BOX SHIFTING MECHANISM

By

DEPARTMENT OF MECHANICAL ENGINEERING

DESH BHAGAT FOUNDATION GROUP OF INSTITUTION ( MOGA )

2013/2014

PROJECT REPORT ON

BOX SHIFTING MECHANISM

1

AKNOWLEDGEMENT

Index

Title of project 1

Function of BSM 2

Mechanism 2

Types of mechanism ( 3)

Kinematics pairs ( 3-4)

Lower pairs (4-5)

Higher pairs ( 5)

Planar mechanism (5)

Spherical mechanism (5-6)

Spatial mechanism (6)

Shifting 6

2

Process use to making project 6- 7

Gear 7-8

Spur gear (9-13)

Bevel gear (13-21)

Chain driver 21-22

History of chain driver (22-23)

Use in vehicle ( 23-24)

Bearing 25-26

History of bearing ( 26-29)

Operation of principle of bearing (29-30)

Maintenance and lubrication (30-33)

Operation on lathe machine 33

Lathe machine (33-34)

Turing operation (35-38)

Facing operation (38-39)

Welding 39-41

Arc welding process

Arc (41)

Power supply (41-43)

Process of welding (43-46)

Tools 46-47

Hacksaw (47-48)

Blade (48-49)

File (50)

3

Final project 51

PROJECT REPORT

ON

BOX SHIFTING MECHANISM

4

FUNCATION OF BOX SHIFTING MECHANIS

The main function of box shifting mechanism is to transfer the object from one place to

another with the help of mechanism or machine. this I is called box shifting mechanism

or shifting mechanism.

MECHANISM

A mechanism is a device designed to transform input forces and movement into a

desired set of output forces and movement. Mechanisms generally consist of moving

components such as gear and gears train , belt and chain drives, cam and follower

mechanisms, and linkages as well as friction devices such as brakes and clutches, and

structural components such as the frame, fasteners, bearings, springs, lubricants and seals,

as well as a variety of specialized machine elements  such as splines, pins and keys.

5

The German scientist Reuleaxu provides the definition "a machine is a combination of

resistant bodies so arranged that by their means the mechanical forces of nature can be

compelled to do work accompanied by certain determinate motion." In this context, his

use of machine is generally interpreted to mean mechanism.

The combination of force and movement defines power and a mechanism is designed to

manage power in order to achieve a desired set of forces and movement.

A mechanism is usually a piece of a larger process or mechanical system Sometimes an

entire machine may be referred to as a mechanism. Examples are the steering system

a car, or the winding mechanism  of a wristwatch . Multiple mechanisms are machines.

Types of mechanism

From the time of Archimedes through the Renaissance, mechanisms were considered to

be constructed from simple machine such as the lever , pulley ,wheel and etc.

and inclined plane. It was Reuleaux who focussed on bodies, called links, and the

connections between these bodies called kinamatic pair, or joints.

In order to use geometry to study the movement a mechanism, its links are modeled

as rigid bodies. This means distances between points in a link are assumed to be

unchanged as the mechanism moves, that is the link does not flex. Thus, the relative

movement between points in two connected links is considered to result from the

kinematic pair that joins them.

Kinematic pairs, or joints, are considered to provide ideal constraints between two links,

such as the constraint of a single point for pure rotation, or the constraint of a line for

6

pure sliding, as well as pure rolling without slipping and point contact with slipping. A

mechanism is modeled as an assembly of rigid links and kinematic pairs.

Kinematic pairs

Reuleaux called the ideal connections between links kinematic pairs. He distinguished

between higher pairs which were said to have line contact between the two links and

lower pairs that have area contact between the links. J. Phillips[4] shows that there are

many ways to construct pairs that do not fit this simple classification.

Lower pair

A lower pair is an ideal joint that constrains contact between a point, line or plane in the

moving body to a corresponding point line or plane in the fixed body. We have the

following cases:

A revolute pair, or hinged joint, requires a line in the moving body to remain co-

linear with a line in the fixed body, and a plane perpendicular to this line in the

moving body maintain contact with a similar perpendicular plane in the fixed body.

This imposes five constraints on the relative movement of the links, which therefore

has one degree of freedom.

7

A prismatic joint, or slider, requires that a line in the moving body remain co-

linear with a line in the fixed body, and a plane parallel to this line in the moving

body maintain contact with a similar parallel plan in the fixed body. This imposes

five constraints on the relative movement of the links, which therefore has one degree

of freedom.

A cylindrical joint requires that a line in the moving body remain co-linear with a

line in the fixed body. It is a combination of a revolute joint and a sliding joint. This

joint has two degrees of freedom.

A spherical joint, or ball joint, requires that a point in the moving body maintain

contact with a point in the fixed body. This joint has three degrees of freedom.

A planar joint requires that a plane in the moving body maintain contact with a

plane in fixed body. This joint has three degrees of freedom.

Higher pairs

 Generally, a higher pair is a constraint that requires a curve or surface in the moving

body to maintain contact with a curve or surface in the fixed body. For example, the

contact between a cam and its follower is a higher pair called a cam joint. Similarly, the

contact between the involute curves that form the meshing teeth of two gears are cam

joints.

