MIFGI,RAJKOT GUJARAT TECHNOLOGICAL UNIVERSITY 1 FAILURE OF THRUST BEARING OF SUBMERSIBLE PUMP-ANALYTICAL APPROACH An IDP Project at “RAVI PUMP INDUSTRY”A PROJECT PEPORT Submitted by: Name Enrollment no. • PARTH GAJERA 150970119051 • SAHIL VASIYANI 150970119060 • RAHUL LUNAGARIYA 150973119511 Guided by: MR.RONAK KAMDAR Mechanical Engineering Department, MEFGI, RAJKOT And MR.
YASH GOTHI “RAVI PUMP INDUSTRY”., Rajkot In fulfillment for the award of the degree of BACHELOR OF ENGINEERING IN MECHANICAL ENGINEERING MARWADI EDUCATION FOUNDATION GROUP OF INTITUDE, RAJKOT GUJARAT TECHNOLOGICAL UNIVERSITY RAJKOTMIFGI,RAJKOT GUJARAT TECHNOLOGICAL UNIVERSITY 2 INDEX NO. PAGE NO.
Acknowledgements 6 Certificate from college 7 PMMS certificate 8 Plagiarism report 12 Abstract 13 CHAPTER 1 INTRODUCTION ABOUT PROJECT PROBLEM DEFINATION 15 COMPANY INTRODUCTION 15 OVERVIEW OF OUR PROJECT 18 LITRETURE REVIEW 21 PSAR 25 MATERIALS REQUIRED 27 CHAPTER 2 ANALYSIS, DESIGN METHODOLOGY AND IMPLEMENTATION STRATERGY AEIOU SUMMARY CANVAS 32 EMPATHY SUMMARY CANVAS 33 IDEATION CANVAS 34 PRODUCT DEVELOPMENT CANVAS 35 BUSINESS MODEL CANVAS 36 CHAPTER 3 INTRODUCTION, DESIGNING & CALCULATION OF COMPONENTS & SYSTEM INTRODUCTION TO THRUST BEARING 39 FAILURE ANALYSIS OF THRUST BEARING 40 MATERIAL SELECTION OF VARIOUS COMPONENTS 44 GENERAL EQUATIONS TO DESIGN THRUST BEARING 46MIFGI,RAJKOT GUJARAT TECHNOLOGICAL UNIVERSITY 3 DESIGN OF VARIOUS COMPONENTS 48 TESTING OF BEARING FOR WEAR OF RUNNER AND 52 RUNNER MATERIAL SELECTION CHAPTER 4 SUMMARY/CONCLUSION OF RESULTS CONCLUSIONS FROM DESIGN CALCULATIONS 57 LIMITATIONS/DIFFICULTIES OF OUR PROJECT 58 SCOPE FOR FUTURE WORK 59 EXPECTED OUTCOME 59 REFERENCES 60 APPENDIX 61MIFGI,RAJKOT GUJARAT TECHNOLOGICAL UNIVERSITY 4 LIST OF FIGURES FIGURE NO. DESCRIPTION PAGE NO. 1.2.
2 Varity of pumps made by company 18 1.3.2 Various elements of thrust bearing 20 1.4.4 Thrust pads 23 1.
6.2 Chemical compositions of bearing 28 2.1 AEIOU Summary Canvas 32 2.2 Empathy Summary Canvas 33 2.3 Ideation Canvas 34 2.4 Product Development Canvas 35 2.
5 Business Model Canvas 36 3.1 Five Segment Bearing for Submersible Pump 39 3.2.1 Total Failure Modes of Thrust Bearing 40 3.4 Diagram of Thrust Bearing 47 3.5.4 Conceptual design of Proposed Solution 51 3.
6.2 Test Result Chart 54MIFGI,RAJKOT GUJARAT TECHNOLOGICAL UNIVERSITY 5 LIST OF TABLES TABLE NO. DESCRIPTION PAGE NO. 1.
2.2.3 Technical details of V-6 submersible pump 17 1.4.4 Thrust bearing geometry and properties 24 1.6.
2 Chemical composition 28 1.6.3 Properties of carbon graphite 29 3.3.1 Material of Construction 44 3.3.2 Mechanical properties of S.S 420 45 3.
6.1. (a) Motor Specifications 52 3.6.1. (b) Bowl Specifications 53 3.6.1.
(c) Wear Test Results 53 4.2 Comparison of Bearings 58MIFGI,RAJKOT GUJARAT TECHNOLOGICAL UNIVERSITY 6 ACKNOWLEDGEMENT In performing our project, we had many difficulties, we had to take the help and guidance of some respected person who has some knowledge related to our topic. We would like to show our deepest appreciation to our team guide mr.ronak kamdar. He continuously conveyed us for further research regarding to this project and without his guidance actually it was not so easy. We are highly thankful to our external guide Mr. YASH GOTHI, for his guidance in industry.
We are also thankful to “RAVI PUMP INDUSTRY”For providing there valuable help in this project. We express our deep gratitude to our Head of Mechanical engineering Department, mr. pinank patel, for encouraging us to prepare the project on ” FAILURE OF THRUST BEARING OF SUBMERSIBLE PUMP-ANALYTICAL APPROACH”. We take this opportunity to express our sincere gratitude to the Director of MARWADI EDUCATION FOUNDATION GROUP OF INTITUDE for his valuable guidance at all the stages of our project. We thank Creator, our team guide, our parents and friends for their constant support and encouragement without which this project work would not be possible. Parth gajera Sahil vasiyani rahullunagariyaMIFGI,RAJKOT GUJARAT TECHNOLOGICAL UNIVERSITY 7 MARWADI EDUCATION FOUNDATION GROUP OF INTITUDE MECHANICAL ENGINEERING 2018 CERTIFICATE Date: 5th October 2018 This is to certify that the dissertation entitled “FAILURE OF THRUST BEARING OF SUBMERSIBLE PUMP-ANALYTICAL APPROACH” has been carried out by Parth gajera(150970119051) Sahil vasiyani(150973119511) Rahul lunagariya (150970119060) Under my guidance in fulfillment of the degree of Bachelor of Engineering in (7th Semester) of Gujarat Technological University, RAJKOT during the academic year 2018-19. INTERNEL GUIDE: MR.
RONAK KAMDAR MECHANICAL ENGINEERING DEPARTMANT RAJKOT HEAD OF DEPARTMENT: PINANK PATEL MECHANICAL ENGINEERING DEPARTMENT RAJKOTMIFGI,RAJKOT GUJARAT TECHNOLOGICAL UNIVERSITY 8 CERTIFICATE FOR COMPLETION OF ALL ACTIVITES AT PMMS 1. PARTH GAJERAMIFGI,RAJKOT GUJARAT TECHNOLOGICAL UNIVERSITY 9 2. SAHIL VASIYANIMIFGI,RAJKOT GUJARAT TECHNOLOGICAL UNIVERSITY 10 3.
