Characteristics of dry friction backward whirl—A self-excited oscillation in rotor-to-stator contact systems

Abstract

In this paper, the response characteristics of dry friction backward whirl of a general rotor/stator model, which accounts for both the dynamics of the rotor and the stator as well as the friction and the deformation at the contact surfaces, are investigated. The existence boundaries and the whirl frequencies of the dry friction backward whirl are determined analytically. It is found that there are two or three existence boundaries of the dry friction backward whirl that usually form two existence regions, either standing completely separately, or overlapping each other partly, or one containing the other completely, depending upon the system parameters. The whirl frequencies in the two existence regions are quite different and may jump between the lower and the higher values with the variation of the rotating speed. The results have been found to have good correspondence in the related rotor/stator rubbing experiments. a general rotor/stator model, dry friction backward whirl, existence boundaries, backward whirl frequencies Citation: Jiang J, Shang Z Y, Hong L. Characteristics of dry friction backward whirl-A self-excited oscillation in rotor-to-stator contact systems. Sci China Tech Sci, 2010, 53: 674683,

The forward and the backward full annular rubbing dynamics of a coupled rotor-casing/foundation system

“…In fact, there is a second existence region of the dry friction backward whirl for the rotor/stator systems as indicated recently in [26] through numerical simulation. It can thus conclude from the above discussion that there should be two separate existence regions of the dry friction backward whirl for a rotor-to-stator contact system with large contact stiffness as also shown in [23,24].…”

“…The third rotor/stator model takes the stator as an elastically supported rigid ring with mass, and is also widely used in modeling the retainer bearings [16][17][18][19][20]. Most recently, an extension of the simple rotor/stator model by taking the stator to be an elastically supported elastic ring with mass was investigated numerically in [21] and analytically in [22][23][24]. It was shown that the general model can be reduced to all of the simpler rotor/stator models mentioned above by assigning the corresponding parameters to some specific values.…”

The global responses characteristics of a rotor/stator rubbing system with dry friction effects

“…With some manipulation as done in [22], a complex equation of a and o b as function of system parameters is obtained, which yields two real polynomial equations about the two unknown variables a and o b after separating the real and the imaginary parts: As pointed out in [22], there are two existence regions of the dry friction backward whirl with different backward whirl frequencies. Fig.…”

Bifurcation on synchronous full annular rub of rigid-rotor elastic-support system

“…Analytical, numerical methods, and experiments are employed to investigate the possible contact responses including periodic motions [3][4][5] , quasi-periodic partial rubs [6][7] , chaotic responses [8][9][10][11] , dry friction backward whirl [12][13][14] , and rubs coupled with other faults [15][16] .…”