BUE, FACULTY OF ENGINEERING June 2017, Cairo, Egypt, MECH- GDP-13
Design and manufacturing of pin on disc machine Supervisor: Major. General. Eng/ Sayed Akl Amr Ahmed Mohamed (116719) Mohamed Alaa Mabrouk(115515) Abanoub Magdy Yacoub (116797) Hossam Ahmed Antar (116720) Faculty of Engineering, Mechanical Department, The British University in Egypt, El Sherouk City, Misr-Ismalia Road, Cairo, Egypt Emails:
[email protected] Definition of Design Problem: Nowadays, friction and wear are very important factors which take into consideration by any designer in manufacturing any product. As, they has an impact on the performance, safety and overall efficiently of the products. The product/material with the best tribological properties is that with low wear and friction. Summary of Previous Designs: N.Marjanovic et al, they explained the changes for the design of the tribometer machine that measures the wear rate of the materials. They modified it when they found that the convention or the simple wear test machine cannot provide precise readings and they claimed that this test can perform more and provide more results at different levels such as variable velocities and variable loads so to give accurate results for some specific applications that uses sever loading methods and very high speeds which affects the wear rate of some machine parts such as the bearings or shafts.(Dougles Godfrey, 1995) Scope and Objectives: The objective of the project is to design an applicable and easy to use machine to give a sensible result for measuring the tribological properties of any material used; these properties of concerned are the coefficient of friction and the wear rate under variable conditions which are. 1. 2. 3.
A wide variety of velocities Wide variety of loads Different materials to be make a sensible comparison of the wear rate.
Conceptual Design and Required Features (If Applicable): Model 1:
Figure 1: first model
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Rejection reason: Due to the orientation of the machine the wiring system is really hard also the lubrication system will be complicated due to the distance the fluid needs to travel in order to hit the disc which may arise lots of problems affecting the results of the experiment especially if you're working with viscous fluid. (D.K.Aggarwal and P.C.Sharma, 2006) Model 2:
Figure 2: second model
Rejection reason: This model have solved the problem of the wiring but the major problem is that the pin is not hundred percent contacting with the surface of disc also it is impossible to set up a lubrication system to hit the disc perpendicularly And it is hard to contain the flow of the viscous fluid.(Charles.R Mischke and Joseph Edward Shigley , 2001) Model 3:
Figure 3: model three
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BUE, FACULTY OF ENGINEERING June 2017, Cairo, Egypt, MECH- GDP-13
This model sold both problems and the casing is pretty securing it so there's no leakage of oil (no losses). And stability is high the pin is hundred percent contacting with the disk with a proper window view to check the process and with an external supply to compensate for the loss of oil easily no need to disassemble the machine.(M.Ramaswamy, 2003) Figure 12 and 13 are isometric drawing for the concept designed machine.
Motor
Arm
Figure 4: pin on disc choosed concept
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BUE, FACULTY OF ENGINEERING June 2017, Cairo, Egypt, MECH- GDP-13
Disc made of steel
Acrylic Specimen holder
Lubrication system oil Figure 5: pin on disc machine
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Methodology: Design of experiment method was used by developing two a model to determine the interdependent relationship among factors affecting a process and the output of that process, ……………….. Each of these factors has two levels with centre points between them. After building the design, the experiment runs are ……… ………… ……… …… … recorded and analyzed. By
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BUE, FACULTY OF ENGINEERING June 2017, Cairo, Egypt, MECH- GDP-13 using this method, it was possible to study the effect of main and mixed (interaction) independent variables on the coefficient of friction …… …… …………… ………………. ……………..