RAHUL LUNAGARIYAMIFGI,RAJKOT GUJARAT TECHNOLOGICAL UNIVERSITY 11MIFGI,RAJKOT GUJARAT TECHNOLOGICAL UNIVERSITY 12 CERTIFICATE OBTAINED FROM THE PLAGIARISM CHECKING SOFTWAREMIFGI,RAJKOT GUJARAT TECHNOLOGICAL UNIVERSITY 13 ABSTRACT A bearing is used to provide a frictionless environment to support and guide a rotating shaft and bushing at a distance piece. It is use in many mechanical machine like pumps, motor, engines, and the list goes on and on. The study about the function of thrust bearing is done by taking knowledge regarding the assembly and working of the submersible pump at Ravi pump Pvt. Ltd. Various problems arises in the thrust bearings of the submersible pumps due to some of the listed faults, they are as follow: 1. Due to low voltage 2.
Due to misalignment of the rotor shaft 3. Due to debris or sand entrance in the motor base In this project we are going to find the possible solutions for the improvement of the bearing life period, and we will also try to improve the pump efficiency up to some limit possible by making changes into the pump bearings. We are going to improve the bearings by changing the bearing material, by modifying the pad design up to some limit and by providing some inclination to the bearing initially.MIFGI,RAJKOT GUJARAT TECHNOLOGICAL UNIVERSITY 14 CHAPTER 1 INTRODUCTION ABOUT PROJECT PROBLEM DEFINATION COMPANY INTRODUCTION OVERVIEW OF OUR PROJECT LITRETURE REVIEW PSAR MATERIALS REQUIREDMIFGI,RAJKOT GUJARAT TECHNOLOGICAL UNIVERSITY 15 PROBLEM DEFINATION There has been many innovations in many different fields which change the world in many ways. First ball bearing was used in the 16th century. Since then there are number of bearings designed suitable to the applications as per requirement. The present project is regarding the failure of thrust bearings used in the submersible pumps, due to various reasons.
Below mentioned are few of them reasons: • Improper lubrication of bearing. • Voltage supply fluctuations. • Misalignment of the rotor shaft. • Wrong selection of the pump required. • Dry running of pump. The type of thrust bearing used in submersible pumps is pivoted segmental bearings.
This bearing has a uniqueness of levitating the runner over the stationary surface, with the help of lubricant flow between runner and base of bearing. The major problem on the bearings used nowadays in submersible pumps are poor levitation of runner at low speed of the rotating shaft, due to this the pads get wear out too quickly during such operation of the pumps. COMPANY INTRODUCTION Ravi pump engineering Pvt. Ltd. Is the leading pump manufacturing company. They are providing number of pumps for various operation as per the need of the applications. They are providing world class pumping solution, technically most advanced, excellent energy efficient product range.
MIFGI,RAJKOT GUJARAT TECHNOLOGICAL UNIVERSITY 16 PRODUCT RANGE Ravi pump engineering Pvt. Ltd. Is providing variety of products, some of them are described below. ? V-3 submersible pump set suitable for 4″ bore well, available from 0.5 HP to 1.
25 HP. ? V-4 submersible pump set suitable for 4″ bore well, available from 0.5 HP to 5.
0 HP. ? V-6 (slim) submersible pump set suitable for 5″ bore well, available from 3.0 HP to 15 HP. ? V-6 submersible pump set suitable for 6″ bore well, available from 3.0 HP to 35 HP.
? V-8 submersible pump set suitable for 8″ bore well, available from 15.0 HP to 75.0 HP. ? V-9 submersible pump set suitable for 10″ bore well, available from 60.0 HP to 100.0 HP.
? Horizontal and vertical open well S.S submersible pump set, available from 0.5 HP to 15.0 HP.
? Regenerative self-priming and centrifugal pump, available from 0.5 HP to 1.0 HP. V-6 SUBMERSIBLE PUMP SAILENT FEATURE ? S.S 304 grade nonmagnetic bowl and S.S 410 impeller.
? Proven and reliable design for critical conditions. ? State of the art design, delivers optimum performance and reliability in toughest conditions. ? Bronze LTB-4 bush and carbon thrust bearing provide low friction and high wear resistance. ? Easy assembling, dismantling, serviceable pump and rewind able motors. ? Suction screen and coupling are made of stainless steel. ? Standard 2 pole, speed 2900 rpm.
MIFGI,RAJKOT GUJARAT TECHNOLOGICAL UNIVERSITY 17 APPLICATIONS A combination of multistage centrifugal pump and submersible motor is designed for: ? Agriculture, industrial and domestic water supply. ? High rise buildings, housing, complexes and bungalows water supply. ? Gardens, farms and other necessary water supply requirement.
TECHNICAL DETAILS (Table 220.127.116.11)Technical details of V-6 submersible pump. H.
P. Range 3.0 HP to 30.0 HP. (Single/Three Phase version) Maximum Head Up to 450 meter.
Discharge at Duty point 125 to 900 LPM/ 7.5 to 54 m3/h Max. Discharge 1300 LPM/ 78.
0 m3/h Max. Head/ Stage 18 meter for radial flow model, 10 meter for mixed flow model. Operating Voltage Range 160-240 volt for single phase, 200-350 volt for three phase- (low volt design), 250-450 volt for three phase- (standard design) Rated Voltage Range -15% +6%, of Rated volt Max.
Start/ Hour 12 Max. Temp of Liquid 33? Max. Permissible amount of sand in the water 25 gram/ cubic meter Rated volts/ Frequency 220 volts/ 50 Hz for single phase, 415 volts/ 50 Hz for three phaseMIFGI,RAJKOT GUJARAT TECHNOLOGICAL UNIVERSITY 18 Fig. 1.2.
2 Variety of pumps made by company OVERVIEW OF OUR PROJECT Mostly failure of submersible pumps is due to the failure of thrust bearings. PURPOSE THRUST BEARING Thrust bearings are used in submersible pumps for supporting the whole assembly of motor and impeller over it. It is the component that is located at the bottom of the entire pump, and it gives support to whole assembly. The major work of thrust bearing is to give desired performance of the pump, by reducing the rotational friction, and serve as machine element that reduces friction between moving parts to only desired motion. Not only in submersible pumps, but thrust bearings are used in almost all the equipment that require to control the rotational motion of its components.
Example Ship impeller,MIFGI,RAJKOT GUJARAT TECHNOLOGICAL UNIVERSITY 19 wind mills, rotational engines like turbo jet engines, etc. this are only few of applications of the thrust bearing. There are number of applications. As thrust bearing is the major component in pump which fails and pump do not operates properly, its failure analysis and modifications is necessary to be done to improve its operating capabilities. In this project we have done research over to main parts of thrust bearings that are rotor and stator.
In rotor, we have focused over the materials used for thrust bearing liner. We tested the bearings in various operating conditions, with various runner materials, and tried to find the most suitable liner material for pump application required. And the other thing that we have done in this project is that, we have modify the design of thrust pads used in thrust bearings. This design is only conceptual and not proved better than the previous one, due to time limitations, and it may need improvement after testing it in actual conditions and designing it with drafting software. ELEMENTS OF THRUST BEARINGS Number of thrust bearings are available according to the required applications, here in submersible pumps we use “Tilting Pad Segmental Thrust Bearing”. The major uniqueness of such bearings is that it levitates the runner over the pads, due to this the friction between the components is greatly reduced and the runner can be operated at high speed.
Hence we can also say that such a kind of bearings are used for the high speed applications majorly. Various elements of the tilting pad segmental thrust bearings are discussed below, and they are shown in fig. 1.3.
