Project Report On Screw Jack 6i5m2w

Certificate

This is certified that the project report titled “DEG OF SCREW JACK USING PRO-E” submitted by Amit, Amit Raj Yadav, Devender Kumar, Sher Singh in partial fulfillment of the requirements for the award of Degree of Bachelor of Engineering (Mechanical) of M.D.University Rohtak is record of bonafide work carried out Under my supervision and has not been submitted Anywhere else for any other purpose.

Head of department Supervisor name

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MR.YAT IN KUMAR SINGH

ACKNOWLEDGEMENT

We would like to thank our project guide “MR. YATIN KUMAR SINGH” for his invaluable help, and guidance. Without his help we would not have been able to complete our project.

We would also like to thanks all the faculty of MECHANICAL ENGINEERING DEPARTMENT who has been instrumental in our learning process and also helped us during the course of project work.

Last but not least, we would like to thanks all the faculty , specially “PROF.B.B.MALHOTRA”& “PROF. B.D. ARORA” associated with the design that not only provided us with the means to complete our project, but also guided us and made us understand the practical aspects/implication of things

AMIT AMIT RAJ YADAV DEVEN DER KUMAR SHER SINGH 2

ABSTRACT

A Screw jack is a portable device consisting of a screw mechanism used to raise or lower the load. There are two types of jacks-mechanical and hydraulic Mechanical jacks can be either hand operated or power driven. The hydraulic jack consist of cylinder and piston mechanism Although a jack is a simple device used to raise various types of loads Proper size, strength and stability are essential requirements for the design of the screw jack from safety consideration

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CONTENTS

1.

INTRODUCTION…………………………………………………………… …..5

2.

COMPONENTS……………………………………………………………… ….6

3.

BILL OF MATERIAL……………………………………………………………..8

4.

DESIGN& CALCULATION……………………………………………………..9

5.

DESIGN IN PROE……………………………………………………………..19

6.

IMPROVEMENTS……………………………………………………………. ..36

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7.

FUTURE SCOPE……………………………………………………………….37

8.

BIBLIOGRAPHY.. ……………………………………………………………...40

INTRODUCTION

A Screw jack is a portable device consisting of a screw mechanism used to raise or lower the load. There are two types of jacks-mechanical and hydraulic Mechanical jacks can be either hand operated or power driven.

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The hydraulic jack consist of cylinder and piston mechanism Although a jack is a simple device used to raise various types of loads Proper size, strength and stability are essential requirements for the design of the screw jack from safety consideration

COMPONENTS

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1. SCREW PART

2. NUT PART

3. CUP PART

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4 .FRAME PART

5. HANDLE PART

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BILL OF MATERIAL SR.NO .

COMPONEN T

QUANTITY

1

FRAME

1

2 3

SCREW NUT

1 1

4 5

HANDLE CUP

1 1

6 7

SET SCREW WASHER

1 1

MATERIAL GREY CAST IRON FG200 (IS:2101993) STEEL30C8(IS:1570-1978) PHOSPHOR BRONZE GRADE1(IS:28-1975) STEEL30C8(IS:1570-1978) GREY CAST IRON FG200 (IS:2101993) COMMERCIAL STEEL COMMERCIAL STEEL

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DESGN & CALCULATION

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Given: W = 3 Ton = 30 KN; H =850 mm; σet = σec = 200 MPa = 200 N/mm2; τe = 120 MPa = 120N/mm 2 ; σet ( nut ) =20 MPa =20N/mm2; σec ( nut ) =30 MPa =30N/mm2 ;

τ e ( nut )

=15 MPa = 15N/mm2 ; ρb =18 N/mm2 The various parts of the screw jack is shown in figure & design procedure is given below:

1. DESIGN OF SCREW FOR SPINDLE: Let dc = Core diameter of the screw Since the screw is under compression, therefore the load (W),

For square threads normal series, the following dimensions are selected from PSG DATA BOOK Core dia. = dc = 21 mm Nominal dia. do=24 mm Pitch of threads p= 5 mm Now let us check the Principal stresses; We know that the mean dia. Of screw,

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Assuming the friction of co-efficient of friction between screw & nut,

µ =tan φ= 0.14

∴Torque required rotate the screw in the nut,

Now compressive stress due to axial load,

And shear stress due to torque,

∴Maximum principal stress (tensile or compressive), 12

We know that maximum shear stress

Since the maximum stresses are within limits, therefore design of screwed spindle is safe.