Fig.5.1. Pin-on-disc type small-scale tribo-tester. Fig.5,2. Pin-on-disc type small-scale tribo-tester Main Results: For this chapter of the report, it is discussing the method of testing the machines that was designed for the purpose of wear or material loss (Tribological properties). This machine is tested for its operation and the result for this test is the wear particles lost from the material. Identifying the factors that are contributing and affecting the material loss is a must to know the results what are they representing. First result that is needed that the machine is performing according to the design which the disk is rotating and the pin is perpendicular to the rotating disk to create the wear that needs to be tested, this is the first result that is needed to be conducted. Second factor to be considered is the speed of the rotating disk because the speed of the rotation increased the wear rate so for this experiment frequency modulator is used because it is much cheaper than the gearbox. More compact in design and less complex in running the experiment and most of all more accurate than the gear box. Thirdly, other factor that affects the experiment is the temperature so to get the reading of the temperature by thermal infrared equipment. This affect the amount of weight loss that happen to the material Finally, the factor that is responsible for the wear is the friction force which measured by the strain gauge in newton So to summarize the concept that was designed for contributing this experiment is Determine: the needed speed (1450 rpm) by frequency modulator the tangential force needed is measured automatically by strain gauge temperature is measured by infrared weight loss measured by a sensitive balance This experiment is designed to measure the weight loss after 20 working hours/ day.
After measuring 15 samples of by using oil showed the following Sample Weight Weight loss Weight after number before 25.54 0.22 25.32 1 25.32 0.26 25.06 2 25.06 0.23 24.83 3 24.83 0.24 24.59 4 24.59 0.31 24.28 5 24.28 0.28 24 6 24 0.19 23.81 7 23.81 0.2 23.61 8 23.61 0.3 23.31 9
Temperature 34 35 34 37 39 33 32 35 38
Friction force 12.927 12.567 13.285 13.628 12.961 12.327 13.241 14.874 13.735 5
BUE, FACULTY OF ENGINEERING June 2017, Cairo, Egypt, MECH- GDP-13 0.16 23.15 36 12.137 0.21 22.94 32 14.219 0.33 22.61 36 14.891 0.25 22.36 31 12.962 0.32 22.04 30 13.129 0.26 21.78 39 13.513 Table 1: result of the experimenta work The table shows the results obtained from the experiment form the 15 samples that show variation in all the factors stated above. 10 11 12 13 14 15
23.31 23.15 22.94 22.61 22.36 22.04
Figure 6: temp vs sample graph This temperature raises variation during the experiments because friction impacts by temperature rise during working.
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Figure 7: wright loss vs sample graph This graph shows the variety of wear that happened to the aluminum pins this variety is because the wear is not constant because the aluminum particles that were mixed with the oil gives different readings as these particles acts as a third body attacking the pin which may increases the material loss during the experiment and also temperature may affect the amount of material loss.
Figure 8: friction force vs sample graph This graph shows a variation of the frictional force during the experiment and since the pin material particles fused with the oil is dispersed randomly so this creates a variation in the force created on the pin then by the frictional force is also affected this creates the random variation of the frictional force as it is shown in the graph above 7
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2. Main Achievements in the New Design
Friction force and weight loss of the material is much less in oil than dry atmosphere. Another achievement is using the oil base fluid which was not used before Also the increase in the pressure applied was concluded to increase the friction force and the removal of material and that happens because the actual contact area at the interface increases with increasing the pressure at that surface, so the friction increase due to the growth of the area and the wear increase due to the formation debris and fragments that act as three body abrasive elements.
3. Recommendation for Further Enhancement: For this design the future development a computer system will be added to achieve more accurate results to give more readings to reduce the gap between reading to predict the amount of wear during the machine operation Temperature sensor to make sure that the oil does not exceed a certain temperature to avoid oil vaporization to reduce the cost of oil refilling Oil sump volume sensor this sensor is responsible for keeping the oil level monitored to make sure the level of the oil the same during the whole procedure Cooling system or heat exchanger to hold the oil temperature so the oil amount last longer during the experiment Mobile application to monitor the whole experiment remotely for better following on the experiment process at any time and to control the activation and stopping’s of the machine remotely at any time. To avoid any failures 4. Conclusion To sum the entire procedure of designing the machine and the results. The machine was first needed to achieve the goal of being able to identify and predict the amount of wear a weight loss of the material used and to simulate the wear as it happen inside the engine parts. In addition to, the design of the machine parts were perfectly selected to achieve the cohesive needed between parts. For example pumping power for oil with the size of pump was perfectly selected to fit the machine needs for this application The machine results from the weight loss measurement showed the lubricant are effective in preventing material loss as it forms a layer upon the material called (Fluid Film) that decreases wear and keeps the materials much more life time and more service time which reduces the cost for replacing parts
5. List of References
1.
