CAREER EPISODE NO # 1 1.1 INTRODUCTIONCE1.1.1Chronology: 10th January,2008 to 28th June, 2008 – Project done as a part of curriculum ofBachelor of Engineering.Organization: AISSMS College ofEngineering, Pune.Geographical location: AISSMSCollege of Engineering, Kennedy road, near RTO, Pune,India – 411001.
Position: Student (B.E.Mechanical).Project: Designand fabrication of hydraulic puller. CE1.
1.2As a part of our degree course in MechanicalEngineering we were supposed to do a project by manufacturing a component so asto understand the subjects with more depth. I undertook a project in my college’AISSMS College of Engineering’, which was ‘Design and fabrication of aHydraulic puller’.
I, along with two of my colleaguescompleted 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 ‘SapsonEnterprises’ which is located in Parmar Industrial Complex in Chinchwad MIDC,Pune. This project was also submitted to the University as a part of curriculumof Bachelor of Engineering. 1.
2 BACKGROUNDCE 1.2.1Ball bearings are generallyinterference fits on the shaft. In some cases gears and pulleys are also interferencefits. While removing these parts, we have to apply uniform pressure from allsides. For this purpose, pullers are used.
In situations such as breakdown ofmachines due to bearing failure, it becomes inevitable to stop production.Manual removal of bearing, by hammering may spoil the bearing or surface finishof shaft. In order to avoid this process, pullers are used. I was given a taskto design and manufacture a puller of 1 ton capacity. Today there are two types ofpullers available in the market, one is mechanical and other is hydraulic. Inmy project, I have fabricated a hydraulic puller which is superior to others inthe market in terms of efficiency and efforts required to operate. CE 1.2.
2Since it was my final yearproject, I intended to score good grade in the project which in turn would helpme in securing a good job in the future. Hence my aim was to make a hydraulicpuller which is unique and better than those available in the market. I workedon following points to make my puller a better one: 1. Makingit compact by not having a separate pumping unit.
2. Makingoil container concentric to the hydraulic cylinder, so that no separate oiltank is required.3. Designingthe equipment in a way that only one person is sufficient to handle it. Usuallytwo persons are required to handle the equipment.4. Reducingfrictional losses to make the puller more effective.
1.3 PERSONAL WORKPLACE ACTIVITYC.E 1.3.1During my project, one of my aim was to make ahydraulic puller which is efficient from the one available in the market. So Itried making the puller as small as possible so that only one person is able tooperate it.
I also intended to save on the cost of production to make the pullercost effective. To reduce the cost and size, I tried to manufacture a few partsby my innovative ideas and tried reducing their size. Instead of using threelegs which are usually required to told the bearing, I designed a puller whichcould hold the bearing in two legs, in turn reducing the cost and weight of thepuller. C.E 1.3.
2Principle of Working 1. Pascals LawI made use of my engineering knowledge and read books on hydraulicsto find out that the basic principle in operation of hydraulic puller isPascals law. Hence, I made a puller which worked on the closed hydrauliccircuit and lever mechanism as shown in figure 1.1. Figure 1.
1 2. Check ValveOne purpose of the project was to make the unit as compact aspossible. However the check valves available in the market were not suitablefor my purpose due to their large size. Hence I manufactured check valve by my innovative idea as shownbelow.
I made use of a ball bearing and spring. When oil tries to flow fromspring side, the ball gets compressed against the tapered surface due to theoil pressure and the spring force. This causes the oil to get pressurized andfurther supports the operation of blocking oil in the respective direction, asshown in figure 1.2 and hence there is no flow in this direction.
Figure 1.2When the oil flows from the channel, it acts against the springwhich is light retaining spring. The spring gets compressed displacing the ballcreating a flow path for oil to flow as shown in figure 1.2, hence we get fullflow in this direction. 3. Shut off valveI used a shut off valve as a quick connect and disconnect valvewhich is manually operated. I used it to return the oil back to tank duringretraction of piston in the main cylinder.
During operation, that is extensionof cylinder piston, the shut off valve is kept closed. 4. Connecting pipesI used connecting pipes to supply oil from tank to the pumpingcylinder. As this line is a suction line pressure, the pressure in this goesbelow atmosphere, so it should be sealed very accurately. I used very lightweightpneumatic connecting pipe which gives very good seal. As there is no highpressurization in connection, it could easily withstand the low pressure.
5. Air ventThe tank is completely sealed by O ring, when the pumping operationcauses suction. This will cause vacuum in the tank without allowing oil toflow. To maintain the pressure above pumping cylinder pressure, I exposed oilin tank to atmospheric pressure through air vent.
This also helped in refillingof oil in tank. C.E 1.3.3I decided to do the project in the followingsteps. · Design of components· Preparing sketches formanufacturing components· Manufacturing of components· Purchase of standard components· Assembly of the equipment· Carrying out trials of the equipment For designing ofcomponents I referred to my engineering books like Strength of machine elementsby professor G.G.
Tawshikar, Mechanical system design by professor R.B.Patil,PSG Design data handbook and Fluid power applications by Anthony. For preparingsketches, I used AutoCAD. Manufacturing of components was done in a workshopunder the guidance of workshop manager.
For procurement of readily availableparts, I approached industry experts and consulted about the location where Icould get genuine and cost effective parts. These parts were then procured frommetal market in Pune. Assembly and trial of the final equipment was done underthe guidance of project guide. C.E 1.3.4DesignMy problem statement was to design a mechanism that removes press fittedcomponents from shaft of outer diameter between 20 mm to 100 mm.
