In this study, analyzed the cause of failure of the cardan shaft for water propulsion of an armored wheeled vehicle. During the development test(DT), the vehicle was deflected to the left on the water. As a result of the confirmation, increasing angular displacement and abrasion of SPIDER(Universal joint) occurred. As a result of a structure analysis and torsion fracture test, cause of failure is not insufficient design and strength deficit of each parts. and as a result of a simulation review of the assembly layout of each part, it was confirmed that excessive rotational vibration occurred. In order to solve this problem, improved the assembly layout of the water propulsion system and the worn SPIDER lubrication. Since there has been no occurrence of the same case between military operations so far, it has been confirmed that the improvement plan is appropriate.

ABSTRACT
1. 서 론
2. 추진축 파손 원인분석
    2.1 카르단샤프트 파손부위 점검
    2.2 해석을 통한 설계안정성 검토
    2.3 카르단샤프트 비틀림 파단시험
    2.4 수상추진구동계의 레이아웃 특성 검토
3. 품질개선 방안
    3.1 십자축 윤활 개선
    3.2 조립레이아웃 개선
4. 결 론
References

• 성수민(국방기술품질원) | S. M. Seong 교신
• 김선도(현대로템) | S. D. Kim