CAREER EPISODE NO # 1
Chronology: 10th January,
2008 to 28th June, 2008 – Project done as a part of curriculum of
Bachelor of Engineering.
AISSMS College of
Geographical location: AISSMS
College of Engineering,
Kennedy road, near RTO, Pune,
India – 411001.
Position: Student (B.E.
and fabrication of hydraulic puller.
As a part of our degree course in Mechanical
Engineering we were supposed to do a project by manufacturing a component so as
to understand the subjects with more depth. I undertook a project in my college
‘AISSMS College of Engineering’, which was ‘Design and fabrication of a
Hydraulic puller’. I, along with two of my colleagues
completed this project under the guidance of project guide Professor ‘S.R.
Patil’. Design and calculations related to the project were done in my college,
whereas manufacturing of the product was done in a workshop named ‘Sapson
Enterprises’ which is located in Parmar Industrial Complex in Chinchwad MIDC,
Pune. This project was also submitted to the University as a part of curriculum
of Bachelor of Engineering.
Ball bearings are generally
interference fits on the shaft. In some cases gears and pulleys are also interference
fits. While removing these parts, we have to apply uniform pressure from all
sides. For this purpose, pullers are used. In situations such as breakdown of
machines due to bearing failure, it becomes inevitable to stop production.
Manual removal of bearing, by hammering may spoil the bearing or surface finish
of shaft. In order to avoid this process, pullers are used. I was given a task
to design and manufacture a puller of 1 ton capacity.
Today there are two types of
pullers available in the market, one is mechanical and other is hydraulic. In
my project, I have fabricated a hydraulic puller which is superior to others in
the market in terms of efficiency and efforts required to operate.
Since it was my final year
project, I intended to score good grade in the project which in turn would help
me in securing a good job in the future. Hence my aim was to make a hydraulic
puller which is unique and better than those available in the market. I worked
on following points to make my puller a better one:
it compact by not having a separate pumping unit.
oil container concentric to the hydraulic cylinder, so that no separate oil
tank is required.
the equipment in a way that only one person is sufficient to handle it. Usually
two persons are required to handle the equipment.
frictional losses to make the puller more effective.
1.3 PERSONAL WORKPLACE ACTIVITY
During my project, one of my aim was to make a
hydraulic puller which is efficient from the one available in the market. So I
tried making the puller as small as possible so that only one person is able to
operate it. I also intended to save on the cost of production to make the puller
cost effective. To reduce the cost and size, I tried to manufacture a few parts
by my innovative ideas and tried reducing their size. Instead of using three
legs which are usually required to told the bearing, I designed a puller which
could hold the bearing in two legs, in turn reducing the cost and weight of the
Principle of Working
1. Pascals Law
I made use of my engineering knowledge and read books on hydraulics
to find out that the basic principle in operation of hydraulic puller is
Pascals law. Hence, I made a puller which worked on the closed hydraulic
circuit and lever mechanism as shown in figure 1.1.
2. Check Valve
One purpose of the project was to make the unit as compact as
possible. However the check valves available in the market were not suitable
for my purpose due to their large size. Hence I manufactured check valve by my innovative idea as shown
I made use of a ball bearing and spring. When oil tries to flow from
spring side, the ball gets compressed against the tapered surface due to the
oil pressure and the spring force. This causes the oil to get pressurized and
further supports the operation of blocking oil in the respective direction, as
shown in figure 1.2 and hence there is no flow in this direction.
When the oil flows from the channel, it acts against the spring
which is light retaining spring. The spring gets compressed displacing the ball
creating a flow path for oil to flow as shown in figure 1.2, hence we get full
flow in this direction.
3. Shut off valve
I used a shut off valve as a quick connect and disconnect valve
which is manually operated. I used it to return the oil back to tank during
retraction of piston in the main cylinder. During operation, that is extension
of cylinder piston, the shut off valve is kept closed.
4. Connecting pipes
I used connecting pipes to supply oil from tank to the pumping
cylinder. As this line is a suction line pressure, the pressure in this goes
below atmosphere, so it should be sealed very accurately. I used very lightweight
pneumatic connecting pipe which gives very good seal. As there is no high
pressurization in connection, it could easily withstand the low pressure.
5. Air vent
The tank is completely sealed by O ring, when the pumping operation
causes suction. This will cause vacuum in the tank without allowing oil to
flow. To maintain the pressure above pumping cylinder pressure, I exposed oil
in tank to atmospheric pressure through air vent. This also helped in refilling
of oil in tank.
I decided to do the project in the following
Design of components
Preparing sketches for
Manufacturing of components
Purchase of standard components
Assembly of the equipment
Carrying out trials of the equipment
For designing of
components I referred to my engineering books like Strength of machine elements
by professor G.G.Tawshikar, Mechanical system design by professor R.B.Patil,
PSG Design data handbook and Fluid power applications by Anthony. For preparing
sketches, I used AutoCAD. Manufacturing of components was done in a workshop
under the guidance of workshop manager. For procurement of readily available
parts, I approached industry experts and consulted about the location where I
could get genuine and cost effective parts. These parts were then procured from
metal market in Pune. Assembly and trial of the final equipment was done under
the guidance of project guide.
My problem statement was to design a mechanism that removes press fitted
components from shaft of outer diameter between 20 mm to 100 mm.
