noise and vibration measurement of a gearbox during the ...

Special Issue 2, Volume VI, May 2011NOISE AND VIBRATION MEASUREMENT OF A GEARBOXDURING THE ACCEPTANCE TEST IN THEMANUFACTURER’S WORKSHOPPál Bánlaki 1 , Ferenc Dömötör 2 , András Stipkovits 3 , Szabolcs Devecseri 4Summary: Gear boxes are key parts of any vehicle, and consequently they shall bemanufactured with the highest possible accuracy. However, this is not alwayspossible and a consequence can be the increased noise and mechanical vibration.These items shall be qualified as rejects and they must be filtered out during theacceptance test at the manufacturer’s workshop test procedure. In this paper aspecial procedure elaborated by the authors shall be presented, which consists of avibration and a noise measurement.Keywords: noise and vibration test, gearbox, automotive industryINTRODUCTIONAll manufacturers in automotive industry have the target to reach zero error. This is thecase with the gearboxes, manufactured by the GM Allison Plant in Szentgotthard, Hungary,too. These gearboxes are typical rotating machinery, and consequently for them a vibrationand noise analysis is a well proven method at the test rig. However, there is a specialcondition: the gearbox is filled up with oil, which resulting damping, and this might have aspecial effect on the noise and the vibration.Just in case one of the many items of the gearbox gets faulty, then the faulty part maycause a special noise and vibration, which can be detected by noise and vibration methods.Other methods are usually unable to detect types of failure.This method is not new in the Allison plant. The former projects at the engine plant fornoise and vibration measurements of the cold test rig proved to be successful. However, someminor failures indicated the need of launching a new research project.1 dr. Pál Bánlaki, Scientific Coworker, Budapest University of Technology and Economics, Faculty ofTransportation Engineering, Department of Vehicles Manufacturing and Repairing, Budapest, Bertalan Lajos u.2. Z building. 608, Hungary H-1111 Tel.: +36-1-463-1931, Fax: +36-1-463-3467,E-mail: banlaki@kgtt.bme.hu2 Ferenc Dömötör, Scientific Coworker, Budapest University of Technology and Economics, Faculty ofTransportation Engineering, Department of Vehicles Manufacturing and Repairing, Budapest, Bertalan Lajos u.2. Z building. 733, Hungary H-1111 Tel.: +36-1-463-1827, Fax: +36-1-463-3467,E-mail: domotor@kgtt.bme.hu3 András Stipkovits, Supervisor Maintenance, Test Engineer, GM Powertrain – Hungary, Szentgotthard, Füzesiút 15. H-9970 Tel:+36-94-551 621 Mobil: +36307031432 Fax: +36-94-551 059E-mail: andras.stipkovits@gm.com4 Szabolcs Devecseri, Senior Manufacturing Engineer, GM Powertrain – Hungary, Szentgotthard, Füzesi út 15.H-9970 Tel:+36-94-551 621 Mobil: +36307031432 Fax: +36-94-551 059E-mail: szabolcs.devecseri@gm.comBánlaki, Dömötör, Stipkovits, Devecseri: Noise and vibration measurement of a gearbox 20during the acceptance test in the manufacturer’s workshop

Special Issue 2, Volume VI, May 20111. THE FORMER TEST RIG, USED FOR GEAR ACCEPTANCE TESTSThe former test rig was updated by a PC based noise diagnostic station. A considerablesoftware development was carried out on both computers. The elements of the test rig were asfollows:NI USB-6009 analogue and digital I/O unit, USB connection, 8 analogue input (14bit,40kS/s), 2 analogue output (12bit, 150S/s), 12 digital I/O of 32 bit, counter. SONY ECM-CZ10 microphone, having a 100Hz – 10Khz band width, 33dB sensitivity,for use in studio, with Zoom tube.Fig. 1 – The former test rig at the plantSource: AuthorsThe tasks of the software: data logging, processing, and data storage. The software hasthe environment: LabView 8.2. Communication: NI DAQ 6009 input via USB, having digitalI/O with the test rig, analogue input to the microphone. This can be operated by hand or usedin automatic mode. The software has a directory structure, file name to be selected for saving.In “Analysis mode” spectrum analysis shall be carried out by comparison of two savedspectra. A cascade diagram can also be created for comparing different spectra.In “Automatic mode” signals coming from the test rig shall be analysed and comparedwith the logged data automatically. Time signals of the gearbox can be recorded as well.Limits shall be determined by self-learning method.Bánlaki, Dömötör, Stipkovits, Devecseri: Noise and vibration measurement of a gearbox 21during the acceptance test in the manufacturer’s workshop

