... unbalance condition. This paper describes research on how active control techniques may eliminate this potentially undesirable behavior. A control scheme based on feedback of rotor-stator interaction forces is considered. Model-based conditions for stability of low amplitude whirl, derived using Lyapunov’s...

...Tsuyoshi Inoue; Yukio Ishida; Gao Fei; Hossain Md Zahid In rotating machinery, rubbing occurs between the rotor and the stator, at the seal, between the rotor and the guide and between the rotor and the backup bearing. The backward rub or the partial impact vibration can be avoided by lubricating...

...G. Chen In this paper, a new rotor-ball bearing-stator coupling system dynamics model is established for simulating the practical whole aero-engine vibration. The main characteristics of the new model are as follows: (1) the coupling effect between rotor, ball bearing, and stator is fully...

...Lee Gorny; Gary H. Koopmann Fan noise challenges noise control engineers in developing products ranging in scale from small ventilation systems to large turbomachines. The dominant noise source in many axial fans is the tonal noise due to rotor/stator interactions at the fundamental blade passing...

... whirl to whip and the associated precession frequencies of whirl and whip motion. Predictions from Black’s simple Jeffcott-rotor/point-mass stator are cited. This model is extended here to a multimode rotor and stator model with an arbitrary axial location for rotor-stator rubbing. Predictions obtained...

...Jun Jiang Dry friction backward whirl is a self-excited vibration state in rotor-to-stator contact systems, by which the rotor is in continuous contact with the stator, slipping continuously on the contact surface and whirling backward at a supersynchronous frequency. To correctly cope the response...

... at numerous transducers on the machine. If the machine has B short bearings, then at any one rotor speed, the dimension of the space spanned by all of the complex vectors of synchronous stator response from the trial runs should be (at most) B . In practice, the dimension of that space is very often larger...

... machine consists of three components: a rotating part (rotor), a stationary part (stator or housing), and multiple bearings. The rotor is assumed axisymmetric and spinning at constant speed. Moreover, the rotor and the housing have arbitrary geometry and complexity. The bearings connecting the rotor...

...Jun Jiang; Heinz Ulbrich Dry whip is an instability of rotor-to-stator contact systems and may lead to a catastrophic failure of rotating machinery. The physical reason for the onset of dry whip in rotor/stator systems with imbalance is not yet well understood. This paper explores the development...

...Timo P. Holopainen; Asmo Tenhunen; Erkki Lantto; Antero Arkkio The electromechanical interaction in cage induction motors induces additional forces between the rotor and stator. Recently, a linear parametric model was presented for these forces and the model was validated experimentally...

...Go¨tz von Groll; David J. Ewins There are a variety of abnormal running conditions in rotating machinery that lead to rotor/stator interaction dynamics which, in turn, have a range of effects associated with them. One of these effects is steady vibration response at frequencies which are different...

... OF VIBRATION AND ACOUSTICS . Manuscript received November 1995; Associate Technical Editor: C. Pierre. 01 November 1995 pumps turbulence damping stators rotors elastic deformation seals (stoppers) Annular seals are used in centrifugal pumps to reduce the leakage through rotor...