2(a). THRUST BEARING PLATE ? Thrust bearing plate is made by stainless steel, cast iron, mild steel and non- ferrous metal. CARBON PAD ? Carbon pad is a mounting on thrust bearing plate.
It is made by the various thermoplastic composite materials.MIFGI,RAJKOT GUJARAT TECHNOLOGICAL UNIVERSITY 20 ? The various materials includes carbon, Teflon, fiber, etc. SEGMENT ? Segment is the part of stator, it is made by stainless steel. ? Segments are mounted over the segment carrier.
SEGMENT CARRIER ? Segment carrier provide support to the segments, it is a part of stator. ? Segment carriers are made with cast iron, stainless steel. They are attach with motor body. THRUST PAD ? This are the pads, also referred as segments, they are made of stainless steels.
? They support the lubrication of the pads, by creating the wedge shape of lubricant. Fig. 1.3.2 various elements of thrust bearingMIFGI,RAJKOT GUJARAT TECHNOLOGICAL UNIVERSITY 21 LITRETURE REVIEW Lyle A. Branagan in his research paper “Survey of Damage Investigation of Babbitted Industrial Bearings” stated that 1 Visual observation of the damage to the white metal(Babbitt) surface of industrial journal and thrust bearing have been categorized and discussed with the goal of supporting the answer to the question that Is bearing suitable for reuse as-is only after the simple cleaning.
The major observation needed to ensure this are as follow: ? Loss of Babbitt(white metal) ? Babbitt displacement ? Surface changes to the Babbitt ? Structural changes to the bearing and supports. The determination of the suitability of reuse of the bearing after simple cleaning depends on many factors. Few of them that are considered during this process are, design load carrying capacity of the bearing, remaining load carrying capacity, ability to create adequate pressure difference in the lubricant, vibrations of the equipment, etc. This research paper states that what do visual observations of the Babbitt surface used in the thrust bearings indicates, in the sense that whether the bearing can be re-used for further operation or not. R. S.
Gregory in his research paper “Performance of Thrust Bearing at High Operating Speeds” stated that 2 A standard 10.5 inch diameter thrust bearing, of the tilting pad, self-equalizing type was tested at shaft speed up to 11,000 rpm and bearing load ranging up to 400 psi. The effect of varying the oil feed rate on bearing temperature and power loss is discussed in this research paper. In this research paper the author has used new termed defined as oil flow ratio, it is defined as the ratio of rate of oil flow in gallons per minute to the bearing and total measured horsepower loss. It has been found from the research that there are wide fluctuations in the temperature of bearing due to n number of reasons, including oil flowMIFGI,RAJKOT GUJARAT TECHNOLOGICAL UNIVERSITY 22 rate is one of the reason. Also any comparison or stipulation of the bearing power loss, must have clearly mentioned the oil flow rate in order to completely determine the bearing performance. The limitation in this research paper which was not solved is getting the answer of transition state points in lubricant from laminar flow to turbulent flow. The Reynolds number was calculated in this research paper, as per the requirement.
The further details about the flow pattern of the lubricant in the bearing will be provided by author in the near future research papers. Xiaodong Yu and all in their research paper “Research on Dynamic Pressure of Hydrostatic Thrust Bearing under the Different Recess Depth and Rotating Velocity” stated that 3 Numerical simulation concerning dynamic pressure of multi-pad hydrostatic thrust bearing under different recess and rotating velocity is described. The study has been carried out with the help of computational fluid dynamics using lubricating theory and finite volume method. Through this method the optimal load carrying capacity of such product can be defined.
Using lubricating theory and finite volume method, the three dimensional dynamic pressure film simulation is carried out using fluid computational software. Few of the important conclusions made from this research paper are stated below. ? Simulation research of three dimensional dynamic pressure of multi pad hydrostatic thrust bearing under the varying recess depth and rotational velocity is carried out using computational fluid dynamics and the finite volume method.
? The simulation results highly resembles with the theoretical results calculated. The results shows that oil recess dynamic pressure is highly affected by recess depth and rotating velocity. ? Under the same value of rotation velocity, it was noted that the dynamic pressure was decreased with the increase in recess depth. ? It was found that as the rotating velocity increases, dynamic pressure increases too.MIFGI,RAJKOT GUJARAT TECHNOLOGICAL UNIVERSITY 23 Farooq Ahmad Najar and all in their research paper “Numerical Investigation of Pressure Profile in Hydrodynamic Lubrication Thrust Bearing” stated that 4 Reynolds equation is solved by using finite difference method (FDM) on surface of tilting pad to find the pressure distribution in the lubricant oil film. The present work evaluates the pressure at different points through a grid refinement. The peak pressure zone of (r,��) coordinate is getting shifted by changing the grid size which will help the designer and the experimentalist to conveniently decide the pressure measurement probs.
In the fluid lubrication, two mating surface are separated from each other with the help of lubricating fluid film. In this research paper the author has tried to find the pressure at different points on the pads of the hydrodynamic thrust bearing. The author has found the simple form of Reynolds equation form the Navier-Stokes (NS equation) using thin film assumption.
The Reynolds equation in the polar form can be easily found in various textbooks. Reynolds equation is commonly used for its practical application, while the full NS equation is used for finding the validity limits of the Reynolds equation. Fig.
1.4.4 Thrust pads. It is assumed that the fluid flow between the pad and runner is never turbulent and the model applied is only validate for the laminar flow. However the turbulent flow exists at certain points on pads, where the film flow is thick. The fluid density and viscosity areMIFGI,RAJKOT GUJARAT TECHNOLOGICAL UNIVERSITY 24 other important parameters affecting the fluid lubrication.
To obtain the desired pressure it is often easier to switch the lubricant then to made changes to the bearing gap height or relative motion between the surfaces. (Table 1.4.4)Thrust bearing geometry and properties Quantity Description Inner radius 57.
15 mm Outer radius 114.3 mm Number of pads 6 Pad angle 50.0o Pivot angle 30.0o Pad thickness 28.58 mm Operating conditions Axial load 52265 N Shaft speed 1500 rpm Inlet temperature 40oC Oil properties Grade Quantity Oil type VG46 Viscosity at 40Oc 39.0 mPas Viscosity at 100oC 5.
4 mPas Density 855.0 kg/m3 Thermal conductivity 0.13 W/m/KMIFGI,RAJKOT GUJARAT TECHNOLOGICAL UNIVERSITY 25 Heinz P. Bloch in his research paper “Root Cause Analysis of Five Costly Centrifugal Pump Failures” stated that 5 Machinery failure analysis and troubleshooting are often pursued in somewhat haphazard, unstructured fashion. In this research paper the author has tried to give the systematic approach to deal with the failure of any equipment and quickly reach to its root cause. This method is based on the fact that the component fail only if subjected to undue forces, a reactive environment, time based exposure, or extreme temperature. In this research paper the author has focused on the five major reasons that cause the failure of submersible pumps.
The author has also tried to give solution to this causes of failure, the modes of failure studied in this research papers are listed below. ? Faulty design causes premature bearing failure. ? Assembly procedure must be right. ? Fabrication and processing errors.