Special Issue 2, Volume VI, May 2011Need for improvement, as a result of the previous experiences:for noise measurements a professional microphone shall be used,triaxial vibration sensor shall be used, instead of a simple one, fixing of the sensor to the measurement point shall be improved.Consequently, some components of the HW system shall be replaced by componentswith better characteristics. Data flow in industrial environment has to be solved, too. Testsshall be carried out to determine the features and location of sensors. Finally the softwareshall be adopted to the new hardware, and further developed.2. IDENTIFICATION OF THE VARIOUS NOISE/VIBRATION SOURCESRolling bearing defect frequenciesInner ring defectfrequencyOuter ring defectfrequencyCage frequencyRotating outer ring:ff4f3knk120cosRotating inner ring:zgdkdb1 f2 1zg3dkd1202nk cos 1120 dkd 3fkncosnb cos1120 dkd32nk dmcos 2 n120 d3dkd3 b dmcos f3 120dgdkd3,In these formula: k stands for the cage, n for speed, 2 for inner ring, 3 for rolling element,4 for outer ring , (analogy to planetary gear!), z g is the number of rolling elements; is theaction angle. In case of a deep groove ball bearing = 0.Bánlaki, Dömötör, Stipkovits, Devecseri: Noise and vibration measurement of a gearbox 22during the acceptance test in the manufacturer’s workshop

Special Issue 2, Volume VI, May 20113. GEARBOX ON THE TEST RIG, DURING OPERATIONFig. 2 – The final test rig at the assembly manufacturing lineIn the picture the following items can be identified: B&K microphone Triaxial vibration sensor on the adopter bolt Gear box on the test rig, during operation Some details of the instruments, used for the test Vibration: DLI Watchman data logger and analyser Digital oscilloscope: PropScope (USB unit+PC), Tektronix TDS420A+: Vibration sensor: DLI Model 993B-7-NC (SN: 2070)Microphon: B&K 4958Pressure sensor: VIATRAN #2186 (part of the test rig)Bánlaki, Dömötör, Stipkovits, Devecseri: Noise and vibration measurement of a gearbox 23during the acceptance test in the manufacturer’s workshop

Special Issue 2, Volume VI, May 2011Fig. 3 – Schematic view of the gearbox4. THE UPDATED SYSTEM OF MEASUREMENTMeasurement data and conditions Measured gearboxes in the course of first measurements were the previously provided 4types (two of these are the same, while the other two are somewhat different)In the course of the second test phase we made measurements according to a new strategy:Speeds: 600 RPM, 2000 RPM (as determined)Gear box setup: N, 2nd gear, 4th gear (as determined)Comments:some measurements were carried out several times (doublecheck the results)altogether, nearly 200 measurements were carried outmost of the measurement data were printed out (they can be seen, if neededFig. 4 – The updated schema of the measurement systemBánlaki, Dömötör, Stipkovits, Devecseri: Noise and vibration measurement of a gearbox 24during the acceptance test in the manufacturer’s workshop

Special Issue 2, Volume VI, May 20115. EVALUATION OF THE NOISE AND VIBRATION MEASUREMENTSRESULTSFig. 5 – The measured noise spectrum of a gearboxFig. 6 – The waterfall diagram of the spectra, measured on a faulty gearboxFig. 7 – Another waterfall diagram, measured on a faultless gearboxBánlaki, Dömötör, Stipkovits, Devecseri: Noise and vibration measurement of a gearbox 25during the acceptance test in the manufacturer’s workshop

Special Issue 2, Volume VI, May 2011The applied evaluation methods are based on the international standards, on thecompany standard of the GM, and on the special method, developed by the authors.According to the prescriptions of thegeneral international standard (11) the new machines shall be in the „Zone A”,gearbox standard (12) the vibration limits can also be traced,chapter 9.5 of the Internal standard of the General Motors (13), there are also limits of thevibration severity.All measured spectra are below the allowed values, which is promising. However, alsothe bearing defect frequencies and the gearbox frequencies shall be identified. On the figuresno sign of defects in the spectra can be observed, and this indicates no defected teeth.As a summary:all tested gearboxes meet the requirements of the general standardsby measurements the noisy (strongly vibrating) gearboxes can be identified;own requirement system needs to be set up, for the evaluation,own aspects of the purchaser must be taken into account.6. NOISE MESUREMENT ON THE TEST RIGSome characteristic features of the noise measurements system (NI Compact DAQmodule):NI-9234 S&V input module with 24 bit resolution, 102dB dynamic range, ± 5V inputrange and IEPE supply,NI-WLS9163 WLAN interface rack module with IEEEv802.11 wireless interface, 128 bitAES 6 WPA2 safety level, 30 m range inside of building, 10/100 BASE T/X EthernetBruel & Kjaer 4958 microphone: sensitivity: 12,5mV/Pa, Frequency : 10 – 20.000 Hz,Dynamic range: 28 – 140 dB, Interface: IEPE 4mASome tasks for the future to be solved: Quick mounting of hardware on the test rig, Setup according to working conditions (environment effects), Cabling to be developed, Strategy for defect identification: studying of constructional data, and theoreticalfeatures; technical literature recommendations (typical spectra), own measurementsand experiences (Artifical Intelligence Data Base)Bánlaki, Dömötör, Stipkovits, Devecseri: Noise and vibration measurement of a gearbox 26during the acceptance test in the manufacturer’s workshop