Planar mechanism

8

A planar mechanism is a mechanical system that is constrained so the trajectories of

points in all the bodies of the system lie on planes parallel to a ground plane. The

rotational axes of hinged joints that connect the bodies in the system are perpendicular to

this ground plane.

Spherical mechanism

A spherical mechanism is a mechanical system in which the bodies move in a way that

the trajectories of points in the system lie on concentric spheres. The rotational axes of

hinged joints that connect the bodies in the system pass through the center of these

spheres.

Spatial mechanism

A spatial mechanism is a mechanical system that has at least one body that moves in a

way that its point trajectories are general space curves. The rotational axes of hinged

joints that connect the bodies in the system form lines in space that that do not intersect

and have distinct common normals.

SHIFTING

9

Shifting is that process in which object is transfer from one place to another place ita

known as shifting.

Combination of both is called shifting mechanism or box shifting mechanism.

The followings process use in making box shifting project as :-

Rods

Metal plates

Gears like bevel gear and spur gear

Chain driver

bearings

Operation on lathe like turning operation and facing operation

Welding

Cutting tools

GEARS

 gear or cogwheel is a rotating machine part having cut teeth, or cogs, which mesh with

another toothed part in order to transmit torque, in most cases with teeth on the one gear

10

of identical shape, and often also with that shape (or at least width) on the other gear.

Two or more gears working in tandem are called a transmission and can produce

a mechanical advantage through a gear ratio and thus may be considered a simple

machine. Geared devices can change the speed, torque, and direction of a power source.

The most common situation is for a gear to mesh with another gear; however, a gear can

also mesh with a non-rotating toothed part, called a rack, thereby

producingtranslation instead of rotation.

The gears in a transmission are analogous to the wheels in a crossed belt pulley system.

An advantage of gears is that the teeth of a gear prevent slipping.

When two gears of unequal number of teeth are combined, a mechanical advantage is

produced, with the rotational speeds and the torques of the two gears differing in a simple

inverse relationship.

In transmissions which offer multiple gear ratios, such as bicycles and cars, the term gear,

as infirst gear, refers to a gear ratio rather than an actual physical gear. The term is used

to describe similar devices even when the gear ratio is continuous rather than discrete, or

when the device does not actually contain any gears, as in a continuously variable

transmission

There are some gears images as below

11

SPUR GEAR

Spur gears or straight-cut gears are the simplest type of gear. They consist of a cylinder

or disk with the teeth projecting radially, and although they are not straight-sided in form

(they are usually of special form to achieve constant drive ratio mainly involute), the

edge of each tooth is straight and aligned parallel to the axis of rotation. These gears can

be meshed together correctly only if they are fitted to parallel shafts.

These are spur gears

.

12

Matetrial use to making spur gears

Acetal

Acetal is a plastic polymer that is used either in its pure state or slightly altered

state---e.g. Derlin---for a number of spur gears. The acetal polymer is much stronger than

common plastic, though it can be easily molded to any shape, including a spur gear. Once

acetal has hardened in the shape of a spur gear, it is stif, strong and resistant to abrasion.

The malleability, strength and resilience make it an ideal material for spur gears.

13

Cast Iron

Cast iron is, like acetal, an easily molded material. It is also highly resistant to

rust. Cast iron is not pure iron, and because of this, any given batch of cast iron will have

different ingredients. These different ingredients cohere for different degrees of strength

and durability. Cast iron is used in machine parts because it is relatively inexpensive, rust

resistant and easy to mold, though it may be either incredibly strong or incredibly weak,

depending upon the admixture.

Stainless Steel

Stainless steel is a metal alloy commonly used in the casting of spur gears. A

metal alloy is a metal composed of two or more distinct elements that are melted

together. Like cast iron, it is highly resistant to oxidation, and like acetal, it is resistant to

abrasions and other weakening blemishes. Stainless steel's resistance to rust and scarring

is due to the infusion of chromium. The strength, durability and corrosion resistance

make stainless steel a popular material for spur gears.

14

Application of spur gears

Spur gears have a wide range of applications. They are used in:

1. Metal cutting machines

2. Power plants

3. Marine engines

4. Mechanical clocks and watches

5. Fuel pumps

6. Washing Machines

7. Gear motors and gear pumps

8. Rack and pinion mechanisms

9. Material handling equipments

10. Automobile gear boxes

11. Steel mills

12. Rolling mills

Advantages of spur gears

15

Spur gears have high power transmission efficiency.

They are compact and easy to install.

They offer constant velocity ratio.

Unlike belt drives, spur gear drives have no slip.

Spur gears are highly reliable.

They can be used to transmit large amount of power (of the order of 50,000 kW).

Disadvantages of spur gears

Spur gear drives are costly when compared to belt drives.

They have a limited center distance. This is because in a spur gear drive, the gears

should be meshed and they should be in direct contact with each other.

Spur gears produce a lot of noise when operating at high speeds.

16

They cannot be used for long distance power transmission.

Gear teeth experience a large amount of stress.

Bevel gear

wo important concepts in gearing are pitch surface and pitch angle. The pitch surface of

a gear is the imaginary toothless surface that you would have by averaging out the peaks

and valleys of the individual teeth. The pitch surface of an ordinary gear is the shape of a

cylinder. The pitch angle of a gear is the angle between the face of the pitch surface and

the axis.

