1. PRELIMINARY STUDY ON BEARING AND BALANCING FAULT SIMULATOR PROJECT TEAM KEERTHI B.M 1BM07ME044 KEISHAM KISHAN SINGH 1BM07ME045 KISHAN S.I 1BM07ME047 NARAYAN H.M 1BM07ME060 GUIDE Mr. R. MAHENDRAN Asst. Professor Department of Mechanical Engineering BMSCE PLACE OF WORK BMS College of Engineering Bangalore

2. CONTENTS  ABSTRACT  INTRODUCTION  LITERATURE SURVEY  METHODOLOGY  RESULTS  CONCLUSION  FUTURE WORK  BIBLIOGRAPHY

3. ABSTRACT  Bearing and balancing fault simulator helps to support the study of bearing faults and unbalance under controlled conditions.  It can be used to generate each type of faults individually or in combination, providing stable platform for study.  Our present work involves determining results for newly fabricated test rig operating under various speed.

4. Various results are obtained such as  Shaft center line during various speed.  Orbit plots.  Bodes plot.  Waterfall spectrum.  Full spectrum.

5. INTRODUCTION  Today’s industry uses increasingly complex rotating machines, some with extremely demanding performance criteria.  The root cause of faults in rotating machinery is often due to faulty bearing.  One way to increase operational reliability and thereby increase machine availability is to monitor faults in these bearings.

6.  It is essential to have a throughout understanding of the associated fault signatures that occur under a variety of operating conditions.  Bearing and balancing fault simulator is portable, robust, cost-effective,balance and bearing vibration trainer.  It develop signal processing techniques to identify bearing fault frequencies in the presence of defects.

7. HISTORY  Before observer based fault detection method were used i.e., model – based approaches.  In this fault were detected when predetermined threshold levels assigned to each residual level are reached.  Willsky gave a comprehensive survey of design methods for bearing fault detection in 1976 but it was only for linear system.  But with the advance of mathematic, computers and software programs more complex problems such as vibration, cracks, minute defect in parts were able to detect and solve.

8. Bearings : A bearing is a device which allows constrained relative motion between two or more parts, typically rotation or linear movement. Bearings may be classified as :  Plain bearing.  Rolling element bearing.  Jewel bearing.  Fluid bearing.  Magnetic bearings.  Flexure bearing.

9. Bush:  It is an independent plain bearing that is inserted into a housing to provide a bearing surface for rotary applications.  A flanged bushing is a sleeve bushing with a flange extending radially outward from the Inner diameter.  The flange is used to positively locate the bushing when it is installed or to provide a thrust bearing surface.

10. Data acquisition system :  Data acquisition is the process of collecting and measuring electrical signals and sending them to a computer for processing.  DAQ systems capture, measure, and analyse physical phenomena from the real world. Building blocks of data acquisition system: 1. Sensor: A device that converts a physical phenomenon such as light, temperature, pressure, or sound into a measurable electrical signal such as voltage or current. 2. Signal: The output of the sensor.

11. 3. Signal conditioning unit: Hardware that is connected to the DAQ device to make the signal suitable for measurement or to improve accuracy or reduce noise. 4. DAQ hardware: Hardware you use to acquire, measure, and analyse data. 5. Software: application software which designed to help easily design and program our measurement and control application.

12. Eddy current transducer(sensor): Eddy Current Transducers (Proximity Probes) are the vibration transducer of choice when installing vibration monitoring on Journal Bearing equipped rotating machinery. Eddy Current Transducers are the only transducers that provide Shaft Relative (shaft relative to the bearing) vibration measurement.

13. Working of eddy current sensor

14. Different plots obtained in data acquisition and analysis system  Orbit + Time base  Time Trend  X-Y  Polar  Bode  Shaft centreline  Cascade  Waterfall Spectrum  Full Spectrum

15. Orbit plots  In orbit plots it shows displacement of shaft from the centre line.  It provides isolated plot obtain at particular speed with helps to determine the position of shaft at variable speed. Bode plot  A Bode plot displays order magnitudes and phases as a function of rotational speed or frequency. A Bode plot helps in identifying the resonance speed of a rotor or examines the rotor dynamics on an order basis.

