This document describes the design of a motorized screw jack. It begins with an introduction to screw jacks and their history. Traditionally, screw jacks required high manual labor to lift vehicles. The objectives of this project were to design a device that can lift vehicles smoothly without impact using a motor as the power source. The proposed system is a remote-controlled cylinder jack that uses a DC motor powered by a battery. Design calculations are provided for the bevel gears, battery, screw dimensions and strength. The motorized screw jack is able to lift vehicles easily without manual effort. Advantages include easy lifting and maintenance, while disadvantages include higher costs and need for a power source. In conclusion, the motorized screw jack meets the

1. Prepared By
1) Shashin Vyas
2) Nikunj Thakkar
3) Gaurav Jagatiya
4) Shivam Joshi
Guided By:
Prof. Santosh Sitapara

2. History Of Screw Jack
 The motorized screw jack has been developed to cater to the needs of small
and medium automobile garages, which are normally man powered with
minimum skilled labors.
 In most of the garages the vehicles are lifted by using screw jack. This
needs high man power and skilled labors.
 More recent developments have concentrated on improved efficiency and
durability, resulting in changes in both lead screw and gearbox design
options for screw jacks.

3. Objectives
 In several automobile garages, revealed the facts that mostly some difficult
methods were adopted in lifting the vehicles for reconditioning.
 Hence a suitable device has been designed, such that the vehicle can be
lifted from the floor land without application of any impact force.
 In order to avoid all such disadvantages, the motorized jack has been
designed in such a way that it can be used to lift the vehicle very smoothly
without any impact force.

4. Details About Motorized Screw Jack
 A screw jack is a portable device consisting of a screw mechanism used to
raise or lower the load.
 A hydraulic jack consists of a cylinder and piston mechanism. The
movement of the piston rod is used to raise or lower the load.
 Mechanical jacks can be either hand operated or power driven.
 It Works In Vertical Manner In Order to raise or lower the load.

5. Proposed System
USAGE OF CYLINDER JACK INSTEAD OF POWER SCREW
Jacks are of mainly two types:
1) Mechanical jack.
2) Hydraulic jack.
They vary in size depending on the load that they are used to lift.

6. Proposed System
CYLINDER JACK
• A Cylinder jack is a device which works in vertical manner to lift or lower
the load with the help of a D.C.motor.
• “REMOTE CONTROLLED CYLINDER JACK” is modified form of
conventional Cylinder jack that helps to lift the load by using motor as a
source of energy with the help of remote to operate the screw jack.
• It typically works in just a vertical manner.

7. Proposed Pictures Of The Project

8. Proposed Pictures Of The Project

9. Diagram Of Motorized Screw Jack

10. Components Used And Calculations
 Car jack
 Motor
 Bevel Gears
 Remote Controller
 D.C. Battery
 12V Cigarette Lighter Adapter

11. Components Used And Calculations
I) Bevel Gear
 The Bevel gears, which are designed to transmit motion and power between
perpendicular shafts, are the most suitable gears for transmitting power and
motion at right angle in power transmission industry.
Application
 Perpendicular power transmission.
 Differential drives.
 Hand drills.

12. Components Used And Calculations

13. Components Used And Calculations
STRENGTH OF BEVEL GEAR:
The Modified Form of Lewis Equation for the Tangential Tooth Load Can be
Calculated as Follows:
WT = ( σo * Cv ) * b π m y’ ( L – b ) / L
σo = Allowable Static Stress.
Cv = Velocity Factor = ( 3 / 3 + v )
v = Peripheral Speed in m/s

14. Components Used And Calculations
m = Module
b = Face Width
y’ = Tooth Form Factor or Lewis Form Factor For The Equivalent Number of
Teeth
L = Slant Height of Pitch Cone = [ (Dp / 2)2 + (Dg / 2)2 ] -1
Where, Dg = Pitch Diameter of the Gear
Dp = Pitch Diameter of the Pinion

15. Components Used And Calculations
II) Battery
Lead-acid wet cell
 Where high values of load current are necessary, the lead-acid cell is the
type most commonly used.
 The electrolyte is a dilute solution of sulfuric acid (H₂SO₄).lead-acid cells
are often used in a series combination of three for a 6-V battery and six for a
12-V battery.
 The lead acid cell type is a secondary cell or storage cell, which can be
recharged.