The most familiar kinds of bevel gears have pitch angles of less than 90 degrees and

therefore are cone-shaped. This type of bevel gear is called external because the gear

teeth point outward. The pitch surfaces of meshed external bevel gears are coaxial with

the gear shafts; the apexes of the two surfaces are at the point of intersection of the shaft

axes.

Bevel gears that have pitch angles of greater than ninety degrees have teeth that point

inward and are called internal bevel gears.

17

Bevel gears that have pitch angles of exactly 90 degrees have teeth that point outward

parallel with the axis and resemble the points on a crown. That's why this type of bevel

gear is called acrown gear.

Miter gears are mating bevel gears with equal numbers of teeth and with axes at right

angles.

Skew bevel gears are those for which the corresponding crown gear has teeth that are

straight and oblique.

Types of bevel gears

Bevel gears are classified in different types according to geometry:

Straight bevel gears have conical pitch surface and teeth are straight and tapering

towards apex.

Spiral bevel gears 

have curved teeth at an angle allowing tooth contact to be gradual and

smooth.

18

Zerol bevel gears 

are very similar to a bevel gear only exception is the teeth are curved: the ends of

each tooth are coplanar with the axis, but the middle of each tooth is swept

circumferentially around the gear. Zerol bevel gears can be thought of as spiral bevel

gears (which also have curved teeth) but with a spiral angle of zero (so the ends of the

teeth align with the axis).

Hypoid bevel gears are similar to spiral bevel but the pitch surfaces

are hyperbolic and not conical. Pinion can be offset above, or below,the gear centre,

thus allowing larger pinion diameter, and longer life and smoother mesh, with

additional ratios e.g., 6:1, 8:1, 10:1. In a limiting case of making the "bevel" surface

parallel with the axis of rotation, this configuration resembles a worm drive.

19

(hypoid bevel gear)

Materials used in manufacturing of bevel gears

Materials used in gear manufacturing process

The various materials used for gears include a wide variety of cast irons, non ferrous

material &non – metallic materials the selection of the gear material depends upon: i)

Type of service ii) Peripheral speed iii) Degree of accuracy required iv) Method of

manufacture v) Required dimensions & weight of the drive vi) Allowable stress vii)

Shock resistance viii) Wear resistance.

20

1) Cast iron is popular due to its good wearing properties, excellent machinability & ease

of producing complicated shapes by the casting method. It is suitable where large gears

of complicated shapes are needed.

2) Steel is sufficiently strong & highly resistant to wear by abrasion.

3) Cast steel is used where stress on gear is high & it is difficult to fabricate the gears.

4) Plain carbon steels find application for industrial gears where high toughness

combined with high strength.

5) Alloy steels are used where high tooth strength & low tooth wear are required.

6) Aluminum is used where low inertia of rotating mass is desired.

7) Gears made of non–metallic materials give noiseless operation at high peripheral

speeds.

Bevel gearing

21

Two bevel gears in mesh is known as bevel gearing. In bevel gearing, the pitch cone

angles of the pinion and gear are to be determined from the shaft angle, i.e., the angle

between the intersecting shafts. Figure shows views of a bevel gearing

(bevel gearing)

Application of bevel gears

The bevel gear has many diverse applications such as locomotives, marine applications,

automobiles, printing presses, cooling towers, power plants, steel plants, railway track

inspection machines, etc.

22

For examples, see the following articles on:

Bevel gears are used in differential drives, which can transmit power to two

axles spinning at different speeds, such as those on a cornering automobile.

Bevel gears are used as the main mechanism for a hand drill. As the handle of

the drill is turned in a vertical direction, the bevel gears change the rotation of the

chuck to a horizontal rotation. The bevel gears in a hand drill have the added

advantage of increasing the speed of rotation of the chuck and this makes it possible

to drill a range of materials.

The gears in a bevel gear planer permit minor adjustment during assembly and

allow for some displacement due to deflection under operating loads without

concentrating the load on the end of the tooth.

Spiral bevel gears are important components on rotorcraft drive systems. These

components are required to operate at high speeds, high loads, and for a large number

of load cycles. In this application, spiral bevel gears are used to redirect the shaft

from the horizontal gas turbine engine to the vertical rotor.

Advantages of bevel gears

This gear makes it possible to change the operating angle.

23

Differing of the number of teeth (effectively diameter) on each wheel

allows mechanical advantage to be changed. By increasing or decreasing the ratio of

teeth between the drive and driven wheels one may change the ratio of rotations

between the two, meaning that therotational drive and torque of the second wheel can

be changed in relation to the first, with speed increasing and torque decreasing, or

speed decreasing and torque increasing.

Disadvantages of bevel gears

One wheel of such gear is designed to work with its complementary wheel and no

other.

Must be precisely mounted.

The shafts' bearings must be capable of supporting significant forces.

These are bevel gear

24

Chain driver

hain drive is a way of transmitting mechanical power from one place to another. It is

often used to convey power to the wheels of a vehicle,

particularly bicycles and motorcycles. It is also used in a wide variety of machines

besides vehicles.

Most often, the power is conveyed by a roller chain, known as the drive

chain or transmission chain,[1]passing over a sprocket gear, with the teeth of the gear

meshing with the holes in the links of the chain. The gear is turned, and this pulls the

25

chain putting mechanical force into the system. Another type of drive chain is the Morse

chain, invented by the Morse Chain Company of Ithaca, New York, USA. This has

inverted teeth.

