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DIRECTORATE OF TECHNICAL EDUCATION
CHENNAI-600025
DIPLOMA IN MECHANICAL ENGINEERING
PROJECT REPORT
2015-2016
FABRICATION OF ABRASIVE BELT GRINDER
DONE BY
NAME REG.NO.
MOHANAVATHANAN R 14255963
RAJESH A 14259982
SARAVANAN C 14255990
SATHISHKUMAR A 14255992
VIJAYAKUMAR B 14256016
GUIDE BY
Mr.S.SARAVANAN,B.E.,
Lecturer in Mechanical Engg.
Dr.M.G.R.POLYTECHNIC COLLEGE,
ACS NAGAR,ARNI-632317.
T.V.MALAI DIST.
BONAFIDE CERTIFICATE
Certified that is the confide record of the project work done
By_____________________________________ of the final year diploma
in MECHANICAL ENGINEERING, during the academic year 2015-
2016.
REGISTER NO :
GUIDE H.O.D
Submitted for the practical examination held on ______________
INTERNAL EXAMINER EXTERNAL EXAMINER
ACKNOWEDGEMENT
We thank our gratitude to our Correspondent Thiru
A.C.SHANMUGAM,B.A.B.L., for his words which inspired us a lot in completing
this project work successfully.
We Thank sourprincipal Mr.D.ARUMUGAMUDALI,
B.E.,B.TECH.ED,M.I.S.T.E.,M.I.E.,C.ENGG for his valuable suggestion and timely
advises during various stages of our work.
We Thanks our regards to Mr.A.KARTHIKEYAN,M.E., Head of the
Mechanical Engineering Department, Dr.MGR Polytechnic College, ARNI for
providing necessary facilities to carry the project.
Our hearty thanks to our Guide Mr.S.SARAVANAN,B.E Lecturer of
Dr.MGR Polytechnic,ARNI. who has been the lifeblood of our project. Amidst him
busy schedule, he had spent her valuable time in explaining certain crucial concepts.
She constantly motivated us and animated our spirits to implement our project in an
efficacious manner. His enriched ideas and his vision beyond horizon have accelerated
us throughout our research.
I also thank all our faculty members and my friends for their kind support and
providing necessary facilities to carry out the work.
Last but not least we are heavily indebted to our beloved PARENTS for their
continuous source of encouragement.
CONTENTS
ACKNOWLEDGEMENT
INTRODUCTION
WORKING PRINCIPLE
PART DRAWING
ASSEMBLY DRAWING
INDUCTION MOTORS
ADVANTAGES AND LIMITATION
APPLICATION
SPECIFICATIONS
LIST OF MATERIALS
PROJECT SHEDULE
COST ESTIMATION
CONCLUSION
PHOTOGRAPHY
BIBLIOGRAPHY
ABSTRACT
ABSTRACT
The Machine we designed and fabricated is used for grinding any shape of object
like Circular, Rectangular, and Polygon. In our project the work abrasive belt is used
to grinding the material. The abrasive belt is rotated by the single phase induction
motor. Hence our project namely abrasive belt grinder is a Special type of Machine.
According to the type of material to be grind, the grinding tool can be changed.
This project gives details of grinding various shapes and sizes of components.
This machine can be widely applied in almost all type of industries. By varying the
pulley sizes I can get a high end speed of over 10,000 rpm if needed. The only change
I would make is to have a totally enclosed motor to keep out the grit.
INTRODUCTION
INTRODUCTION
Our project is design and fabrication of Multi Use abrasive belt
Grinder. It is used to grind the machining surfaces to super Finish and accuracy.
It can be used as an external Grinder by fixing the belt grinder attachment on the
conveyor roller. The principle parts of this attachment are main body, motor with
pulley, bearings, rope pulley and conveyor abrasive belt etc.
WORKING
PRINCIPLE
WORKING PRINCIPLE
The abrasive belt is used to grind the material. This abrasive belt is rotated by
the single phase induction motor. In our project consist of end bearings with bearing
cap, roller wheel, shaft, single phase induction motor and abrasive belt. This whole
arrangement is fixed on the frame structure where the component rests.
