Design of multi-directional department of mechanical

powered screw jack engineering

Acknowledgements
We would like to ex press our sincere gratitude to our advisor, Mr. Mekonnen Ayane for his
continual encouragement and patient guidance throughout the course of this project. His deep
insight into the subject of Fracture Mechanics, material handling, its many applications and his
communicable interest, his tolerances in helping our project design, and his endless supplying of
interesting ideas, have all greatly enriched our experience as a graduate student. Next thanks to
Mr. Azemeraw Tadese who help us how we can do any project successfully and what procedures
must be included in organized project. Beside this, thanks to all mechanical engineering teachers
those help us through different activities that approach to our project. Our thanks and
appreciations also go to our college in developing the project and people who have willingly
helped us with their abilities.
Authors Name; Boru Bedeya, Andualem Gete, Namo Tadele, Mehari Hailu
ID.NO. ITR/0262/03, ITR/0121/03, ITR/ 0733 /03, ITR/0621 /03 Respectively.
BSc in Mechanical Engineering
Wollo University Kombolcha Institute of Technology, 2015

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 Design of multi-directional department of mechanical
powered screw jack engineering

Abstract
The project related to the design of multi directional powered screw jack. Conventional car jacks
uses mechanical advantage to allow a human to lift a vehicle and components of heavy duty by
manual force. This paper analyzes the modification of the current screw jack by incorporating an
electric DC motor in order to make load lifting easier. Universal head and sliding or adjusting
bases for emergency use power of car batter (12 Volts). In the problem of low battery we can use
manually, by removing the motor side gear meshing easily. And in workshop we can use other
sources. Gear ratio is used to determine the lifting power. The significance and purpose of this
work is to modify the existing screw jack in order to make the operation easier, safer and more
reliable to save individual internal energy and reduce health risks especially back ache problems
associated with doing work in a bent or squatting position for a long period of time. For these
problems we design Multi-directional powered screw jack developed using AUTOCAD and
analyzed using Finite Element Analysis to check safety factor and force acting. Maximum
weight to be lifted is assumed to be 500 kg. The manufacturing process is written as we can use
with milling, drilling, grinding, and welding lathe machines. The developed powered Multi-
direction jack is tested on car. Implementation of design will solve problem associated with
ergonomics.

Keywords: Battery, D.C motor, Gear ratio, Jack, Screw

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 Design of multi-directional department of mechanical
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Table of Contents
Acknowledgements…………………………………………………………………….. I
Abstract ............................................................................................................................ II
Table of contents…………………………………………………………………………………………………………………...III

List of figures………………………………………………………………………………………………………………………….IV

List of tables…………………………………………………………………………………………………………………………...V

Acronomys ..................................................................................................................... VI
List of conversation factor ............................................................................................ VII
CHAPTER ONE: INTRODUCTION .......................................................................... 1
1.1 Back ground information and justification .................................................................... 1
1.2 Statement of problem ......................................................................................................... 2
1. 3 Objectives .......................................................................................................................... 3
1.3.1 General objective……………………………………………………………………...3
1.3.2 Specific objective……………………………………………………………………..3
1.4 Significance of the project .................................................................................................. 4
1.5 Scope of the project ............................................................................................................ 5
1.6 Project methodology ........................................................................................................... 6
1.7 Organization of Study ......................................................................................................... 7
CHAPTER TWO: LITERATURE REVIEW .................................................................. 8
2.1 Types of jack………………………………………………………………………………...9
2.1.1 Hydraulic jack…………………………………………..………………………………9
2.1.2 Scissor jack………………………………………………………….………………...11
CHAPTER THREE: RESULT AND DISCUSSION ............................................... 12
3.1 Over view of Multi-directional Power Screw Jack ................................................ 12
3.2 Geometric analysis of Multi-directional Powered screw Jack .......................................... 13
3.3 Working principle of Multi-directional powered screw jack ............................................ 13
3.4 Components of Multi-directional powered screw jack ..................................................... 15
3.5 Design analysis of Multi directional powered screw ........................................................ 16
3.5.1 Design procedure……….…………………………………………………………....16
3.6 Force Analysis .................................................................................................................. 17

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 Design of multi-directional department of mechanical
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3.7 Material selection .............................................................................................................. 22

3.8 Components material selection ......................................................................................... 23
3.8.1 Motor selection………………………………………….…………………………...23
3.8.2 Gear design…………………………………………….…………………………….25
3.9 Housing ............................................................................................................................. 30
3.10 Design of Side Member .................................................................................................. 30
3.11 Design of Main Base ....................................................................................................... 30
3.12 Design of Middle Base .................................................................................................... 32
3.13 Design of Jack Supporter Base ....................................................................................... 32
3.14 Design of Ball Bearing.................................................................................................... 32
3.15 Design of Helical Spring ................................................................................................. 34
3.15.1 Helical spring………………………………………………...……………………..35
3.15.2 Material selection for helical spring……………………….……………………….36
3.16 Wheel Design .................................................................................................................. 39
3.17 Design of Power Screw ................................................................................................... 40
3.18 Design of base slider screw............................................................................................. 44
3.19 Design of supporter cup .................................................................................................. 44
3.20 Design of lifting member ................................................................................................ 46
3.21 Design of pin ................................................................................................................... 48
3.22 Design of differential supporter head.............................................................................. 50
3.23 Manufacturing process .................................................................................................... 51
3.23.1 Manufacturing process main base……………………………………….…………51
3.23.2 Manufacturing process of lifting member…………………………….……………52
3.23.3 Manufacturing process of ball bearing……………………………….…………….53
3.23.4 Manufacturing process of power screw thread………………..…………………….54
3.24 Lubrication system .......................................................................................................... 55
CHAPTER FOUR: CONCLUSION AND RECOMMENDATION ....................... 56
4.1 Conclusion ........................................................................................................................ 56
4.2 Recommendation .............................................................................................................. 57
4.3 References ......................................................................................................................... 58

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 Design of multi-directional department of mechanical
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List of figures………………………………………………………………………...59
Figure 2.1 Hydraulic jack………………………………………………………………………………………………………...9

Figure 2.2 Bottle jack…………………………………………………………………………………………………………….10

Figure 2.3 Floor car jack………………………………………………………………………………………………………..11

Figure 2.4 Scissor car jack………………………………………………………………………………………………………11

Figure 3.9 (a) Upper position jack FBD .................................................................................. 59

Figure 3.9 (b) Lower position of jack FBD ............................................................................... 59
Figure: 1 Load supporter cup that holds socket head through standard square hole. .... 60
Figure: 2 Lifting member ............................................................................................... 60
Figure: 3 Side member ................................................................................................... 61
Figure: 4 Pin ................................................................................................................... 61
Figure : 6 Middle base ................................................................................................... 62
Figure :7 Small screw supporter plate ........................................................................... 62
Figure: 8 Main base ....................................................................................................... 63
Figure: 9 Wheel.............................................................................................................. 63
Figure: 11 The motor supporter helical spring cylinder and smallest slider base ......... 63
Figure: 12 Helical spring and its sliding cylinder .......................................................... 64
Figure :13 The motor and gear meshing diagram .......................................................... 64
Figure: 13 power screw ................................................................................................. 65
Figure: 14 power when we use for manual system ........................................................ 65
Figure: 15 Socket lever for manual operation................................................................ 66
Figure :16 3rd differential supporter head ...................................................................... 66
Figure: 17 propeller shaft supporter head ...................................................................... 66
Figure: 18 Assemble of multi- directional power screw jack…………………………68
List of tables ................................................................................................................... 69
Table 3.1 Components of Multi -directional Powered screw jack…………………………………………..15

Table 3.2 Material Property of C45 and C35 Mn75 are given in .................................. 69
Table3.3 Properties of material ...................................................................................... 68
Table 3.5 Form factor (y) for use in Lewis strength from …………………………….70

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 Design of multi-directional department of mechanical
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Acronomy

BHN Brinell hardness number

Dc core diameter

Dg Diameter of gear

Dp Diameter of pinion

Ƞ Efficiency

g gravitational acceleration

HD Heavy duty

LD Light duty

Rpm revolution per minutes

n factor safety

ω angular velocity

µ Coefficient of friction

ƛ Helix Angel

ɸ friction angel

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 Design of multi-directional department of mechanical
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List of conversation factor

1KN 1000N
1m 1000mm
1cm 10mm
1m3 1000000mm3
1KWatt 1000watt

ω (1rev./min ) 2 rn/60

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 Design of multi-directional department of mechanical
powered screw jack engineering

CHAPTER ONE: INTRODUCTION

1.1 Back ground information and justification
A jack is mechanical device used to lift heavy loads or apply great forces. Jacks employ a
screw thread or hydraulic cylinder to apply very high linear forces. The Multi-direction powered
screw jack is modified and different from another due to its function. It uses powered screw jack
its bases are sliding with the help of small screw and main base has wheel for transport small
distance in work shop and Universal head that required to holding or supporting the load which
is changeable according to the shape that we want to maintain and it has the standard socket
square hole. While the problem of battery will occur we can use manually by removing the
motor part gear meshing. Most of the jacks are modified before this, but they only uses to lifting
or lowering the objects those have flat shape. After they lift the load they can’t slide to any
position and transport. These are lack of the most jacks. Some of these jacks are;
The Floor jacks usually use mechanical advantage to allow a human to lift a vehicle by
manual force alone. More powerful jacks use hydraulic power to provide more lift over greater
distance. The mechanical advantage is the factor by which a mechanism multiplies the force or
torque applied to it. An automotive jack is a device used to raise all or part of a vehicle into the
air in order to facilitate repairs. But it has limitation as written under the limitation topic.

The jackscrew is a type of jack which is operated by turning a lead screw. It is also known as
a screw jack, and is commonly used as car-jacks. In the case of a screw jack, a small force
applied in the horizontal plane is used to raise or lower large load [1]. This screw-type is scissor
jacks, common in newer cars, and bumper jacks, common in older cars. A jackscrew's
compressive force is obtained through the tension force applied by its lead screw. An Acme
thread is most often used, as this thread is very strong and can resist the large loads imposed on
most jackscrews while not being dramatically weakened by wear over many rotations.

The hydraulic jack uses fluid but no screw. This is achieved by pumping or increasing the
pressure of the fluid in the cylinder to raise the loaded shaft. This jack is invented by Richard
Dudgeon, the owner and inventor of hydraulic jack, started in machine shop. In the year of 1851,
he was granted a patent for his hydraulic jack. In the 1855, he literally amazed on lookers in
Neyork when he drove from his abode to his place of work in a stream carriage. Richard made a
claim that his invention had the power to carry near about ten peoples on a single barrel of a
thractice coal at speed of 14m.p.h. After hydraulic jack invented the others jack types are
invented. Some of them are; service jack, Hydraulic bottle jack, long ram jack, shop press jack,
scissor jack, and etc. Most people are familiar with the basic auto jack that was still included as
standard equipment with most new vehicles. This is due to the continuing improvements in
modern technology. Who may install snow tires before the winter and remove them in the spring
need to use a jack to perform the job [2].