A.S.Adamou,J.Denape and E. Andrieu. (2006). wear: an environmental tribometer for the study of rubbing surface reactivity.
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Anthony Esposito. (2009). Fluid power with applications. Pearson Prentice Hall.
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B.L.Theraja and A.K.Theraja. (2012). Abc of electrical engineering. S.Chand.
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Bharat Bhushan. (2011). Nanotribology and Nanomechanicsl. Springer.
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Bharat Bhushan. (1999). Principles and application of tribology. Canada: John Wiley and Sons.
6.
Brain Nesbitt. (2006). Handbook of pumps and pumping. Elsevier in association with Roles and Associates Ltd. 8
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Charles Kingsely, A.E.Fitzgerald. (2003). Electric Machinery. McGraw Hill.
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Charles.R Mischke and Joseph Edward Shigley . (2001). Mechanical engineering design. McGraw Hill.
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D P Kothari and I J Nagrath. (2011). Modern power system analysis. McGraw-Hill.
10. D.K.Aggarwal and P.C.Sharma. (2006). A Textbook of Machine Design: Mechanical Engineering design. S.K.Kataria. 11. Dougles Godfrey. (1995). Friction Oscillations with a Pin-on-disc "Tribometer" . Tribology international . 12. Er. Arun Kumar. (2014). tribology. S.K.Kataria and Sons. 13. Evangelos D. Manies. (1995). surface force apparatus. groningen university. 14. Fatima Zivic. (2007). Nanotribometer area of application. Serbia: kragujevac university. 15. Igor J Karassik. (2008). Pump handbook. McGraw Hill. 16. Jacob Israelachvilli. (2006). Surace forces: Instrumentation. Acandamic press . 17. Johnston, R. L., and J. P. Wilcoxon. (2012). Metal nanoparticles and nanoalloye. Amsterdam: Elsevier. 18. Karl T Ulrich and Steven D Eppinger. (2008). Product Desgin and Development. McGraw Hill. 19. Kristen Wood and Kevin Otto. (2001). Product Design . Pearson Education. 20. M.Ramaswamy. (2003). Design and Manufacturing. S.K.Kataria and Sons. 21. N.Marjanovic,B.Tadic and S.Mitrovic. (2006). Tribology in industry. 22. Nabil El-Tayeb. (2016). friction theories and mechanisms. Cairo: The British University In Egypt. 23. Nabil El-Tayeb. (2016). wear theoires and mechanisms. Cairo: The British University In Egypt. 24. NabilEl-Tayeb. (2016). lubrication fundamentals, types and mechanisms. Cairo: The British University In Egypt. 25. Peter J. Blau. (2010). Elevated-temperature tribology of metallic materials. 26. R.K.Agarwal. (2007). Principles of electrical machine design. Delhi,India: S.K kataria and sons. 27. R.K.Rajput. (2002). Alternating current machines. Lamxi publicatrions. 28. Rohit Mehta and V.K.Netha. (2002). Pinceples of electrical machines . S.Chand and Company Ltd. 29. T.nani Pradeep. (2008). The essentials: understanding nanoscience and nanotechnology. New York: McGraw-Hill. 30. V.K.Mehta and Rohit Mehta. (2005). Principles of power system. S.Chand. 31. Wesley P.James and Ralph Allen Wurbs. (2002). Water resources engineering . Prentice Hall.
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