The roller wheel is mounted on the two end bearings with bearing cap by suitable
arrangement. There are two roller wheel is used in our project to rotate the abrasive
belt. One side of the roller wheel shaft, one v-pulley is coupled by the suitable
arrangement. The single phase induction motor with V-pulley arrangement is used to
rotate the abrasive belt through the belt drive mechanism.
Belt grinding is an abrasive machining process used on metals and other
materials. It is typically used as a finishing process in industry. A belt, coated in
abrasive material, is run over the surface to be processed in order to remove material
or produce the desired finish.
APPLICATIONS
Belt grinding is a versatile process suitable for all kinds of different
applications. There are three different applications of the belt grinding technology:
1. Finishing: surface roughness, removal of micro burrs, cosmetic finishes,
polishing
2. Deburring: radiusing, burr removal, edge breaking
3. Stock removal: high stock removal, cleaning (e.g. of corrosion), eliminating mill
or tool marks, dimensioning
GRINDING METHODS
Wide belt grinding is a familiar process in industry as well as home applications.
There are several basic methods for belt grinding:
Stroke belt
Platen belt
Wide belt
Backstand (pressure)
Centreless
Portable (manual)
WIDE BELT GRINDING
One of the most common methods is wide belt grinding.
The belt grinding process is variable by adjusting certain parameters such as belt
speed, grinding pressure, feed speed, durometer of the contact drum, size of the contact
drum and the abrasive belt that is used. The machines can be made for wet or dry
operation. Furthermore, a wide belt grinding machine can be constructed with single
or multiple heads. The first head is used for coarse grinding and the next heads
gradually make a finer finish. Wide belt grinding is also used as a high stock removal
method for special
CHANGING VARIABLES
There are several objectives possible for grinding with coated abrasives. Among
them are the right application (e.g. finish or stock removal), time saving and efficiency
of the abrasive tool.
To achieve the above objectives, it is essential to look in more detail to the
variables which affect them. These include the work material properties, the grit and
abrasive type of the grinding belt, belt speed, belt sequences, contact wheel hardness
and diameter, serration, type of lubricant (or dry) and grinding pressure
ABRASIVE
An abrasive is a material, often a mineral, that is used to shape or finish a
workpiece through rubbing which leads to part of the workpiece being worn away.
While finishing a material often means polishing it to gain a smooth, reflective surface
which can also involve roughening as in satin, matte or beaded finishes.
Abrasives are extremely commonplace and are used very extensively in a wide
variety of industrial, domestic, and technological applications. This gives rise to a large
variation in the physical and chemical composition of abrasives as well as the shape of
the abrasive.
MECHANICS OF ABRASION
Abrasives generally rely upon a difference in hardness between the abrasive and
the material being worked upon, the abrasive being the harder of the two substances.
Typically, materials used as abrasives are either hard minerals (rated at 7 or
above on Mohs scale of mineral hardness) or are synthetic stones, some of which may
be chemically and physically identical to naturally occurring minerals but which cannot
be called minerals as they did not arise naturally.
Abrasive minerals
Abrasives may be classified as either natural or synthetic. When discussing
sharpening stones, natural stones have long been considered superior but advances in
material technology are seeing this distinction become less distinct. Many synthetic
abrasives are effectively identical to a natural mineral, differing only in that the
synthetic mineral has been manufactured rather than been mined. Impurities in the
natural mineral may make it less effective.
