………………………. 20-21
4.3. Extension screw …………………………………………………………………………………. 22-24
4.4. Plunger rod ……………………………………………………………………………………………. 25-26
4.5. Main cylinder ………………………………………………………………………………………… 27
4.6. Pump cylinder ………………………………………………………………………………………… 28
4.7. Handle ………………………………………………………………………………………………….. 29-31
4.8. Pine at the plunger rod ………………………………………………………………………….. 32
4.9. Pin at the link ………………………………………………………………………………………. 34
4.10. Socket of handle (gasket) …………………………………………………………………….. 35
4.11. Reservoir ……………………………………………………………………………………………… 37-38
4.12. Valve spring …………………………………………………………………………………………. 39-41
Chapter five: Manufacturing proses and assembly procedure ……………………………… 45

Conclusion …………………………………………………………………………………………………………………

Recommendation ………………………………………………………………………………………………………

Reference …………………………………………………………………………………………………………………

Assembly drawing …………………………………………………………………………………………………….

 CHAPTER ONE

BACK GROUND OF HYDRAULIC BOTTLE JACK

1.1. INTRODUCTION

Hydraulic Jacks are mechanical devices that use hydraulic power and acts as lifting devices in
lifting heavy loads. There are many types of hydraulic jacks such as floor jack, hydraulic bottle
and long ram jack; hence they are rated according to their maximum capacity.

The history of the hydraulic jacks can be dated many years ago when French mathematician
and philosopher by the name Blaise Pascal illustrated the principle of hydraulic jack in the
17th century. Later in 1795, Joseph Bramah the British engineer obtained a Patent for certain
new methods of producing and application of more power to all machinery that requiring
motion and force, and this involved the first hydraulic press. Richard Dudgeon incorporation
started in New York as a machine shop and on July 8, 1851, inventor, and founder Richard
Dudgeon was awarded a patent for ‘portable hydraulic press’. These jacks were operated by
water or any other fluids as whiskey and whale oil; the heads device was the location for fluid
reservoir. During the winter, other liquids tend to freeze and thicken hence the most applied
fluid was whiskey and the name Whiskey or bottle Jack came into existence.

A bottle jack or whiskey jack is a hydraulic jack which resembles a bottle in shape, having a
cylindrical body and a neck, from which the hydraulic ram emerges. In a bottle jack the piston
is vertical and directly supports a bearing pad that contacts the object being lifted. With a
single action piston the lift is somewhat less than twice the collapsed height of the jack,
making it suitable only for vehicles with a relatively high clearance. For lifting structures such
as houses the hydraulic interconnection of multiple vertical jacks through valves enables the
even distribution of forces while enabling close control of the lift. They have a capacity of up
to 50 tons and may be used to lift a variety of objects. Typical uses include the repair of
automobiles and house foundations.

1.2. MAIN COMPONENTS

I. Manually operated pumps

II. Ram(pistons)

III. Valves

IV. Extension screw

V. Saddle

VI. Oil reservoir

VII. Cylinder
 VIII. Handle

IX. Handle socket

X. Oil filler plug

1.3. WORKING PRINCIPLE

A hydraulic bottle jack's functioning is described very accurately by Pascal's principle, which
states that a force applied to an enclosed fluid is transferred equally throughout the entire
fluid. This means that the fluid must not be able to be compressed. When the jack's pump is
activated, it applies pressure on the hydraulic fluid, which fills the cylinder. Because the
cylinder is completely filled while the pump is active, and the one-way valve completely
encloses the fluid, pressure builds within the cylinder. The pressure escapes via the easiest
way possible: it pushes up on the plate of the jack, hence putting out force. The pump
basically exerts a small force on the fluid continuously until the fluid has enough pressure to
push up the jack, which lifts whatever is being lifted at the time. This means that the jack can
exert massive forces with simply a pump. However, all hydraulic jacks must be engineered so
that the pressure inside the cylinder, which gets very high, is not released by a structural
failure of the cylinder or the valve connecting the cylinder to the pump while the jack is in
operation. To release the pressure of the jack, the one-way valve is simply released so that
the hydraulic fluid flows back out of the jack's cylinder.

1.4. LITRATARE REVIEW

Hydraulic bottle jacks are commonly and widely applied everywhere all over the world. They
have a lot of merits and benefits in the current generation since they have made the lifting
processes easier, comfortable and reliable as compared to other jack types. The hydraulic
jacks can lift objects of low pounds to thousands of pounds. They use gasoline, compressed
air, electricity and hand power as power sources. Hydraulic jacks’ clients have opportunities in
choosing their best types moreover according to a power source. The function of components
of hydraulic bottle jack are listed below.

1.4.1. Manually-Operated Pump

Pump used in hydraulic bottle jack is a plunger type reciprocating pump. The pumping
chamber of this type of pumps are surrounded by one-way valves, so that the hydraulic fluid
only moves in from the low pressure side i.e. suction side and out from the high pressure side
i.e. discharge side. Therefore, this type of pump is used to converts mechanical energy to
hydraulic energy in the form of flow. This pump consists of:
a). Plunger
b). Cylinder
c). O-ring (seal)
1.4.2. Valves
The simplest type of valve are used in hydraulic jack which used to control the transfer of
hydraulic energy through the system by controlling the fluid flow direction by moving the
valve stem (ball) against or away from valve seat. And also used to control the pressure
requirement of the system.
The jack consists of the following type of valves:
a). Intake valve
b). Discharge valve and
c). Pressure release valve

1.4.3. Rams (Actuating Pistons)

The rams are used to converts hydraulic energy in to mechanical energy in the form of linear
motion. This mechanical energy is used to perform the lifting work (mechanism). Therefore,
the rams are used as a force multiplying device.