? Operation errors can cause frequent bearing failures. ? Maintenance omissions can cause loss of life. PSAR Some of the patents studied which help to get information regarding the project are discussed below. Theodor Parlevliet in his patent “Pivoted, Segmental, Thrust Bearing Providing Simulated Offset Support of Centrally Supported Bearing Segments” stated that 6 The key aim of the invention is to provide a hydrodynamic, pivoted, segmental thrust bearing having centrally supported bearing segment. Its friction loss during operation in one or two directions of rotation are similar to those of offset supported pivoted segmental thrust bearing.MIFGI,RAJKOT GUJARAT TECHNOLOGICAL UNIVERSITY 26 Willis W. Gardner in his patent “Pad Construction for Tilting Pad Thrust Bearing” stated that 7 According to the invention, the unique objectives are achieved by facing of thrust bearing pads with the layer of material which has good bearing properties, low coefficient of thermal expansion parallel to its surface, the low coefficient of thermal conductivity transvers to its surface. The low thermal conductivity transverse to the surface insulates the pad from the oil-shear heat and minimize the deflections due to temperature differentials.
The low coefficient of thermal expansion parallel to the surface allows the facing material to withstand relatively high temperatures without significant dimensional distortion. The graphite fiber embedded are parallel to the pads surface. Kozo Matake in his patent “Thrust Bearing Device” stated that 8 The invention can be summarized as, in the invention the inventor has replaced the prior technology of tilting pad segments in the stationary part of the bearing due to high complexness of the bearing manufacturing using that technology. Inventor has replaced it with the number of segments attached to a common base through their respective ribs. The segments are made from the metals.
This sliding shoe member are fixed to a motor bracket with the designed required gap between the retaining surface of the motor bracket and bottom surface of the common base of the sliding shoe member at each of the portion. By the above arrangement when the load is applied to the bearing device, the shoes get elastically deformed and the liquid film having a wedge shape is formed between shoes and rotary disk. Leonard L. Tyson in his patent “Thrust Bearing Having Lubrication System” stated that 9 In the invention the inventor has placed the lubricant supply jet to the stationary bearing surface in order to give the efficient lubrication system to the bearings which may give low efficiency in some of the working condition. The direction of some of the jet head in the invention is in the direction opposite to the direction of centrifugal force acting due to the rotation of the rotor. The other jets have the direction same as that of the direction of the centrifugal force. The lubricating head are incorporated with the filters to prevent theMIFGI,RAJKOT GUJARAT TECHNOLOGICAL UNIVERSITY 27 entry of the foreign particles to the bearing environment, and also to prevent the clogging of the lubricant jet, so that the lubrication starvation condition does not comes in action.
Willis W. Gardner in his patent “Tilting Pad Thrust Bearing” stated that 10 The invention is to remove the faults in the previously designed self-adjusting pads of the bearings. In the prior technology the problems were the change of shape of the pad surface to convex shape on the application of the heavy load, but this change in shape in beneficial in the circumferential direction up to some extend.
But it is not good for the bearing lubrication in the radial direction. And second problem was the not the complete aligning of the bearing pads according to the loads, due to the effect of friction in between of the connecting links. This problems are solved in the invention by providing the radial hole under the pad, for pivoting of the pad over the flat face of the component. This will reduce the change of shape of the pad in radial direction. And the friction effects are reduced with the help of giving the angular inclination to the wings of the connecting links. If this wings are extrapolated, then they would intersect at the line passing through the pivot point and the link which extend through the link. Hence the frictional force will not get any moment for its action over the links. Hence the complete align of the bearings pads would be possible according to the uneven load.
Materials Required Carbon material for runner The self-lubricating properties and ability to transfer an electrical current to a moving conductor led to the first application of carbon as a material for electrical brushes. The application as a purely mechanical components was as used in submersible pump as the part of thrust bearing. PROPERTIES OF CARBON ? Self-lubricating ? Dimensionally stable ? Chemically inertMIFGI,RAJKOT GUJARAT TECHNOLOGICAL UNIVERSITY 28 Proportion Fixed Carbon Sulphur Ash Content Volatile matter Moisture ? Non contaminating ? Resistance to oxidation ? Low thermal expansion ? High thermal conductivity ? Good thermal shock resistance CHEMICAL COMPOSITION OF BEARING (Table 1.
6.2) Chemical Composition Fixed carbon 27.29% Sulphur 15.67% Ash content 20.39% Volatile matter 52.02% Moisture 0.30% Fig. 1.
6.2 Chemical Composition of BearingMIFGI,RAJKOT GUJARAT TECHNOLOGICAL UNIVERSITY 29 CARBON GRADES We are selecting four grades of carbon for analysis. There are three grades as CY grades and one is MY grade among it. We are selecting this grades on the basis of hardness of grades.
That hardness is available in Morgan carbon material sheet. The name of the carbon grades are listed below: ? CY10 Grade ? CY2C Grade ? CY10C Grade ? MY10K Grade Those designated CY10 is baked carbon. Grade CY2C and CY10C are impregnated with epoxy. Grade MY10K is impregnated with antimony.
It is observed that the impregnated grades exhibits higher elastic modulus and hardness than the plain carbons. Some of the important properties of this Grade of carbon are listed below: (TABLE 1.6.3)PROPERTIES OF CARBON GRAPHITE Grade Generic Name Hardness (Scleroscope) Thermal Conductivity (W m-1 K-1) Elastic Modulus (GPa) CY10 Plain carbon 67 0.03 18 CY2C Plain carbon 73 0.03 23 CY10C Epoxy impregnated carbon 76 0.03 24 MY10K Antimony impregnated carbon 80 0.03 34MIFGI,RAJKOT GUJARAT TECHNOLOGICAL UNIVERSITY 30 ABRESION WEAR Abrasion wear is occurred when a hard particle is dragged against the softer surface.
It is separated in two categories, two body abrasive wear that is due to low surface roughness. And three body wear that is allowed when the particles are free to roll or move between the solid surfaces. Such damaging hard particles may be outside contaminants. The carbon graphite lining is provided over the collar to prevent its material abrasion, the lining provided serves as sacrifice. So that no damage occurs to the rotating collar of the bearing, and bearing operates fairly good for some time even after the wear without damaging other major parts.MIFGI,RAJKOT GUJARAT TECHNOLOGICAL UNIVERSITY 31 CHAPTER 2 ANALYSIS, DESIGN METHODOLGY AND IMPLEMTATION STRATEGY AEIOU SUMMARY CANVAS EMPATHY SUMMARY CANVAS IDEATION CANVAS PRODUCT DEVELOPMENT CANVAS BUSINEES MODEL CANVASMIFGI,RAJKOT GUJARAT TECHNOLOGICAL UNIVERSITY 32 AEIOU SUMMARY CANVAS Fig. 2.1 AEIOU summary canvas ? In this canvas, we first of all targeted all the users of submersible pumps that are majorly used by farmers, industrialist, community, government municipalities, etc.
? The major activates performed by us to solve the problem of thrust bearing was brainstorming the ideas, collecting information regarding the components from the industries, taking guidance from the guide, and many more. ? We analyzed the working environment of the pumps, as it is one of the major effecting parameter in the operating efficiency of the pump. ? We tried to interact the major users of the submersible pumps, that what kindof problems they are facing due to failure of the pumps, we also interacted with the pump manufacturing company for providing us the required guidance.MIFGI,RAJKOT GUJARAT TECHNOLOGICAL UNIVERSITY 33 EMPATHY SUMMARY CANVAS Fig. 2.2 Empathy Summary Canvas ? In this canvas we take the input from AEIOU canvas, that what kind of problems we are dealing with in this project. ? Then we brainstormed all kinds of problems that can fail whole submersible pumps not only bearings. ? That problems include, all kinds of problems, like poor priming of the pump, poor water quality, improper pump selection, etc.
