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Thrust Bearing Design for High-Speed Composite Air Spindles

고속 복합재료 공기 주축부를 위한 추력베어링 설계

  • 방경근 (한국과학기술원 기계공학과) ;
  • 이대길 (한국과학기술원 기계공학과)
  • Published : 2002.10.01

Abstract

Composite air spindles are appropriate for the high-speed and the high-precision machining as small hole drilling of printed circuit board (PCB) or wafer cutting for manufacturing semiconductors because of the low rotational inertia, the high damping ratio and the high fundamental natural frequency of composite shaft. The axial load and stiffness of composite air spindles fur drilling operation are determined by the thrust ben ring composed of the air supply part mounted on the housing and the rotating part mounted on the rotating shaft. At high-speed rotation, the rotating part of the thrust bearing should be designed considering the stresses induced by centrifugal force as well as the axial stiffness and the natural frequency of the rotating shaft to void the shaft from failure due to the centrifugal force and resonant vibration. In this work, the air supply part of the thrust bearing was designed considering the bending stiffness of the bearing and the applied load. The rotating part of the thrust bearing was designed through finite element analysis considering the cutting forces during manufacturing as well as the static and dynamic characteristics under both the axial and con trifugal forces during high-speed rotation.

Keywords

Air Spindle;Carbon Composite Shaft;Thrust Bearing;Centrifugal force;Axial Stiffness;Machining Deformation

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