2. Design for nut Let

n = number of threads in with the screwed spindle h = Height of nut = n × p and t = Thickness of screw

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Assume that load is distributed uniformly over the cross section area of nut. We know that the bearing pressure ( ρb ),

And height of nut.

h = n × p =10

×

5 =50mm

Now let us check the stress induced in the screw and nut. We know that shear stress in the screw,

And shear stress in nut,

Since these stresses are within permissible limits, therefore design for the nut is safe. Let

D1= Outer diameter of nut , D2=Outside diameter for nut collar, and t1=Thickness of nut collar.

First of all considering the tearing strength of nut, we have

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∴ D1 = 67 mm

Now considering the crushing of the collar of the nut, We have

Considering the shearing of the collar of the nut, We have

3. Design for handle and cup Height of cup = 5.3mm Thickness of cup = 4mm

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Diameter of top of cup = 60mm Now let us find out the torque required (T2) to overcome friction at the top of the screw. Assuming uniform pressure condition, we have

Total torque to which handle is subjected,

Assuming that a force of 200N is applied by a person intermittently, therefore length of handle required = 189 × 103/200 = 900mm Allowing some length for gripping, we shell take the length of handle as 950mm.

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A little consideration will show that an excessive force applied at the end of the lever cause bending. Considering bending effect, the maximum bending moment on the handle,

M= force applied length of lever = 200 × 950 =190 × 103N-mm

Let

D= Diameter of the handle.

Assuming that material of the handle is same as that of screw, therefore taking bending stress

We know that bending moment (M),

The height of head (H) is taken as 2D H =2D=2 × 13=26mm

Now let us check the screw for bucking load.

We know that the effective length for the buckling of screw, L

= Lift of screw+1/2 Height of nut=H1+h/2 =200+80/2=240mm

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When screw reaches the maximum lift, it can be regarded as a strut whose lower end is fixed and the load end is free, we know that critical load,

Since critical load is more than the load at which screw is designed (I.e. 40 × 103N), therefore there is no chance of screw to buckle.

4. Design of body The various dimension of the body may be fixed as follows: Diameter of the body at the top,

D5 =.82 D2

=67 mm

Thickness of the body, t3

= 0.25d0

= 6 mm

Inside diameter at the bottom, D6 = 0.9 D2 = 74 mm Outside diameter at the bottom, D7 = 1.5 D6 = 110mm

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Thickness of base,

Height of the body

t2

=0.5 t1

= 9.8 mm

= maximum lift +height of nut + 100 mm extra = 200 + 27+ 100 =327 mm

The body is made tapered in order to achieve stability of jack. Let us now find out the efficiency of the screw jack .we know that the torque req. to rotate the screw with no friction,

Efficiency of the screw jack,

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DEG IN PRO-E

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COMMAND USED 1. SKETCH 2. EXTRUDE 3. BLEND

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COMMAND USED 1. EXTRUDE 2. HELICAL SWEEP 3. REMOVE MATERIAL

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COMMAND USED 1 .SKETCH 2. CIRCLE 3. EXTRUDE

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COMMAND USED 1. SKETCH 2. EXTRUDE 3. HELICAL SWEEP 4. DEFINE LENTH & PITCH 5. MAKE SQUARE THREAD

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COMMAND USED 1. SKETCH 2. RECTANGLE 3. EXTRUDE 4. CYLINDER 5. REMOVE MATERIAL

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COMMAND USED 1 .ASSEMBLY 2. USE DEFAULT TEMPLETE 3. SELECT THE PARTS TO BE ASSEMBLED