16. Components Used And Calculations

17. Components Used And Calculations
III) Screw Jack
There Are Mainly Two Types Of Jacks:
1) Mechanical Jack
A. Scissor Jack
B. Bottle Jack
2) Hydraulic Jack

18. Components Used And Calculations
Cylinder Jacks
• A Motorized cylinder jack has simpler construction.
• A screw thread keeps moving vertically over the assembly. As the screw
threads are turned, the jack starts linear motion accordingly. The forward
and reverse motion of the screw rises and lowers the load respectively.
• The load F produces bending and it is maximum, when the screw is at its
maximum lift. The screw also experiences twisting moment due to F. the
shear stress is also induced in the screw due to the twisting moment between
the threads of screw and nut.

19. Components Used And Calculations

20. Components Used And Calculations
DESIGN AND LIFT
Weight to be lifted By Cylinder Jack;
F = m a, Newton
Here,
a= Acceleration due to gravity i.e. gravitational acceleration “g”.
F = Torque applied to cylinder jack through motor.
Core Diameter:
For Selected Material,
Syc = Syt = 560 MPa
So, σc = 560/5 = 112 MPa

21. Components Used And Calculations
Now,
σc = W [ π/4 * ( dc )2]
dc= 30mm
The diameter only consider compressive stress but screw is subjected to
torsion and bending moments for that we increase a diameter to higher values
we will use a screw with 55mm nominal diameter & 9mm pitch.
d = 55mm
p = 9mm
dc = 55-9 = 46mm > 30mm
dm = d-0.5p = 55-4.5 = 50.5mm

22. Components Used And Calculations
Assuming Screw has single start threads.
l = p = 9mm
tanα = [ l / (π*dm)]
= 9 / ( π*50.5)
α =3.246°
.

23. Components Used And Calculations
Coefficient of friction between screw and nut is 0.1 i.e. μ = 0.1 considering bad
lubricating conditions assume μ = 0.18.
tanφ = μ = 0.18
φ=10.20 > 3.02
Hence we can say that screw is self locking .
Torque Required Raising the Load:
T = W*(dm/2) * tan ( φ + α )
T = 452.89 * 103 N-mm

24. Components Used And Calculations
IV) D.C. motor (permanent magnet)
• An electric motor is a machine which converts electrical energy to
mechanical energy.
• When a motor is in operation, it develops torque. This torque can produce
mechanical rotation. DC motors are also like generators classified into shunt
wound or series wound or compound wound motors.

25. Components Used And Calculations

26. Components Used And Calculations
V) Car Cigarette Lighter Adapter

27. Advantages
• The loaded light vehicles can be easily lifted.
• Checking and cleaning are easy, because the main parts are screwed.
• Handling is easy
• No Manual power required.
• Easy to Repair.
• Replacement of parts is easy .

28. Disadvantages
 Cost of the equipment is high when compared to ordinary hand jack.
 Care must be taken for the handling the equipment such as proper wiring
connection, battery charging checkup, etc.
 Can Be Operated Only With Power Source.

29. CONCLUSION
 Screw Jacks are the ideal product to push, pull, lift, lower and position loads
of anything from a couple of kilograms to hundreds of tones.
 The need has long existed for an improved portable jack for automotive
vehicles.
 The Primary Thing Is That It Should Be Capable of lifting a wheel of a
4,000-5,000 pound vehicle off the ground.
 Further, it should be stable and easily controllable by a switch so that
jacking can be done from a position of safety.

30. References
 A text book of Machine Design by R.S.Khurmi.
 Machine Design by S.G.Kulkarni.
 “DESIGN OF MACHINE ELEMENTS” V.B.BHADARI -
McGraw Hill publication
 Design of machine elements by K.Rao.

31. Any Query?

32. THANK YOU…