Investigation of Modal Parameters on Planetary Gearbox using Finite Element Analysis to Minimize Vibration

[Prashant S. Walunj, V. N. Chougule, Anirban C. Mitra] Volume 2: Issue 4, Dec 2015, pp 147-152
Abstract— The advantage of a planetary transmission is determined by load distribution over multiple planet gears. It is thereby possible to transfer high torques utilizing a compact design. The designed transmission system comprising two degrees-of-freedom compound planetary gear train with two conjoined planetary gear trains and four torque-transfer devices. The different combinations of states of various torque-transfer devices yield multiple modes of operation. Planetary gears have problem of vibration. Since a planetary gear has internal and external meshes in several gear pairs, power distribution is unequal in gears, and loads can be concentrated in a specific planet gear. These vibrations are transferred to the gearbox casing through shafts and bearings. As the gearbox is coupled to engine, there are more probabilities of coincidence of natural frequency of engine and gearbox which causes resonance and leads to damage in gearbox. The natural frequencies and mode shapes are important parameter in the design of a structure for dynamic loading conditions. Subsequently, it is necessary to investigate modal parameters of gearbox and study the dynamic characteristics of gearbox. In this work, modal analysis is done using Finite Element Analysis and results shows range of frequencies obtained is suitable for gearbox which can avoid maximum amplitude of vibration and hence resonance. Dynamic analysis in ANSYS is used to solve the vibration problem, by using the modal analysis method of dynamic analysis; natural frequencies and mode shapes of systems are found out. The fundamental frequency obtained by the analysis is 87.015 Hz which is far away from the forcing frequency which is engine frequency in the range of 30-50 Hz and avoids resonance. Results of modal analysis after structural modification are also presented which shows enhancement in rigidity of the gearbox.

Index Terms— Planetary gear transmission system, Modal Analysis, Natural Frequency, Mode shape, Finite Element Analysis

[1] Parag V. Bute , R. J. Patil , Swapnil S. Kulkarni, ― Vibration analysis using finite element methodology to evaluate the response of gear housing of an automotive to the material and its mass properties‖, International Journal of Scientific Research and Management, Vol.1, Issue-9, pp. 289-296.
[2] Nilofar Hajikhan Pathan. V.P. Singh, Swapnil S. Kulkarni, ―Modal Analysis of spur gear to determine the natural frequencies and its effect over the geometry of the gear‖, International Journal of Advanced Engineering Research and Studies Vol.3, Issue-1, pp. 76-78, 2014.
[3] Ashwani Kumar and Pravin P Patil, ―Dynamic Vibration Analysis of Heavy Vehicle Truck Transmission Gearbox Housing Using FEA‖, Journal of Engineering Science and Technology Review Vol.7, Issue 4, pp. 66-72, 2014.
[4] R.V. Nigade, T.A. Jadhav, A.M. Bhide, ―Vibration Analysis of Gearbox Top Cover‖, International Journal of Innovations in Engineering and Technology, Vol.1, Issue-4, pp. 26-33, 2012.
[5] Mr. Vijaykumar, Mr. Shivaraju, Mr. Srikanth, ―Vibration Analysis for Gearbox Casing using Finite Element Analysis‖, The International Journal Of Engineering And Science, Vol.3, Issue-2, pp.18-36, 2014.
[6] Shrenik M. Patil, S. M. Pise, ―Modal and Stress Analysis of Differential Gearbox Casing with Optimization‖, International Journal of Engineering Research and Applications, Vol.3, Issue-6, pp.188-193, 2013.
[7] Shuting Li, ―Experimental investigation and FEM analysis of resonance frequency behavior of three-dimensional, thin-walled spur gears with a power-circulating test rig‖, Mechanism and Machine Theory, Vol.43, pp.934–963, 2008.
[8] D.S. Chavan, A.K. Mahale, A.G. Thakur, ―Modal Analysis of Power Take Off Gearbox‖, International Journal of Emerging Technology and Advanced Engineering, Vol.3, Issue-1, pp.70-76, 2013.
[9] Tianmu ZHANG, Dongyan SHI, Zhong ZHUANG, ―Research on vibration and acoustic radiation of planetary gearbox housing‖, Proceedings of Inter-Noise 2014 Conference, Melbourne, Australia, 16-19 Nov.2014, pp. 1-10.
[10] Bagul A. D,Barijibhe R. B. and Patil A. V, ―Vibrational Analysis of Gearbox Casing Component using FEA Tool ANSYS and FFT Analyser‖, International Journal of Engineering Research & Technology, Vol.3, Issue-2, pp. 938-942, 2014.
[11] Abhinav Saxena, Biqing Wu, George Vachtsevanos, ―A Methodology for Analyzing Vibration Data from Planetary Gear Systems using Complex Morlet Wavelets‖, Proceedings of American Control Conference, Portland, OR, USA, June 8-10, 2005. pp. 4730-4735.
[12] Jimin He and Zhi-Fang Fu, Modal analysis, Butterworth-Heinemann-Reed Educational and Professional Publishing Ltd, First Edition 2001.
[13] D.J. Ewins, Modal Testing: Theory, Practice and Applications, Research Studies Press, Second Edition, 2009, Beldock, Hetforshire, England.
[14] Nitin S. Gokhale, Sanjay S. Deshpande, Sanjeev V. Bedekar, Anand N Thite, ―Practical Finite Element Analysis‖, Finite To Infinite, Pune, First Edition, 2008.

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