Differential diagnosis of spall versus cracks in the gear tooth fillet region
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This paper presents a technique to differentially diagnose two localized gear tooth faults: a spall and a crack in the gear tooth fillet region. These faults could have very different prognoses, but existing diagnostic techniques only indicate the presence of local tooth faults without being able to differentiate between a spall and a crack.
The effects of spalls and cracks on the behavior/response of gear assemblies were studied using static and dynamic simulation models. Changes in the kinematics of a pair of meshing gears due to a gear tooth root crack and a tooth flank spall were compared using a static analysis model. The difference in the variation of the transmission error caused by the two faults reveals their characteristics. The effect of a tooth crack depends on the change in stiffness of the tooth, while the effect of a spall is predominantly determined by the geometry of the fault.
The effect of the faults on the gear dynamics was studied by simulating the transmission error in a lumped parameter dynamic model. A technique had previously been proposed to detect spalls, using the cepstrum to detect a negative echo in the signal (from entry into and exit from the spall). In the authors’ simulations, echoes were detected with both types of fault, but their different characteristics should allow differential diagnosis. These concepts are presented prior to experimental validation in hopes that the diagnostic techniques will be useful in the failure analysis community prior to the validation by ongoing experimental testing of the concepts and the evaluation of how metallurgical defects may influence fault development and detection.
Keywordsgear machine diagnosis simulation spall tooth fillet crack
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- 1.W. Wang and A.K. Wong: “Model-Based Gear Diagnostic Techniques,” DSTO, TR-1079, Airframes and Engine Division, Aeronautical and Maritime Research Laboratory, Victoria, Australia, Dec 2000.Google Scholar
- 4.H.J. Decker: “Gear Crack Detection Using Tooth Analysis,” NASA/TM-2002-211491, U.S. Army Research Laboratory, NASA Glen Research Center, Cleveland, OH, April 2002.Google Scholar
- 5.P. Giblin: “An Introduction to Single Flank Testing of Gears, Interpretation of Data and Application to Problem Solving,” The Gleason Works, Rochester, NY.Google Scholar
- 6.J.W. Swanger: “G-Age Single Flank Output Explanation,” The Gleason Works, Rochester, NY.Google Scholar
- 7.Y. Gao and R.B. Randall: “Simulation of Geometric, Static and Dynamic Gear Transmission Errors,” DSTO, CEVA-2000-01, Aeronautical and Maritime Research Laboratory, Victoria, Australia, Jan 2000.Google Scholar
- 8.S. Du: “Dynamic Modelling and Simulation of Gear Transmission Error for Gearbox Vibration Analysis,” Ph.D. Thesis, School of Mechanical and Manufacturing Engineering, University of New South Wales, Sydney, Australia, 1997.Google Scholar
- 9.H. Endo, C. Gosselin, and R.B. Randall: “The Effects of Localized Gear Tooth Damage on the Gear Dynamics—A Comparison of the Effect of a Gear Tooth Root Crack and a Spall on the Gear Transmission Error,” Eighth International Conference on Vibrations in Rotating Machinery, Sept 7–9, 2004 (University of Wales, Swansea, Wales), Institute of Mechanical Engineers.Google Scholar
- 10.T.E. Tallian: Failure Atlas for Hertzian Contact Machine Elements, ASME Press, New York, NY, 1992.Google Scholar
- 11.Y. Ding and N.F. Rieger: Spalling Formation Mechanism for Gears, Elsevier Science B.V., Amsterdam, The Netherlands, Feb 2003; Wear, 2003, 254, pp. 1307–17.Google Scholar
- 14.A.K. Nandi, D. Mampel, and B. Roscher: “Blind Deconvolution of Ultrasonic Signals in Nondestructive Testing Applications,” IEEE Trans. Signal Process., May 1997, 45(5).Google Scholar
- 15.M. Boumahdi and J. Lacoume: Blind Identification Using the Kurtosis: Results of Field Data Processing, IEEE, Piscataway, NJ, 1980.Google Scholar
- 18.R.B. Randall: Frequency Analysis, 3rd ed., Brüel & Kjaer, Naerum, Denmark, 1987.Google Scholar