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A Rotordynamic Analysis of Dry Vacuum Pump Rotor-Bearing System for High-Speed Operation

고속 운전용 건식진공펌프 로터-베어링 시스템의 전체동역학 해석

  • 김병옥 (한국기계연구원 e-엔지니어링연구센터) ;
  • 이안성 (한국기계연구원 e-엔지니어링연구센터) ;
  • 노명근 (㈜엘오티베큠)
  • Published : 2007.06.30

Abstract

A rotordynamic analysis was performed with a dry vacuum pump, which is a major equipment in modem semiconductor and LCD manufacturing processes. The system is composed of screw rotors, lobes picking air, helical gears, driving motor, and support rolling element bearings of rotors and motor. The driving motor-screw rotor system has a rated speed of 6,300rpm, and was modeled utilizing a rotordynamic FE method for analysis, which was verified through the results of its 3-D finite element model. As loadings on the bearings due to the gear action were significant in the system considered, each resultant bearing load was calculated determinately and indeterminately by considering the generalized forces of the gear action as well as the rotor itself. Each resultant bearing loading was used in calculating each stiffness of rolling element bearings. Design goals are to achieve wide separation margins of critical speeds and favorable unbalance responses of the rotor in the operating range. Then, a complex rotordynamic analysis of the system was carried out to evaluate its forward synchronous critical speeds, whirl natural frequencies and mode shapes, and unbalance responses under various unbalance locations. Results show that the entire system is well designed in the operating range. In addition, the procedure of rotordynamic analysis for dry vacuum pump rotor-bearing system was proposed and established.

Keywords

References

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