The development stage of the transmission belt

　　 For more than half a century, the technical development of the world transmission belt has gone through the following stages: First, from the perspective of the materials used for transmission belts, rubber has evolved from natural rubber to synthetic rubber, and further expanded to special synthetic rubber CSM, HNBR: the skeleton material has been expanded from cotton fiber to rayon, polyester, nylon, glass fiber, For details of steel wire and aramid, see Table 2. Goods. In order to improve the durability of the V-belt, since the 1960s, there has been a cutting triangle belt, which has no wrapping on the side, and it has very good bending fatigue resistance. It has replaced most of the wrapping triangle belt. On the other hand, after entering the 1980s, the V-shaped flat belt combined with the V-shaped belt has been rapidly developed. Due to its excellent performance and a sharp increase in output, it has now partially replaced the cutting V-belt. Shortly thereafter, wedge-shaped V-belts appeared in countries such as the United States and Japan. Because the thickness of this belt is thin, the contact area with the pulley is large, and the bending performance is good, it can be used on a small pulley, so it has greatly contributed to the miniaturization and energy saving of the transmission device. In addition, the principle that the back of the transmission belt can also be driven, for example, in car fans, AC motors, power control systems, air conditioners, etc., the so-called serpentine transmission method that uses a single transmission belt to drive once has attracted the attention of all walks of life, and the scope of use has been expanding. . The representative products of this multi-faceted, multi-directional, multi-machine transmission include hexagonal belt and round belt. 　　 The latest product in the transmission belt is toothed belt, also known as timing belt. It integrates the advantages of gears, chains, and belt transmission devices, and has the characteristics of high transmission efficiency, accurate transmission ratio, low noise, energy saving, and convenient maintenance. Although its transmission principle had some patents as early as 1900, it did not begin industrialization until half a century later, and finally became the leading transmission product of precision machinery since the 1980s. In particular, high-precision micro-belts made of saturated nitrile rubber and polyurethane elastomer have entered the high-tech field. The biggest difference between the toothed belt and the traditional transmission belt is: synchronization and mute. Therefore, it is the most respected and environmentally friendly product today. In recent years, after the teeth of the toothed belt have been changed from square teeth to round teeth, the transmission force has been further increased, and the development prospect is extremely broad. 　　Due to the different characteristics of different mechanical requirements and the wide difference in the price of various transmission belts, the transmission belt will develop in the direction of diversification of structure and materials in the future, and its uses and varieties and specifications will also become increasingly diversified. The composition ratio of V-belt, toothed belt and flat belt in the transmission belt will generally change up and down within the range of 6:3:1.