Study of impact factor on dynamics parameters of the floating ring bearing for micro gas turbogenerator

Floating ring bearings (FRBs) are widely used in high speed rotating machines. In this paper, the carrying capacity of outer oil film, which can represent the total capacity of FRBs, in floating-ring bearing was analyzed only because the bearing capacity of inner oil film is larger than that of the outer one. Based on the rotordynamic DyRoBes software and finite difference method, the pressure of outer oil film in relatively heavy load micro gas turbogenerator was computed and the results were analysed and compared. Because of the structural characteristics of FRBs , the relationship of stiffness and damping of inner and outer films is equivalent to the series of spring and damper, thus the total stiffness and damping of FRB could be calculated under different rotation speeds. The important parameters, such as eccentricity ratio, static balance position, which give the influences on the oil film characteristics and rotordynamic behavior were also studied. At last, the stability of oil film was determined using Routh-Hurwitz criterion.