On consulting my professors I found that in small industries load
required for pulling press fitted bearings or gears is generally less than one
ton. I assumed that a human can easily apply a force of 150 N on a handle of
300 mm for pumping.
1. Handle Length (comfort): 300mm
2. Required force at output: 1 Ton
3. Human force: 150 N
4. Displacement required for piston: 100 mm
5. Plunger diameter (for machine convenience): 15 mm
Basis these assumptions, I did calculations related to thickness of
cylinder, diameter of the cylinder, thickness and design of legs, design and
thickness of handle, design of bolt to assemble legs to the flange, design and diameter
of the piston rod, design of plunger rod, design of bolts to assemble
connecting rod and plunger hub, design of flange, design of C bracket, design
of tie rod and design of bolt connecting C bracket to flange.
Once the design calculations were made, I got them approved by my project
guide before starting the manufacturing process.
After designing all the components, came the critical
part of manufacturing them. I decided to get all the components manufactured in
a workshop named ‘Sapson Enterprises’ which is located in Parmar
Industrial Complex in Chinchwad MIDC, Pune. As most of the components were
circular and symmetrical, I decided to manufacture them using Lathe. Apart from
handle which was readily available, I manufactured all other components by
operations like facing, lapping, boring, grinding, drilling, milling, turning,
tapping, threading, knurling, welding and grooving. Workshop manager and
operators helped me a lot during manufacturing operations. Workshop manager
suggested me to do bore grinding to achieve good surface finish in case of
pressurized cylinder to achieve positive sealing.
Parts which I manufactured were
cylinder, flanges, legs, connecting road, piston, plunger, C bracket and
List of standard components
I procured standard
components from metal market in Pune. Details of the same were given by one of
the purchase managers in ‘Alfa Laval’ which has its factory of manufacturing
heat exchangers in Pune. With his advice I could procure all the standard
components at a very reasonable rate.
components included piston seal, plunger seal, ‘o’ rings, square c/s rings,
gasket, teflon ring, air vent, shut off valve, various bolts, sockets and hose
Next step in the
project was to get the equipment assembled. I started assembling the components
in our college workshop under the guidance of project guide. Once the equipment
was assembled, I was quite curious for its trial. I carried out two trials with
gears of different sizes fitted on the shaft. On both the occasion, I was
successful in removing the gear on the shaft.
detailed report of design, manufacturing and cost analysis was submitted to
project guide. My project guide graded me
with 137 marks out of 150 marks for the project which is equivalent to
distinction grade. Figure 1.3 shows detailed AutoCAD drawing of my project and
figure 1.4 shows photograph of the actual developed equipment.
I was appreciated
for my work and ethics not only by project guide and other professors from
college, but also by the owner of ‘Sapson Enterprises’. This was my first
practical experience with the manufacturing process. I learned various design
considerations, materials and their properties and various operation processes.
I also did cost analysis of my project. Total cost of my project was INR
5,405.00 including raw material, machining cost and cost of standard
equipments. This was much less than compared to the equipments available in the
market. Also the total weight of the equipment was just 6 kg which is quite
easy to hold for a single individual.
CAREER EPISODE NO # 2
Chronology: 14th July,
2008 to 13th November, 2008 – Project done after graduation as a
part of enhancing practical engineering knowledge.
Geographical location: Plot
No. 870/11, G.I.D.C. Estate,
Gujarat – 390010, India.
Position: Trainee Engineer.
of device for rotating a job at low RPM.
Being a mechanical engineer, I decided to gain
some practical knowledge and hands on experience in a manufacturing company
before I start my first professional job as a mechanical engineer. As soon as I
completed my graduation in mechanical engineering, I did a project in a company
named ‘Paras Engineers’ based in Baroda district in the state of Gujarat, India.
The company wanted to develop a device that enables one of their job to rotate
at a very low RPM. I undertook this project under the guidance of the plant
manager. All the calculations, design and assembly related to the project were
done on the company’s shop floor. Once the final product was ready, it was used
in company’s assembly line.
The company Paras Engineers Pvt. Ltd. is into manufacturing of
various types of oil separators, air filters, oil filters and fuel filters.
Entire manufacturing and assembly of these filters is carried out in their
Baroda plant located in Gujarat GIDC.
On interacting with the plant manager and the
owner, I understood that in manufacturing of one such type of filter, the
company wanted to roughen a cap that seals the sides of filters. These caps are
fixed on sides of the filter by using adhesives. Complaints were received from
the users of the filters regarding the caps that seal either side of filters.
The caps were getting loosened from their place upon usage. This was due to
inadequate bonding of caps. The caps were actually fixed by adhesive. It was
initially felt that the caps became loose due to insufficient adhesion of the
adhesives. Exhaustive investigation was carried out on adhesives and several
adhesives were attempted but none could give satisfactory outcome. Ultimately,
it was realized that the problem was not with the adhesives but smooth surface
of the cap was responsible for this problem. Hence, it was decided that side
faces of the caps should be roughened manually using tools and filters with
such caps were supplied. With roughened face of cap, the adhesion between the
cap and sides of the filter was perfect and in turn these filters worked
without any problem during actual usage.
The company now wanted to make a device that
rotates this cap at a very slow rpm so that roughening process can be carried
out properly. I took on this challenge and decided to make the device.