표제지

목차

Ⅰ. 서론 9

1.1. 연구 배경 9

1.2. 연구 목적 11

1.3. 이론적 배경 12

1.3.1. 트랙터 변속기 12

1.3.2. 기어 강도 설계 13

1.3.3. 기어 손상 유형 16

1.3.4. 기어 강도 해석 19

Ⅱ. 재료 및 방법 26

2.1. 공시 트랙터 26

2.2. 포장시험 29

2.3. 기어 손상 분석 31

2.3.1. 부변속 A단 31

2.3.2. 부변속 B단 32

2.4. 기어 재질 변경 34

2.5. 시뮬레이션 해석 34

2.5.1. 시뮬레이션 모델링 34

2.5.2. 시뮬레이션 해석 조건 37

2.6. 차축 부하 다이나모 시험 38

2.6.1. 가속 수명 시험 38

2.6.2. 차축 다이나모 시험 장치 구성 40

2.6.3. 차축 다이나모 시험 조건 42

Ⅲ. 결과 및 고찰 45

3.1. 시뮬레이션 모델 개발 및 검증 45

3.2. 재질 변경에 따른 시뮬레이션 해석 결과 48

3.2.1. 부변속 A단 48

3.2.2. 부변속 B단 51

3.3. 차축 다이나모 시험 결과 55

3.3.1. 부변속 A단 55

3.3.2. 부변속 B단 56

3.4. 기어 수명 해석 결과 비교 57

Ⅳ. 결론 및 요약 59

LIST OF REFERENCES 61

ABSTRACT 66

Table 1. Specification of 86 kW agricultural tractor used in this study 27

Table 2. Specification of implements used in this study 29

Table 3. Chemical composition of alloy steel for machine structure use according to gear materials 34

Table 4. Specification of main shift gears for 86 kW class agricultural tractor used in this study 36

Table 5. Specification of range shift gears for 86 kW class agricultural tractor used in this study 37

Table 6. Fatigue damage exponent by heat treatment 40

Table 7. Conditions of axle dynamometer test used in this study 44

Table 8. Results of service life for range shift A driving gear of 86 kW class agricultural tractor transmission 49

Table 9. Results of service life for range shift A driven gear of 86 kW class agricultural tractor transmission 51

Table 10. Results of service life for range shift B driving gear of 86 kW class agricultural tractor transmission 53

Table 11. Results of service life for range shift B driven gear of 86 kW class agricultural tractor transmission 55

Table 12. Comparison of life for range shift gears between simulation analysis and axle dynamo test 58

Figure 1. Power flow of tractor for agricultural transmission 12

Figure 2. Gear wear 16

Figure 3. Gear plastic flow 17

Figure 4. Gear pitting 18

Figure 5. Gear breakage 19

Figure 6. A photo of 86 kW class agricultural tractor for field test used in this study 26

Figure 7. 3D model of agricultural tractor transmission used in this study 28

Figure 8. Power flow of agricultural tractor transmission used in this study 28

Figure 9. C type method for agricultural field operation used in this study 30

Figure 10. Results of field test for range shift A gear of 86 kW class agricultural tractor 31

Figure 11. View of gear plastic flow by stages 32

Figure 12. Results of field test for range shift B gear of 86 kW class agricultural tractor 33

Figure 13. Determination of normal chordal dimensions of tooth root critical section for ISO 6336 : Method B (external gears) 33

Figure 14. KISSsoft interface used in this study 35

Figure 15. Inverse power model 39

Figure 16. Configuration of the axle dynamometer system used in this study 41

Figure 17. A photo of the axle dynamometer test of 86 kW class agricultural tractor used in this study 42

Figure 18. Engine performance diagram of 86 kW class agricultural tractor 43

Figure 19. Simulation model of transmission for 86 kW class agricultural tractor transmission used in this study 45

Figure 20. Results of bending safety factor for transmission of 86 kW class agricultural tractor transmission 46

Figure 21. Results of contact safety factor for transmission of 86 kW class agricultural tractor transmission 47

Figure 22. Results of safety factor for range shift A driving gear of 86 kW class agricultural tractor transmission 48

Figure 23. Results of safety factor for range shift A driven gear of 86 kW class agricultural tractor transmission 50

Figure 24. Results of safety factor for range shift B driving gear of 86 kW class agricultural tractor transmission 52

Figure 25. Results of safety factor for range shift B driven gear of 86 kW class agricultural tractor transmission 54

Figure 26. Results of dynamometer test for range shift A gear of 86 kW class agricultural tractor transmission 56

Figure 27. Results of dynamometer test for range shift B gear of 86 kW class agricultural tractor transmission 57