Special Issue 2, Volume VI, May 2011CONCLUSIONSurvey of the results:excellent results with the NI wireless system,outside noise could be eliminated,wireless system could successfully transfer measurement (there is only one anotherapplication in Hungary available) an automatic separation/selection of the noisy gearbox can be achieved by the method,suggested by the JJT method, developed together with NIOur target was to reach the zero defect rate in the gearbox manufacturing process, bynoise and vibration analysis with modern, professional equipment. This brought verypromising results, according to our experiences. Another decision can soonbe made about theextension of the measurement system.ACKNOWLEDGEMENTThis work is connected to the scientific program of the "Development of qualityorientedand harmonized R+D+I strategy and functional model at BME" project. This projectis supported by the New Hungary Development Plan (Project ID: TÁMOP-4.2.1/B-09/1/KMR-2010-0002).Authors are grateful for the support of GMPTH Szentgotthárd and express their thankspersonally to colleges Pál Henter, Szilveszter Kulcsár, Csaba Pál, and József Mesics. Also,many thanks to the staff of NI Hungary, especially for the kind support from Attila Péter,Tamás Sárosi and Márton Litkei.REFERENCES(1) BÁNLAKI, P., KULCSÁR, Sz..: Monitoring the Operation of Internal Combustion EnginesUsing Order Analysis of Noise and Vibration Data, Journal Of Machine ManufacturingVolume XLIX.2009 Issue E3-E5 pp 142-144.(2) BRUEL & KJAER: What is order Analysis and What is used for, B&K 1999,www,bksv.com.(3) DENTON, T.: Advanced Automotive Fault Diagnosis, Butterworth-Heinemann 2006,ISBN 0750669918 pp. 98-121.(4) DIETSE, H.:.Automotive Sensors, Robert Bosch Gmbh, 2005, ISBN 978-3-86522-049-3(5) DÖMÖTÖR, F. (szerk.): Rezgésdiagnosztika I. Főiskolai Kiadó Dunaújváros 2008, ISBN978-963-87780-0-0 pp. 249-261.(6) FANTANA, N. E: Study Regarding Vehicle Noise Analysis, ANNALS of the ORADEAUniversity, Fascicle of Managament and Technological Engineering, Volume VI (XVI),2007, pp 447-450.(7) FILEP, E.: Mechanikai Hullámok,Ábel Kiadó Cluj-Napoca, 1999, ISBN 973-98092-8-6 pp. 38-51.Bánlaki, Dömötör, Stipkovits, Devecseri: Noise and vibration measurement of a gearbox 27during the acceptance test in the manufacturer’s workshop

Special Issue 2, Volume VI, May 2011(8) NAGY, I.: Technical Diagnostics I. -Vibration Analysis, Delta3N 2007 ISBN 978-963-06-0806-0 pp 57-67.(9) NATIONAL INSTRUMENTS:: Understanding Order Analysis and Resampling, NI DSAOverview, 2007, www.ni.com.(11) ISO 10816 Mechanical vibration – Evaluation of machine vibration by measurements onnon-rotating parts.(12) ISO 8579-2 Acceptance code for gears – Determination of mechanical vibrations of gearunits during acceptance testing.(13) General Motors Corporation, Vibration Standard for new and rebuilt machinery andequipment, GM Specification, North American Operations, Warren, Michigan, 48090-9040, GM-1761.Reviewer: doc. Dezso Szoke, Ph.D.Budapest University of Technology and Economics, Faculty of TransportEngineering, Department of Chassis and Lightweight Structures;Bánlaki, Dömötör, Stipkovits, Devecseri: Noise and vibration measurement of a gearbox 28during the acceptance test in the manufacturer’s workshop