? From those problems we listed the problems that causes the failure of pump, due to failure of thrust bearings, this includes failure of thrust bearings due to improper assembly, high heat generation, poor lubrication, etc. ? Then we noted down five major problems that we need to focus during this project, from them we will try to solve some of the problems during this project.MIFGI,RAJKOT GUJARAT TECHNOLOGICAL UNIVERSITY 34 IDEATION CANVAS Fig. 2.3 Ideation Canvas ? In this canvas we listed all the major users of submersible pumps, and also thrust bearings, who will be interested in our product. ? This users includes farmers, industrialist, government municipalities, communities, etc. ? Then we noted down all activates that are needed to be performed during the project, and which need are necessary to create our final product. ? This activities includes preparation of plan, plan implementation, design calculations, testing of product, etc.
? Then we studied situations under which this pumps are going to be operated. ? In the props and possible solutions part we listed down all the problems in the thrust bearings and also listed there possible solutions, which we can implement to solve some of the problems listed.MIFGI,RAJKOT GUJARAT TECHNOLOGICAL UNIVERSITY 35 PRODUCT DEVELOPMENT CANVAS Fig.
2.4 Product Development Canvas ? In product development canvas we mentioned better performance, long life, ease of maintenance, and easy replacement with standard parts as the key features of our developed product. ? The major purpose of our project is to reduce the cost of manufacturing, ease of manufacturing, lesser wear of bearings, low vibrations of pump that are mentioned in product purpose. ? We collected the review from customers after use of our product that they would feel, so that we can made the required changes to our product if required.MIFGI,RAJKOT GUJARAT TECHNOLOGICAL UNIVERSITY 36 ? Product functions are to improve the pumping capacity of pump, to get better operational safety, to reduce the vibrations of pump, etc. ? The major components of the pumps are submersible motor, impeller bowl, impeller shaft, thrust bearing. And the major components of thrust bearings are tilting pads, runner, stator, base, rotor collar, levelling mechanism, etc. ? We have retain the basic design of submersible pumps and redesigned the thrust bearing component of submersible pumps.
? In people we have targeted the major users of submersible pumps that are farmers, industries, government sector, communities, etc. BUSINESS MODEL CANVAS Fig. 2.5 Business Model CanvasMIFGI,RAJKOT GUJARAT TECHNOLOGICAL UNIVERSITY 37 ? In this canvas we mentioned the name of key suppliers of the components of pumps for the manufacturing of submersible pumps.
? We have also mentioned the major competitors that are present in the market. ? In value propositions we have mentioned the additional facilities that we provide to our customers for their satisfaction, and for better operating knowledge of pumps. ? We mentioned various ways through which we built relationship with our customers, various segments through which we deliver our product to the customers and various customers segments. ? We have also mentioned various thing that adds to the cost of our product, this are mentioned in cost structure, and we have also mentioned various streams through which we make revenues.MIFGI,RAJKOT GUJARAT TECHNOLOGICAL UNIVERSITY 38 CHAPTER 3 INTRODUCTION DESIGNING AND CALCULATION OF COMPONENTS AND SYSTEM INTRODUCTION TO THRUST BEARING FAILURE ANALYSIS OF THRUST BEARING MATERIAL SELECTION OF VARIOUS COMPONENTS GENERAL EQUATIONS TO DESIGN THRSUT BEARING DESIGN OF VARIOUS COMPONENTS TESTING OF BEARING FOR WEAR OF RUNNER AND RUNNER MATERIAL SELECTIONMIFGI,RAJKOT GUJARAT TECHNOLOGICAL UNIVERSITY 39 INTRODUCTION TO THRUST BEARING Generally there are two types of thrust bearing available in the market which are majorly used.
This two types of bearings are as follows: ? Foot step or pivoted thrust bearing ? Collar thrust bearing. In pivoted or foot step thrust bearings, the shaft is vertical and it is supported in the bearing itself. In collar bearing the shaft continues through the bearing. The shaft may be vertical or horizontal, with single or multi collar. Here in submersible pumps we uses foot step or pivoted bearing at the bottom of the assembly. Hence the whole of weight load of the motor and multiple impeller, and also the dynamic load due to rotation of the shaft is needed to be supported by the thrust bearing. Due to these condition the load acting on the thrust bearing is very high, and it majorly depends on the power of the motor.
Fig. 3.1 Five Segment Bearing For Submersible PumpMIFGI,RAJKOT GUJARAT TECHNOLOGICAL UNIVERSITY 40 In thrust bearings the common practice is to use the bearing having a plate or segments in between to reduce the wear of lower plate. Also lubrication is provided to the plate. Generally in thrust bearings the wear rate is proportional to the velocity of the rubbing surface speed, which increases with the distance from the axis (radius) of the bearing. Therefore the wear will be different at different radii. Due to this wear the distribution of the bearing pressure is not uniform at all the point on the bearing surface. Hence in usual practice an alternate disc is provide of different materials in between the surface.
Martials used are like stainless steel, bronze, etc. so that the next disc comes into play, if one disc seizes due to improper lubrication. FAILURE ANALYSIS OF THRUST BEARING TYPES OF THRUST BEARING FAILURE The data regarding various percentage possibilities of thrust bearing failure is taken from the research and development department of Ravi pump Engineering Pvt. Ltd. Failures in thrust bearings majorly depends upon the working conditions of the pump. The data provided is represented as below: Fig. 3.2.
1 Total failure modes of thrust bearings Sales 6% 17% 46% 7% 5% 19% Wear Voltage Fluctuations Installation Manufacturing Miscellaneous Selection of SystemMIFGI,RAJKOT GUJARAT TECHNOLOGICAL UNIVERSITY 41 FAILURE ANALYSIS OF THRUST BEARING Thrust bearing failure is possible due to wear, voltage fluctuations, installation faults, manufacturing faults, wrong selection of system, and many more. But mostly thrust bearing is failed due to wear. It is possible that the failure of thrust bearing happens due to other causes but its possibilities are very less. WEAR Mostly the failure of thrust bearing is done due to the wear of the thrust pads and the segments present in the thrust bearings.
This wear happens might due to the present of more abrasive particles in the lubricant, or the sever operating conditions. It also happens due operation of the pump in the conditions which are above the designed conditions. The abrasive particles may enter the system with the lubricant, or are the wear out particles that are eroded from the runner pads, and segmental pads. Mostly the wear are of two types.
One is called two body abrasive wear that occurs due to the rubbing of rotating body with the stationary bode. And other type is three body abrasive wear that occurs due to the free rotation of the abrasive particles between the runner and stator. The wear resistivity of the runner material, and segmental pads depends upon the hardness of the material selected. Higher the hardness more resistivity toward wearing of the components.
Major causes of wearing are misalignment of the shaft, improper assembly, unbalancing of rotor and stator, impurities in water and voltage differences. ? Misalignment of the shaft The misalignment of the shaft is produced due to more load acting on the shaft then the desired loads, temperature gradient created over the shaft, due to which more flexible materials deforms and the shaft gets elongated. Inaccurate assembly and if relative position is charged after assembly is done. The misalignment of the shaft generates the angle between the bearing runner and the stator.