Some naturally occurring abrasives are:
Calcite (calcium carbonate)
Emery (impure corundum)
Diamond dust (synthetic diamonds are used extensively)
Novaculite
Pumice
Rouge
Sand
Corundum
Garnet
Sandstone
Tripoli
Powdered Feldspar
Staurolite
Some abrasive minerals (such as zirconia alumina) occur naturally but are
sufficiently rare or sufficiently more difficult/costly to obtain such that a synthetic
stone is used industrially. These and other artificial abrasives include:
Borazon (cubic boron nitride or CBN)
Ceramic
Ceramic aluminium oxide
Ceramic iron oxide
Corundum (alumina or aluminium oxide)
Dry ice
Glass powder
Steel abrasive
Silicon carbide (carborundum)
Zirconia alumina
Boron carbide
MANUFACTURED ABRASIVES
Abrasives are shaped for various purposes. Natural abrasives are often sold as
dressed stones, usually in the form of a rectangular block. Both natural and synthetic
abrasives are commonly available in a wide variety of shapes, often coming as bonded
or coated abrasives, including blocks, belts, discs, wheels, sheets, rods and loose grains.
BONDED ABRASIVES
Assorted grinding wheels as examples of bonded abrasives.
A grinding wheel with a reservoir to hold water as a lubricant and coolant.
A bonded abrasive is composed of an abrasive material contained within a
matrix, although very fine aluminium oxide abrasive may comprise sintered material.
This matrix is called a binder and is often a clay, a resin, a glass or a rubber.
COATED ABRASIVES
A German sandpaper showing its backing and FEPA grit size.
A coated abrasive comprises an abrasive fixed to a backing material such as
paper, cloth, rubber, resin, polyester or even metal, many of which are flexible.
Sandpaper is a very common coated abrasive. Coated abrasives are commonly the same
minerals as are used for bonded abrasives.
OTHER ABRASIVES AND THEIR USES
Here the abrasiveness of toothpaste is detailed by its Relative Dentin Abrasivity (RDA)
Sand, glass beads, metal pellets copper slag and dry ice may all be used for a
process called sandblasting (or similar, such as the use of glass beads which is "bead
blasting"). Dry ice will sublimate leaving behind no residual abrasive.
INDUCTION MOTOR
I. OBJECTIVES
A.
To experimentally evaluate the circuit model elements for a 3-phase induction
motor.
B.
1. To start and test the performance of an induction motor under full load when it
is powered from the three-phase line by a FVNR (full voltage, non-reversing)
combination starter.
2. To compare the actual performance of a three-phase induction motor with that
predicted by the circuit model.
3. To start an induction motor, examine variable speed operation, and perform a
full-load test when it is powered by the AC Test Drive.
4. To obtain the data for the torque vs. speed and current vs. speed characteristics
of the induction motor using a lab computer program.
II. THEORY AND BACKGROUND
A. CONSTRUCTION
The induction machine has two parts - stator and rotor. The stator carries a
distributed 3-phase winding. The stator winding is the input/output winding and is the
armature of the machine. The lab machine has a squirrel cage rotor. A squirrel cage
rotor has solid bars in the slots and they are shorted together at the ends.
B. OPERATION
When a balanced 3-phase voltage is supplied to the armature, a rotating magnetic
field is produced (just as in a synchronous machine). The speed of rotation is the
synchronous speed given by
s 4f1
p rad / s
or
ns 120 f1
p rpm,
where p is the number of poles of the armature winding and f1 is the line frequency.
However, the rotor rotates at a speed less than the synchronous speed. We will
designate the angular speed of the rotor in rad/s by w and the speed in rev/min (rpm)
by n. The slip speed is speed of the rotor relative to the field, i.e.,
Slip speed = ws – w (rad/s)
= ns – n rpm
C. EQUIVALENT CIRCUIT
The equivalent circuit given in Figure 1 serves as an approximate circuit model
for one phase of the induction motor.
Figure 1. Per phase Equivalent Circuit of Induction Motor
The symbols used in Figure 1 are defined below:
V1 = line-to-neutral terminal voltage. The phase windings are considered to be
in a Y configuration.
r1 = stator resistance per phase
x1 = stator leakage reactance per phase
r2 = rotor resistance referred to the stator, per phase
x2 = rotor leakage reactance referred to the stator, per phase
xm = a shunt reactance supplied to provide a path for the magnetizing
component of the current flowing in the stator. It is this current which
produces the revolving field in the motor.
