Reliability Study of the Belt-Type Continuously Variable Transmission System of A Scooter

• Main Authors: Su Yan Huang, 黃蘇煙
• Other Authors: W.F. Wu
• Format: Others
• Language: zh-TW
• Published: 2001
• Online Access: http://ndltd.ncl.edu.tw/handle/34894206627680058964

碩士 === 國立臺灣大學 === 機械工程學研究所 === 89 === The scooter has many advantages such as easy to ride, low cost and can be operated under various traffic conditions. It is always a major product for the motorcycle manufacturers. How to improve the scooter’s quality and performance under the given cost constraint has been a challengeable task for those manufactures. The purpose of the present thesis is to carry out a reliability study of the scooter’s continuously variable transmission (CVT) system that is considered to be one of the key components of the scooter. In the study, many reliability analytical tools such as failure mode effect analysis (FMEA) and fault tree analysis (FTA) are used to identify possible failure modes of the CVT system and its subsystems. Their effects on the CVT system are evaluated as well. Aside from the qualitative evaluation, a quantitative analysis is also performed to appropriately allocate the components’ failure rates while maintaining the required manufacturing cost as well as system reliability. Through the above study, it is found that mechanical wear of the V-belt is the most serious problem that affects the CVT performance. The seal collar is another component that has to be watched carefully. Some design improvements are pointed out at the end of the study accordingly.