An Analysis of the Influence of Friction Forces on Dynamic Loads in Gears

The influence of dry and viscous friction forces in the meshing of teeth on dynamic loads in gears is studied using a model developed by the authors. Frictional forces in the model are presented as an external vibration source that varies in accordance with a polyharmonic function, that takes into account the equivalent coefficient of friction, the number of meshing pairs, the change of direction of the frictional force during the meshing period, the arm of friction force and other factors. It is shown that viscous damping in the elastic-hydrodynamic layer of lubricant in gearing does not have a significant effect on dynamic loads and torsional vibrations, including those in the resonance region. Based on the study of frictional forces in meshing, it is concluded that when gears are diagnosed using vibration analysis, it is effective to measure vibration signals separately, along and normal to the line of meshing. This makes it possible to independently evaluate the influence of various sources of vibration excitation on vibration signals and use them when developing diagnostic indicators of the condition of gears.

References

[1] Tamminana V.K., Kahraman A., Vijayakar S. A study of the relationship between the dynamic factor and the dynamic transmission error of spur gear pairs. Proceedings of the ASME International Design Engineering Technical Conferences and Computers and Information in Engineering Conference – DETC2005, 24–28 September 2005, vol. 5, pp. 917–927.

[2] Li S., Kahraman A. A spur gear mesh interface damping model based on elastohydrodynamic contact behavior. International Journal of Powertrains, 2011, vol. 1, no. 1, pp. 4–21.

[3] Kahraman A., Lim J., Ding H. A Dynamic model of a spur gear pair with Friction. Materials of 12th IFToMM World Congress, Besançon, France, June18–21, 2007.

[4] Parker R.G., Vijayakar S.M., Imajo T. Non-linear dynamic response of a spur gear pair: modelling and experimental comparisons. Journal of Sound and Vibration, 2000, vol. 237(3), pp. 435–455.

[5] Kragel’skii I.V. Trenie i iznos [Friction and wear]. Moscow, Mashinostroenie publ., 1968. 475 p.

[6] Chichinadze A.V. Osnovy tribologii (trenie, iznos, smazka) [Fundamentals of tribology (friction, wear, lubrication)]. Moscow, Mashinostroenie publ., 2001. 664 p.

[7] Rebbechi B., Oswald F.B., Townsend D.P. Measurement of gear tooth dynamic friction. NASA, Technical report ARL-TR-1165, 1996.

[8] Drozdov Iu.N., Smirnov V.I. Issledovanie koeffitsienta treniia skol’zheniia pri vysokikh parametrov kontakta [Investigation of the sliding friction coefficient at high contact parameters]. Vestnik mashinostroeniia [Russian Engineering Research]. 1977, no. 6, pp. 19–23.

[9] Aviatsionnye zubchatye peredachi i reduktory. Spravochnik [Aviation gears and reducers. Directory]. Ed. Vulgakova E.B. Moscow, Mashinostroenie publ., 1981. 374 p.

[10] Kalinin D.V., Temis Iu.M. Modelirovanie nelineinykh kolebanii tsilindricheskikh zubchatykh peredach aviatsionnykh privodov [Dynamic modelling of non-linear vibrations in cylindrical tooth gearing of aircraft drive systems]. Vestnik SGAU [Vestnik of Samara University. Aerospace and Mechanical Engineering]. 2015, vol. 14, no. 3, pt. 1, pp. 193–202.

[11] Airapetov E.L., Genkin M.D. Dinamika planetarnykh mekhanizmov [Dynamics of planetary mechanisms]. Moscow, Nauka publ., 1980. 256 p.