Sometimes the power is output by simply rotating the chain, which can be used to lift or

drag objects. In other situations, a second gear is placed and the power is recovered by

attaching shafts or hubs to this gear. Though drive chains are often simple oval loops,

they can also go around corners by placing more than two gears along the chain; gears

that do not put power into the system or transmit it out are generally known as idler-

wheels. By varying the diameter of the input and output gears with respect to each other,

the gear ratiocan be altered, so that, for example, the pedals of a bicycle can spin all the

way around more than once for every rotation of the gear that drives the wheels.

History of chain driver

The oldest known application of a chain drive appears in the Polybolos,

a repeating crossbow described by theGreek engineer Philon of Byzantium (3rd century

BC). Two flat-linked chains were connected to a windlass, which by winding back and

forth would automatically fire the machine's arrows until its magazine was empty.

[3]Although the device did not transmit power continuously since the chains "did not

transmit power from shaft to shaft",[4] the Greek design marks the beginning of the history

of the chain drive since "no earlier instance of such a cam is known, and none as complex

26

is known until the 16th century. It is here that the flat-link chain, often attributed

to Leonardo da Vinci, actually made its first appearance."[3]

The first continuous power-transmitting chain drive was depicted in the

written horological treatise of the Song Dynasty (960–1279) Chinese engineer Su

Song (1020-1101 AD), who used it to operate the armillary sphere of

his astronomical clock tower as well as the clock jack figurines presenting the time of day

by mechanically banging gongs and drums.[5] The chain drive itself was given power via

the hydraulic works of Su's water clock tank and waterwheel, the latter which acted as a

large gear.

Use in the vehicles

Bicycles

Main article: Bicycle chain

Chain drive was the main feature which differentiated the safety bicycle introduced in

1885, with its two equal-sized wheels, from thedirect-drive penny-farthing or "high

wheeler" type of bicycle. The popularity of the chain-driven safety bicycle brought about

the demise of the penny-farthing, and is still a basic feature of bicycle design today.

Automobiles

27

Transmitting power to the wheels

Chain drive was a popular power transmission system from the earliest days of

theautomobile. It gained prominence as an alternative to the Système Panhard with its

rigidHotchkiss driveshaft and universal joints.

A chain-drive system uses one or more roller chains to transmit power from

a differential to the rear axle. This system allowed for a great deal of vertical axle

movement (for example, over bumps), and was simpler to design and build than a rigid

driveshaft in a workable suspension. Also, it had less unsprung weight at the rear wheels

than the Hotchkiss drive, which would have had the weight of the driveshaft and

differential to carry as well. This meant that the vehicle would have a smoother ride. The

lighter unsprung mass would allow the suspension to react to bumps more effectively.

Breaing

28

A bearing is a machine element that constrains relative motion between moving parts to

only the desired motion. The design of the bearing may, for example, provide for

free linearmovement of

ball bearing

the moving part or for free rotation around a fixed axis; or, it may prevent a motion by

controlling the vectors of normal forces that bear on the moving parts. Many bearings

also facilitate the desired motion as much as possible, such as by minimizing friction.

Bearings are classified broadly according to the type of operation, the motions allowed,

or to the directions of the loads (forces) applied to the parts.

29

The term "bearing" is derived from the verb "to bear";[1] a bearing being a machine

element that allows one part to bear (i.e., to support) another. The simplest bearings

are bearing surfaces, cut or formed into a part, with varying degrees of control over the

form, size,roughness and location of the surface. Other bearings are separate devices

installed into a machine or machine part. The most sophisticated bearings for the most

demanding applications are very precise devices; their manufacture requires some of the

highest standards of current technology.

History of bearing

The invention of the rolling bearing, in the form of wooden rollers supporting, or bearing,

an object being moved is of great antiquity, and may predate the invention of the wheel.

Though it is often claimed that the Egyptians used roller bearings in the form of tree

trunks under sleds,[2] this is modern speculation.[3] They are depicted in their own

drawings in the tomb of Djehutihotep  as moving massive stone blocks on sledges with

the runners lubricated with a liquid which would constitute a plain bearing. There are also

Egyptian drawings of bearings used withhand drills.

The earliest recovered example of a rolling element bearing is a wooden ball

bearingsupporting a rotating table from the remains of the Roman Nemi ships in Lake

Nemi, Italy. The wrecks were dated to 40 AD.

30

Leonardo da Vinci incorporated drawings of ball bearings in his design for a helicopter

around the year 1500. This is the first recorded use of bearings in an aerospace design.

However, Agostino Ramelli is the first to have published sketches of roller and thrust

bearings.[2] An issue with ball and roller bearings is that the balls or rollers rub against

each other causing additional friction which can be prevented by enclosing the balls or

rollers in a cage. The captured, or caged, ball bearing was originally described

by Galileo in the 17th century. The mounting of bearings into a set was not accomplished

for many years after that. The first patent for a ball race was by Philip

Vaughan of Carmarthen in 1794.

Bearings saw use for holding wheel and axles. The bearings used there were plain

bearings that were used to greatly reduce friction over that of dragging an object by

making the friction act over a shorter distance as the wheel turned.

