Imported V-belt, also known as V-belt, is a product with the largest output, the most varieties and the most versatile transmission belts. Since the automobile fan belt was first made in the United States in 1917 and popularized for industrial and agricultural machinery in the early 1920s, it has been in prosperity for more than half a century and has developed very rapidly, and has now become the mainstream of transmission belts. In the transmission belts of various countries in the world, from the perspective of the amount of rubber, the triangle belt now accounts for 65%, the toothed belt is 25%, and the flat belt has been reduced to less than 10%. At present, the V-belt has become the main equipment for power transmission and speed change of various mechanical devices in the world. It plays an increasingly important role in today's wide fields of agricultural machinery, machine tools, automobiles, ships, office equipment and so on. According to the cross-sectional size, the imported triangle belt can be divided into seven industrial models of Y, O, A, B, C, D, E for industrial machinery and various fan belts for automobiles and tractors, totaling two categories. Y and O types are the smallest V-shaped belts, which are mainly used for office equipment such as typewriters and book cutters, and household electrical appliances (washing machines, juicers, vacuum cleaners). In general industrial machinery, with the increase of horsepower, V-belts such as A, B, C, D, and E are used in sequence, of which D and E are heavy-duty belts, which are used for large machinery such as ships and electric power. As for fan belts, in addition to cars and tractors, they are also widely used in water pumps and air conditioners. In developed countries, the production ratio of imported triangle belts and fan belts has reached the level of 2: 1-3: 2, and fan belts have shown a clear upward trend.