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 Design of multi-directional department of mechanical
powered screw jack engineering

1.1 Statement of problem

Nowadays in most countries, the vehicles were equipped with the hydraulic jack, scissor jack,
floor jack and e.t.c. We found that many jacks are simply lifting or lowering the only flat shape.
And they are operating by single mechanism. Due to this they can’t uses for irregular shape and
they can’t move or slide to any direction after they carry the load and if one mechanism is failed
their function completely stop. These were very difficult to operate irregular components of the
vehicles those wants position after they lifted and difficulties to operate under body of the
vehicles which is bent or unavailable. To solve this problem we design multi-directional power
screw jack. Most scissor or screw jack were very difficult to be used especially by women
because this types of jack needed more strength and energy to operate this jack by turning the
lead screw, but now a days we can use powered screw jack. The hydraulic jack is used to lift or
down the flat shape during the maintenance of the vehicles. Most of these jacks are used simply
to lift and down the heavy load that has flat shape.

Limitations of those jacks are as follows;

 They can’t carry irregular shape easily
 After they lift the load they can’t position the object to the direction that we want to
operate
 Most of the time the object is carried by human whether it is in work shop or under the
operation of heavy duty( during maintenance of truck) components
 They can’t uses for adjustment to fit the two components during assembling or
maintenance
 Most of the screw jacks need human effort to lift or down the load and it operates
manually
 They have fixed flats shape head or supporter (not change for others shape)
 The hydraulic jack cannot lift the loads below its minimum height of cylinder
 They can’t uses for transportation of machine components for small distance in work
shop
 They can’t work by more than one mechanism (they are single mechanism)

This design is to develop a product based on the problem faced the users who operate the
vehicles regarding to this issue. To overcome this problem, a project has been conducted to the
solution on how to design a Multi-directional jack for the truck components and light duty
maintenances in the simple and cheap way while it is energy saving and manufacturing process.
During the project, we have found that most of the heavy duty technicians has difficulties in
maintaining their vehicles breakdown especially trucks in the scope of operating rear differential,
propeller shaft, steering It also requires much energy from the person to rotate the jack. So, this
project to solve these problems depends up on the fact that found in society.

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 Design of multi-directional department of mechanical
powered screw jack engineering

1. 3 Objectives

1.3.1 General objective

The main objective of this project is the design analysis of Multi-direction powered screw jack
and its principles of operation.

1.3.2 Specific objective

The objective of the study is to develop a mechanism in power Multi-directional jack that is
more efficient, stress free, saves time and a reliable way to achieve lifting of the load. These
include:
 To modify the flat head to universal socket system head
 To modify the base system to sliding forward and backward during operation
 To operate easily the components with qualified system
 To lift irregular shape easily during maintenance
 To reduce the operation time
 To transports some components in work shop during maintenance
 To modify the screw jack to work both manual and power system

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 Design of multi-directional department of mechanical
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1.4 Significance of the project

A Multi-direction power screw jack is a machine which is used to lift the different weight during
maintenance of vehicles. Due to its modified parts and easily uses for maintenance, it has many
functions for the users. The advantages of this jack are;
 It can be used starting from low garage up to high maintenance work shop
 It is available for all person during maintenance of vehicles
 Due to it is working both manually and powered system it is more preferable than single
system jack those operated by only hydraulic, manually, or powered
 It can transport components for small distance in the workshop
 It does not cause the environmental problem, so it can uses at every where we require and
generally for the technological society those uses their time actively, it is more prefer
than other. By assuming, cost, reliability, serviceability, efficiency, safe time, safety of
worker, and easily manufacturing etc.

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 Design of multi-directional department of mechanical
powered screw jack engineering

1.5 Scope of the project

This project is focusing on the designing and fabricating processes of Multi-directional
powered screw jack. The type of jack that used in this project is screw jack which is available for
this project. In order to develop new concept of design, we got this idea during the maintenance
of: emergency tire changing, rare differential of truck, auxiliary gear box and supports other
components. This machine used for LD and HD duty, while in the car it was used only for light
duty maintenance. The scopes of project were on the designing 500Kg maximum lifting
capacity. But, by using optimization concept the 300kg is optimum capacity.

To help the operators, the concepts that are used in this project were adding the sliding bases
and the changeable load supporter head according to the shape of object that needed to be
operate. By this, mechanical advantages while lifting and lowering it uses to adjust the position
for tightening components or to simply support the load for the period of operation. The force
distribution and raw material selection for each component was done carefully. Fabrication
process is also included. Therefore, the force analyses guide us for selection of materials and to
accomplish according to the force that applied to each part. And each detail drawings are
included.

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 Design of multi-directional department of mechanical
powered screw jack engineering

1.6 Project methodology

This project focus on Multi-directional powered screw jack for lifting and sliding the different
body or components of vehicles depend on their shape during maintenance. The applied
methods, primary and secondary sources, which are well-structured; provide a step-by-step
approach to complete the task of this project. The primary source is direct observation and
secondary sources are mechanical Engineering and different manuals those available for our
project, and internet websites. Based on these methodologies, there are three steps expected.
Firstly, the problems are selected, and then decision is completely made, Secondly, ensure that
the important issues are not forgotten like satisfaction of the customer and being beneficial.
Thirdly, different mechanisms are compared and the best one is selected and modified. The
structured methods are largely self-documenting; in the process of executing the method, the
goodness of the performance of the machine can be used for future.

Identifying customer needs

The goal of this activity is to understand customer’s need through observation. The identification
of the current machine design weakness is really helpful in providing the target specification for
the modification of any machine.
Problem Identification through observation
 Time wasting to lift irregular shape.
 Numbers of workers are needed to operate under unavailable places.
 Many jacks are used to support flat shape only.
 Many jacks can’t slide to any position after they lift the loads those required for mounting or
tightening.
 There is emergency causes to workers that operates under bent area like; maintenance of HD
rare differential.
 During the maintenance technicians uses their own effort whether the jack is hydraulic or
screw system, but now we select the safe and modified powered screw jack which is simple
for any person.
 They can’t use for component transportation in work shop for small distance around the
vehicle maintenance

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 Design of multi-directional department of mechanical
powered screw jack engineering

1.7 Organization of Study

The paper is organized from four chapters. Each chapter classified according to the approach
used to solve the problem raised.
The first chapter: Deals with the introductory parts of the paper.
The second chapter: Consists of the literature review that is used as a resource for
accomplishment of the project, the explain methodologies how to approach the problem and
solve it progressively and Geometric analysis of Multi-direction power screw jack.
The third chapter: Result and discussion deals with the detail design of the Multi
directional powered screw jack components and over view of this jack and this part of the
project is the solution for the problems that we have mentioned in the statement of the
problem and lastly manufacturing process.
This part of the paper is the solution for the problems that we have mentioned in the
statement of the problem.
The fourth chapter: puts the conclusion, recommendation, reference, appendix and General
assembly

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 Design of multi-directional department of mechanical
powered screw jack engineering

CHAPTER TWO: LITERATURE REVIEW

Multi-directional Powered screw Jack is used to lift the car during side road emergency, the
rare differential of HD maintenance, support propeller shaft e.tc. A mechanical jack is a device
used to lift heavy equipment, all or part of a vehicle into the air in order to facilitate vehicle
maintenances or breakdown repairs. Changing a flat tire is not a very pleasant experience.
Nowadays, a variety of car jacks have been developed for lifting an automobile from a ground
surface and to for some components of HD during maintenance (rare differential, propeller shaft,
steering gear box, auxiliary gear box e.t.c). [7]

Available screw jacks, however, are typically manually operated and uses for specific
purpose, therefore require substantial laborious physical effort on the part of the user. Such jacks
present difficulties for the elderly and handicapped and it further requires the operator to remain
in prolonged bent or squatting position to operate the jack. Doing work in a bent or squatting
position for a period of time is not ergonomic to human body. It will give back ache problem in
due of time. A multi-direction jack is operated by power turning a lead screw. In this case of a
jack, a small force applied in the horizontal plane is used to raise or lower large load. A
jackscrew's compressive force is obtained through the tension force applied by its lead screw.[2]

An Acme thread is most often used, as this thread is very strong and can resist the large
loads imposed on most jackscrews while not being weakened by wear over many rotations. An
inherent advantage is that, if the tapered sides of the screw wear, the mating nut automatically
comes into closer engagement, instead of allowing backlash to develop. These type are self
locking, which makes them safer than other jack technologies like hydraulic actuators which
requires continual pressure to remain in locked position The automobile service stations are
commonly equipped with large and hi-tech car lift, wherein such lifts are raised and lowered via
electrically-powered systems. However, due to their size and high costs of purchasing and
maintaining, such lifts are not feasible to be placed in car and owned by car owner. Such
electrical-powered portable jacks not only reduce the effort required for lifting an automobile
and HD components via manually-operated jacks, but also decrease the time needed to repair the
vehicles. Such a feature can be especially advantageous when it is necessary to repair or maintain
an automobile (LD) and trucks (HD) on the side of a roadway or under other hazardous
conditions [7].

A specified jack purposed to hold up to 500 kilograms, but tests undertaken by Consumer
Affairs has revealed that is fails to work after lifting 250 kilograms and may physically break
when it has a weight close to its 500 kilograms capacity. Tests have proven that the jack has the
tendency to buckle under the weight it is subjected to withstand. The purpose of this project is to
develop a Multi-directional power screw jack which is easy to be operated, safe and able lift and

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 Design of multi-directional department of mechanical
powered screw jack engineering

lowering the automobile and HD components without involving much physical effort. So to
design this jack some types must be compared with it. Some types are as following;

2.1 Types of the jacks

2.1.1 Hydraulic jack

It is a short stroke hydraulic lift which is fed from hand pump. The hydraulic jack may be
portable. This is extensively used for lifting automobiles usually to facilitate and repair, And to
replace the punctured wheels. The hydraulic jack is perhaps one of the simplest forms of a fluid
power system. By moving the handle of a small device, an individual can lift a load weighing
several tons. A small initial force exerted on the handle is transmitted by a fluid to a much larger
area. The operation of hydraulic jack depends on Pascal‘s law. This states that when a fluid is at
rest in a closed vessel and if a certain pressure is applied at any point the pressure will be
transmitted equally in all direction. Mechanical advantage is obtained by a practical application
of Pascal‘s law of transmission of fluid pressure. Two pistons of different sizes operate inside
two cylinders suitably connected with a pipe so that pressure in each is the same. If the volume
of liquid is constant, the displacement of large piston wills be proportionately to smaller plunger
[1].

Figure 2.1 hydraulic jack

Principle of hydraulic jack

Hydraulic jack works on the principle of Pascal‘s law. When the handle is operated, the
plunger reciprocates then the oil from the pressure on the surface of a confined fluid is
transmitted undiminished throughout the confined vessel or system. Two common types of
hydraulic jacks include; bottle jacks & floor jacks.

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 Design of multi-directional department of mechanical
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Bottle jacks became popular in the early 1900s when the automobile industry began to
take off. Also called hand jacks, bottle jacks provided an easy way for an individual to lift up a
vehicle for roadside inspection or service. Their resemblance to milk bottles earned bottle jacks
their name- today; they range in size and weight to offer a lifting capability ranging from one
hundred to several tons. Bottle jacks feature a vertical shaft, which supports a platform (called a
bearing pad) that directly bears the weight of the object as it is lifted. Although they are most
commonly used in the automobile industry (1.5 to 5 ton jacks are frequently used to lift cars),
bottle jacks have other uses as well. In the medical industry they can be used in hydraulic
stretchers and patient lifts. In industrial applications, they can be found as pipe benders used in
plumbing, as cable slicers for electrical projects, and as material lifts within warehouses. Their
ability to lift heavy loads plays a big role in enabling the repair of large agricultural machinery
and in many construction operations. Bottle jacks can be secured within a frame, mounted on a
beam, or simply used as they are for easier jack transportation [3].

