기어의 구조 안정성 및 치물림 성능을 분석하기 위하여 유한요소해석이 널리 사용된다. 본 연구에서는 스퍼 기어의 유한요소 모델 링 조건이 해석 결과 및 간소화 효과에 미치는 영향을 분석하였다. 기어 구조 해석의 간소화 방법으로 기어 몸체 및 잇수 간소화, 요소 망 생성 방식, 접촉 및 마찰 조건, 해석 조건 등을 선정하였다. 기어의 성능해석 지표로써 1주기의 기어 치물림 사이클 동안의 정전달 오차를 계산하였고, 간소화 지표로써 해석 소요 시간을 측정하였다. 유한요소해석을 통해 치물림 주기에 따른 접촉 응력 분포 및 변화 양상을 확인하였다. 모델링 조건에 따라 최대 전달 오차와 해석 소요 시간에 차이를 확인하고 원인을 분석하였다.

This study has been performed to investigate on the spur gear with the spline key of heat treatment process analysis. The heat treatment process for gear has been widely used at the production of moving parts in order to improve its manufacture productivity. A driving spur gear is modeled with three dimensions for the heat treatment process. The variable conditions for the heat treatment analysis are the shape of gear tooth, the environmental heating temperature, heating time, cooling temperature and cooling. The analytical results of mechanical properties as micro structure and hardness are analyzed using the software. As the analysis result, the hardness value(HRC) becomes 20.2 of the inner part at gear body and of the surface part of gear tooth has shown the max. valve of HRC 47.5. The beinite structure forms up to 70%. This is because the cooling becomes slow at the center part than the end part. Therefore, it is estimated that the gear tooth have the high anti-wear property and the inner center part maintains the sufficient stiffness. These results can be utilized for the production of the driving gear by the heat treatment process as the fundamental information

Manufacturing technologies of micro parts were studied in nano grained Al-1.5mass%Mg alloy. During compressive test at 300 , the Al alloy showed stain softening ℃ phenomenon by grain boundary sliding regardless of strain rate. Micro spur gear with ten teeth (height of 200 μm and pitch of 250 μm) was fabricated with sound shape by micro forging. During micro forging, increase of applied stress induced by friction between material and die surface was effectively compensated by decrease of stress by strain softening behavior and as a result, flow stress increased only about 50 MPa more than that in compressive test.