摘要：随着国民经济的持续发展，机车工业也在不断地发展着，自行车无极变速器也在不断地发展，创新着，在一些特定的工作场合，变速器体积小，变速灵活，价格成本低廉很受欢迎，根据市场调查发现，变速器必须满足当今人们对自行车速度调节方面的灵活性操控等需求，能够在不改变输出扭矩和转速的情况下，改变自行车的驱动力和行驶速度。
    目前市面上的自行车无极变速器大多都是采用传统的变速结构，在某些特定的区域，这种结构形式的变速器非常不受欢迎。由于以往的变速器采用传统的结构形式，这样就造成传动精度不好控制，保养维护费用较高;同时存在一定的安全隐患。因此，对整车的安全性要求较高，操作时也会给驾驶人员带来强烈的震动,使得操作很不舒服。虽然传统的变速器传动效率较高，变速效果较好，但是价格也较昂贵，对于一般的用户难以接受，所以研究一种新式的自行车无极变速器势在必行！
    本文介绍了自行车无极变速器的结构组成、工作原理以及主要零部件的设计中所必须的理论计算和相关强度校验，以及对其结构进行创新设计，该变速器的优点是传动链短、效率高、易加工、使用和维护都很方便，较适合在恶劣的环境下工作，最主要的是其传动效率很高。
 
关键词：自行车无极变速器；扭矩；结构；校验
Abstract：With the sustainable development of national economy and industrial locomotive also in constant development, bicycle without transmission and also in the continuous development and innovation, in some specific workplace, transmission has the advantages of small volume, flexible speed, low cost price is very popular, according to market research, the transmission must meet today's people of bicycle speed adjusting flexibility control needs to does not change in the output torque and speed, changing the bicycle driving force and speed.

Currently on the market most of the bicycle transmission is the use of the traditional transmission structure, in some particular areas, this kind of structural form of transmission is not very popular. As the previous transmission using the traditional structural form, so that the transmission accuracy is not good control, maintenance costs are high; at the same time there is a certain security risk. Therefore, the safety requirements of the vehicle is higher, the operation will give the driver a strong vibration, making the operation is very uncomfortable. Although the traditional transmission efficiency is higher, the transmission effect is better, but the price is also more expensive, it is difficult for the average user to accept, so it is imperative to study a new type of bicycle!In this paper, based on the analysis of all kinds of continuously variable transmission and continuously variable speed bicycle, the outer cone type stepless speed changer of the steel ball is modified to form the stepless speed change device of bicycle. The device can be used for inputting and outputting power by eight steel balls, and a pair of helical gears are used for indexing and regulating speed, so that the bicycle can be stepless speed regulation between 1.22 and 0.75. Research shows that: continuously variable transmission can be used in the bicycle can greatly improve the performance of the use of bicycles, to facilitate the use of the vast number of consumers.
This paper introduces the bicycle without transmission structure composition, working principle and main parts design must have the theoretic calculation and strength check, and to carry out innovative design of the structure, the advantages of the transmission is the transmission chain is short, high efficiency, easy processing, so that is convenient in use and maintenance, and is suitable for work in the harsh environment. The main is the transmission efficiency is high.
Key words：planetary gear type power shift gear box;Crankshaft;Processing craft;Fixture
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