III. THE LABORATORY MACHINE
The induction machine of the laboratory has the following name plate data:
H.P. 5; Phase 3; Hz 60; Design B;
RPM 1750; Amps (for 230V) 12.5; Amps (for 460V) 6.25
The stator has two 3-phase windings. The corresponding phases may be
connected in series or in parallel. For a series connection, the rating of 460 V, 6.25 A
applies and for a parallel connection 230 V, 12.5 A. The latter applies for our case.
Thus before starting lab work, you must remember to connect the two 3-phase windings
in parallel
+
–
I1 I2 x2 x1
xm
r1
r2
r2 1 s
s
r2
s V1
IV. INSTRUCTOR LABORATORY PREPARATION
The blocked rotor test in Day 1 will need a special supply, namely, 3-phase AC
of 15 Hz. This section assists the instructors to generate this supply. A separate work
station with a synchronous machine is to be used and the supply will reach other
stations through the station tie line.
Figure 2. Circuit for Generating the Special Supply
Turn the dyno and AC Test Drive circuit breakers ON and put the contactor
panel in the HAND mode. 2M may be OFF as it is not used. To protect the field
exciter, make sure that the field connection is made and the exciter is off. Now make
the following settings on the dyno:
SPEED mode; FULL field; Current Limit = 50%.
Field Exciter
Synchronous Machine
3-phase Meter
Package
F
F
1
2
Tie Line
1M
V. LABORATORY PROCEDURE - DAY 1
In the first day's work, experiments will be performed for determining
impedances of the equivalent circuit. The MONITOR computer program will act as
your "multimeter" for these experiments.
A. DC RESISTANCE TEST
The schematic for this test is given in Figure 3. Connect the two leads from the
DC circuit to any two stator terminals of the induction motor. Make sure all of the
load box switches are in the off (center) position. Using proper procedures, connect
the input to the 125 V DC laboratory supply. Have your wiring checked by your
instructor
If the 250 V DC supply is used instead of 125 V, a slightly different
configuration is to be adopted for the load box. If the resistors (which are 39 ohms
each) are connected in parallel then the current through each would be about 6.4 amps,
which would be well over the rated current of the element. Thus, groups of two
resistors (in series) should be connected in parallel in this case.
Figure 3. Schematic for DC Stator Resistance Test
B. NO-LOAD TEST
The schematic for this test is given in Figure 4. Be sure that the motor is
uncoupled from the dynamometer. Connect the motor terminals to the output of the
transducer package which encompasses power measurement by the 2-wattmeter
method. Then make connections to the Combination Starter output, using proper safety
procedures. Your wiring should be checked by your instructor before proceeding.
Close the circuit breaker and press START on the Combination Starter panel. The no-
load speed should be about 1799 rpm. Read and record the line currents, line voltage,
and wattmeter readings (you may prefer to just print the monitor and highlight the
channels of interest, as usual).
Figure 4. Schematic for No-Load and Full-Load Motor Tests.
VI. LABORATORY PROCEDURE - DAY 2
For this period, the objectives are full load operation of the induction motor with
line supply and AC Test Drive supply, and obtaining data for induction motor
characteristics by a computerized test.
A. FULL LOAD TEST WITH LINE OPERATION
The motor must be coupled to the dyno with the chain guard in place. Unpin
and zero the torque table with the computer. The circuit for this test is the same as that
used for the no-load test (Figure 4). After your instructor has checked your wiring,
START the induction motor. If the direction of rotation is not positive (as per our
I
Induction Motor
I
I
A
C
B
P
P
P
A
C
B
V
V
Combination Starter
230 V
360 Hz
convention), STOP the motor, interchange two terminals at the motor connection, re-
zero the torque table, and again START.
B. AC TEST DRIVE SUPPLY
A detailed description of AC Test Drive is in the Synchronous Machine
Experiment 6 (Section III: Laboratory Equipment). Here, the induction machine is
operated with this kind of supply.
The circuit diagram is the same as in Figure 4, except for two differences:
(a) The AC input is from the 3-phase output terminals of the AC Test Drive
(rather than the combination starter).
and (b) Connect one of the line voltages to an isolation package.