The first plain and rolling-element bearings were wood closely followed by bronze. Over

their history bearings have been made of many materials

including ceramic, sapphire, glass, steel, bronze, other metals and plastic

(e.g., nylon, polyoxymethylene,polytetrafluoroethylene, and UHMWPE) which are all

used today.

Watch makers produce "jeweled" watches using sapphire plain bearings to reduce friction

thus allowing more precise time keeping.

Even basic materials can have good durability. As examples, wooden bearings can still be

seen today in old clocks or in water mills where the water provides cooling and

lubrication.

31

The first practical caged-roller bearing was invented in the mid-1740s by horologist John

Harrison for his H3 marine timekeeper. This uses the bearing for a very limited

oscillating motion but Harrison also used a similar bearing in a truly rotary application in

a contemporaneous regulator clock.

A patent on ball bearings, reportedly the first, was awarded to Jules Suriray, a Parisian

bicycle mechanic, on 3 August 1869. The bearings were then fitted to the winning bicycle

ridden by James Moore in the world's first bicycle road race, Paris-Rouen, in November

1869.[8]

In 1883, Friedrich Fischer, founder of FAG, developed an approach for milling and

grinding balls of equal size and exact roundness by means of a suitable production

machine and formed the foundation for creation of an independent bearing industry.

The modern, self-aligning design of ball bearing is attributed to Sven Wingquist of

the SKFball-bearing manufacturer in 1907, when he was awarded Swedish patent No.

25406 on its design.

Henry Timken, a 19th-century visionary and innovator in carriage manufacturing,

patented the tapered roller bearing in 1898. The following year he formed a company to

produce his innovation. Over a century the company grew to make bearings of all types,

including specialty steel and an array of related products and services.

Erich Franke invented and patented the wire race bearing in 1934. His focus was on a

bearing design with a cross section as small as possible and which could be integrated

into the enclosing design. After World War II he founded together with Gerhard

32

Heydrich the company Franke & Heydrich KG (today Franke GmbH) to push the

development and production of wire race bearings.

Richard Stribeck’s extensive research  on ball bearing steels identified the metallurgy of

the commonly used 100Cr6 showing coefficient of friction as a function of pressure.

Designed in 1968 and later patented in 1972, Bishop-Wisecarver's co-founder Bud

Wisecarver created vee groove bearing guide wheels, a type of linear motion bearing

consisting of both an external and internal 90-degree vee angle.

In the early 1980s, Pacific Bearing's founder, Robert Schroeder, invented the first bi-

material plain bearing which was size interchangeable with linear ball bearings. This

bearing had a metal shell (aluminum, steel or stainless steel) and a layer of Teflon-based

material connected by a thin adhesive layer.

Today ball and roller bearings are used in many applications which include a rotating

component. Examples include ultra high speed bearings in dental drills, aerospace

bearings in the Mars Rover, gearbox and wheel bearings on automobiles, flexure bearings

in optical alignment systems and bicycle wheel hubs.

Principle of operation of bearing

There are at least 6 common principles of operation:

plain bearing , also known by the specific styles: bushing, journal bearing, sleeve

bearing, rifle bearing

33

rolling-element bearing  such as ball bearings and roller bearings

jewel bearing , in which the load is carried by rolling the axle slightly off-center

fluid bearing , in which the load is carried by a gas or liquid

magnetic bearing , in which the load is carried by a magnetic field

flexure bearing , in which the motion is supported by a load element which bends.

Maintenance and lubrication of bearings

Many bearings require periodic maintenance to prevent premature failure, but many

others require little maintenance. The latter include various kinds of fluid and magnetic

bearings, as well as rolling-element bearings that are described with terms

including sealed bearingand sealed for life. These contain seals to keep the dirt out and

the grease in. They work successfully in many applications, providing maintenance-free

operation. Some applications cannot use them effectively.

Nonsealed bearings often have a grease fitting, for periodic lubrication with a grease gun,

or an oil cup for periodic filling with oil. Before the 1970s, sealed bearings were not

encountered on most machinery, and oiling and greasing were a more common activity

than they are today. For example, automotive chassis used to require "lube jobs" nearly as

often as engine oil changes, but today's car chassis are mostly sealed for life. From the

late 1700s through mid 1900s, industry relied on many workers called oilers to lubricate

machinery frequently with oil cans.

34

Factory machines today usually have lube systems, in which a central pump serves

periodic charges of oil or grease from a reservoir through lube lines to the various lube

points in the machine's bearing surfaces, bearing journals, pillow blocks, and so on. The

timing and number of such lube cycles is controlled by the machine's computerized

control, such as PLC or CNC, as well as by manual override functions when occasionally

needed. This automated process is how all modern CNC machine tools and many other

modern factory machines are lubricated. Similar lube systems are also used on

nonautomated machines, in which case there is a hand pumpthat a machine operator is

supposed to pump once daily (for machines in constant use) or once weekly. These are

called one-shot systems from their chief selling point: one pull on one handle to lube the

whole machine, instead of a dozen pumps of an alemite gun or oil can in a dozen

different positions around the machine.

The oiling system inside a modern automotive or truck engine is similar in concept to the

lube systems mentioned above, except that oil is pumped continuously. Much of this oil

flows through passages drilled or cast into the engine block and cylinder heads, escaping

through ports directly onto bearings, and squirting elsewhere to provide an oil bath. The

oil pump simply pumps constantly, and any excess pumped oil continuously escapes

through a relief valve back into the sump.