Hence the shaft does not rotate in the axis parallel to the bearing. This generates the rubbing of the surfaces, hence the wear of runner pad and segments occurs. This wear is termed as two body abrasion as rubbing of two surfaces is included in it.MIFGI,RAJKOT GUJARAT TECHNOLOGICAL UNIVERSITY 42 ? Unbalancing of Rotor and Stator. Unbalancing of rotor and stator generates high rotational dynamic loads acting on the shaft, and it also generates the misalignment of the shaft. The rotor and stator should operate in condition parallel to each other, so that the unbalancing of the rotor can be avoided.
Various ways employed to balance the unbalanced rotor are material adding to the rotor (Rotor pin) and material removal – submersible rotors (balancing ring). The major purpose of balancing is to reduce the vibration of the assembly, to reduce audible and signal noises, reduce structural stress, reduce power loss, increase bearing life, and increase quality of ride. ? Dust in Motor If there any presence of the external material in the operating environment then the wearing of the thrust bearing takes place, due to that runner pads get wear out as they are made up of softer material then the segmental pads.
The presence of the dust in the water is limited to several extends, above which if there is presence of the dust then, the wearing of runner will takes place earlier. ? Up thrust failure When the pump in operation and if the rate of flow at the output of the pump is higher than the designed value then the up thrust forces are acting on the pump impeller. This will generate very high up thrust loads acting on the bearings ultimately, and hence the wear of bearing pad takes place. Such a kind of situation arises when the pump selected is higher than the required capacity of operation. ? Down thrust failure When the pump is pumping less water than the required quantity of water, then the loads on the shaft increases and this leads to the failure of bearing, by bearing pad wear. This kind of situation arises due to the impurities present in water, which gets into the filters.MIFGI,RAJKOT GUJARAT TECHNOLOGICAL UNIVERSITY 43 ? Failure due to overheating The major causes of overheating are high ambient water temperature, low flow rate of external cooling water, very high flow rate of external cooling water, low supply voltage, high supply voltage, incorrect installation procedure, selection of pump. The possible reasons of overloading are excessive hydraulic load, an oversized or wrongly sized pump fitted to the motor, misalignment, failure of components in the motor or the pump, foreign bodies or solids in the water being pumped.
? Improper assembly If the assembly of the pump made is not done properly with high precision then the pump might get failed due to many reasons, like misalignment, overheating, unbalance of rotor and stator. The pump assembly fault will causes the effects like loss of power, failure of thrust bearing, failure of pumps in short period of time, thermal elongation of shaft vibrations of pump, unpleasant noise during operation, etc. Hence focus must be given to reduce the improper assembly defects, by testing the pump under standard conditions before delivery of pumps to the customer to improve the customer satisfaction. ? Voltage Fluctuations During the operating condition of the pump, when voltage is suddenly changed at that time it effects the performance of the pump. If this condition of high and low voltage is frequent, then the shaft of the pump frequently moves up and down.
This causes the deformation of the bearing pads and segment of thrust bearing. ? Defects in manufacturing of bearings If any defects during the manufacturing of the bearings are formed over the bearing surface then it may also lead to the sever accidents. Thrust bearings required high surface finish, which need to be provided for smooth operation of the bearings. Hence at manufacturing the bearings should be manufactured under controlled environment and they should be inspected well after the completion of operations over it.MIFGI,RAJKOT GUJARAT TECHNOLOGICAL UNIVERSITY 44 MATERIAL SELCETION OF VARIOUS COMPONENTS MATERIAL OF CONSTRUCTION Various materials of construction of submersible pump are stated below in the table. (Table 3.
3.1) Material of Construction Bowl 26 Grade Cast Iron or S. S. 410 with Noryl Diffuser Impeller S. S. 304 Suction and outlet 26 Grade Cast Iron (FG260) with Epoxy Coating Motor body Stainless Steel Motor and pump shaft S.S.
410 or S.S 431 Stator Vacuum Impregnated CRNO M45 Rotor EC Grade Copper Conductors Winding EC Grade Copper(Three coated polywrap) Journal bearing LTB-4 Thrust bearing Carbon Vs. Self-Align S.S 420 Segments Housing, connection plate and base 26 Grade cast iron (F260) with epoxy coatingMIFGI,RAJKOT GUJARAT TECHNOLOGICAL UNIVERSITY 45 MATERIALS OF THRUST BEARINGS COMPONENTS The main components of thrust bearings and general materials preferred for its making are stated below.
Base – generally made of cast iron (C.I). Rotating Collar – generally made of cast iron (C.I). ? Lining – generally used are plain carbon lining with high surface finish. ? Tilting segments – generally made of stainless steel 420 Properties of lining materials are already discussed here the properties of stainless steel with grade 420 are listed below.
(Table 3.3.2) mechanical properties of S.S 420 Tensile Strength in N/mm2 770 Yield Strength in N/mm2 555 Hardness HB 223 ASSUMPTIONS FOR CALCULATIONS OF BEARING SPECIFICATIONS The bearing lubrication is done with the thin film of water.
The working conditions of the pump are under the design limits. Efficient cooling is provided by the water used. The pump designed is suitable for clear, cold, non-aggressive, non-explosive water. This assumptions are made to simplify the bearing calculations, otherwise they need to be solved using highly complex equations.
The design proposed here is only simple design, and further validation to the design needs to be done further.MIFGI,RAJKOT GUJARAT TECHNOLOGICAL UNIVERSITY 46 GENERAL EQUATIONS TO DESIGN THRSUT BEARING The various equations that are used in the design of thrust bearings are stated in this segment of design. The various terms used and there designations are listed below. W = Load transmitted over the bearing surface, R = Radius of bearing surface, A = Cross-sectional area of bearing surface, p = Bearing pressure per unit area of the bearing surface between rubbing surfaces, µ = Co-efficient of friction, N = Speed of shaft in r.
p.m. ? Assuming bearing pressure is uniformly distributed over the bearing area. p = �� = �� (i) �� ����2 Total Frictional Torque, T = 2µ.W.R (ii) 3 Power lost in friction, P = 2����.�� 60 (iii) ? When counter boring of the shaft is considered then, Bearing pressure, p = �� ��(��2 – ��2) , (iv) Where r = radius of counter boreMIFGI,RAJKOT GUJARAT TECHNOLOGICAL UNIVERSITY 47 Total frictional torque, T = 2 µ.
�� ��3 ? ��3 (v) 3 ��2 ? ��2 ? For selecting the allowable bearing pressure: For rubbing speed (V) from 15 to 60�?����, the bearing pressure should be such that p.V ? 42. When p is in ��?��2 and V in�?����. For V over 60�?����, the pressure should not exceed 0.7��?��2. For intermediate service, the bearing pressure may be taken as 10.5��?��2.
