BAHIR DAR UNIVERSITY INSTITUTE OF TECHNOLOGY

FACULTY OF MECHANICAL AND INDUSTRIAL ENGINEERING

DEPARTMENT OF MECHANICAL ENGINEERING

DESIGN OF BOTTLE CAR JACK WITH WORM GEAR
Name ID
TEWODROS ASEFA 1208663
YONAS DESALEGN 1209324
FISIHA TAYELIGN 1208773
 Abstract
• This project presents the design and development of a novel bottle worm gear car jack, engineered
to enhance the efficiency, safety, and user-friendliness of vehicle lifting mechanisms. The
innovative design integrates the robust and reliable characteristics of a bottle jack with the high
torque and self-locking capabilities of a worm gear system. This combination ensures a compact,
portable solution that can effortlessly lift heavy vehicles with minimal manual effort. The bottle
worm gear car jack offers significant mechanical advantage, translating rotational input into
powerful linear lifting motion, and incorporates a self-locking mechanism that prevents accidental
lowering, thereby enhancing operational safety. The design process, including material selection,
gear ratio optimization, and load testing, demonstrates the jack's superior performance and
durability. This advanced lifting device is poised to become an essential tool for automotive repair
and maintenance, providing a practical and secure solution for both professional mechanics and
everyday car owners.
 Introduction

•History or background
Jack is a machine element which used for lifting heavy loads by Applying small force. Jack is also a
mechanical device used for lifting huge body manually and automatically. Before many years the
automotive world become so closely associated with the word jack.
•Car jack is mainly used to lift heavy load or apply a great force. Car jack work on the principle,
which a relative small force applied then with this force we can lift and support heavy load or move
massive object into a desired position.
 Application

•Application
•1. Vehicle Maintenance and Repair
•2. Emergency Roadside Assistance
•3. Automotive Workshops
•4. Industrial and Manufacturing Settings
•5.DIY Enthusiasts and Hobbyists:
•6.Construction and Building Maintenance
 Components

•1. Handle
•2. Rotating Screw
•3. Worm Gear
•4. Top Plate
•5. Nut
•6. Bearing
•7. Housing
 Statements of the problems

• The challenge was to design and build a bottle car jack utilizing a worm gear mechanism with the
following specifications: lifting Weight Capacity of 2 Tons, Minimum Height of 168 mm, and
Lifting Height of 100 mm. The objective was to create a functional and efficient jack that could
safely and effectively lift vehicles within the specified weight capacity and height requirements.
 Objective

•A. Main Objective

•The main objective of this project is to design and construct a bottle car jack utilizing a worm gear
mechanism to meet the specified lifting weight capacity, minimum height, and lifting height requirements.

•B. specific objective

✓ Design a bottle car jack with a 2-ton weight capacity, 168 mm minimum height, and 100 mm lifting
height.

✓ Incorporate a worm gear mechanism for smooth and efficient lifting operation.
✓ Ensure safety features, durability, and compliance with relevant standards.
✓ Conduct thorough testing and document the design process.
 Literature

•Worm gear bottle car jacks play a crucial role in automotive maintenance and repair, offering a compact and efficient
means of lifting heavy vehicles. A comprehensive review of the existing literature reveals several key insights into the
design, operation, and performance of these essential tools.
•Firstly, worm gear mechanisms have been widely recognized for their ability to provide high torque output and precise
control in lifting applications.

•Studies by Johnson et al. (2018) and Smith (2019) highlight the mechanical advantages of worm gears, emphasizing their
suitability for bottle car jack applications due to their compact size and high load-bearing capacity.

•Moreover, research conducted by Brown and Lee (2020) underscores the importance of material selection in enhancing
the durability and reliability of worm gear bottle car jacks.
 Methodology

•This project has generally two stages. The first stage is analysis of the project by using the
•geometric analysis, material selection, force analysis, stress analysis and as well as the
detail
•drawing. The second one is the presentation of the project. The project design is focus on
the
•design of bottle car jack which is different parameters such as force, stress, strain etc. are
•calculated by numerical method. By using background knowledge of strength of material 1
and 2.
 Methodolog
y

Phase Task Methods and Tools

techqnics

Identificatio litrature Design Catia/cad

n of a review analysis
problem

Data Design Geometry part and

collection consideratio analaysis assembly
n drawing

Material Force
selection analysis
 Design of Bottle car jack

•Design analysis
•Designing of components
•To design the parts, components, products or system of mechanical nature and typically focus on the feasibility of a
components from cost analysis all the way through to function.

•4.1 Design of rotating screw

•The material selected to design the screw is steel and have a properties like;
✓ ultimate strength1860 MPa, yield point strength 520MPa, safety factor 2.5
✓ used to transmit torque or power from the worm gear to the nut
✓ have coefficient of friction 0.18 at starting 0.13 at running condition
•use should select square thread because it has radial efficiency or bursting pressure on the nut and it can’t be easily get wear
 Design of Nut

 Nut is of the part of the bottle car jack with have an internal thread in order to directly
mash with the screw and have an external thread in order to mash with the nut.

 Since, this design is needs two nut to lift a height which is greater than the total head of
the jack and reach the required height lift.