Figure 2.2 Bottle Jacks

Floor jack: Unlike bottle jack shafts, the shaft in a floor jacks is horizontal. The shaft
pushes on a crank that connects to a lifting pad, which is then lifted horizontally. Floor jacks
typically provide a greater range of vertical lift than bottle jacks, and are available in two sizes.
The original jack is about four feet long, a foot wide, and weights around 200 pounds. They can
lift 4-10 tons. A more compact model was later made, which is about three feet in length, and
can lift 11/2 tons. Although mini jack are also produced, they are not a recognized standard type
of floor jack. Typically, one of the first two sizes should be used. [3].

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 Design of multi-directional department of mechanical
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Figure 2.3 Floor Car Jack

2.1.2 Scissor jack

A scissor jack is a machine which, when a small force is applied in its horizontal plane is
used to raise or lower a large load. It is usually applicable in the automobile industry for raising a
side of the vehicle during tire changing. These small automotive jacks are of various different
types. Bumper jacks have a protuberance that fits into a slot under the vehicle's bumper,
providing some security against sudden sideways movement. Scissors jacks and ratchet jacks are
other kinds of hand-operated jacks. Any time a small jack is used, it's critical that the vehicle be
in a stable position on a flat surface. Be sure that the jack is pushing up against a solid frame
member that will support the weight of the vehicle, or else you will need to repair more than
your tire [5].

Figure 2.4 Scissor Car Jack

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 Design of multi-directional department of mechanical
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CHAPTER THREE: RESULT AND DISCUSSION

3.1 Over view of Multi-directional Power Screw Jack

The Multi-directional powered screw jack is the jack that uses for different function as it is
name implies. It is modified from another’s jacks by three main things. It has the over sliding
bases to different position, uses the powered screw system to lift the load and it has the
changeable load supporter or head based on the shape that needed to be operated. The sliding and
powered system is very important system for all persons. Most women and elder man need it
during maintenance of vehicles. Many are used mostly for the similar purpose whether they are
manually, pneumatic, or hydraulically operated. They are used for the lifting the loads those have
the flat shape. But this jack is used not only to lift the load that has flat shape during the vehicles
maintenance. After it lifts the load or components of the truck we can move to the position that
we want. E.g. Maintenance of rear differential of the truck (HD) and auxiliary gear box of trucks.

Multi-directional powered screw jack is the modification of screw jack that operates powered
system and has additional sliding bases and changeable head. Screw jack is used to lift the car
during side road emergency i.e. tire puncher. Also it is a device used to lift heavy equipment, all
or part of a vehicle into the air in order to facilitate vehicle maintenances or breakdown repairs.
Changing a flat tire is not a very pleasant experience, but with this modification multi-directional
jack uses for multi-functions in vehicle maintenance. Some examples are; during maintenance of
rear differential, propeller shaft, auxiliary gear box and e.tc in operation of heavy duty or truck
components and uses for LD operation obviously.

This jack has three bases those slides over one another. The first is the main base which found
at ground and that supported by the tires. The second is the middle base which is found between
the upper base and lower main base. The last which found at the upper part that mount with the
powered screw jack base and it carries the screw jack that carries the load, and then slides over
middle base. Between all the bases there is the ball bearing to make the sliding system easy. To
slide these bases there are two screws those fixed with the middle base to slide over main base
and next is with the upper base to slide over middle base. The screw to rotate and to lift the load
it must mount with the gear meshing to the servo motor. This motor gets power from vehicles
12V battery. In lack of this, we can use another source in work shop like; generator, direct
electric power after we adjust the lifting speeds of the jack.

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 Design of multi-directional department of mechanical
powered screw jack engineering

3.2 Geometric analysis of multi-directional powered screw jack

This analysis contains some main dimensions and main components that combined to form the
machine. General height that lifted is 500mm and its minimum height before load lifting is
221.899mm ≈222mm. The diameter of the wheel is 60mm and Clearance of roller bearing is
2mm for middle base, similarly 2mm for second base is 4mm. Height of the jack at minimum
angle above the bases = 87.899mm and the summation height of three bases and clearance of
wheel is 138mm. Overall height of this jack at max height is 60+30+20+20+ 500+ the load
supporter cup height (80mm) + 4mm = 714mm or 0.714mm

257
654

50
0

Figure 2.6 Geometry of multi-directional screw powered jack

3.3 Working principle of multi-directional powered screw jack

Under working condition the jack will lift a vehicle chassis or components in contact with head
supporting or top plate or supporter head when the power screw is rotated through its connecting
gear with the pinion when electrical power applied to the wiper motor when plugged to the 12V
battery in car, but in workshop it prefer to use another motor (generator). Motor transmits its
rotating speed to the pinion gear meshing with the bigger gear connected to the power screw to
be rotated with required speed reduction and increased torque to drive the power screw. The
power screw rotates within the threaded bore of side member in the clockwise direction that will
cause the links to be drawn along the threaded portion towards each other during load-raising
process and vice versa.

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 Design of multi-directional department of mechanical
powered screw jack engineering

Initially the jack will first be placed below the chassis to be lifted such that at least a small
clearance space will exist between the top plate and the vehicle chassis to be raised. Then after
power screw will be turned so that the top plate makes contact with the car chassis or for the
components required socket head, we put the load over the load supporter after socket the
supporter to the square head of screw jack, if we want to lift from ground to chassis. But, for the
load lowering from chassis to ground simply socket the load supporter then adjust the position to
the shape of load and the clearance space is eliminated. As contact is made, load of car or
component will be increasingly shifted to the top plate and cause forces to be developed in and
transmitted through links and side member. The force transmitted through the side member will
be transferred on threads of screw. A switching circuit connected to the motor is used to regulate
the lifting and lowering process.
Steps in working of multi-directional powered screw jack.
The principles are depending on its specific function. If we want to lift the axle of light duty;
 First; check all the components of jack are assembled carefully
 Second; slide the two bases (middle and jack supporter base) to the center of main
base
 Third; remove if the socket load supporter head is mounting over it. Because, to lift
axle flat shape is preferred.
 Fourth ; down the jack until it reach its minimum height
 Fifth ; move the jack under the chassis until the axle or the body wanted to be lift is
perpendicular to the contact cup ( load supporter cup)
 Sixth; socket the power source from the battery and lastly use the switch (ON/ OFF).
To lift up ON and OFF to down.

Steps for heavy duty components maintenance

 The steps 1- 4 are similar with the LD
 Fifth : socket the load supporter head depend on shape to be maintain
 Sixth : put the load carefully on the load supporter head
 Seventh : move by the help of wheel to the operation chassis (under vehicle chassis)
e.g for differential operation
 Eighth: socket the power source and adjust as possible and lastly after we lift up the
load until the height you want, then carefully adjust to the bolt holes by sliding the
bases and after operation will be accomplished minimize the jack to its lower position
and move out.

During the problem of battery, the jack operates manually by removing motor part with pinion
gear. The motor housing opens carefully by removing the bolt. Then dismantle the gear meshing
and remove the motor part with supporter helical spring and base. Then after socket the holed to

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 Design of multi-directional department of mechanical
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small hexagonal head to the hexagonal head of screw rotates the screw manually. Lastly with the
help of lever rotate the screw manually to lift or down the weight.

3.4 Components of Multi-directional Powered Screw Jack

The components are the parts of machine that combined together to give the function that the
users required. Each part has its function to keep the quality, performance, reliability,
conformability, etc of the designed machine. Due to these they must designed carefully.
Table-1 Includes details of all components required for building the actual model or prototype of
multi-directional powered screw jack.
Component Description Quantity
number
1 Wheel 4
2 Main base 1
3 Base sliding screws 2
4 Ball bearing 16
5 Middle base 1
6 Jack supporter base 1
7 Pin 8
8 Bottom links 1
9 Power screw 1
10 Upper links 1
11 Load supporter head
1
12 Link 4
13 M 10 bolt 4
14 Stabilizer bar 1
15 Gear and hub 1
16 Pinion and hub 1
17 Bracket assembly 1
18 Wiper motor 1
19 Square head 1
20 Gear and pinion house 1
21 Bracket assembly holder 1
22 Base slider screw supporter 4

Table 3.1 components of Multi-directional powered screw jack

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 Design of multi-directional department of mechanical
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3.5 Design analysis of multi directional powered screw

3.5.1 Design procedure
After the preliminary study, it was discovered that a D.C motor in combination with two gears
can produce the required turning effect on the screw at less amount of time, thus eliminating the
use of manually operated lever and the corresponding inconvenience that goes with it. The next
step involved choosing the appropriate Servo motor (because of its ability to provide high
torque) and the corresponding gear ratio to transmit the torque. However, the choice of thread on
screw and nut, after calculations on appropriate internal and external diameter was chosen.
Single point cutting tool was used in the cutting of the required links, while hammer and shaping
machine was used to bend them to shapes. Components assembly and balancing on roads was
done while giving consideration to torsion, bending and shear forces acting on strategic point. It
is important to note that iterative comparison of stress values obtained, with those required for
safe operation (yield stress) was made and the cycle repeated when necessary.

Using the methodology and principle of manual jack which works on the bases of when the
threaded shaft of a manual jack is turned manually using a T-handle in a clock wise direction,
this causes the jack to contrast thus lifting the load and when turned anticlockwise brings the
load down. So therefore, the Multi-direction jack works on this principle but the difference is
that the turning of the threaded shaft in the jack is not done manually but with the aid of an
electric motor and there are two main parts are added (the sliding bases to four direction and load
supporting socket system to the required shape). Methodology of the powered screw jack is
simply on the conversion of electric energy to mechanical energy so as to lift load.

Lastly, the bases and links are designed carefully because, they slides and lift or down after
they carry the load. So their force analysis must be calculated carefully to select the best material
for manufacturing.

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3.6 Force Analysis

In the engineering practice the machine parts are subjected to various forces which may be due to
one or more of the following.

 Energy transmitted
 Weight of the machine
 Change of temperature
 Lack of balance of moving parts
 Types of load applied to the machine etc.

Note; to select the best material for the designing components the distribution of forces in each
component must be known. If not, our design easily faced by many failures during service.

The different forces acting on a machine produces various types of stresses, bending, torque,
shear force, and etc. Stress-when some external systems of forces or loads act on a body the
internal force (equal and opposite) are set up at various section of machine which resists the
external force. This internal force per unit area is known as unit stress or stress. Main types of
stresses are; e.g. tensile stress and compressive stresses are the two main types of stress.

In this machine these both stresses applied on different parts of the machine. E.g. tensile
stress applied on the screw part of jack when load is push down. The compressive stress applied
on the jack parts like; load supporter head. That is why it is found between the bases and load
required to lift. To select the factor of safety the loads types must be known. There are different
types of loads are considered depend on application of them on the body.