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COMMAND USED 1. OPEN FRAME PART 2. USE DEFAULT CONSTRAINT 3. ENTER

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COMMAND USED 1. OPEN NUT PART 2. MAKE PIN CONNECTION 3. MATCH AXIS OF BOTH

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COMMAND USED 1 .OPEN HANDLE PART 2. MAKE AXIS ALIGNMENT 3. FIX CONSTRAINT

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COMMAND USED 1. OPEN SCREW PART 2. MAKE CYLINDER CONNECTION 3. SELECT EITHER AXIS OR SURFACE OF BOTH SURFACE FOR MATING

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COMMAND USED 1. OPEN CUP PART 2. MAKE AXIS ALIGNMENT 3. FIX CONSTRAINT

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MECHANISM USED FOR RUN MODEL 1.

ROTATIONAL

2.

TRANSLATION

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3. USE SERVO MOTOR CONNECTION IN NUT PART FOR ROTATION

4. MAKE CYLINDER CONNECTION IN SCREW PART FOR TRANSLATION

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5. GIVE THE VALUE OF VELOCITY TO FIRST SERVO MOTOR

6 GIVE THE VALUE OF VELOCITY TO SECOND SERVO MOTOR

7. APPLY THESE CHANGES

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8. AT LAST DEFINE END TIME AND RUN ANALYSIS

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IMPROVEMENT The differential screw jack can be improved in comparison of a simple screw jack. Generally the unit consist of two threaded element A &B of different diameters and pitches, but having threads in the same direction .The element A is a cylinder with threads on its outer and inner surface .The threads on outer surface mesh with the thread nut C ; this nut also function as body of jack .The segment B has threads only on its outer surface and this engaged with the internal threads of element A

So in this case

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FUTURE SCOPES The S-Series Screw Jacks Power Jacks high performance "S-Series" screw jacks are a range of metric screw jacks with a cubic shaped gearbox designed to have a higher duty cycle and improved mounting flexibility over conventional single-face worm gear screw jacks. The higher duty rating has been attained by optimizing the design of the screw jacks worm gearbox for a higher thermal efficiency. In general, tests showed that the "S-Series" screw jacks had a 50% higher duty cycle than conventional worm gear screw jacks, for a given lead screw type

Compact screw jack delivers high performance A new precision machined worm screw jack from Thomson provides powerful, reliable lifting and positioning in a compact form factor, making it very versatile for materials handling, hydraulic replacement and complex positioning systems.

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The Muli 0 worm gear screw jack extends Thomson's Muli series and is designed specifically to save space where it’s Muli and Jumbo 1-5 ranges cannot be used. Despite its comparatively small housing dimensions of 60x50x50mm (L x W x H), the Muli 0 delivers a lifting force of 2.5kN that enables its tried-and-tested Muli technology - a proven, robust precision worm-gear and lead screw technology - to be used in more space-critical or complex multi-axis systems. Muli worm gear screw jacks are suitable for a very broad range of applications where the lifting, lowering, tilting or rotating of loads is required. They provide particularly high lifting forces and adjustment speeds with a proven track record for reliability and low maintenance costs. The Muli 0 is available in both axially shifting (optionally torsionally rigid) screw, and rotating screw models. The screw itself can be specified with a cost-effective trapezoidal thread or with high-precision ball screws and preloaded lowbacklash options that cater for a broad spectrum of applications

Worm Gear Screw Jacks

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Thomson's worm gear screw jacks MULI® and JUMBO® set new engineering standards for precision and reliability. Designed with state-of-the-art CAD and CAE systems and adhering to stringent manufacturing requirements, these jacks meet all the necessary safety, cost-efficiency, and durability mandates of your application. Large projects can be realized at short notice thanks to the use of preassembled modules. These modules can be customized to your application's specifications. Above all, the heart of every MULI® and JUMBO® screw jack is a precision trapezoidal or ball screw drive of superb quality from Thomson's own screw production. In general, there are two worm gear screw jack

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BIBLIOGRAPHY

1.

Design of machine element by V.B.BHANDARI

2. Machine Design by R.S. KHURMI

3. PRO-E-4

4. P.S.G Design data book

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