On consulting my professors I found that in small industries loadrequired for pulling press fitted bearings or gears is generally less than oneton. I assumed that a human can easily apply a force of 150 N on a handle of300 mm for pumping.Suitable Assumptions:1. Handle Length (comfort): 300mm2.
Required force at output: 1 Ton3. Human force: 150 N4. Displacement required for piston: 100 mm5.
Plunger diameter (for machine convenience): 15 mmBasis these assumptions, I did calculations related to thickness ofcylinder, diameter of the cylinder, thickness and design of legs, design andthickness of handle, design of bolt to assemble legs to the flange, design and diameterof the piston rod, design of plunger rod, design of bolts to assembleconnecting rod and plunger hub, design of flange, design of C bracket, designof tie rod and design of bolt connecting C bracket to flange. Once the design calculations were made, I got them approved by my projectguide before starting the manufacturing process. C.E 1.
3.5ManufacturingProcess:After designing all the components, came the criticalpart of manufacturing them. I decided to get all the components manufactured ina workshop named ‘Sapson Enterprises’ which is located in ParmarIndustrial Complex in Chinchwad MIDC, Pune. As most of the components werecircular and symmetrical, I decided to manufacture them using Lathe. Apart fromhandle which was readily available, I manufactured all other components byoperations like facing, lapping, boring, grinding, drilling, milling, turning,tapping, threading, knurling, welding and grooving. Workshop manager andoperators helped me a lot during manufacturing operations. Workshop managersuggested me to do bore grinding to achieve good surface finish in case ofpressurized cylinder to achieve positive sealing.
Parts which I manufactured werecylinder, flanges, legs, connecting road, piston, plunger, C bracket andconnecting plate. C.E 1.3.
6List of standard componentsI procured standardcomponents from metal market in Pune. Details of the same were given by one ofthe purchase managers in ‘Alfa Laval’ which has its factory of manufacturingheat exchangers in Pune. With his advice I could procure all the standardcomponents at a very reasonable rate. Standardcomponents included piston seal, plunger seal, ‘o’ rings, square c/s rings,gasket, teflon ring, air vent, shut off valve, various bolts, sockets and hosepipes. C.E 1.3.7Next step in theproject was to get the equipment assembled.
I started assembling the componentsin our college workshop under the guidance of project guide. Once the equipmentwas assembled, I was quite curious for its trial. I carried out two trials withgears of different sizes fitted on the shaft. On both the occasion, I wassuccessful in removing the gear on the shaft. C.
E 1.3.8Adetailed report of design, manufacturing and cost analysis was submitted toproject guide. My project guide graded mewith 137 marks out of 150 marks for the project which is equivalent todistinction grade. Figure 1.3 shows detailed AutoCAD drawing of my project andfigure 1.4 shows photograph of the actual developed equipment.
Figure 1.2 Figure 1.3 1.4SummaryC.E1.
4.1I was appreciatedfor my work and ethics not only by project guide and other professors fromcollege, but also by the owner of ‘Sapson Enterprises’. This was my firstpractical experience with the manufacturing process.
I learned various designconsiderations, materials and their properties and various operation processes.I also did cost analysis of my project. Total cost of my project was INR5,405.00 including raw material, machining cost and cost of standardequipments. This was much less than compared to the equipments available in themarket.
Also the total weight of the equipment was just 6 kg which is quiteeasy to hold for a single individual. CAREER EPISODE NO # 2 2.1 INTRODUCTIONCE2.1.1Chronology: 14th July,2008 to 13th November, 2008 – Project done after graduation as apart of enhancing practical engineering knowledge.
Organization: Paras Engineers.Geographical location: PlotNo. 870/11, G.I.
D.C. Estate, Makarpura,Vadodara, Gujarat – 390010, India.Position: Trainee Engineer.Project: Developmentof device for rotating a job at low RPM. CE2.
1.2Being a mechanical engineer, I decided to gainsome practical knowledge and hands on experience in a manufacturing companybefore I start my first professional job as a mechanical engineer. As soon as Icompleted my graduation in mechanical engineering, I did a project in a companynamed ‘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 rotateat a very low RPM. I undertook this project under the guidance of the plantmanager. All the calculations, design and assembly related to the project weredone on the company’s shop floor.
Once the final product was ready, it was usedin company’s assembly line. 2.2 BACKGROUNDCE 2.2.1The company Paras Engineers Pvt. Ltd. is into manufacturing ofvarious types of oil separators, air filters, oil filters and fuel filters.Entire manufacturing and assembly of these filters is carried out in theirBaroda plant located in Gujarat GIDC.
On interacting with the plant manager and theowner, I understood that in manufacturing of one such type of filter, thecompany wanted to roughen a cap that seals the sides of filters. These caps arefixed on sides of the filter by using adhesives. Complaints were received fromthe 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 toinadequate bonding of caps. The caps were actually fixed by adhesive. It wasinitially felt that the caps became loose due to insufficient adhesion of theadhesives.
Exhaustive investigation was carried out on adhesives and severaladhesives were attempted but none could give satisfactory outcome. Ultimately,it was realized that the problem was not with the adhesives but smooth surfaceof the cap was responsible for this problem. Hence, it was decided that sidefaces of the caps should be roughened manually using tools and filters withsuch caps were supplied. With roughened face of cap, the adhesion between thecap and sides of the filter was perfect and in turn these filters workedwithout any problem during actual usage. The company now wanted to make a device thatrotates this cap at a very slow rpm so that roughening process can be carriedout properly.
I took on this challenge and decided to make the device.