Load is defined as any external force acting up on the machine parts. In this design we assume
the loads like; loads of rear differential cover, auxiliary gear box, propeller shaft of HD and
quarter load of LD are assumed. Among these our force calculation is depend on the quarter load
of LD. Hence, other loads are less than this weight and it will be safe.

Generally there are four types of loads;

 Dead or stead load

 Live or variable load
 Suddenly load
 Impact load

Among these the load that we assume is dead or stead load that can’t change in its
magnitudes and direction. Since, the force analysis is the part of design which contain the
calculation of the load that exert to each components according to their working principle and

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how they must resist the external load (bending, stresses, compression or tension, torque, and
.etc) for available function like; quality, competence, durability, reliability, efficiency, strength,
and .etc of the designed machine we should consider these all.
We can use the powered screw jack which needs a little alteration, Parts like power screw,
side member, slide bases, load supporter head, and base slider screws are newly designed and
replaced. Designs of them are as follows:
Assumptions:
The ground clearance of the vehicle is assumed to be 200 mm. (Decided after study of various
car specifications medium standard). When the wheel of the vehicle leaves the ground, the screw
jack is assumed to have moved in the vertical axis (linearly) by a distance of 80mm. (Decided
after different observational analysis of conditions). The powered screw jack supports a quarter
of the total car mass, which is approximately 300 kg, i.e. 3000 N of force of car of weight 1200
kg i.e. 12000 N. For safety design weight is taken as 500 kg.
i.e. 5000N.
Input:
This analysis contains some main dimensions and main components that combined to form the
machine.
Maximum weight assumed = 500 kg or 5000 N.
Ground clearance = 200mm.
Maximum height of jack above base = 500mm
Total height of three bases =130mm
Minimum height before lifting = 221.88mm≈ 222m
Overall height of this jack to lift is 500mm and its minimum height before load lifting is
221.899mm ≈222mm

Clearance of roller bearing = 2mm for middle base similarly 2mm for second base = 4mm
Height of the jack at minimum angle above the bases = 87.899mm.
The summation height of three bases and clearance of wheel = 138mm
Overall height of this jack at max height = 60+30+20+20+ 500+ the load supporter cup height
(80mm) + 4mm = 714mm = 0.714m

Derived:
A) Max load on jack depending on condition of road:
Conditions:
i. On horizontal road surface.
ii. On slop.

It is observed that maximum load acts on jack when vehicle is on horizontal surface.

B) Angle between the links with respect to horizontal axis (Ө). As shown in figure 3(a) and
figure 3 (b) after studying different jacks as follows.

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 Angle in upper position of jack( )

)=
Therefore,
=76.5ᵒ

 Angle in lower position of jack )

Then to get a minimum angle we can depend on the lift member length as follow length of
each lift member is= 257mm then triangle method using sine law the valeu of minimum angle
can known. Opposite side is= 85mm

 Sine law of triangle

= , then = ( )

=20ᵒ

The FBD of the jack when it is in upper position and lower position are drawn as follows. During
this, the screw rotation is different. When the jack at upper position, the screw rotates counter
clockwise to lift the load required. When the jack at the lower position the screw rotates to anti
clockwise direction. But it is not always, in special case may reverse screw can be manufactured.
For example to reverse the rotation of clockwise screw. In order to determine many calculation
regarding to components of jack;

 Length of lifting member

 Minimum height before the jack starts to lift the load
 To know force distribution to each components and etc. the upper position
angle(maximum angle) and the lower position(minimum angle) are the key
parameters in force analiysis

Figure 3.10 force ditribution in jack body

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 Design of multi-directional department of mechanical
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From above figure the force that distributies in power screw is determined by depending on the
summation of equilibrium analiysis of forces that found horzontaly or verticaly.
Therefore;
=0
- =0…………………………………………………….(1)

OR
Total axial force in screw (Ws)

=2F1 then = ……………………………….. ………… (2)

Hence, the axial force (Ws) in a screw is maximum when Ө is minimum.

Therefore ; = =

=13737.387N

From table [1]

We have tensile yield strenght =834N/ and
then shear stress (‫= ح‬ /2)
‫ح‬s=834N/ /2=417N/

Depending on material selection the factor of sefety can be up to 5, therefore up on

this we select (Ns)=2 and service factor k=1.6 for most of jacks.

 Then = Ns*k = = 260.625

 Also, = = = 130.3
The direct tensile stress in screw body is given as follow

= OR 260.625 = from this equation solve for dc

= 15.46mm ≈ 15mm

Where, dc =core diameter of screw

Selecting standard screw

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 Design of multi-directional department of mechanical
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Core diameter(dc)=15.46mm≈ use 16mm

Outer diameter(do)=22mm

Mean diameter(dm)=18.73mm

Pitch(p) =5

Length of screw (L) =485mm + 2*dm=485mm + 2*18.73mm = 529mm

Torque required for overcoming the thread friction ( )

To do this the standard values for acme thread must be known;

For acme thread,β=14.5ᵒ, (µ)=0.15

Then helix angle ,(λ) = = = 4.857ᵒ

Coefficient of friction, ( ) = = = 0.154

β

Friction angle, (Ø) = )= (0.154) =8.80ᵒ

Required Torque, ( = * (Ø + λ)

= * (8.80ᵒ+ 4.857ᵒ) = 29228.7Nmm = 29.228Nmm

Efficiency of threads,(Ƞ) = = =73.46ᵒ =0.7346

Actual torque required, (T) = = 29228.7Nmm/0.7346 = 39788.5924Nmm = 39.788594Nmm

The direct tensile stress in screw body, ( ) = = = 73.18

Shear stress due to torque, (Zs) = = = 54.84

Maximum principle stress theory, ( ) = +

= + =

Therefore, check this value with the allowable

= 102.516 260.625

Hence, design is safe.

Maximum shear stress theory,

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 Design of multi-directional department of mechanical
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(Z) = =

Shear(z) = 65.926

ȥ =65.926

Hence, design is safe

Then check of factor of safety

=0.5 where, n = factor of safety

yts= max. Yield tensile strength

260.625N/mm2 = 0.5( then n= 1.6 which safe to check this design.

3.7 Material selection

Most jacks are usually made of materials that are very strong and are suitable for
withstanding heavy loads. The two main materials used for making good quality jacks are Steel
and Aluminum. When selecting the material suitable for the construction of the Scissor jack one
has to consider the properties that will enable it to function with no expected failure and at the
same time the weight and ease of machining the product. Therefore, the main areas that can be
classified in this case are the strength of the material, weight, ease and cost of manufacturing.
Aluminum is around one-third the density of steel at 2.72 mg/m cubed compared to steel's 7.85
mg/m cubed. The light weight and low melting point of aluminum makes it easier and more
efficient to machine than steel. Aluminum’s fatigue performance is half that of steel, which is an
advantage steel has over aluminum in car jack life durability. Therefore Steel is the most viable
material selected for the manufacture of the car scissor jack. Material is selected on bases of
application. The selection of the proper material for engineering purposes is one of the most
difficult problems for the designer. The best material is one which serves the desired objective at
the minimum cost. The following factors should be considered while selecting the material.
 Availability of the materials
 Suitability of the material for the working conditions in service, and
 The cost of the materials and others are as following.
The important properties, which determine the utility of the materials, are physical (luster,
color, size and shape, density, electric and thermal conductivity, and melting point .etc),
Chemical (acidic or basic) and mechanical (strength, stiffness, elasticity, ductility, brittleness,
malleability, toughness, fatigue, and etc.) are properties that should be considered. The problem
of material selection is solved by selecting some materials on the basis of their strength and
modulus of elasticity. We here compared mild steel , aluminum , plain carbon steels and alloy
steel, stainless steel and got an overall result for the best fit material to be low-medium carbon
steel.

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 Design of multi-directional department of mechanical
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The material will be designed completely using plain carbon steel. Designing a scissor jack
using plain carbon steel is a work of sheet metal shop. To overestimate the safety we will use
calculations of strength using the plain carbon steel in its undisturbed, solid form.
Low medium carbon steel 0.29% to 0.54% carbon –e.g. AISI 1040 steel
Medium carbon steels can be heat treated to have a good balance of ductility and strength. These
steels are typically used in large parts, forgings and machined components. Material properties at
25 : low-medium carbon steel Density = 7845kg/m3 Young’s modulus (E) =200GPa
Poisson’s Ratio (v)-0.3 Ultimate shear strength= 57420 PSI=342.4MPa approx. 66% of the UTS
(87000 PSI=18.8Mpa) Yield strength= 52500 PSI =353.4MPa and c =176.7Mpa permissible
crushing stress ( c). From [7] and [8].

3.8 Components material selection

3.8.1 Motor selection
To select the motor the power estimation that was used by human must be
calculated. Therefore, depend on initial data and human force range from 130N –
300N (text book of machine design 3rd Edition) we can select the related motor
Power = torque * angular velocity
But, angular velocity = velocity /radius of leveler arm
Velocity =
Consideration of time depend on average time
Time at minimum speed = 300sec
Time at medium speed = 180sec
Time at high speed = 100sec

T avg = = 193. 33sec (average time= 3.22minutes) where: Tavg = average

time
The velocity = = 2.5863
Now calculate angular velocity (ω) = = 0.01724
While 150mm (0.15) is from half of arm that rotate the lever 300mm length that make a circle
like diameter.
Then power (P) = T*ω
But, torque (T) = F*r while r is radius of arm that rotates the lever, to rotates the screw.
F= is human force, we choice 300N
T = 300N*0.15 = 45Nm
P = 45Nm * 17.24 = 775.875watt = 0.775875Kwatt
It is very low power which cannot lift up the load easily. Depend on these we select the related
motor to lift the required motor easily.

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 Design of multi-directional department of mechanical
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The drive mechanism of the jack will make use of a motor as its prime mover. The motor
required for this particular design is expected to transmit a relatively low speed at high power.
The motor is from the junk yard company and it’s from used bus wiper motor from the
manufacturer and calculated value standard torque from 13-15Nm. This torque is high enough
and suitable for this project. Then we select the 14Nm for our design. Since the motor is prime
mover for this jack the particular design is expected to transmit a relatively low speed at high
power. Therefore, the specification from label on motor.
Brand name; Lucas TVS
Part No: 35W60
Use: wiper
Type: DC Motor
Motor; Brush
Power; 1.34KW/130rpm
Torque; 14Nm
Voltage; 2V
Current; 2A
Weight; 2.9kg

Time required lifting the load to maximum height

Power (P) = but, work done (w) = force * distance(s)

Force (F) = = = 233.33N

W = 233.33N *500mm= 116,666.5N

Time (t) = = 87.0645sec.

The time required by the motor = 87.0645sec < time required by human 193.33sec
NB. This shows the motor required a few time to lift the load and by human there is high time
down of operation.

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 Design of multi-directional department of mechanical
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3.8.2 Gear Design

In design of gear, the following factors were considered.

