표제지
목차
Nomenclature 12
국문요약 15
제1장 서론 16
1.1. 연구 배경 및 문헌조사 16
1.2. 연구 내용 20
제2장 빔포일을 갖는 가스 포일 저널 베어링 개요 21
2.1. 가스 빔포일 저널 베어링 소개 21
2.2. 가스 빔포일 저널 베어링 모델링 22
제3장 빔포일 가스 저널 베어링 단품 특성 측정 및 비교 27
3.1. 빔포일 가스 저널 베어링 구조 정특성 27
3.2. 가스 빔포일 저널 베어링 구조 동특성 36
3.3. 가스 빔포일 저널 베어링 구동 특성 47
제4장 회전체동역학 특성 측정 및 해석과의 비교 54
4.1. 공기압축기 고속 구동 시험평가 54
4.2. 공기압축기 바닥가진 시험 평가 66
제5장 결론 76
ABSTRACT 80
참고문헌 82
Table 1. Geometry and material properties of GBFJB 25
Table 2. Geometry of beams 26
Table 3. Imbalance mass locations and phase 60
Figure 1. Schematic view of Beam foil gas journal bearing(left) and beam foil(right) 21
Figure 2. Simplified configuration of underspring beam element as a pair of cantilever... 22
Figure 3. schematic view of beam foil(left) and clearance profile(right) 26
Figure 4. Photo of test set up for static load test 27
Figure 5. Schematic view of static load test rig 28
Figure 6. Measured GBFJB static load versus displacement of (a) vertical... 29
Figure 7. Schematic view of foil bearing underspring elements and fixed coordinate... 30
Figure 8. Comparison of measured and predicted displacement versus static load for... 31
Figure 9. Comparison of calculated and predicted displacement versus stiffness... 32
Figure 10. Comparison of calculated and predicted static load versus stiffness... 32
Figure 11. Comparison of measured (a) static load versus foil deflection and... 33
Figure 12. Comparison test results of displacement versus static load for beam foil and... 35
Figure 13. Comparison test results of displacement versus stiffness coefficients for beam... 35
Figure 14. Photo of test set up for dynamic load test 36
Figure 15. FFT results of (a)bearing displacement, (b)dynamic force and (c)bearing... 37
Figure 16. Measured bearing displacement at frequency of 300 Hz and... 38
Figure 17. Measured dynamic force at frequency of 300 Hz and excitation... 39
Figure 18. Measured bearing acceleration at frequency of 300 Hz and... 39
Figure 19. Measured bearing displacement at excitation... 40
Figure 20. Measured bearing displacement at excitation... 41
Figure 21. Estimated dynamic coefficients versus excitation frequency from... 43
Figure 22. Measured impact test results of bearing-dynamic test rig system : (a) magnitude... 44
Figure 23. Comparison estimated dynamic coefficients versus excitation frequency of... 46
Figure 24. (a)Photo of driving test rig and (b)schematic view of bearing... 47
Figure 25. Measured rotor speed and drag torque during lift-off and coast-down test up... 49
Figure 26. Measured impact test results of bearing-driving test rig... 49
Figure 27. Rotor speed versus time measured during rotor... 50
Figure 28. (a)Drag torque versus rotor speed and (b)rotor speed versus... 52
Figure 29. Comparison of beam foil and bump foil bearings : measured (a)drag torque... 53
Figure 30. Schematic view of air compressor supported on gas beam foil journal bearings 54
Figure 31. Waterfall plots of displacements for air compressor rotor with gas beam foil... 55
Figure 32. Measured air compressor rotor speed versus time during coast-down test 56
Figure 33. Measured air compressor rotor vertical vibration motions (a) waterfall... 57
Figure 34. Comparison of measured air compressor rotor speed versus time... 58
Figure 35. Finite element model of rotor bearings system for air compressor 59
Figure 36. Predicted rotor natural frequency versus rotor speed 60
Figure 37. Predicted (a)stiffness and (b)damping coefficients versus rotor... 62
Figure 38. Predicted (a)damped natural frequency and (b)damping ratio for... 64
Figure 39. Comparison of predicted imbalance response and measured synchronous... 65
Figure 40. Schematic view of base excitation test rig 66
Figure 41. Measured rotor's displacement (a)base excitation synchronous... 67
Figure 42. Measured rotor's vertical displacement versus excitation frequency for... 68
Figure 43. Simple model of rotor-bearing system with vertical direction base excitation test 69
Figure 44. Static load versus displacement with removing... 70
Figure 45. Comparison of predicted displacements of liner model and... 72
Figure 46. Comparison of predicted displacements of non-liner model and... 73
Figure 47. Waterfall plots of rotor's displacements for excitation... 74
Figure 48. Waterfall plots of rotor's displacements for excitation force 8G... 75