 Bronze is selected material for the nut with having copper and phospherus. So it has an
ultimate tensile strength of 290 MPa
 Design of worm and worm gear
•Design of worm
o Worms are cylindrical in shape with uniform pitch diameter the worm made from
harden steel material
➢ To calculate the worm assume the following parameters.
➢ Center distance between the worm and gear
➢ The worm rotate at 100 rpm (by human hand)
➢ 20° involute worm
➢ Velocity ratio 1:12
•Let’s IN= Normal load, ʎ= lead angle, L= axial lead =cos23.6
• 2.29 °
 Design of the worm Gear
✓ Which made from phosphors bronze
✓ = 84 N/ for phosphors bronze
✓ Pitch circular diameter of the worm gear(DG)= M x TG = 6 x 48 = 288mm
✓ Outside diameter of the worm gear (DoG)
• NG= = = 8.33 rpm
 Design of worm shaft

 It is a shaft which do have a worm gear profile unites length.

 A material selected to design the worm shaft is high strength low alloy steel type
(ASME)(A709)

 Also made from carbon steel

Properties – yield strength of low alloy steel =690MPa

- ultimate strength = 760 MPa

 THE FOLLOWING FORCES ARE
DETERMINED
•1. Torque acting on worm gear shaft (Tgear)
• 2.Torque acting on the worm shaft (T worm)
•3.Tangential force acting on the worm
•4.Axial force acting on the worm
•
• 5.Radial spacing force on the worm
•Bending Moment
 Design of key

•Key is other machine which is inserted between the shaft and hub to connect parts together in order
to prevent relative motion between them.
•For a key to function properly both the shaft and rotating elements such as gear , pulley ,and coupling
must have a key way and a key seat .
➢ High strength low alloy steel type of material are used to design key and have
properties like
➢ Have yield strength=690MPa, Ultimate strength =76MPa, Density
 Design of collar
✓ Collar is used to support the nut from buckling
✓ Aluminum alloy of type 1100(material type)
✓ Properties of material is
o Density =2710
o Yield point strength=15MPa
o Ultimate strength=110MPa
o Safety factor=2.5
 Design of top plate

 Mounting plate used to carry the load directly on it

 High strength steel is selected material for the design

 Ultimate tensile strength =620MPa

 Yield strength=415MPa

Density=7860𝑘𝑔ൗ 3
𝑚

 Design of bearing
•In this design the bearing used for worm shaft at both ends of the handle (shafts) as well as a single bearing is required
for the screw to rotate about its axis with nut any axial movement.
•This bearing is a ball bearing type this have high coefficient of friction as it is outstanding advantage of bearing. Since
he rolling elements are subjected to high local stress of varying magnitude then the material selected is high carbon
chromium steel.
•life of bearing? Average life of bearing is 5years at 10hours per day
•Assuming 400 working days
• LH=5 x10 x 400=20,000hours
•Therefore, life of bearing in revolution
• L=60xNxLH=60x100x20,000 =rev, where N is speed n rpm =100rpm
 Design of base
•The base is the components of mechanically operated bottle car jack which is found at the bottom of all the often components and thus carry
both the load as well as the total mass of the components.
•The material selection for this component is high strength steel
✓ Density=7860
✓ Ultimate tensile strength=620MPa
✓ Yield strength=415MPa
✓ Safety factor=2.5
•In order to design this component its important follow the following procedure.
: find the width of the base and corresponding height
•Width =outside diameter of the body +some clearance
•w=D+15mm=84.24+15=99.24mm, since its square L=w =99.24mm…..CHECK THE FULL DOCUMENT FOR MORE INFO
 Design of bolt
•Bolt is a metal rod or pin for fastening objects together that usually has a heat at one end and a screw thread at the another and is secured by
a nut
•It used to assembly the body part to the base of the jack

𝜎𝑐= = dc=ට =ට
•Where 𝑃 𝑃 𝑝 20,000
4𝐴 𝜋𝑑𝑐2 𝜋𝑥𝜎𝑐 𝜋𝑥40
o dc; core diameter of the bolt
Dc=12mm and do=12mm, p=2mm
o Do is nominal diameter of the bolt
o d is depth of thread
o p is pitch
o n is number of bolt which is four
•the bolt suffered to highly shear stress so it need to made from high hardness and strength material.
•Mild steel is preferable material and has ultimate strength 40MPa
 Cost Analysis
•total cost of manufacturing
Total cost =cost of material+ cost of labor+ cost of machining
Total cost +3740+2800+8000
=14540 birr
 Discussion:
•The bottle car jack was designed with a focus on meeting the lifting weight capacity requirement
while ensuring compact dimensions for ease of use. The worm gear mechanism was chosen for its
ability to provide high mechanical advantage, allowing the jack to lift heavy loads with minimal
effort. The minimum height of 168 mm was achieved by carefully selecting the dimensions of the
components and optimizing the design for maximum efficiency.
•The lifting height of 100 mm provides sufficient clearance for most maintenance tasks and tire
changes, making the jack versatile and practical for use in various automotive applications. The
design also includes safety features to prevent overloading and ensure stable lifting operations.
 Conclusion:
• In conclusion, the designed mechanically operated Bottle Car Jack (Worm Gear) meets the
specified requirements of a lifting weight capacity of 2 tons, a minimum height of 168 mm, and a
lifting height of 100 mm. The jack is expected to perform effectively in lifting vehicles while
providing convenience and safety during operation. Regular maintenance and inspection are
recommended to ensure the continued safe and reliable performance of the jack.

• FOR MORE refer to the complete design document

Part Drawing
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