 The input and output torque of the gears

 type, dimension and strength of gears
 durability
 wear
 Face width for adequate strength
 Economy of manufacture

Condition for initiating design of gear pair

In put parameters are decided studying and understanding the parameters at output of motor and
input required for screw of jack and certain a caption considered for designing gear pair.
Initial data
a) Input torque (T) =14
b) Input speed(N)=130 rpm
c) Output torque (TO )=39.8Nm
d) Gear ratio(G) =

G= =2.842857≈3

e) actual output torque (T2 )=G*T1 = 42Nm

f) output speed(N2 ) = =
N2 = =43rpm
Assumptions
The two diameters have been chosen on basis of achieving a reasonable velocity ratio of 1:3
between the pinion and the gear respectively. The drive transmission of DC Motor is via
the spindle then depend on these we select the gear diameters as follows
Diameter of gear (Dg) =90mm
Diameter of pinion gear (DP) =30mm

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The following geometry shows all the components of gear that uses to rotate the power screw.
From this we can easily understand how it assembles, because it draws in series reduction
follow. These components must combine carefully to accomplish the required purpose.

Gear
Gear Key Way
Motor Shaft
Pinion
Pinion Gear Key
Pinion Gear
Power Screw Key and Power Screw are shown as follow drawing.
Gear Power screw

Gear key Power screw

way key

scre
Motor shaft

Pinion

Pinion gear key

Figure 3.12 Gear Reduction Systems

Calculation of Gear parameters

Dg =90mm
Dp =30mm
Speed of pinion gear (np) =130rpm
Speed of gear (ng)
N umber of teeth of pinion gear =Ng
But, np *Dp =ng *Dg, then
ng =
ng =43.33≈43.33
Design Equation
Since, the pitch diameters of the gears are known, the following Lewis equation will be
used [3]. From Table 3.5

= Where, S =allowable stress ( )

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F = transmitted force (N)

M = Module (m)
Y= form factor
K= 4, upper limit
Since, both gears will be made of the same materials.
The weaker gear or pinion will be the weaker gear and governs the design.
The number of teeth on either gear for spur gears should not be less than fifty (˂15). Assuming
=16teeth for the pinion gear

Torque transmitted by pinion (T),

P=Tω but ω= then, T= =
Where,
P=power
ω=angular speed
N=speed
T= =98.4Nm
Transmitted force of pinion gear
F= = = =656.23N

Pitch line velocity of the pinion gear

V= *ω but ω=
V= = =0.482
Allowable stress, = ( )
For V less than 10 (˂10 ), where, =endurance strength form (high strength low
carbon steel with =410Mpa)
=410* ( ) =368.792M

Hence, = =2325.374* (allowable)

For, =16teeth and assuming

Y≈0.1 (for stub involutes)

Table (13.2) form factor (Y), for use in Lewis strength equation standard

Source [2].

=2325.374* ;

M=2.0737* m

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Let M=2mm; = =15teeth

Y=0.111(from table--)

=2252.25* (induced)

 Design is satisfactory since, ˂ , hence the gear is strong

Hence reducing K from K=4 to K=4( ) = 4(

K=3.87 therefore, face width (b)

Width (b) = KM= *3.87*2=24.3mm

.e the minimum width that can be used is 24.3mm, but to increase the life span reliability and
efficiency 25mm face width will be used.
Checking the tentative design value from stand point of strength, wear and dynamic load

Allowable endurance load ( )

= bY =4* Y

Where, = M

= average stress concentration

=4*410* * *(0.002)2 *0.111=7181.65N

Dynamic load ( )

= +F

For v=0.482 , an error of 0.05mm could be tolerated from the a noise stand point

C 570k (R.S khurmi2005)

F= +6560N

=6567.97N

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Wear load ( )

= *Qbk

But Q=2 ( )

= = =45teeth

Hence, Q= = =1.5

K =⦋ ( ( + )⦌⧸1.4

Assuming a brinell hardness number (BHN) of 250 it’s corresponding;

=618M [3]

Where, p modules of elasticity of pinion material .

= modules of elasticity of gear material,

=surface endurance limit of gear pair

Ф = pressure angle,

k=0.8871729*106, hence FW = 0.03*0.025*0.8871729 = 9980.0695N

Then design is satisfactory,

Since, Fo, Fw > FD

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3.9 Housing
Housing is a suitable external structure of the gear. Its main purpose is to protect the gear
from dusts and other external forces. It also gives a beauty for the motor part. Housing protects
the gear from damages and it cover the gear and pinion those are mesh to transmit the power
from motor ton needed mechanical advantages. It can manufacture from medium carbon steel or
aluminum.

3.10 Design of Side Member

The side member should be strength full to couple the components that are mount through its
system. For this reason the material for its design must be comfortable to accomplish material.
So medium carbon steel is selected, Due to its heat treated and has a good balance of ductility
and strength. These steels are typically used in large parts, forgings and machined components.
For this 0.29% to 0.54% carbon steel. E.g. AISI 1040 steel. The sleeve channels are to open
inwards as shown in Figure blow. This is so because the flanges (Lips) are subjected to tension
instead of compression. The bending moment from the power screw creates tension on the inner
edge of the sleeve and compression on the outside edge. Tension along flanges on the inside
prevents the possibility of localized bucking in the flanges from compressive forces.

3.11 Design of Main Base

The main base is part of multi-direction jack that support by the tires. It carries all the loads
that found above. Due to this it must be have enough strength to resist these loads. It supports by
the tires and mount with tire.
Material Selection: This base is manufactured by sheet metal processes and forming by low-
medium carbon steel. Low-medium carbon steels can be heat treated to have a good balance of
ductility and strength. These steels are typically used in large parts, forgings and machined
components.
Input assumption depend on the all load above the main base
Length (l) = 500mm
Width (w) = 500mm
Height = 30mm
Then depending on the principle of bending moment and section by inertia IXX

= but, I = where h= 500mm and h1= 10mm and b = 500mm

Then after substitution I= 10.0041667*106 and the value of allowable stress from material
selection = 260.625 then substitute to get thickness at x-x the y =

But, determine the maximum bending moment by taking the value 0 x 250mm and
0 x 500mm
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 Design of multi-directional department of mechanical
powered screw jack engineering

Bending moment at first interval is 159.3375*106Nmm and when the moment is about
= 0 then solve reaction force we got RA = 2550N
M x(-)

Vx Mx (+) we have general load of 5100N

-Mx + P* * …………………………………………………………………………………………..(1)

-Mx+ 5100N * * =0 then Mx = 159.3375*106Nmm

Similarly for 0<x<500mm at the end

Mx(-)

Mx (+)
x Vx

-Mx + 5100N * X* + RA * ( X - )……………………………………………………………………..(2)

Then Mx it is equals to 638.1375*105Nmm

-Vx + RA +RB = 0

Vx = 5100N equal with applied force

Then we select the maximum bending moment Mx = 638.1375*105Nmm

all = the use allowable stress 260.625

The thickness will be 8.19mm ≈ use 0.8cm

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 Design of multi-directional department of mechanical
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3.12 Design of Middle Base

The middle base is used to support the jack and the base that support the jack with the
required load. This base slides over main base when forth and back movement is required.
Depending on this we assume the dimensions as follows:-
H=20mm, L=140mm and W=120. The material we select to this also which is manufactured by
sheet metal processes and forming by low-medium carbon steel. Low-medium carbon steels can
be heat treated to have a good balance of ductility and strength. These steels are typically used in
large parts, forgings and machined components.
Length=500mm
Width =300mm
Height =20mm

As similar to the above bending moment principle the thickness of middle base 0.6mm
3.13 Design of Jack Supporter Base
This base supports the jack and slides over the second or middle base when right to left or
left to right movement is required. The material that selected to this is which manufactured by
sheet metal processes and forming by low-medium carbon steel. Low-medium carbon steels can
be heat treated to have a good balance of ductility and strength. These steels are typically used in
large parts, forgings and machined components. Depending on this the following assumptions are
made. H=40mm, W=200mm and L=300mm, a= 10mm, b=20mm.

Input value

Height = 20mm

Length =300mm

Width =300mm
The thickness of this middle base is thicker than other because the jack is mounted over it by the
bolt, so when calculate up on the above principle it will be 1cm it can be get by calculation.

3.14 Design of Ball Bearing

Bearing are machine elements included to support axles and shafts or sliding components. They
take up the radial and axial loads impose on the shaft or axle or sliding member they carry and
transmit them to the casing or machine body. In this system to slide the bases horizontally over
one another the bearing must be needed. After analyzing the different types of bearings we have
decided to select a ball bearing type. During selection bearing we have considered the following
parameters.
1) Basic dynamic load rating (c)
2) Basic static load rating ( )
3) Combined radial and thrust load (p)

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 Design of multi-directional department of mechanical
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For design proposed we select deep groove bearing because load capacity by the number of balls
and primarily designed to support radial loads the thrust load capacity is about 70 of the radial
load.
Bearing Life
Life: Number of revolution or hours operating at constant speed required the failure criterion
develop.
Rating life: Design the number of revolution or hours of operation at constant speed in such a
way that 90 of the bearing tested (from the same group) will computer exceed before the first
evidence of failure develops. This is known as bearing
Basic dynamic load|: Contact radial load that a group of bearing can carry for life.

life =( where a is constant ,a=3for ball bearing and ,a= for roller bearing

F=applied radial load

C=dynamic load rate

( = ( where =dynamic load

=rating life
=rating speed
= Desired radial load
=design load
=desired speed Bearing selection data for
single row, deep-groove, and Conrad type ball bearing.
We select the standard bearing diameter 10mm from the table. Therefore we select bearing
diameter 10mm-25mm from Standard Table [9] has inner diameter of 10mm, width 9mm, Static
load rate 440lb, and dynamic load rate 1000lb.
Life of Bearing
The expected life of bearing is
Where n=revolution per minute
T=hour of operation
The life of the bearing decrease with an increase with load.
Where k=3 ball bearing Ld=Desired life
K=10/3 for roller bearing Lc= life
From the table of reference [9],
Pd= designed load
The equation can be rewritten as depending up on the variable to be calculated

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 Design of multi-directional department of mechanical
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And Where Cd=dynamic load from table

Then

But =1500hr
Life expectance of the bearing is 1500hr as application of bearing
Table values of X and Y

The combined radial load

The Combined

their
properties and working principles are more related.
Material selection of bearing
In design of ball bearing as special criteria consider performance and bearing life, strength,
hardiness resistivity of temperature, high carrying capacitance, wear resistance, the bearing loads
such like as radial and trust, bearing reliability, bearing speed (rpm) space limitation, and
accuracy etc. depend on these aspects we select the medium carbon steel due its availability and
reliability to required purpose.

3.15 Design of Helical Spring

Spring is a flexible object that is used to store mechanical energy and is usually made of
steel. The spring chosen for this design will be made of alloy steel, for rigidity and elasticity.
This device allows controlled application of force or torque; the storing and release of energy can
be another purpose. The spring is incorporated to extend the motor and its components along

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 Design of multi-directional department of mechanical
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with the movement of the lifting members to avoid the gears meshing from disengaging. The
spring is embodied in a sliding member made of mild steel with the inner part of the cover also
coated with mild steel coating.

