Abstract
The paper presents a simplified multibody model of a soft mounted electrical machine for theoretical vibration analysis, considering different kinds of rotor eccentricity. The most important dynamic eccentricities in electrical machines—eccentricity of rotor mass, magnetic eccentricity, and bent rotor deflection—are analyzed. The aim of the paper is not to replace a detailed three-dimensional finite-element calculation by a simplified plane multibody model, but to show the mathematical correlation between rotor dynamics, electromagnetic influence, oil film characteristics of the sleeve bearings, the influence of a soft foundation, and excitations by different kinds of rotor eccentricity, based on a simplified analytical model. Beside the absolute orbits of the rotor, stator, shaft journals, and bearing housings, also the relative orbits between rotor and stator and between shaft journals and bearing housings are mathematically described. In addition to these theoretical considerations, a numerical example for a soft mounted 2-pole induction motor is also shown. Finally, the paper shows the possibility of optimizing the system—electrical machine and foundation—regarding vibrations, caused by rotor eccentricities.
Similar content being viewed by others
References
Gasch, R., Nordmann, R., Pfützner, H.: Rotordynamik. Springer, Berlin (2002)
Gasch, R., Maurer, J., Sarfeld, W.: The influence of the elastic half space on stability and unbalance of a simple rotor-bearing foundation system. In: Proc. Conference Vibration in Rotating Machinery, C300/84, IMechE, Edinburgh (1984)
Seinsch, H.-O.: Oberfelderscheinungen in Drehfeldmaschinen. Teubner, Leipzig (1992)
Holopainen, T.P.: Electromechanical interaction in rotor dynamics of cage induction motors. Ph.D. Thesis, VTT Technical Research Centre of Finland, Helsinki University of Technology, Finland (2004)
Schuisky, W.: Magnetic pull in electrical machines due to the eccentricity of the rotor. Electr. Res. Assoc. Trans. 295, 391–399 (1972)
Belmans, R., Vandenput, A., Geysen, W.: Calculation of the flux density and the unbalanced magnetic pull in two pole induction machines. Arch. Elektrotech. 70, 151–161 (1987)
Werner, U.: Rotordynamische Analyse von Asynchronmaschinen mit magnetischen Unsymmetrien. Dissertation, Technical University of Darmstadt. Shaker, Aachen (2006)
Früchtenicht, J., Schroeder, R.-D., Seinsch, H.O.: Physikalische Ursache und praktische Bedeutung von Gehäuseschwingungen doppelter Netzfrequenz bei zweipoligen Asynchronmaschinen. ETZ Arch. 3(11), 389–396 (1981)
Werner, U.: A mathematical model for lateral rotor dynamic analysis of soft mounted asynchronous machines. Z. Angew. Math. Mech. 88(11), 910–924 (2008)
Glienicke, J.: Feder- und Dämpfungskonstanten von Gleitlagern für Turbomaschinen und deren Einfluss auf das Schwingungsverhalten eines einfachen Rotors. Dissertation, Technische Hochschule Karlsruhe (1966)
Lund J, Thomsen K.: A calculation method and data for the dynamics of oil lubricated journal bearings in fluid film bearings and rotor bearings system design and optimization. In: ASME, New York, pp. 1–28 (1978)
Tondl, A.: Some Problems of Rotor Dynamics. Chapman & Hall, London (1965)
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Werner, U. Theoretical vibration analysis of soft mounted electrical machines regarding rotor eccentricity based on a multibody model. Multibody Syst Dyn 24, 43–66 (2010). https://doi.org/10.1007/s11044-010-9190-2
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11044-010-9190-2