Many bearings in high-cycle industrial operations need periodic lubrication and cleaning,

and many require occasional adjustment, such as pre-load adjustment, to minimise the

effects of wear.

Bearing life is often much better when the bearing is kept clean and well lubricated.

However, many applications make good maintenance difficult. For example, bearings in

35

the conveyor of a rock crusher are exposed continually to hard abrasive particles.

Cleaning is of little use, because cleaning is expensive yet the bearing is contaminated

again as soon as the conveyor resumes operation. Thus, a good maintenance program

might lubricate the bearings frequently but not include any disassembly for cleaning. The

frequent lubrication, by its nature, provides a limited kind of cleaning action, by

displacing older (grit-filled) oil or grease with a fresh charge, which itself collects grit

before being displaced by the next cycle.

These are bearing images

36

(Internal and external parts)

Operation on lathe machine

Lathe machine

A lathe  is a machine tool which rotates the workpiece on its axis to perform various

operations such as cutting, sanding, knurling, drilling, or deformation, facing, turning,

with tools that are applied to the workpiece to create an object which has symmetry about

anaxis of rotation.

37

Lathes are used in woodturning, metalworking, metal spinning, Thermal spraying/ parts

reclamation, and glass-working. Lathes can be used to shape pottery, the best-known

design being the potter's wheel. Most suitably equipped metalworking lathes can also be

used to produce most solids of revolution, plane surfaces and screw threads or helices.

Ornamental lathes can produce three-dimensional solids of incredible complexity. The

material can be held in place by either one or two centers, at least one of which can be

moved horizontally to accommodate varying material lengths. Other work-holding

methods include clamping the work about the axis of rotation using a chuck or collet, or

to a faceplate, using clamps or dogs.

Examples of objects that can be produced on a lathe include candlestick holders,gun

barrels, cue sticks, table legs, bowls, baseball bats, musical instruments

(especially woodwind instruments), crankshafts, and camshafts.

38

turning operation

facing operation

turning operation

Turning is a machining process in which a cutting tool, typically a non-rotary tool bit,

describes a helical toolpath by moving more or less linearly while the workpiece rotates.

The tool's axes of movement may be literally a straight line, or they may be along some

set of curves or angles, but they are essentially linear (in the nonmathematical sense).

Usually the term "turning" is reserved for the generation of external surfaces by this

cutting action, whereas this same essential cutting action when applied

to internal surfaces (that is, holes, of one kind or another) is called "boring". Thus the

phrase "turning and boring" categorizes the larger family of (essentially similar)

processes. The cutting of faces on the workpiece (that is, surfaces perpendicular to its

rotating axis), whether with a turning or boring tool, is called "facing", and may be

lumped into either category as a subset.

Turning can be done manually, in a traditional form of lathe, which frequently requires

continuous supervision by the operator, or by using an automated lathe which does not.

Today the most common type of such automation is computer numerical control, better

39

known as CNC. (CNC is also commonly used with many other types of machining

besides turning.)

When turning, a piece of relatively rigid material (such as wood, metal, plastic, or stone)

is rotated and a cutting tool is traversed along 1, 2, or 3 axes of motion to produce precise

diameters and depths. Turning can be either on the outside of the cylinder or on the inside

(also known as boring) to produce tubular components to various geometries. Although

now quite rare, early lathes could even be used to produce complex geometric figures,

even theplatonic solids; although since the advent of CNC it has become unusual to use

non-computerized toolpath control for this purpose.

The turning processes are typically carried out on a lathe, considered to be the oldest

machine tools, and can be of four different types such as straight turning, taper

turning,profiling or external grooving. Those types of turning processes can produce

various shapes of materials such as straight, conical, curved, or grooved workpiece. In

general, turning uses simple single-point cutting tools. Each group of workpiece materials

has an optimum set of tools angles which have been developed through the years.

The bits of waste metal from turning operations are known as chips  . In some areas they

may be known as turnings.

40

(turning of rod)

(finish turning)

41

so we can say that turning is That operation is one of the most

basic machining processes. That is, the part is rotated while a single point cutting tool is

moved parallel to the axis of rotation.[1] Turning can be done on the external surface of

the part as well as internally (boring). The starting material is generally a workpiece

generated by other processes such ascasting, forging, extrusion, or drawing.

Facing operation

n machining, facing is the act of cutting a face, which is a planar surface, onto the

workpiece. Within this broadest sense there are various specific types of facing, with the

two most common being facing in the course of turning and boring work (facing planes

perpendicular to the rotating axis of the workpiece) and facing in the course

of milling work (for example, face milling). Other types of machining also cut faces (for

example, planing, shaping, and grinding), although the term "facing" may not always be

employed there.

Spotfacing is the facing of spots (localized areas), such as the bearing surfaces on

which bolt heads or washers will sit

42

( facing operation )

Welding

Welding is a fabrication or sculptural process that joins materials,

usually metals orthermoplastics, by causing coalescence. This is often done

by melting the workpieces and adding a filler material to form a pool of molten material

(the weld pool) that cools to become a strong joint, with pressure sometimes used in

conjunction with heat, or by itself, to produce the weld. This is in contrast

with soldering and brazing, which involve melting a lower-melting-point material

between the workpieces to form a bond between them, without melting the workpieces.

