Air Hammer Phenomenon in Rotors Supported in Elastically Mounted Gas Bearings

• Autorzy: Czołczyński K. , Kapitaniak T.
• Konferencja: Polish-German Workshop on Dynamical Problems in Mechanical Systems (5 ; 31.08-6.09.1997 ; Zakopane, Poland)
• Języki publikacji: EN

Abstrakty

EN

When during the operation of rotors supported in gas bearings their rotational velocity reaches a sufficiently high value, loss of steady-state stability occurs. This instability is caused by the loss of damping properties of the gas film, which leads to self-excited vibrations. These vibrations are the basic obstacle to a widespread application of a gas bearings. The phenomenon of self-excited vibrations can be avoided by introducting an elastic supporting structure between the bearing bushes and the casing, characterized by properly selected stiffness and damping coefficients. In practice such a structure can have the form of an externally pressurized gas ring. In this paper we demonstrate, on the basis of selected examples, in what ranges of the frequencies of vibrations the "air hammer" phenomenon may cause the instability, and what happens on the stability thresholds - is there a sub- or supe-critical Hopf bifurcation. We also show a design of the ring structure, especially of its feeding system, which ensure the required values of stiffnes and damping coefficients (with regard to the stability). Our investigations have been carried out by means of a numerical simulation method with the use of a mathematical model of the gas bearing, verifield already many times.

• Wydawca: Oficyna Wydawnicza Politechniki Warszawskiej
• Czasopismo: Machine Dynamics Problems
• Rocznik: 1998
• Tom: Vol. 20
• Strony: 101--112
• Opis fizyczny: Bibliogr. 13 poz.

Twórcy

autor

Czołczyński K.

autor

Kapitaniak T.

• Division of Dynamics, Technical University of Łódź, Stefanowskiego 1/15, 90-924 Łódź, Poland