摘要:隨著經濟的極速發展及社會的快速進步，人類所生活的環境越來越惡劣，特別是 汽車尾氣承擔了非常重要的一部分，電動自行車在這樣的社會大背景下應運而生，特 別在中國的農村和鄉鎮，它不僅可以改善人們的生活，也給節能減排帶來福音，但是， 目前的電動自行車存在爬坡能力不強，不夠力的現狀，針對這一現狀，本文設計了一 套能在電機額定功率一定的情況下提升電動自行車的爬坡能力的行星齒輪傳動機構。

　　　首先，論文論述了目前電動自行車傳統的傳動系統的基本結構和工作原理，分析 了它們的優缺點，針對目前的傳動系統不能有效克服爬升坡度小的問題，提出了一套 行星齒輪減速傳動系統，對其結構和工作原理進行了說明。

　　　其次，根據國家相關規定對電動自行車的技術要求，在分析電動自行車行駛過程 中驅動力和行駛阻力平衡的基礎上，對電機和減速機構的參數進行了計算和選擇，并 且對其是否滿足要求進行了校核和驗證，然后根據所選定的參數確定了齒輪傳動機構 的具體結構尺寸。

最后，對全文工作進行了總結和展望。

關鍵詞：電動自行車，傳動系統，20Km/小時，齒輪減速機構

Abstract:With the rapidly development of the world economy and the society, the environment of the human beings live in is becoming more and more terrible, especially the emission of the vehicles, so ,the electrical bicycle (EB) is the trend. In the countryside of china, it’s common, not only it can improve the life level of people, but also applying for the policy of Nation. But now, the bicycle in the market have a problem that it difficulty climb，in response to this situation, the paper design a kind of planetary gear transmission, it can meet the using requirements.

　　　First , the paper discussed the basic structure and principle of the current EB’s transmission system, and analysis their advantages and disadvantages, then proposed the kind of planetary gear transmission and introduce it’s structure and principle.

　　　Then, according the Nation’s rule about the technology demand of EB, the paper calculated  and  chosen  the  motor’s  and  gears’ corresponding  parameters  based  on  the analysis of the balance equation about EB, and then checked it that if it can satisfy the driving demands, finally , make sure the gears’ exactly structure parameters .

　　　Finally, the dissertation is summarized and some precious proposal is put forward to the next research.

Key words: electrical bicycle, transmission system, 20km/h, gear system