C. COMPUTERIZED TEST FOR CHARACTERISTICS
In this part of the experiment, the dyno will force the induction motor through
speeds zero (blocked rotor) through 1800 rpm (synchronous speed). The computer will
run the test in accordance with your specifications and record the data.
(a) the actual maximum magnitude of the current
and (b) avoidance of saturation (for the sake of accuracy).
Figure 5. Circuit Diagram for Computerized Characteristics Test
For the numerical values (test parameters) requested by the program, enter
the following:
Initial Speed (RPM): 1860
Final Speed (RPM): 0
Ramp Time (seconds) 10 (sec.)
Dyno Current Limit : 100 %
Figure 6. Wiring Diagram for Figure 5.
Once you press a key to start the test, the dyno will be turned on first and then
the 1M contactor will be turned on. Note that the dyno is set to SPEED mode by the
program. The speed setting will be ramped according to the test parameters entered
and the data stored. When the program exits, save the data file.
FURNAS
125 V DC 250 V DC
DYNAM- DRIVE
DC TEST DRIVE
230 V ACAC TEST
DRIVE
ICL
STARTERAC COMB
IAL
IBR
ID
ICR
IBL
IAR
230 V AC AC STARTER
TIE LINE
AC TEST DC TEST
125 V DC 250 V DC
A F
Furnas Motor Control Center
CIRCUIT BREAKERS
CONTROL POWER 110 V AC
THERMOCOUPLE
2-STEP STARTER
TACH
BLOWER
2A
IE
2B
Induction Motor
CT
sec
pri
VII. CALCULATIONS AND GRAPHS
1. Determine the impedances (resistances and inductances) of the equivalent circuit
model using the DC test, Blocked Rotor test, and No-Load test data.
2. Use this model to predict motor performance at the same voltage and speed as
in the full load line operation.
3. Calculate the average line current, power, power factor, horsepower, and
efficiency from:
(a) full load line operation data,
and (b) full load AC Test Drive Supply data.
4. From the computer controlled experiment data, plot Torque vs. Speed and
(Average) Current vs. Speed from 0 to 1800 rpm. Discard points (if any) above
1800 rpm.
VIII. ANALYSIS
1. Prepare a table comparing predicted and measured performance of the induction
motor operated from the 230 V line. Mention some sources of the discrepancies.
2. Compare efficiencies from line and inverter (AC Test Drive) operation and
comment on the difference.
3. In terms of the equivalent circuit, explain the relationship of increasing current
and decreasing power factor as the motor is slowed below synchronous speed.
4. Examine the graphs in the neighborhood of ns. In terms of the equivalent circuit,
what are the speed, torque, power, and stator current at ns?
Dynamic modelling of the induction motor
Vector control purpose
Mechanical motion.
Linear motion
For linear motion, the forces acting on a body may usually be simplified to a driving
force, Fe, acting on the mass, and an opposing force (or load), Fl, as shown on Figure
1.
Figure 1: A body acted on by two forces.
For translational motion the following may be written:
e LF Fdv
dt M
In any speed and position control of linear motion, force is the fundamental variable
which needs to be controlled.
Rotary motion
If the motion is rotary about an axis instead of translational, a situation as shown in
Figure 2 arises.
Figure 2: A body acted on by two torques.
For rotary motion the following may be written:
Ldw T T
dt J
In any speed and position control of rotary motion, torque is the fundamental variable
which needs to be controlled.
Torque in an electric drive
Electromagnetic torque produced by a motor is opposed by load torque. The difference,
em LT T , will accelerate the system.
Figure 3: A load acted on by a motor
Transformation of currents, voltages, flux-linkage, etc.
What remains is to define a method for performing the phase transformations to
the rotating frame of reference. The transformation is done by defining a
transformation-matrix for the systems as
dq abc dq abcf T f
where f denote currents, voltages, flux-linkage, etc. For current case, this is shown in
Figure 4.