43

Many different energy sources can be used for welding, including a gas flame, an electric

arc, a laser, an electron beam, friction, and ultrasound. While often an industrial process,

welding may be performed in many different environments, including open air, under

waterand in outer space. Welding is a potentially hazardous undertaking and precautions

are required to avoid burns, electric shock, vision damage, inhalation of poisonous gases

and fumes, and exposure to intense ultraviolet radiation.

Until the end of the 19th century, the only welding process was forge welding,

whichblacksmiths had used for centuries to join iron and steel by heating and

hammering. Arc welding and oxyfuel welding were among the first processes to develop

late in the century, and electric resistance welding followed soon after. Welding

technology advanced quickly during the early 20th century as World War I and World

War II drove the demand for reliable and inexpensive joining methods. Following the

wars, several modern welding techniques were developed, including manual methods

like shielded metal arc welding, now one of the most popular welding methods, as well as

semi-automatic and automatic processes such as gas metal arc welding, submerged arc

welding, flux-cored arc weldingand electroslag welding. Developments continued with

the invention of laser beam welding, electron beam welding, electromagnetic pulse

welding and friction stir welding in the latter half of the century. Today, the science

continues to advance. Robot welding is commonplace in industrial settings, and

researchers continue to develop new welding methods and gain greater understanding of

weld quality.

44

Arc welding process

Arc

These processes use a welding power supply to create and maintain an electric arc

between an electrode and the base material to melt metals at the welding point. They can

use either direct (DC) or alternating (AC) current, and consumable or non-

consumableelectrodes. The welding region is sometimes protected by some type of inert

or semi-inert gas, known as a shielding gas, and filler material is sometimes used as well.

Power supplies

To supply the electrical power necessary for arc welding processes, a variety of different

power supplies can be used. The most common welding power supplies are

constant current power supplies and constant voltage power supplies. In arc welding, the

45

length of the arc is directly related to the voltage, and the amount of heat input is related

to the current. Constant current power supplies are most often used for manual welding

processes such as gas tungsten arc welding and shielded metal arc welding, because they

maintain a relatively constant current even as the voltage varies. This is important

because in manual welding, it can be difficult to hold the electrode perfectly steady, and

as a result, the arc length and thus voltage tend to fluctuate. Constant voltage power

supplies hold the voltage constant and vary the current, and as a result, are most often

used for automated welding processes such as gas metal arc welding, flux cored arc

welding, and submerged arc welding. In these processes, arc length is kept constant, since

any fluctuation in the distance between the wire and the base material is quickly rectified

by a large change in current. For example, if the wire and the base material get too close,

the current will rapidly increase, which in turn causes the heat to increase and the tip of

the wire to melt, returning it to its original separation distance.[1]

The type of current used also plays an important role in arc welding. Consumable

electrode processes such as shielded metal arc welding and gas metal arc welding

generally use direct current, but the electrode can be charged either positively or

negatively. In welding, the positively charged anode will have a greater heat

concentration, and as a result, changing the polarity of the electrode has an impact on

weld properties. If the electrode is positively charged, the base metal will be hotter,

increasing weld penetration and welding speed. Alternatively, a negatively charged

electrode results in more shallow welds.[2] Nonconsumable electrode processes, such as

gas tungsten arc welding, can use either type of direct current, as well as alternating

current. However, with direct current, because the electrode only creates the arc and does

46

not provide filler material, a positively charged electrode causes shallow welds, while a

negatively charged electrode makes deeper welds.[3] Alternating current rapidly moves

between these two, resulting in medium-penetration welds. One disadvantage of AC, the

fact that the arc must be re-ignited after every zero crossing, has been addressed with the

invention of special power units that produce a square wave pattern instead of the

normal sine wave, making rapid zero crossings possible and minimizing the effects of the

problem.

Process of welding

One of the most common types of arc welding is shielded metal arc welding (SMAW);

[5] it is also known as manual metal arc welding (MMA) or stick welding. Electric current

is used to strike an arc between the base material and consumable electrode rod, which is

made of filler material (typically steel) and is covered with a flux that protects the weld

area from oxidation and contamination by producing carbon dioxide (CO2) gas during the

welding process. The electrode core itself acts as filler material, making a separate filler

unnecessary.

he process is versatile and can be performed with relatively inexpensive

equipment, making it well suited to shop jobs and field work.[5][6] An operator can become

reasonably proficient with a modest amount of training and can achieve mastery with

47

experience. Weld times are rather slow, since the consumable electrodes must be

frequently replaced and because slag, the residue from the flux, must be chipped away

after welding.[5]Furthermore, the process is generally limited to welding ferrous materials,

though special electrodes have made possible the welding of cast iron, nickel,

aluminum, copper, and other metals.