16. Waterfall and cascade plots: Waterfall and cascade plots are three- dimensional graphs of spectra at various machine speeds and times. They allow us to see the entire frequency content from a location as a function of speed Horizontal relationships can be analyzed for resonance, looseness, rubs, instability, etc. Vertical relationships onset and progress of resonant related activity, and any constant- frequency vibration that may be present.

18. Vertical relationships may be due to:  Adjacent machineries and their speeds must be checked against the data  Ground faults or electrical noise in the instrumentation – the peaks will line up vertically at 60 Hz (3600 cpm)  Structural resonances will get easily excited by orders of running speed as machine speed increases or decreases

20. METHODOLOGY Fabrication : Dimensions and material of the bearing and balance fault simulator test rig is based on the design used by the data physics (R & D unit).

21. Specifications of different components of test rig Mechanical parts: Foundation 460*10*2 mm die cast Aluminium base H15 grade, 20 grooves M8 thread to move plumber block, 4 grooves M6 thread to accommodate motor, 4 grooves of M6 at each end for rubber isolators shaft 10mm diameter, length 230 mm, H30 grade, turned, ground and polished. bearing Bush type, phosphorus bronze wear resistance material with rubber oaring’s. couplingJaw coupling, with rubber elastomer

22. Electrical: Motor Universal AC/DC single phase,1/12 HP, 62 watt, 0-15000 rpm variable speed, Voltage and current 230 volt, 0.75 amp AC to DC converterDimmer stat, with steps of 2 Volt, range 0- 270 volt

23. Test rig setup

24. BLOCK DIAGRAM OF BEARING AND BALANCE FAULT SIMULATOR TEST SETUP

25. Input to the signalcalc turbo software

31. RESULTS

46. THEORITICAL CALCULATION OF CRITICAL SPEED: We have, Diameter of the shaft, d = 0.010m Distance between the two plumber block, l =0.08m Weight of the shaft, w = 0.03g Moment of inertia, I=(3.14*d^4)/64 =(3.14*10^4)/64 = 4.9087*10^(-10) m4 Deflection of the shaft, y =-(5wl^3)/ (384EI) = 0.0000199 m Stiffness constant of the shaft, k =mg/y = 14724N/m Frequency at resonance of the shaft = (k/m)^ 0.5 =700 rad/sec Critical speed, n = (60*700)/(2*3.14) =6689.96 rpm

47. CONCLUSION  It provide safe platform to determine resonant frequency as well as critical speed.  From previous study it reveals the vibration signatures can be determined easily.  Even a slight mistake in fabrication will have a huge impact in results.  It provide more design option by providing safe platform for study.

48. FUTURE WORK  Same system can be utilized to determine faults in rolling element bearing by few modifications.  It can be used as test rig to collect different data’s of a newly designed bearings for verification.

49. BIBLIOGRAPHY TECHNICAL PAPER  Review of Techniques for Bearings & Gearbox Diagnostics, Presented at IMAC Conference, Feb. 3, 2010 Jacksonville, FL by Suri Ganeriwala, PhD, SpectraQuest Inc.  Transient Speed Vibration Analysis, Insights into Machinery Behavior, 07-Dec-2007,By Stanley R. Bognatz, P.E.President & Principal Engineer, M&B Engineered Solutions, Inc. BOOKS  Vibration Data Collector Signal Analysis by James Zhuge, Ph.D., President Crystal Instruments Corporation.  Automatic fault diagnosis of rolling element bearings using wavelet based pursuit features by hongyu Yang, B.E, M.E, Dalian University of technology, china.

50. WEBSITES  http://www.spectraquest.com  http://www.wikipedia.org/  http://www.kingdom.com.au/Turbo%20Rotor%20D ynamics.html  http://www.dataphysics.com/  http://iitkgp.vlab.co.in/?sub=40&brch=213&sim=7 31&cnt=1&id=0