Gear transmission is a main form of transmission of machine power and motion. Gear industry is the most technology - intensive and capital - intensive industry in machinery industry. China's gear industry mainly includes three parts: vehicle gear transmission manufacturing, industrial gear transmission manufacturing and gear equipment manufacturing.

In 2009, China's gear, transmission and drive components manufacturing withstood the negative impact of the international financial crisis, the industry continued to maintain steady growth, although the growth rate compared with last year fell sharply, but in the United States, Japan and other developed countries affected by the financial crisis causes a decline in the industry sales environment, China's gear, transmission and drive components manufacturing steady growth is still the world attention, China has become a global production gear transmission equipment such as power.

Gear, transmission and drive parts are one of the most basic parts in mechanical equipment, and there are a large number of enterprises in various countries to produce gear parts. In foreign countries, the production of transmission drive parts are mainly specialized, the general enterprise scale for medium, small, personnel in dozens to hundreds of people; There are also many companies that are global, with production, sales and service outlets in countries around the world; Other driveline parts companies are part of a larger conglomerate. China has now become one of the world's leading producers of drivetrain components, but mainly low-end products. At present, several countries or regions with the largest global market share of transmission drive components are Germany, North America, Japan, South Korea, And some European countries such as Italy and France, as well as China.

The rapid development of China's national economy and the adjustment of industrial structure in foreign developed countries have brought development opportunities to the industry of gear, transmission and driving parts in China. The increasing domestic and foreign market demand has driven the rapid development of the whole industry, resulting in the rapid increase of industrial capacity and a substantial increase in the total production.

The application of gear die can be divided into three parts: plastic gear die, powder metallurgy gear die and precision forging bevel gear die. Among them, plastic gear mold demand is relatively large. The gear has two main USES, one is to transmit motion, the other is to transmit power. At present, domestic plastic gear is mainly used to transmit motion, and the United States is now in the transmission of power choice, more and more plastic gear. This is because plastic gear has many advantages, such as low transmission noise, vibration absorption, self-lubrication and so on, and plastic gear can open mold processing, high production efficiency. It should be said that plastic gear in the gear industry will be more and more applications, this is a worldwide trend.

At present, the low-end gear molds can be produced in China, while the high-end gear molds are mostly imported. There are not many factories in China that specialize in making gear molds, most of which are made by the gear factory themselves. The gear factory often sets up a section or a workshop to undertake this work. In terms of precision forging bevel gears, the bevel gear molds made by Zhuoge, Jiangsu Spacecraft, Pacific Precision forging and other enterprises are relatively good in the gear die industry, and the quality of precision forging bevel gears is also relatively high. In terms of plastic gears, generally speaking, plastic gears and their molds are mainly distributed in two regions. One is Ningbo, Zhejiang, where there are more than 340 plastic gear factories, which is also the largest plastic gear mold production base in China. The other is Shenzhen Baoan, mainly hong Kong-invested enterprises, high precision products, mainly used for export.

Throughout China's gear mold status, it can be said that mixed. The good news is that the gear mold production has a certain foundation, and the general trend of the development of plastic gear will bring more market space to the gear mold; Worry is that the level of domestic production of gear mold and the world's advanced level is still a long way off, and in the gear industry, especially in the plastic gear industry under the trend of development, the domestic response to market changes is not sensitive enough, supporting research is difficult to keep up with the market demand.

In the world, gear device is developing along miniaturization, high speed and standardization. The application of special gear, the development of planetary gear device, the development of low vibration and low noise gear device are some characteristics of gear design. In order to achieve the purpose of miniaturization of gear device, the bearing thrust of existing involute gear can be increased. Hard tooth surface technology is widely used in many countries to improve the hardness and reduce the size of the device. Special tooth shapes represented by circular gear may also be used. The main transmission system of the ship-borne helicopter developed by Britain and France adopts circular gear, which greatly reduces the height of the gear reducer. With the trend that ship power is replaced by medium speed diesel engine, it is effective to adopt high power planetary gear in large ships. Now metallurgy, mining, cement rolling mill and other large transmission assembly

The planetary gear has been applied more and more because of its small size, good coaxiality and high efficiency.