Sliding member

Hard cover

Helical spring

Figure 3.12 Motor Supporter Helical Spring

3.15.1 Helical spring

This is the type of spring type according to their shape. It is made up of a wire coiled in form
of a helix and is primarily intended for comprehensive or tensile loads. The cross section of the
wire from which the spring is made may be circular, square or rectangular.
The two forms of helical springs are
1. Compression helical spring
2. Tension helical spring
Also helical springs are said to closely coil when the spring wire is coiled so close that plane
containing each turn is nearly at right angles to axis of helix and wire is subjected to torsion.
Helix angle is very small. It is usually less than 10ᵒ. Open coiled helical spring are the helical
spring in which the gap between the two consecutive turns are occur as a result the helix angle is
large. Hence, the applications of open coiled helical spring are limited.
Therefore; closed coiled is available.
Advantage of helical spring
 It is easy to manufacture
 Available in wide ranges
 Reliable
 Have constant spring rate
 Their performance can be predicted more accurately
 Their characteristics can be varied by changing dimensions

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 Design of multi-directional department of mechanical
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3.15.2 Material selection for helical spring

The material of the spring should have high fatigue strength, high ductility, high resilience
and it should be creep resistant. It largely depends upon the service for which they are used .i.e.
severe service, average or light service.
Severe service: means rapid continues loading where the ratio minimum to maximum load
(stress) is one half of or less as in automotive valve springs.
Average spring: it includes the same stress range as in server service but which only intermittent
operation, as in engine governor springs and automobile suspension springs.
Light service: includes springs subjected to load that are static or very infrequently varied, as in
safety valve springs.
The sprigs are mostly made from oil‒tempered carbon steel wires containing 0.60 to 0.70 percent
carbons and 0.60 to 1.0 percent manganese.
The helical springs are either cold formed or hot formed depending up on the size of the wires of
small sizes( less than 10mm diameter) are usually round cold, where as large size wires are
round hot. The strength of the wire varies with size. Smaller size wires have greater strength and
less ductility, due to the greater degree of cold working [3].

Terms used in compression helical spring

Solid springs: when the compression is compressed until the coils come in contact with
each other, then the springs is said to be solid. The solid length of springs is the product total
number of coils and the diameter of wires.
Solid length of spring ( )

=n´*d where
n´=total number of coils
d=diameters of the wire
Free length: It is the length of the compression spring (the length of the spring in the free or
unloaded condition). It is the solid length plus the maximum deflection or compression of the
spring and the clearance between the adjacent coils.
Free length of the spring ( )
=solid length + maximum compression + clearance between adjacent coils (clash allowance)
=n´*d + +0.15
In the relation may also be used to find the free length of spring
l.e, =n´*d+ + (n´-1)*1mm
In this expression the clearance between the two adjacent coils is taken as 1mm.

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Spring index: It is defined as the ratio of the mean diameter of the coil to the diameter of the
wire.
Mathematical calculation of spring index(c) =
Where D=mean diameter of coil
d=diameter of the wire
Spring rate: It is stiffness or spring constant and defined as the load the load required per unit
deflection of the spring.
Spring rate (K) =
Where; W =load
d=deflection of the spring
5, pitch: it is defined as the axial distance between adjacent coils in uncompressed state.
Pitch of coil (p) =
May also can obtain
P= +d
Where, =free length of the spring
=solid length of the spring
n´=total number of coil
d=diameter of wire
Note: ‒to choice p must be
A) The pitch of the coils should be such that if the spring is accidently or carelessly
compressed, the stress does not increase the yield point stress in torsion.
B) The spring should not close up before the maximum service load is reached.
From reference [3]
Total number of turns n´=n+2
Solid length ( ) = (n+2) d
Free length ( =P*n*2d
Where n=number of active turns
P=pitch of the coils
D=diameter of square wires
Initial data
Compression of spring for maximum load of 10kg
Deflection depend on range value of spring index is 5 deflection is 25mm
Maximum permissible shear stress for spring wire is 300Mpa and modulus of rigidity (G) is
80KN/mm2. Data from reference [6]
Then shear stress factor (k)
K= +
Where, c = spring index

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K= + = 1.31
From maximum shear stress (ȥs)
350 =
D = 2.54mm≈ 3mm
(From table 23.2 we can select a standard wire of size SWG3 having diameter of 3mm)
Therefore mean diameter of the spring coil
D=c+d = (15+3) mm=18mm
Number of turns of the coils, let n=number of turns of the coils we know the compression of
spring ( ) =25mm.OR use this formula.
=

= ═ n =60 because our circular diameter of wire (coil) is smaller and is assumed to lift
the maximum height of jack.
NOTE; this turning value is used to lift maximum height of 500mm. But, we need to support the
motor up to the half length or maximum lifting of the lower link. So n = (60)
n = 30
For square and ground ends, n´=n+2=60+2=62
Therefore, free length ( ) =n´*d+ +0.15
=63*3+25+0.15*25=214.75mm
Solid length ( ) = (n+2) d = (60+2)3=186mm
Then the pitch of the coil (P)
= +d or
+ 3 = 3.52 select for standard 4mm

Spring rate (k’) = = =4

The maximum axial load that spring can carry (‫)ح‬
=
300 = then W= 212N it is very high at this level the spring coils are completely
useless.

Check factor of safety

Working load = maximum load divided by factor of safety. From this let check factor of safety.
Working load = 100N
Maximum load at which will damage the spring coil = 212.05N

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, 100N = , then n = 1.06 it’s safe. We can use

up to 1.5 Standard.
Check with material selection
Ns = 0.5
Ycs = 651Mpa spring yield compression strength for light service (table 23.1 R.S Khurmi 2010)
t = 300Mpa
Ns= = 1.085 also safe.

3.16 Wheel Design

From geometric analysis, diameter of wheel=60mm
Total stress of the wheel can be calculate as

=F/A where = stress at wheel

F is force=5000N
A=Area of wheel=Пd²/4
=5000N*4/П*(0.06mm)²
=1.299224MPa
Since the number of wheel is two at back leg the stress in induced on each wheel (n =2)
1= 1/n
1= 1.768388257MPa/2
1=0.8841941283MPa
Where, n is number of the wheel, for two wheels only.
NB. The force distribution is similar at all wheels.
Material selection for wheel
The material that used for caster wheel must have high compression ratio, high wear
resistance, excellent machinablity also must have low cost, good casting characteristic.
Due to this we select cast iron for caster wheel.
Tensile strength = 100 to 200MPa
Compressive strength = 400 to 1000MPa
Shear strength = 120 MPa
 Depending on each part design their weight
N.B the dead weight of machine (jack) = 8.091Kg so 10Kg needed because of some
fining parts.
 Mass of main base = 3.998kg = 39.98N
 Mass of middle base = 1Kg = 10N
 Mass of small base = 0.893kg = 8.93N
 Weight of lifting members = 10N

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 Assumptions of others weight = 12N

 Maximum load assumed to lift = 5000N
AREA; (A) = D2/4
A1 = *602 = 2827mm2 where, D = outer diameter
A2 = *402 = 1256.6mm2 d= inner diameter
Therefore, area of wheel = A1 – A2
= 1570mm2

P= 5080.91N all loads from above to wheels

480

A B

Ra Rb

Then find action and reaction forces that distributed to each wheels. By applying condition of equilibrium.

To calculate the reaction force Ra

∑MA= 0

Rb*480 - *480 = 0 while, = = 1270.2275N and number of wheel = 4

Rb = 1270.2275N they are equal in magnitude but, opposite direction.

Solve the reaction force at B by assuming the summation of momemtem about B .

∑MB = 0

Ra * 480 - 480 = 0

Ra = 1270.2275N

 These shows the distribution of force to each wheel is equal = 1270.2275N

3.17 Design of Power Screw

Power screws are used to convert rotary motion in to translational motion. It is also called
translational screw. They find use in machines such as universal tensile testing machines,
machine tools, automotive jacks, vises; aircraft flap extenders, trench braces, linear actuators,
adjustable floor posts, micrometers, and C-clamps. A screw thread is formed by cutting a
continuous helical groove around the cylinder. These grooves are cut either left hand or right
hand. The majority of screws are tightened by clockwise rotation, which is termed a right-hand
thread. Screws with left-hand threads are used in exceptional cases. For example, anticlockwise

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 Design of multi-directional department of mechanical
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forces are applied to the screw (which would work to undo a right-hand thread), a left-hand-
threaded screw would be an appropriate choice.
Power screws are typically made from carbon steel, alloy steel, or stainless steel and they are
usually used with bronze, plastic, or steel mating nuts. Bronze and plastic nuts are popular for
higher duty applications and they provide low coefficients of friction for minimizing drive
torques.
There are important terms and figures that need to be understood before designing power screws:
Pitch: is the distance from a point on one thread to the corresponding thread on the next
adjacent thread, measured parallel to the axial plane.
Lead: is the distance the screw would advance relative to the nut in one rotation. For single
thread screw, lead is equal to pitch.
Helix Angle: is related to the lead and the mean radius by the equation below;

Figure 3.13 how screw out raises load

Basics of power screw

Power screws provide a compact means for transmitting motion and power. They are ideal for
replacing hydraulic and pneumatic drive systems as they require no compressors, pumps, piping,
filters, tanks, valves or any other support items required by these systems. Also, screws don't
leak so there are no problems with seals which are so common to hydraulic and pneumatic
systems. And, screw systems are quiet running - no noisy compressors, pumps or exhaust valves.
Screw systems are simple, reliable and easy to utilize.
There are four distinct motion converting actions that can be produced by power screws and
nuts. The two most common involve torque conversion to thrust. The screw is rotated (torque)
and the nut moves linearly producing thrust or the nut is rotated (torque) and the screw moves
linearly. The two less common motions involve thrust conversion to torque. The nut undergoes a
linear force (thrust) and the screw rotates or the screw undergoes a linear force (thrust) and the
nut rotates. These two motions are commonly referred to as "back driving", "overhauling", or,
improperly, "reversing".

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Figure 3.13a figure 3.13b

For this project we select the acme thread depend on its function
Acme threads:
 It is a modification of square thread
 Efficiency is slightly lower than square threads
 The slope increases the area for shear
 It is easily manufactured and it’s not need more cost
 It’s much stronger than others threads
 It can easily manufactured on lathe machine
This data from [1]

Among these types we select an Acme threaded screw with collar at both ends, with one end in
contact with members and the other end having a square key way to enable the transmission of
torque from the gears. The collar is assumed to be frictionless and the power screw has been
designed to be self-locking.

Hexagon head
Acme
thread
Key way
Collar

Figure 3.14 power screw

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FBD of powered screw

F16 F41
ө

ө F17 F15 Ө

Depending up the principle of Newton 3rd law

‘Action and reaction force applied on body are equal and opposite in direction’
Therefore, from the lifting member to the screw
F41= 7309.511N but opposite in direction
Let as check the force that applied to screw
∑Fx = 0
F41cosӨmin + F15cosӨmin – F16COSӨmin – F17COSӨmin = 0
COSӨmin (F41+ F15 - F16 - F17) = 0
F41+ F15 - F16 - F17 = 0……………………………….(1)
The two forces F15 and F17 unknown.
∑Fy = 0

F17sinӨmin + F15sinӨmin - F16sinӨmin - F41sinӨmin = 0

F17 + F15 – (-7309.511N) – (-7309.511N) = 0
F17 + F15 = 14619N…………………………………………………………..(2)
But, F17 and F15 they are equal. Then we can say
2 F15 = 14619N
F15 = 7309.51N
Therefore, F15 = 7309.511N = F17
The value is checked for eq.(1).
Other values are calculated under force analysis
Length =529mm
Core diameter = 15.56≈ 16mm

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Outer diameter = 22mm

Mean diameter = 18.73mm
Pitch = 5
This value is from table 23.11 [11] after related calculation.