Diagram of arc and weld area, in shielded metal arc welding

1. Coating Flow

2. Rod

3. Shield Gas

48

4. Fusion

5. Base metal

6. Weld metal

7. Solidified Slag

Gas metal arc welding (GMAW), also known as metal inert gas or MIG welding, is a

semi-automatic or automatic process that uses a continuous wire feed as an electrode and

an inert or semi-inert gas mixture to protect the weld from contamination. Since the

electrode is continuous, welding speeds are greater for GMAW than for SMAW.[7]

A related process, flux-cored arc welding (FCAW), uses similar equipment but uses wire

consisting of a steel electrode surrounding a powder fill material. This cored wire is more

expensive than the standard solid wire and can generate fumes and/or slag, but it permits

even higher welding speed and greater metal penetration.[8]

Gas tungsten arc welding (GTAW), or tungsten inert gas (TIG) welding, is a manual

welding process that uses a nonconsumable tungsten electrode, an inert or semi-inert gas

mixture, and a separate filler material.[9] Especially useful for welding thin materials, this

method is characterized by a stable arc and high quality welds, but it requires significant

operator skill and can only be accomplished at relatively low speeds.[9]

GTAW can be used on nearly all weldable metals, though it is most often applied

tostainless steel and light metals. It is often used when quality welds are extremely

important, such as in bicycle, aircraft and naval applications.[9] A related process, plasma

49

arc welding, also uses a tungsten electrode but uses plasma gas to make the arc. The arc

is more concentrated than the GTAW arc, making transverse control more critical and

thus generally restricting the technique to a mechanized process. Because of its stable

current, the method can be used on a wider range of material thicknesses than can the

GTAW process and it is much faster. It can be applied to all of the same materials as

GTAW except magnesium, and automated welding of stainless steel is one important

application of the process. A variation of the process is plasma cutting, an efficient steel

cutting process.[10]

Submerged arc welding (SAW) is a high-productivity welding method in which the arc is

struck beneath a covering layer of flux. This increases arc quality, since contaminants in

the atmosphere are blocked by the flux. The slag that forms on the weld generally comes

off by itself, and combined with the use of a continuous wire feed, the weld deposition

rate is high. Working conditions are much improved over other arc welding processes,

since the flux hides the arc and almost no smoke is produced. The process is commonly

used in industry, especially for large products and in the manufacture of welded pressure

vessels.[11] Other arc welding processes include atomic hydrogen welding, electroslag

welding, electrogas welding, and stud arc welding

Tools

Tools used during the making projects

50

hacksaw

blade

file

scale

drill

etc.

Hacksaw

A hacksaw is a fine-tooth hand saw with a blade held under tension in a frame, used

forcutting materials such as metal or plastics. Hand-held hacksaws consist of a metal

arch with a handle, usually a pistol grip, with pins for attaching a narrow disposable

blade. A screw or other mechanism is used to put the thin blade under tension. The

blade can be mounted with the teeth facing toward or away from the handle, resulting

in cutting action on either the push or pull stroke. On the push stroke, the arch will

flex slightly, decreasing the tension on the blade, often resulting in an increased

tendency of the blade to buckle and crack. Cutting on the pull stroke increases the

blade tension and will result in greater control of the cut and longer blade life

51

Blade

Blades are available in standardized lengths, usually 10 or 12 inches for a standard hand

hacksaw. "Junior" hacksaws are half this size. Powered hacksaws may use large blades in

a range of sizes, or small machines may use the same hand blades.

The pitch of the teeth can be anywhere from fourteen to thirty-two teeth per inch (tpi) for

a hand blade, with as few as three tpi for a large power hacksaw blade. The blade chosen

is based on the thickness of the material being cut, with a minimum of three teeth in the

material. As hacksaw teeth are so small, they are set in a "wave" set. As for other saws

they are set from side to side to provide a kerfor clearance when sawing, but the set of a

hacksaw changes gradually from tooth to tooth in a smooth curve, rather than alternate

teeth set left and right.

Hacksaw blades are normally quite brittle, so care needs to be taken to prevent brittle

fracture of the blade. Early blades were of carbon steel, now termed 'low alloy' blades,

and were relatively soft and flexible. They avoided breakage, but also wore out rapidly.

Except where cost is a particular concern, this type is now obsolete. 'Low alloy' blades

52

are still the only type available for the Junior hacksaw, which limits the usefulness of this

otherwise popular saw.

For several decades now, hacksaw blades have used high speed steel for their teeth,

giving greatly improved cutting and tooth life. These blades were first available in the

'All-hard' form which cut accurately but were extremely brittle. This limited their

practical use to benchwork on a workpiece that was firmly clamped in a vice. A softer

form of high speed steel blade was also available, which wore well and resisted breakage,

but was less stiff and so less accurate for precise sawing. Since the 1980s, bi-metal blades

have been used to give the advantages of both forms, without risk of breakage. A strip of

high speed steel along the tooth edge is electron beam welded to a softer spine. As the

price of these has dropped to be comparable with the older blades, their use is now almost

universl

hacksaw blade

53

File

A file is a metalworking, woodworking and plastic working tool used to cut fine amounts

of material from a workpiece. It most commonly refers to the hand tool style, which takes

the form of a steel bar with a case hardened surface and a series of sharp, parallel teeth.

Most files have a narrow, pointed tang at one end to which a handle can be fitted.[1]

A similar tool is the rasp. This is an older form, with simpler teeth. As they have larger

clearance between teeth, these are usually used on softer, non-metallic materials.

Related tools have been developed with abrasive surfaces, such as diamond

abrasives orsilicon carbide. Because of their similar form and function, these have also

been termed 'files'.

( file )

54

( FINAL PROJECT )

By using all this process , gears , operation and tools we have completed our project

This are our project images as

55