For very slow speeds, the bearing pressure may be taken as 14��?��2. ? The coefficient of friction for the footstep bearing may be taken as 0.015. The schematic diagram of the bearing used in submersible pump is shown below. Fig 3.4 Diagram of thrust bearingMIFGI,RAJKOT GUJARAT TECHNOLOGICAL UNIVERSITY 48MIFGI,RAJKOT GUJARAT TECHNOLOGICAL UNIVERSITY 49 DESIGN OF VARIOUS COMPONENTS DESIGN OF BEARING DIAMETER ? Let us consider medium capacity 12?? bowl. For such bowl the load on the bearing without considering the weight is W = 3.19 kN.
? Take bearing pressure ratio as 0.7��?��2, take motor speed grater then 60�?����. Take coefficient of friction as 0.015. Calculating radius of the bearing surface. p = �� = �� (i) �� ����2 0.7 =3.
19?2.103, ����2 ��2 = 2901.167 R = 53.86 mm Assuming the diameter of thrust bearing equal to 80mm, according to the standards. But as the above calculation is for plain bearing, for segmental bearings the bearing diameter is assumed somewhat more than the calculated diameter. Hence assuming bearing diameter=110mm for the segmental bearing. DESIGN OF RUNNER AND LINING Diameter of bearing= 110 mm. Let the diameter of the rotor shaft according to the standard be equal to 15 mm.
DIMENSION OF KEY Assuming square key attached with the rotor and shaft. Let the material of rotor shaft and the material of key be same Steel grade 316. Its compressive stress is 310 MPa and shear stress is 82 MPa.MIFGI,RAJKOT GUJARAT TECHNOLOGICAL UNIVERSITY 50 For square key, width of key b= d/4 (ii) Where d= diameter of rotor. And height of key h= d/4. (iii) Therefore b= (15/4) = 3.
75 mm And h= (15/4) = 3.75 mm. Length of key, Shear stress, �� = �� ��� 82=4612.5 , L=15 mm 3.75?� (iv) Check for the design of key, Crushing stress �� = �� �?/2 , (v) Value of ��, should be less then the calculated value. key is safe.
�� = 4612.5 15?3.75/2 = 164 MPa, which is less then 310 MPa hence the design of Dimensions of key, Length of key= 15 mm Height of key= 3.
75 mm Width of key= 3.75 mm ? Let the thickness of the carbon lining be selected as 2 mm according to the required application. This carbon lining is fit to the rotor with the 45° inclination to the rotor. DESIGN OF PADS The pads are made up of stainless steel, let the number of pads here be equal to 6.MIFGI,RAJKOT GUJARAT TECHNOLOGICAL UNIVERSITY 51 Hence each pad will be fitted at an angle of 60° to the centre of the bearing. Let the inner diameter of the pad arc be equal to 50 mm with respect to the bearing centre.
(r= 25 mm) The outer diameter of the pad arc is 110 mm with respect to the bearing centre. (R= 55mm) The geometric imaginary circle line of pads, has the diameter equal to 80 mm. (rg= 40 mm) Width of pad in radial direction is equal to 30 mm. Design validation with consideration of bearing pressure. As we know that the considered bearing pressure for the bearing design above is 0.7 ��?��2, here the calculated bearing pressure with the help of pad area must be less then 0.
7 ��?��2. Area of each segment is given by a= � 360 ��(��2 ? ��2). (vi) Area of segment a= 55 ��(552 ? 252). (Here arc angle ofeach segment is 55° as 5° 360 clearance is kept between each segment.) a= 1151.
91��2. Total segment bearing area A= 6911.5��2. Bearing pressure p=��, here we know that W= 3.19 kN. �� p=3.19?1000 = 0.
461��?��2. 6911.5 Which is less than 0.7 ��?��2 hence the design of bearing pads is safe, for design load. DESIGN OF LEVELLING LINKS ? Levelling links are present inside base ring of the bearing. There is one link between two pair of pads pivot points. ? Hence the number of levelling links inside the ring is equal to 6.MIFGI,RAJKOT GUJARAT TECHNOLOGICAL UNIVERSITY 52 Length of each link at the imaginary geometric radius, L=2������ = 2��?40 = 20.94 mm. (vii) 2?6 12 Say length of levelling link L= 30 mm. ? Let thickness of levelling ring equal to 30 mm. Fig. 3.5.4 Conceptual design of the proposed solution from US patent US4403873.10 DESIGN OF ECCENTRIC PIVOT POINT ? In various researches it has been found that somewhat eccentric pivoting of the pad in direction of rotation of the runner is beneficial for the lubrication of the bearing and also for the quick reaction to the load variation. ? In this proposed design pads are pivoted over the levelling link, from the two points. This are near to the edge of the pads, and also eccentric in the direction of rotor in both the direction.MIFGI,RAJKOT GUJARAT TECHNOLOGICAL UNIVERSITY 53 ? The advantage of this design is better lubrication at the starting of the bearing, increases in load carrying capacity, and better response to the load variation over the bearing. TESTING OF BEARING FOR WEAR OF RUNNER AND RUNNER MATERIAL SELECTION TESTING METHODOLOGY Abrasive wear test was performed on four grade using modified test rig. Company provided us test rig for testing of different material grades of bearing. Then we check the wear resistivity of the material with the help of weight rejection. 1HP motor is attached vertically to the structure, motor have 2800 rpm. Grade sample is fitted with the help of nuts and bolts. This sample is attached at the end of motor shaft, and the assembly made is flexible to change the sample easily. Every grade sample is rotating 90min at three different stages of solution. In first stage sample is tested in plain water. In second stage sample is tested in dusty water with dust level of 88mm in bowl. And in third stage sample is tested in salty and dusty water, during third stage 1kg of salt is add to the dusty water used in second stage. Wear of the bearing was measured by calculating weight loss after every stage of test run of each sample. The specifications of motor used and bowl diameter are provided in the table below. (Table 3.6.1. (a)) MOTOR SPECIFICATIONS Power supply AC Motor Speed 2800rpm Power 1HPMIFGI,RAJKOT GUJARAT TECHNOLOGICAL UNIVERSITY 54 (Table 3.6.1. (b)) BOWL SPECIFICATION Bowl Height 160mm Bowl Diameter 145mm Total water Level 133mm Quantity of water 2.1kg Dust Level 88mm Weight of Dust 0.97kg Weight of Salt 1kg ? Testing Time: 90min at ambient temperature ? Stage 1: Plain water ? Stage 2: Dusty water ? Stage 3: Salty Dusty water (Table 3.6.1. (c)) Wear test results Sample Actual Weight (gm) Weight after Testing (gm) Weight Rejection by percentage after testing (%) Stage 1 Stage 2 Stage 3 Stage 1 Stage 2 Stage 3 CY10 106 104 101.01 98.39 1.9 4.7 6.8 CY2C 250 246.75 240.57 235.85 1.3 3.77 5.66 CY10C 16 15.80 15.53 15.18 1.1 2.9 5.12 MY10K 39 38.68 38.29 37.59 0.8 1.8 3.6MIFGI,RAJKOT GUJARAT TECHNOLOGICAL UNIVERSITY 55 WEAR TEST RESULTS Fig. 3.6.2 Test Result Chart EFFECT OF HARDNESS ON ABRASIVE WEAR From the results shown in the table 3.6.1.c we can conclude that the rate of wear increases as the hardness of the material reduces, hence we can say that the material selected for the application must have hardness value high, so that the runner does not gets wear out to quickly. Hence the materials impregnated with epoxy and antimony have good wear resistance than plain carbon materials, as there hardness value is higher. EFFECT OF ELASTIC MODULUS From the properties of various materials tested, we can conclude that as the elastic modulus of the materials increases the hardness of the materials increases too. Hence higher the elastic modulus, lower is the wear rate of the materials. Hence