3.18 Design of base slider screw

This screw operates manually; it uses to slide the bases over one another. So the force that
occurs in screw is tension force (tensile stress) must be known to select the available material
which stands the external load that makes it fracture. Typically it made from carbon steel, alloy
steel, or stainless steel and they are usually used with bronze, plastic, or steel mating nuts.
Bronze and plastic nuts are popular for higher duty applications and they provide low
coefficients of friction for minimizing drive torques. Among these material we select carbon
steel of 35% carbon steel, the tensile strength is 485 MN/m2, with yield strength of 345 MN/m2.
Factor of Safety of 2.5 is chosen, because the material is known under reasonably constant
service conditions subjected to loads and stresses that can be determined
easily. We select this screw from standard dimensions of screw threads according to IS; 4218
(part III) 1976 (reaffirmed in 1996) table 11.1and reference [7]
Length of screw = 520mm
Nominal diameter = 1.6mm
Pitch = 1.373mm ≈ 2mm
Core diameter = 1.2mm
Depth of thread = 0.215mm
Stress area = 1. 27mm2
Look at the figure below to understand how it connects the three bases to make the required
sliding system.
Small screw
that uses for
bases sliding

Figure 3.15 bases slider screw.

3.19 Design of supporter cup

This part is the main part of our jack and which must be enough strength to support and hold
the load carrier supporter. It has the square hole at its top. Which the load supporter head is
socket through it. So it contact with high load before it distributed to the different parts of jack
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 Design of multi-directional department of mechanical
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(lifting member) and others. The members that make contact with small base and the service load supporter and the
end link (lifting member) supporting base respectively. This member has a broader area to provide a stable base for
the mechanism while servicing the load. It is used to hold load supporter head through its square socket shape. This
square must be standard for each socket head. So the connecting members must provide sufficient contact area. Most
scissor jacks have ridges which lower the area of contact. This causes stress concentrations which can damage the
underside of a car. But, in the multi-direction it can’t damage underside area easily.

The contact member as this design it is standard to socket any load supporter through it. So we design the socket
part square hole length of 100*100mm and deep hole size 80mm depend on these values the area can be calculate;
area = (100mm)2 = 10,000mm2 .Force distribution in load supporter cup and its free body diagram (FBD)

F1 F2 Ө
W=5000N

F1
F2 Ө
F1cosӨ
In previous section we calculated
= and =
From force analysis by using these angles we can do the force analysis in this part
∑ =0, min + min –W=0
From the above equation we get
+ =14619.022N……………………………………………….(1)
- =0
From this equation we get
( + ) min=0……………………………………………….(2)
But, since the force distribute to each lifting member is equal
=
Then from equation we can say 2F1= 14619.022N
F1= 7309.51N
Check at eq.(2)
- =0
=
From this analysis we can conclude

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Most forces distributed to all links through contact member are equal and opposite in direction.

So, F2= F2= F12= F21 = 7309.51N

3.20 Design of lifting member

These members are made from simple c-shapes. The web of the lifting member is cut out
near the pin connections to allow proper serviceability of the multi-direction jack at its maximum
and minimum heights. Members have connections to balance the load between the left and right
side. The shape of this part is channel or (C- shape), depending on its advantages than others
geometers.
Advantages;
 resistance to stress concentration is high
 The load is distribute easily to its shape
 Its geometrical properties to carry the load that applied to any side
 All resistance to external loads related to; tensile strength, bending resistance,
compression resistance, e.t.c. Source from;[3]
Force distribution in lifting member as following:
FBD diagram

W
F13sin Өmin

F13 Өmin

F13cosӨmin

F14
F14sinӨmin
F14cosӨ

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The value of is known from load supporter cup calculation. It is equal with but opposite
in direction.
i.e. =-7309.51N
Then ∑ =0
∑ =- min + min=0
Then, = =7309.51N
Therefore the force distribution in all four links are equal in magnitude depend on their
mechanism their direction may be different.
To calculate (know) the length of lifting member depending on triangle sine law depend on .
NB; take the half or upper part of jack at maximum angle when the vertical is
(500* ) mm=250mm

X =length of lifting member

y

To find x Use sine law

= , y= 250mm
+
Then we get x=257.10379≈257mm length of each lifting member
Check the summation of two links are greater than our maximum lifting height (500mm)
and we select thickness 8mm is enough as our assumption depend on load required to
lifting. The determination of thickness of lifting member depends on the above data and c
channel principle formula.
t

257

20

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Lifting member force is 7309N

Solve the area A 28.044

Therefore, for c shape when have area thickness can be calculated as following
A B t (H t)a equation from [2]
28.044 = 257 *t + (20 –t)*40
Then t= 3.574mm≈ 4mm = 0.4cm from standard comparison.
3.21 Design of pin
A pin is a permanent mechanical fastener. Before being installed a pin consists of a smooth
cylindrical shaft with a head on one end. The end opposite the head is called the buck-tail. On
installation the pin is placed in a punched or pre-drilled hole, and the tail is upset, or bucked (i.e.
deformed), so that it expands to about 1.5 times the original shaft diameter, holding the lifting
member in place. To distinguish between the two ends of the pin, the original head is called the
factory head and the deformed end is called the shop head or buck-tail. It’s subjected to shearing
stress. This shearing stress is uniformly distributed over the pin. The cross-section is simple
joint. Join the two flat plates. It can be made using a pin those made through both the plates
where diameter is equals to the diameter of pin. When pin is inserted the hole then lifting
member contact to the load that required to lift.

P’ p’

FBD of pin

Then the load(p) verticaly applied to the pin

P= ȥs

But, the yield tensile strenth from selected material is yts =342.4Mpa

t = 490Mpa tensile strength.

Then let n=2 depend on material selected at plain carbon steel with its properties avaliable to
to this design.

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Then, ‫= = ح‬ Mpa=171.1Mpa

The diameter (d)of the pin and thickness of the plate is ( ) can be calculated by using this formula p= ‫ ح‬where
=
‫ح‬

P= =

=13737.38N

From the force analysis , =

Then (p) = load to the one side pin

P’= =18.871KN

Then we can calculate diameter of the pin (d)

= = =140.4367
‫ح‬

d=11.85mm≈12mm available by up rounding

the pin is compressed to against the plate when the load (p) act on the joint.

Hence , one more way in which crushing against the plate. The area which resists depend on the thickness of the
plate. Then depend on the diameter of pin the plate thickness can be calculate

→permissible crushing stress in pin material But

= = Mpa

Yield strength 354.4Mpa from material selection in table.

P =dt →t= =6.56068mm≈7mm

Therfore to standard thickness we can round to 8mm thickness sheet metal.When pins pushed against the plate in the
hole it is possible that the margin in the plate can shear off.margine in the distance of edge of the plate from center
line of pin hole.

The area is (A)=m*2t

Where m=margin, Then from load formula

P=2mt‫→ ح‬m= ‫ح‬

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Substitute m= =8.1189mm

m=8.1189mm ,because its t is sheared

if the permissible tensile stress of the plate material is ( ). Thenthe load which can be applied
upon the load (p). let width w=60mm

p= (W-d)t → =

, ˂260.625

Therfore 59.74 ˂ 260.625 then the design is safe.

3.22 Design of differential supporter head

Head is one of the parts of the jack which is used to support or hold the required part on it
during maintenance. This design of head is designed depending on the part that to be maintained
or operate. For our particular design we select 3rd differential supporter (head). Since, the 3rd
differential have a half of cup shaped like structure we design accordingly.
Its socket part is standard to easily socket to the square hole of contact member as we design
under cup or head load contact member. Its base length 98*98mm and height that completely
insert to the hole is 80m.
The material selection for from table as we summarize for all material by considering the
different properties and principles to select the spesifical material to spesifical purpose the
medium carbon steel is the best to manufacture this component.

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3.23 Manufacturing process

The knowledge of manufacturing process is a great importance for a design engineer. Then it has
five main processes.
1, primary shaping processes
2, machining processes
3, surface finishing process
4, joining processes
5, processes effecting change in properties
Depending on this process we can manufacture the machine components

3.23.1 Manufacturing process main base

To manufacture the base the sheet metal from medium carbon steel must be prepared with design
specified dimension.
: cutting process
Cut the prepared metal to square dimension of 500mm, number of prepared sheet metals is two
and also cut the sheet metal of length 500mm, height 30mm and for width cut with height and
length of width 500mm.
NB: the cutting process is used with the help of power hacksaw or powered grader.
: welding process
Before welding cut the one width plate which is assumed to be at the direction of motor side by
460mm at the center of plate with height of 12mm.
Therefore, weld carefully by keeping the dimension of the plates. It should give the square box
after welding (use the arc welding which is more prefer than others)
Step 3 by using the grader or milling machine groove on the upper surface to the width direction
by deep length of 4mm in which half part of ball bearing is insert through it. The grooves are far
to each other over upper surface 460mm.
Lastly: surface finishing
Checking and make smooth the parts of welding if any.

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3.25.3 Manufacturing process of wheel

In manufacturing casters there are three key important things that must improve;
1. Increasing strength
2. Improving quality
3. Shortening production time
These improvements have come from the laser cutting and forming of the rig removing
approximately 40% of the welding and dramatically changing the design process.
1. Increasing strength, in the production of heavy duty caster the plot form that the length rare
attached to the manufacture in one single flat blank, the blank is developed to accommodate the
material that will be consumed at the time the length are formed.
The forming process, using a press brake, movies the leg material so that the legs are in the 90
degree orientation to the platform in a welding process the leg would be welded to platform.
The forming process when complete, make a part that is 25% stronger than the welded product
and cannot fail unless there is total material failure.
The laser cutting or forming process totally removed an area of potential failure from the
finished product.
2. Improving quality; when parts are made in a stamping process this is initial a clean failure of
the material (approximately half of the thickness of the material) and them the reminder of the
material will break out leaving an edge that has variability in the range of 0.762mm.
When apart is laser cut the edge quality and hole (for the axle placement) can be held with
0.0508mm.
The most significant impact of this accuracy is in fact with the axle, instead of grinding the hole
to the final dimension, the hole is cut initially to an ideal fit which significantly improves the
quality of final product.
3. Shortening production time; when designed property the laser cutting or forming process
results in a processed part that is closer to the finished product at the time it is cut. The reason for
this is all components of the rig are essentially integrated in to the original laser blank hence
avoiding tittles or no additional welding. The avoidance of secondary operations will always
speed the product through the manufacturing process while controlling additional costs. The
engineering staff of caster concepts can design heavy duty casters that utilize the most modern of
manufacturing process to maximize the ability of caring the load.

