공기 스테이지의 형상 오차가 운동정밀도에 미치는 영향

• Published in: Tribology and Lubricants Vol. 36; no. 2; pp. 68 - 74
• Main Authors: 류대원(Daewon Ryu), 이재혁(Jae Hyeok Lee), 박상신(Sang-Shin Park), 김규하(Gyu Ha Kim)
• Format: Journal Article
• Language: Korean
• Published: 한국트라이볼로지학회 2020
• Subjects: 기계공학; air-bearing stage(공기베어링 스테이지); shape error(형상 오차); averaging effect(평균화 효과)
• ISSN: 2713-8011; 2713-802X
• DOI: 10.9725/kts.2020.36.2.68

In this study, the effect of the shape error of a guideway on the movement of a stage that uses an air bearing is analyzed. The shape error of moving parts supported by the air bearing is known not to affect the vibrations of moving parts as much as the magnitude of the shape error. This is called the "averaging effect." In this study, the effect of shape error on a guideway, as well as the averaging effect of an air-bearing system, is analyzed theoretically using a dynamic-analysis program. The dynamic-analysis program applies a commercially available code in COMSOL and solves the Reynolds equation between the stage and the guideway, along with the equation of motion of the stage. The stage is modeled as a two-degree-of-freedom system. The shape error is applied to the film thickness function in the form of a sine wave. The stage movement is analyzed using the fast Fourier transform process. The eccentricity and tilting are found to be proportional to the amplitude of the shape error of the guideway. Stage vibrations are less than 10% of the amplitude of the shape error on the guideway. This means that the averaging effect of the air bearing is verified quantitatively. Moreover, if the air supply position matches the shape error in the guideway, there is a notable change in eccentricity and tilting.