impregnated materials are more wear resistive than the plain carbon materials. Wear resistance is directly proportional to dynamic elastic modulus of carbon grades. MY10K(80) CY10C(76) CY2C(73) CY10 (67) 0.8 1.1 1.3 1.8 1.9 2.9 3.6 3.77 4.7 5.12 5.66 6.8 Chart Title Stage 1 (Plain Water) Satge 2 (Dusty Water) Stage 3 (Salty Dusty Water)MIFGI,RAJKOT GUJARAT TECHNOLOGICAL UNIVERSITY 56 EFFECT OF DENSITY As the density of the material increases, its hardness value increases too. Hence higher the density of the material, higher wear resistivity offered by the material. Epoxy and antimony impregnated materials have higher density than plain carbon materials.MIFGI,RAJKOT GUJARAT TECHNOLOGICAL UNIVERSITY 57 CHAPTER 4 SUMMARY/CONCLUSION OF RESULTS CONCLUSION FROM DESIGN CALCULATION COMPARISION OF DESIGNED BEARING & PRESENT BEARING LIMITATIONS/DIFFICULTIES OF OUR PROJECT SCOPE FOR FUTURE WORK EXPECTED OUTCOMEMIFGI,RAJKOT GUJARAT TECHNOLOGICAL UNIVERSITY 58 CONCLUSIONS FROM DESIGN CALCULATIONS In this project, we studied about various components of the thrust bearings that are very essential for the operation of bearings. We studied about various reasons that are associated with the failure of submersible pumps. And from that reasons we found that the most of the time thrust bearings used in the pumps are failed due to various reasons like overheating of thrust bearings, operational environment, improper lubrication, etc. In this project we have tried to solve the problem of frequent failure of thrust bearings, by merging the design used at present and some of concept of previously used design. We have tried to make the segments more tilt able to provide better lubrication to thrust bearing during the starting and stopping of operation. As most of the time thrust bearing fail during the starting and stopping of the operation, as wear is high during this period of operation. We have also tested regarding the wear of bearing pads using different suggested materials of the bearing pad, we found that the materials having higher value of hardness, more elastic modulus, higher density should be used to reduce the wear. The materials that impregnated with epoxy and antimony are more suitable for thrust bearing applications then the plain carbon materials. From the four materials tested, the most suitable material for the application found was MY10K. This material has more hardness value, higher density, and also low wear during the testing of bearing. COMPARISON OF DESIGNED BEARING AND PRESENT BEARING The major difference between the designed bearing in this project and the present bearings are of manufacturing difficulties, and manufacturing cost. Also other major difference is of operating conditions, and efficiency of operation. Few of the comparisons for the bearings are shown in the table below.MIFGI,RAJKOT GUJARAT TECHNOLOGICAL UNIVERSITY 59 (Table 4.2) Comparison of bearings POINTS DESIGNED BEARINGS PRESENT BEARINGS Operation Better operation than present bearings Fair operation Manufacturing Cost High cost High cost Manufacturing Difficulties Less difficulties More difficult Starting Friction Low starting friction High starting friction Maintenance Less maintenance required High maintenance requirement Power loss Low power loss High power loss Effect of voltage fluctuations Low voltage fluctuation effect More high voltage fluctuation effect LIMITATIONS/DIFFICULTIES OF OUR PROJECT Major difficulties with our project is to prove the betterness of the designed bearings than the present bearings, as number of companies are present in the market and they are designing their bearings according to their requirement, hence standardization is one of the major problem with our designed bearing. The other difficulties are, to test the design, as the manufacturing of the bearing requires high precision and also considerable amount of time, our designed bearing can’t be manufactured in simple facilities, it requires advance facilities used by the manufacturing companies to make the product. Some of the other difficulties is in bearings we require to do lots of analysis before manufacturing, and also we need to consider many aspects related to bearings, which are of very complex situations to make designed bearing in this project successfully better.MIFGI,RAJKOT GUJARAT TECHNOLOGICAL UNIVERSITY 60 Some of the kind of analysis required are, CFD analysis, and motion analysis of levelling links, pressure reduction analysis, surface heat distribution analysis and lot more. It requires considerable amount of time and needs to learn all the aspects of bearings. Hence it can be said that to prove the design is lot more difficult task in our project. SCOPE FOR FUTURE WORK As we have mentioned earlier, that there are many limitations in proving the design, in future this project can be continued on the bases of proving that the designed is better than the present bearings used in submersible pumps. Also in future the in-depth study of the project might give help to the researcher for future designing of the bearing. Also this project can improve the operational life of submersible pumps. The designed suggested here can also be used for heavy operations, like ship propeller, wind turbine propeller, etc. Hence in future this project can bring lot of revolution in many fields of engineering. EXPECTED OUTCOME Expected outcomes from this project is to reduce the maintenance and failure of submersible pumps, for which the bearing suggested here is designed. Other outcomes is to make improvement in the bearings used in heavy applications also, like ship propeller. Also through this project it is intended to reduce the cost of bearing manufacturing and manufacturing difficulties. Also it will improve the lubrication system of the bearings.MIFGI,RAJKOT GUJARAT TECHNOLOGICAL UNIVERSITY 61 REFERANCES 1 Lyle A. Branagan; Survey of Damage Investigation of Babbitted Industrial Bearings; Lubricants 2015, 3, 91-112. 2 R. S. Gregory.; Performance of Thrust Bearing at High Operating Speeds; July, 9, 1973. 3 Xiaodong Yu, Zhiqiang Wang, Xiuli Meng, Huanhuan Li, Dan Liu, Xu Fu, Bo Wu, Li Tan, Bai Qin and Xuezhe Dong.; Research on Dynamic Pressure of Hydrostatic Thrust Bearing under the Different Recess Depth and Rotating Velocity.; International Journal of Control and Automation, Vol.7. No.2 (2014), pp.439-446. 4 Farooq Ahmad Najar and G.A.Harmain.; Numerical Investigation of Pressure Profile in Hydrodynamic Lubrication Thrust Bearing.; Hindawi Publishing Corporation International Scholarly Research Notices Volume 2014, Article ID 157615, 8 pages. 5 Heinz P. Bloch.; Root Cause Analysis of Five Costly Centrifugal Pump Failures.; Machinery Failure Analysis and Troubleshooting, Houston, Texas; Gulf Publishing Company. 6 Theodor Parlevliet.; Pivoted, Segmental, Thrust Bearing Providing Simulated Offset Support of Centrally Supported Bearing Segments.; US3784266 7 Willis W Gardner.; Pad construction for tilting pad thrust bearing.; US3829180A 8 Kozo Matake.; Thrust bearing device.; US5209579A 9 Leonard L Tyson.; Thrust Bearing Having Lubrication System.; US3893737A 10 Willis W Gardner.; Tilting Pad Thrust Bearing.; US4403873AMIFGI,RAJKOT GUJARAT TECHNOLOGICAL UNIVERSITY 62 APPENDIX ? Copy of PPR of all members (4 PPR each) ? Copy of PSAR of all members (5 PSAR each) ? All canvases pics