Design And Fabrication Of Motorized Screw Jack

Design And Fabrication OfMotorized Screw Jack

Prepared By1) Shashin Vyas2) Nikunj Thakkar3) Gaurav Jagatiya4) Shivam Joshi

Guided By: Prof. Santosh Sitapara

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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.

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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.

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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.

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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.

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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.

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Proposed Pictures Of The Project

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Proposed Pictures Of The Project

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Diagram Of Motorized Screw Jack

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Components Used And Calculations

Car jackMotorBevel GearsRemote ControllerD.C. Battery12V Cigarette Lighter Adapter

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Components Used And CalculationsBevel GearThe 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.

ApplicationPerpendicular power transmission.

Differential drives.

Hand drills.

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Components Used And Calculations

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Components Used And CalculationsSTRENGTH OF BEVEL GEAR:The Modified Form of Lewis Equation for the Tangential Tooth Load Can beCalculated as Follows:WT = ( o * Cv ) * b m y ( L b ) / Lo = Allowable Static Stress.Cv = Velocity Factor = ( 3 / 3 + v )v = Peripheral Speed in m/s

Components Used And Calculationsm = Moduleb = Face Widthy = Tooth Form Factor or Lewis Form Factor For The Equivalent Number of TeethL = Slant Height of Pitch Cone = [ (Dp / 2)2 + (Dg / 2)2 ] -1 Where, Dg = Pitch Diameter of the GearDp = Pitch Diameter of the Pinion

Components Used And CalculationsII) 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 (HSO).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.

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Components Used And Calculations

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Components Used And CalculationsIII) Screw Jack

There Are Mainly Two Types Of Jacks:

Mechanical JackScissor JackBottle Jack

Hydraulic Jack

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Components Used And CalculationsCylinder 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.

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Components Used And Calculations

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Components Used And CalculationsDESIGN 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 MPaSo, c = 560/5 = 112 MPa

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Components Used And CalculationsNow,c = W [ /4 * ( dc )2]dc= 30mmThe diameter only consider compressive stress but screw is subjected totorsion and bending moments for that we increase a diameter to higher valueswe will use a screw with 55mm nominal diameter & 9mm pitch.d = 55mmp = 9mmdc = 55-9 = 46mm > 30mmdm = d-0.5p = 55-4.5 = 50.5mm

Components Used And Calculations

Assuming Screw has single start threads.l = p = 9mmtan = [ l / (*dm)] = 9 / ( *50.5) =3.246

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Components Used And Calculations

Coefficient of friction between screw and nut is 0.1 i.e. = 0.1 considering badlubricating conditions assume = 0.18. tan = = 0.18 =10.20 > 3.02Hence we can say that screw is self locking .

Torque Required Raising the Load:T = W*(dm/2) * tan ( + )T = 452.89 * 103 N-mm

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Components Used And CalculationsIV) 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.

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Components Used And Calculations

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Components Used And CalculationsV) Car Cigarette Lighter Adapter

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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 .

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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.

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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.

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ReferencesA text book of Machine Design by R.S.Khurmi.Machine Design by S.G.Kulkarni.DESIGN OF MACHINE ELEMENTS V.B.BHADARI - McGraw Hill publicationDesign of machine elements by K.Rao.

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Any Query?

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THANK YOU

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