Toothed castings

Dongguan Precision CastingGear refers to a mechanical element with gears on the rim that continuously meshes to transmit movement and power. The application of gears in transmission appeared very early. At the end of the 19th century, the principle of the generative gear cutting method and the special machine tools and tools that used this principle to cut gears appeared one after another. With the development of production, the smoothness of gear operation has been paid attention to.

With the continuous intensification of competition in the gear industry, mergers and acquisitions and capital operations among large gear companies have become more frequent. Excellent domestic gear manufacturers are paying more and more attention to the research of the industry market, especially the in-depth development of the corporate development environment and changes in customer demand trends. Research. Because of this, a large number of excellent domestic gear brands have risen rapidly and have gradually become leaders in the gear industry!

In 2011, the overall sales of the gear industry reached 178 billion yuan, an increase of 23% year-on-year; although the value of imports was far higher than the value of exports, the growth rate of exports was significantly stronger than that of imports.

2012Precision cast steelThe development of the gear industry may show a trend of "low growth at the top and high growth at a medium speed". The slowdown in industry growth in the fourth quarter of 2012 will continue into this year. In the second half of the year, as the country's policy to expand domestic demand is gradually put in place, the development of strategic emerging industries and the implementation of the country's "three basic plan" will surely upgrade the modern equipment manufacturing industry, thereby driving a new round of growth in the entire gear industry. It is estimated that the sales revenue of the gear industry will increase by more than 10%, and the increase in exports may reach 15%.

Gears can be classified according to tooth shape, gear shape, tooth line shape, surface on which the gear teeth are located, and manufacturing method.

The tooth profile of the gear includes tooth profile curve, pressure angle, tooth height and displacement. Involute gears are easier to manufacture, so in modern gears, involute gears account for the absolute majority, while cycloid gears and arc gears are less used.

The commonly used steels for making gears are quenched and tempered steel, quenched steel, carburized and quenched steel and nitrided steel. The strength of cast steel is slightly lower than that of forged steel, and it is often used for larger gears; gray cast iron has poor mechanical properties and can be used in light-load open gear transmissions; ductile iron can partially replace steel to make gears; plastic gears are more commonly used In places where light load and low noise are required, the paired gears generally use steel gears with good thermal conductivity.

In the future, gears are developing in the direction of heavy load, high speed, high precision and high efficiency, and strive to be small in size, light in weight, long life and economical and reliable.

The development of gear theory and manufacturing technology will further study the mechanism of gear tooth damage, which is the basis for establishing a reliable strength calculation method, and the theoretical basis for improving the load-carrying capacity of gears and extending the life of gears; the development is represented by the arc tooth profile New tooth profile; research new gear materials and new technology for manufacturing gears; research the elastic deformation of gears, manufacturing and installation errors, and the distribution of temperature When increasing the contact area of ​​the gear teeth, so as to improve the bearing capacity of the gear.

Friction, lubrication theory and lubrication technology are the basic work in gear research.Lost wax castingResearching the theory of elastohydrodynamic lubrication, popularizing the use of synthetic lubricating oil and adding extreme pressure additives to the oil can not only improve the load-bearing capacity of the tooth surface, but also improve the transmission efficiency.