Gear manufacturing process:

The development of gear manufacturing technology largely reflects the improvement of accuracy levels and production efficiency. Since the 1970s, the manufacturing accuracy of all kinds of gears has been generally improved by about one level, some even by 2 ~ 3 levels. General low speed gear accuracy from the past 8 ~ 9 to 7 ~ 8. The gear of machine tool is improved from 6 ~ 8 to 4 ~ 6. Mill gear from 7 ~ 8 to 5 ~ 6. For small and medium sized gears with small modulus, the gear hobbing efficiency has been significantly improved due to the development of high-performance gear hobbing machine and the improvement of tool material. Multi-head hob is used to achieve a cutting speed of 90m/s. If super hard hob processing module 3 or so tempered steel gear, cutting can be up to 200m/s, improve the efficiency of gear shaping, gear shaping machine tool reciprocating movement of the restrictions. Recently, after the development of new structures such as tool unloading, the use of static bearing, and the enhancement of rigidity of tool holder and column, the efficiency has been improved significantly. The number of strokes of the new gear shaper can reach 2000 times per minute. Development trend of gear steel; One is low alloy steel containing Cr, Ni and Mo. Second, boron steel; The third is carbonitriding steel; The fourth is free cutting steel. Due to the lack of Ni and Cr in China, 20CrMnTi carburized carbon steel or boron containing steel with rare earth is commonly used. 18CrMnNiMo carburized carbon steel or medium carbon alloy steel is commonly used in heavy machinery. Machine tool industry 40Cr, 38CrMoAl and other steel and high-speed gear with 25Cr2MoV steel for nitriding.

Informatization trend:

People can use the computer to calculate, analyze and compare all kinds of possible design practice, and through the optimization, get more ideal results. For example, in the analysis of the contact area of the tooth surface and the calculation of the Angle between the meshing line and the relative velocity, the elastohydrodynamic lubrication and the calculation of geometric parameters are programmed. In addition, the calculation of gear modification and gear bearing capacity are programmed. China has developed the gb3480-83 program software for calculating the load capacity of involute cylindrical gear. For production applications. In gear processing, the entire tooth cutting process can be controlled by computer. Make the manufacturing quality stable and reliable. At present, the domestic research and application of the computer to calculate the bevel gear of arc tooth cutting adjustment card, can adjust the machining deviation in time, make the tooth surface contact to reach a more ideal position, and greatly improve the work efficiency. In addition, according to the principle of NUMERICAL control, the parabolic modification of spiral tooth surface of annular worm by microcomputer has been applied in production. Although the work in this field is still in its infancy in China, it is of great significance to improve the manufacturing quality and technical level of gears.

Mold industry expert Luo Baihui believes that the effective way to formulate gear mold standards should consider the cooperation between industry associations, industry associations should establish standards, unified. In addition to the dalian Institute of Technology, South China Institute of Technology and other universities are studying gear mold, now there is no specialized research institute to do this work. It is an urgent task for the relevant associations and departments to concentrate the power of the gear industry and some university research institutions to conduct integrated research and cooperation in such aspects as process equipment and internal deformation law of plastics. The purpose of setting up "small module gear working committee" is to discuss and solve the problems existing in the production of small module gear. Nowadays, the most advanced and complete gear mold standard in the world should be the United States, China gear mold should learn from the Standards of the United States, and according to the needs of development, gradually establish their own industrial standards and national standards. To be specific, it is to upgrade the factory standard of some enterprises that have done better, combine with the advanced standard of foreign countries, and become the industrial standard of Our country. By standardizing the market through standards, it will promote the development of the industry.

Speaking from the whole industry, the sound of gear mold is very small, and in a spontaneous state, and the relevant professional associations were established to change this situation. But the establishment of the association is only the first step, the next mold industry expert Luo Baihui believes that the effective way to formulate the gear mold standards should consider the cooperation between industry associations, industry associations should establish standards, unified. In addition to the dalian Institute of Technology, South China Institute of Technology and other universities are studying gear mold, now there is no specialized research institute to do this work. It is an urgent task for the relevant associations and departments to concentrate the power of the gear industry and some university research institutions to conduct integrated research and cooperation in such aspects as process equipment and internal deformation law of plastics. Set up a "small module gear.

The purpose of "working committee" is to focus on discussing and solving the problems existing in the production of small module gear. Nowadays, the most advanced and complete gear mold standard in the world should be the United States, China gear mold should learn from the Standards of the United States, and according to the needs of development, gradually establish their own industrial standards and national standards. To be specific, it is to upgrade the factory standard of some enterprises that have done better, combine with the advanced standard of foreign countries, and become the industrial standard of Our country. By standardizing the market through standards, it will promote the development of the industry.

Throughout China's gear mold status, it can be said that mixed. The good news is that the gear mold production has a certain foundation, and the general trend of the development of plastic gear will bring more market space to the gear mold; Worry is that the level of domestic production of gear mold and the world's advanced level is still a long way off, and in the gear industry, especially in the plastic gear industry under the trend of development, the domestic response to market changes is not sensitive enough, supporting research is difficult to keep up with the market demand.