Figure 4. Transformation of phase quantities into dq winding quantities (current
case).
The electromagnetic torque
Properly the most important task for the induction motor is to produce a torque
on the shaft. The developed torque may be written on the flowing form,
2
em rq rd rd rq
pT i i
d-q equivalent circuit
The result from the above is a set of equations describing the electromagnetic
system in the rotating frame of reference. The equations describing the system may be
interpreted as equivalent circuits, which may help in understanding the dynamics of
the system.
a) d-axis
b) q-axis
Figure 5. dq-winding equivalent circuits.
Computer simulation
In order to carry out computer simulations, it is necessary to calculate intial
values of the state variables, that is, of the flux linkages of the dq windings. These can
be calculated in terms of the initial values of the dq windings currents. These currents
allow us to compute the electromagnetic torque in steady state, thus the initial loading
of the induction machine. Initial conditions are computed in Example 3-1 and in the
matlab file EXE_1.m (or EXE_2.m).
Finally, the Simulink model is shown in Figure 6.
Eq. 3-48
Figure 3-13 Simulation of Example 3-3; File Name EX3_3_1.mdl
Entrada
trifasica
ELECRODINAMICS
DQ-WINDING REPRESENTATION
-K-
rad/s --> RPM
1
s
Va
Vb
Vc
Wmech
i_dq
abc --> dq
Vc
Vb
Va
f(u)
Torque Eq. 3-47
Info
Load Torque
1/Jeq
Inertia
Start
Double Click to
load parameters and initial conditions
Plot
After Simulation, Double Click to
plot results using MATLAB
Wmech
Tem
Tem RPMi_dq
ADVANTAGES AND DISADVANTAGES
ADVANTAGES:
The machine is compact and rigid in size.
Maintenance is less.
It can be used on any place of small grinding application
By varying the pulley diameter the speed of the abrasive belt to be
changed.
DISADVANTAGES :
The abrasive belt should be changeable one for different material. This
process takes more time.
APPLICATIONS
Grinding outside the job in any size of body can be done.
As the feed is given automatic, 0.8 micron finish may be achieved.
By changing the grades of abrasive belt grinding it can be used to
grind the carbon steel, Alloy steel and stainless steel etc.
SCHEDULE FOR PROJECT
SL.NO PROGRESS OF
WORK OCT NOV DEC JAN FEB MAR
1. Received the approval for
project title
2. Collecting the information
from various text book
and selecting materials
3. Construct the body of the
project.
4. Purchasing
5.
Collecting the Additional
information to complete
the project and painting
work
6. Report and extra work
was completed. Attending
the final evaluation
COST ESTIMATION
S.NO. NAME OF THE PARTS QUANTITY TOTAL
COST
1 MOTOR 1 2800
2 PULLEY BEARING 2 500
3 V-BELT 1 100
4 PULLEY 1 200
5 PAINTING 1 Lit 110
6 ABRASIVE BELT 1 45
7 TRANSPORT …. 1200
8 REPORT …. 1150
TOTAL 6105
TOTAL COST : 6,105.00
CONCLUSION
Grinding has traditionally been associated with small rates of
material removal and finishing operations. However, grinding can also be used
for large-scale metal removal operations similar to milling, shaping, and planing.
In creep-feed grinding, the depth of cut d is as much as 6mm, and the workpiece
speed is low. The wheels are mostly softer grade resin bonded with open structure
to keep temperatures low. Creep-feed grinding can be economical for specific
applications, such as grinding cavities, grooves, etc.
PHOTOGRAPHY
BIBLIOGRAPHY
REFERENCES
Stephenson, David A.; Agapiou, John S. (2006). Metal Cutting
Theory And Practice. CRC Press. p. 52. ISBN 0824758889.
Cubberly, W.H. (1989). Tool and Manufacturing Engineers
Handbook. Society of Manufacturing Engineers. Ch. 26. ISBN
0872633519. Retrieved 2013-01-31.
O.p kanna.Tool and Manufacturing Engineers hand book Society
of Manufacturing Engineers