터보차저 공급 오일 압력과 온도가 풀-플로팅 베어링의 동적 거동에 미치는 영향

다국어 초록 (Multilingual Abstract)

In this paper, the effect of oil conditions in rotor dynamic behaviors of a FFRB (Fully-Floating Ring Bearing) is investigated. Through the characteristic of a FFRB has two films, it has several advantages such as less friction loss and better stability over a wide speed range. However, it is difficult to supply a oil to the inner film. Thus, turbocharger makers have been paid significant attention to the lubrication of a FFRB because of its importance. This work focuses on the influence of oil inlet pressure and temperature. The methodologies of computational simulation and experimental test were used to estimate the rotor dynamic behaviors. In experimental test, the single-scroll turbocharger for the 1.4L diesel engine was used. The results show that the oil inlet pressure and temperature will place considerable influence on the rotor response. Oil conditions affect RSR (Ring Speed Ratio) which is cause of sub-synchronous vibrations, which also cause of oil whirling and whip even a critical speed. At higher speed range, the phenomenon of self-excited vibrations which is cause of instability of fluid whirl is investigated through the orbit shapes that consist of small orbit and large amplitude orbit. It is shown that some performance of a FFRB can be controlled by the conditions of oil supply. Finally, it was revealed that the oil induced operating conditions will strongly affect the turbocharger rotor dynamics behaviors.

참고문헌 (Reference)

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