1.4.4. Tank (Reservoir)

The type of tank used in hydraulic bottle jack is pressurized tank with filler screw; this type of
tank is sealed from the atmosphere, keeping dirt and humidity out of the tank. The internal
pressure also forces oil towards the pump, avoiding pump cavitation. The filler screw is used
to check reservoir (tank) for proper fluid content and if fluid level is low, we add up to correct
level through the filler by removing the filler screw.

The working condition of hydraulic bottle jack can be conclude as: When the handle is
operated, the plunger reciprocates then the oil from the reservoir is sucked into the plunger
cylinder during upward stroke of the plunger through the suction valve. The oil in the plunger
cylinder is delivered into the ram cylinder during the downward stroke of the plunger through
the delivery valve. This pressurized oil lifts the load up, which is placed on top plate of the
ram. After the work is completed the pressure in the ram cylinder is released by unscrewing
the lowering screw thus the pressure releases and the ram is lowered, then the oil is rushed
into the reservoir. It consists of plunger cylinder on one side and ram cylinder on the other
side. These two cylinders are mounted on base which is made of mild steel. Plunger cylinder
consists of plunger which is used to build up the pressure by operating the handle. Plunger
cylinder consists of two non-return valves i.e. one for suction and other for delivery. Ram
cylinder consists of ram which lifts the load. The ram cylinder connected to delivery valve of
plunger cylinder. It is also consists of lowering screw this is nothing but a hand operated valve
used for releasing the pressure in the ram cylinder for get down the load.
1.5. ALTERNATIVES

Almost all hydraulic bottle jacks have similar structure and working principle. However, all of
them have not the same lifting capacity, weight, cost, reliability, e.t.c. Based on the
arrangement rams they can be manufacture or designed as the following.

1.5.1. Hydraulic bottle jack with single lift and extension screw

This jack is the simplest one as defined above it operates on the principle of Pascal’s law i.e,
as the fluid pressure force the piston at the end of the ram by the action of pump plunger the
ram rise and it lower by opening the pressure release valve.

1.5.2. Hydraulic bottle jack with double telescopic rams

A telescopic hydraulic jack is used when a long stroke length and a short retracted length are
required. The telescopic cylinder extends in stages, each stage consisting of a sleeve that fits
inside the previous stage. They are more expensive than standard jack due to their more
complex construction. The tubes are supported by bearing rings, the innermost (rear) set of
which have grooves or channels to allow fluid flow. The front bearing assembly on each
section includes seals and wiper rings. Stop rings limit the movement of each section, thus
preventing separation. When the cylinder extends, all the sections move together until the
outer section is prevented from further extension by its stop ring. The remaining sections
continue out-stroking until the second outermost section reaches the limit of its stroke; this
process continues until all sections are extended, the innermost one being the last of all. For a
given input flow rate, the speed of operation increases in steps as each successive section
reaches the end of its stroke. Similarly, for a specific pressure, the load-lifting capacity
decreases for each successive section.

1.5.3. Dual speed Hydraulic bottle jack

A type of dual speed vertical hydraulic jack, including pedestal featuring hydraulic control
pressure regulating assembly and oil drain valve assembly; jacket, hydraulic cylinder and
pump body fixed on pedestal; oil storage cavity formed between jacket and hydraulic
cylinder; piston rod with piston assembly at bottom; top cap, pump core, button, first oil path
and second oil path; on bottom of said pump core, a step is provided and constitutes sealing
with inner wall of pump cavity, third oil path and fourth oil path are provided on the step
respectively, first steel ball valve and second steel ball valve that control connection and
disconnection of said pump cavity with third oil path and fourth oil path respectively are
provided on these oil paths, and at lower part of pump core, a fifth oil path is provided for
connecting third oil path with upper cavity of pump cavity. Advantages: oil paths are simpler,
as well as processing and assembling of parts, favoring higher efficiency; operating
performance is stable and fault rate is low; and fast lifting at no load and slow driving under
load are fully ensured, favoring increase of efficiency.

1.6. DESCION MATRIX

In order to select the better jack alternatives on let’s compare and contrast them with above
listed key function. Assume each key function have value of 10 i.e,

1= very poor , 5 = Good , 10 = Excellent

Key function Alternative 1 Alternative 2 Alternative 3

Reliability 7 9 7
Maintainability 6 7 6
Manufacturability 9 7 7.5
Durability 8 9 7
Efficiency 6 8.5 8
control 7 8 5
Weight 8 7 8
Cost 8 6 7
Total =59 = 61.5 = 50.5

From above alternatives I select the second jack type i.e, telescopic Hydraulic bottle jack
because it is reliable and efficient with optimum cost as the decision matrix table shows.
 ADDIS ABABA UNIVERSITY
ADDIS ABABA UNIVERSITY INSTITUTE OF TECHNOLOGY

SCHOOL OF MECHANICAL AND INDUSTRIAL ENGINEERING

MACHINE DESIGN 1 PROJECT 1

TITLE: HYDRAULIC BOTTLE JACK

SUBMITTED BY:

NAME ID NO

BELSTIE TILAY ATR/3978/07

SUBMITTED TO: ATO MULUGETA

SUBMITTED DATE: 25/05/2017 G.C