3.23.2 Manufacturing process of lifting member

Before starting the manufacturing any component the shape that we want to produce must be
understand carefully. This component is formed from the channels or c-shape.
4) Shaping process
After preparing the plate of medium carbon steel of thickness 80mm, length 257mm,
width180mm, measuring and sign the size measured. Then cut the plates carefully by the help of
power hack-saw or other machine Chamfering the both ends by the optimum radius
recommended in design from both sides and remove out from width center to edge by 80
diameter and length 60mm. this all are by machining process then make the c-shape by bender

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machine the left c corner from both sides by fifty millimeter and drill the hole by the diameter of
pin at both tip by drilling machine.
Lastly: check the surface finishing and dimension
NB: all for lifting members are manufactured by similar process

3.23.3 Manufacturing process of ball bearing

Ball bearings are manufactured to a very high precision level in high volume quantities. In
some cases, lines are completely automated starting from the raw material phase to the finished
product. Great care has to be taken to keep all parts clean and free of rust. The specification for
ball bearing steel is very demanding. In normal service the steel must withstand compressive
stresses more than 5000N and, in extreme service. The standard grade steel for ball bearings is
high carbon, high chromium, vacuumed degassed AIS/SAE 52100. The high carbon content of
l% gives the steel excellent response to heat treatment resulting in very high strength and
hardness. The high chromium content of 1.35% further increases responsiveness to heat
treatment and adds depth of hardness penetration. Vacuum degassing removes impurities making
the steel extra clean. For extremely critical applications, consumable electrode vacuum melted
steel is available for an even higher degree of cleanliness and uniformity.
Rings and balls are heat treated to the RC60 level for optimum toughness and strength at
o o
operating temperatures up to 300 F. For operating temperatures over 300 F, the steel softness
and loses dimensional stability. A special stabilization heat treat procedure is available for
o
continuous operation at temperatures up to 400 F. Stabilization tempers the steel at a temperature
above what is encountered in service resulting in a slight decrease in hardness from the RC60
level. Stainless steel is used for rings and balls for corrosion resistance and high temperature
o o
operation up to 550 F. For even higher operating temperatures up to 1100 F, special tool steels
and cobalt alloys are used.
Separator steel for most bearings is low carbon steel. Most angular contact bearings operating at
high speed use a non-metallic separator material. Non-metallic separator material combines low
o
friction, light weight, and strength up to 275 F. With higher temperatures and speeds, iron silicon
bronze and phosphor bronze provide low friction and a high strength-to-weight ratio. For
o
temperatures up to 1000 F, S-Monel, special tool steel, and alloy steel are available.
Balls are processed as follows:
 They are cold-headed to a spherical shape from drawn bar.
 They are soft ground.
 They are heat treated in high temperature furnaces.
 They are hard ground.
 They are lapped to a mirror-like finish.
Assembly of most ball bearings is as follows:
 On a flat surface the inner ring is placed off-center inside the outer ring.
 The balls are loaded inside the crescent shape that is formed.

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 The inner ring is centered and the balls evenly spaced.

 The separator is installed.
Ball bearing inner and outer ring process
 All rings are machined from special sized steel tubing.
 They are thru-hardened in heat treat furnaces.
 Every surface is fine ground to exacting tolerances.
 Pathways are honed to even finer surface finishes.
Thread rolling is accomplished by shifting work material by plastic deformation, instead of
cutting or separation, with the help of a pair of dies having same threads desired..
Different types of dies and methods are used for thread rolling which include,
 Thread rolling between two flat dies
 Thread rolling between a pair of circular dies
 Thread rolling by sector dies

3.23.4 Manufacturing process of power screw thread

There are three types of production of screw thread .those are;
(a) Machining
(b) Rolling
(c) Grinding

Forming (Rolling)
 blanks of strong ductile metals like steels are rolled between threaded dies
 large threads are hot rolled followed by finishing and smaller threads are straight cold
rolled to desired finish
 cold rolling attributes more strength and toughness to the threaded parts
 Widely used for mass production of fasteners like bolts, Pin, screws etc.
Rolling of external screw threads by flat dies
The basic principle is schematically flat dies; one fixed and the other moving parallel, are used in
three configurations:
Horizontal: most convenient and common
Vertical: occupies less space and facilitates cleaning and lubrication under gravity
Inclined: derives benefit of both horizontal and vertical features.
All the flat dies are made of hardened cold die steel and provided with linear parallel threads like
grooves of geometry as that of the desired thread.

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Figure 3.16 Principle of thread rolling by flat dies

3.24 Lubrication system

Lubrication of any vehicle is important to prevent damage to moving parts. Because all
moving parts are not subject to the same operating conditions. The lubricants specified are those
which most nearly meet the requirements of the parts involved. In some places excessive heat or
cold is a problem to overcome, in others it is extreme pressure, water, sand (grit). A lubricant is
a substance introduced to reduce friction between surfaces in mutual contact, which ultimately
reduces the heat generated when the surfaces move. It may also have the function of transmitting
forces, transporting foreign particles, or heating or cooling the surfaces. The property of reducing
friction is known as lubricity. Lubricants are generally composed of a majority of base oil plus a
variety of additives to impart desirable characteristics. Although generally lubricants are based
on one type of base oil, mixtures of the base oils also are used to meet performance
requirements.
There are three main types of lubricants
 liquid lubricant
 semi-solid lubricant and
 solid lubricant
Among these the liquid and grease are mostly used for moving machine parts. But, liquid is
uses for components have high speed and required more lubricant. While semi-solid is used for
low speed machine components. For these, since the sliding bases have very low speed the semi-
solid is best. This contains greases and others. So the grease is available to them. For the gear
meshing we can use the liquid lubricants.
NB. The process of lubrication system must be done before any machine components starts
assemble. Advantage of lubricants: Keep moving parts apart, Reduce friction, Carry away
contaminants ,Transmit power, Protect against wear ,Prevent corrosion, Seal for gases, Stop the
risk of smoke and fire of objects and Prevent rust and etc.

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CHAPTER FOUR: CONCLUSION AND RECOMMENDATION

4.1 Conclusion
The existing screw jack was modified by making small alteration and making use of an electric
motor to drive power screw, connecting gear with the pinion mounted on the motor shaft and two
additional main parts to make the maintenance easy. The bases those slides over one another and
the changeable socket load supporter head according to the shape required to be maintain. The
automobile 12V battery source operates prime mover (motor), to facile load lifting easier and
also used to transport short distance in work shop and the sliding bases to operate the
components of heavy duty assembling. The power screw is rotated through its gear when
electrical power flows through it. The advantages of this jack is it will save time, be faster and
easier to operate and requires less human energy and additional work to operate. There by
effectively curb the problems associated with Ergonomics which is a fundamental concept of
design process.

When consider all available car jacks in the market, this manufacturing process can be
improved by a few modifications on the features and design. The objectives are to design a
multi-directional power screw jack that is safe, reliable and able to raise and lower the level, to
develop a jack that is powered by internal car power and automated with buttons system. Based
on the estimation and results from the analysis, it is considered safe to use this Jack for vehicle
works under certain specifications. Furthermore the torque supplied on the system is more than
enough to lift a weight around 500 kg. There are certain weak point that can be improved based
on gear, motor and design.

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4.2 Recommendation
As can be seen from design the wheel of this jack uses only on the horizontal or leveled
surface. We can recommended that further research should be conducted with a view to making a
wheel system is more universal to any surface wither it is inclined or horizontal with the help of
adjustable wheel system for required slope.
Also we recommend that the base can be changed to a universal rotating system to 360 degree
depend up on the view of making a base one and vertically grooved hole then insert the bearing
and the shaft is fixed to the base of the jack, then by inserting to the bearing the system can be
rotate easily.
This further work should go beyond the result achieved by this project, which was handicapped
by time, and design information. There is need for improving efficiency and reliability if
possible.

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4.3 References
1) Shigley’s Mechanical Engineering Design 8th Edition 2010.
2) Khurmi, R.S. and Gupta, J.K. (2005), A Textbook of Machine Design, Eurasia
Publication House (P.V.T) Ltd. 14th Edition, 1230pp. ISBN: 81- 219-2537- 1.
3) Rajput, R.K, (2007), A Textbook of Manufacturing Technology.
BJC (Boston Jacks Corporation). 2008. Jacking beams manufacturer ISO 9002 (BS5750)
500.www.boston ge.com and Strength of materials and Structures 4th Edition 1999 and
Beer Jons 5th Edition. And mechanical design R.S Khurmi 2010 and 2005
4) Appratus and Method for an Electric Jack II, US Patent No. US2007/0256526 A1. Date
of patent. Nov 8, 2007.
5) A Textbook of Material Science and Metallurgy I, Dhanpat Rai, 5th Edition.
6) Design of Machine element II, Tata McGraw-Hill Education.
7) Design of Toggle Jack Considering Material Selection of Screw Nut Combination I,
International Journal of Innovative Research in Science, Engineering and Technology,
(Vol. 2, Issue 5, May 2013) ISSN: 2319-8753.
8) Modeling and Finite Element Analysis of Spur Gear International Journal of Current
Engineering and Technology (Vol.3, No.5, December 2013) ISSN: 2277 – 4106.
9) HiTech Division,www.nhbb.com radial ball bearings standard diameter 10-25mm

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Appendixes I: List of figures

This appendix contains all the components drawing and assembly of them.

Figure 3.9 (a) upper position jack FBD

Figure 3.9 (b)lower position of jack FBD

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Figure: 1 Load supporter cup that holds socket head through standard square hole.

Figure: 2 lifting member

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Figure: 3 side member

Figure: 4 PIN

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Figure: 5 jack supporter small base

Figure : 6 middle base

Figure: 7small screw supporter plate

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Figure: 8 main base

Figure: 9 wheel

Figure: 11 the motor supporter helical spring cylinder and smallest slider base

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Figure: 12 helical spring and its sliding cylinder

Figure :13 the motor and gear meshing diagram

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Figure: 13 power screw

Figure: 14 power when we use for manual system

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Figure: 15 socket lever for manual operation

Figure: 16 3rd differential supporter head

Figure: 17 propeller shaft supporter head

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ASSEMBLING DRAWING OF MULTI-DIRECTION JACK

Figure: 19 Assemble of multi- directional power screw jack

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Appendix: II List of tables

Material properties tables
We depend on this table to select the materials for each component that we were designed.
Depend on data from [7]

Tensile strength of 931Mpa 135000psi

material
Tensile strength yield 834Mpa 121000psi
Elongation at beak 20.2 20.2
Modulus of elasticity 205Gpa 29700ksi Typical for steel
Bulk modulus 140Gpa 20300Ksi Typical for steel
Poisons ratio’s ratio 0.29 .29 Calculated
Shear modulus 80Gpa 11600ksi

Material Property of C45 and C35 Mn75 are given in Table 3.2
Table depend on data from [8]

Steel plate(sheet (Mpa) (Mpa) (sample from of cold bending

thickness)mm the standard for test
50mm(2in)
Hot rolled(cold 520 415 16-18 longitudinalhorizontal
rolling) 5-150 2a 3.5a

Table3.3 Properties of material

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Parameter Pinion Gear

Material C45 C35Mn75
Tensile strength 670 600n
BHN 229 223
Elastic modulus 210GPa 190Mpa
Izod impact value 41 55

Table 3.4 Material Property of C45 and C35 Mn75 from [9]

No. of teeth 14 full-depth 200 full-depth 200 sub-involutes

involutes
involutes or
composite
14 0.075 0.083 0.108
15 0.078 0.088 0.111
16 0.081 0.092 0.115
17 0.084 0.094 0.117

Table 3.5 Form factor (y) for use in Lewis strength from reference [3]

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